Introduction to the Worldâ€™s Oceans
Marine Science Safari Throughout the British Virgin Islands Dolphin Written By: Michael J. Meighan BSc. Kris Stevenson MOcean Marina Knapp BSc.
Table of Contents 1. Introduction to the Aquatic Realm…………………………………….2 2. The Origin of Life………………………………………………………..5 3. Evolution……………………………...…………….……………………8 4. Tides and Currents………………………...…………………………...10 5. Palaeoceanography…………………………..………………………....14 6. Plate Tectonics………………………………….…………………….…16 7. Weather…………………………………………….………………..…...20 8. The Evolution and Ecology of Coral Reefs………….………….…….25 9. Marine Habitats.....…………………………….………….……….……30 10. Marine Creatures…………………………….…………………….……35 11. Fish-y Facts………………………………….………………..…….……44 12. Caribbean Sea Turtles…………………….……………………….……50 13. Ocean Threats and Marine Management………………………..……54 14. Science in Action…………………………………………………..…….58 15. Group Projects/Field Notes………….…………………………..…….61 16. Identification Journal………………….………………………….….....71 17. Oceanography/Marine Biology Quiz…………………………..…….89
Tropical Marine Biology and Oceanography Course
We have compiled the following notes for your use during the next three weeks that we are onboard together. To paint a complete picture of the planetâ€™s oceans and the animals that live within them would be impossible in such a short space of time, so the guide has been written as an overview and we hope you will find it interesting. You will see that certain areas have been covered in greater detail than others, this is due to our personal interests and their relevance to the Caribbean Sea. This, we hope, will lead to questions and further discussions on other areas of ocean science that particularly interests you. Together we will try to unravel and explain some of the wonderful mysteries of the deep. 1
Introduction to the Aquatic Realm Biologists believe that life first began in the sea. Since these primitive beginnings, different and more complex species have evolved and life now inhabits every corner of the world, from the highest mountains to the deepest oceans. We all have a pretty good idea of what we need to survive, but how has life adapted to all these different environments and what are the requirements that aquatic organisms have in order to live? Despite the huge diversity of different animals and plants on the planet, almost all require pretty much the same simple things in order to survive. So what are these things?
The first section will introduce some of these basic oceanographic pre-requisites for aquatic life, and we will see how these vary around the world.
A. Light Light is the “basis of all life” and is essential for a great number of reasons, some of which we be discussed here. •
Can you explain the differences between a plant and an animal?
Well, a plant produces its own food by using the energy from the sun to combine carbon dioxide and water to form a sugary energy food source called glucose. This process is known as photosynthesis. It is an important process because oxygen, vital for breathing, is a by-product of glucose. Around 80% of the world’s oxygen is produced by marine photosynthetic algae!
An animal, on the other hand, must forage for its food by either eating photosynthetic plants (herbivores), other animals (carnivores), or a mixture of both (omnivores). This succession energy use and transfer is known as a food chain. A terrestrial example may be: grass (eaten by) à rabbit (eaten by) à fox In this example, grass is the primary producer, or the original source of all food in the chain. In the ocean photosynthetic algae are the primary producers, not plants. They can either exist as a single cell (diatom) or in a chain (macrophyte). Some parts of the oceans are too deep for light to reach. The area in which light can penetrate is known as the photic zone. Photosynthetic algae must live in this realm in order to contribute both food and oxygen. Despite the lack of sunlight, life can still exist in the deep ocean. Some deep ocean creatures migrate up to the photic zone for feeding or air trips while others simply 2
wait for food to drift down to them. The depth to which light can penetrate is affected by several things such as water quality or suspended sediment levels. One way of determining the photic zone is by using a secchi disc and a simple equation: Depth of photic zone = secchi disc depth x 3.5 Place the secchi disc (a black and white disc) in the water and lower it into the water until you can no longer see it. Try this out with the one we have on board! As divers, we know that that light attenuates (gets absorbed) as depth increases. Red is the first color to go followed orange, yellow, green, blue and indigo. â€˘
Why do you think the water around England and California is green whilst the water in the Caribbean is so clear?
Although light is essential for the primary producers to photosynthesize, like anything too much of a good thing is bad. High intensities of light can actually be lethal to the algae, known as Photoinhibition. This is why the Caribbean is so clear, the sun is too strong for the algae. To find out how the Caribbean can support so much life when there appear to be no primary producers, turn to the section on corals to learn about photosynthetic algae that live inside corals!
B. Temperature Temperature is one of the most important environmental factors in the ocean, limiting what organisms can live where. Seasonal (summer-winter) fluctuations in water temperature only effect the surface ocean. Very deep waters, formed at the poles, remain at a very stable and very cold 2OC all year! Waters of different temperatures also have different densities and tend to form boundaries between them called thermoclines. You may have noticed one while diving, although they are not very common in the B.V.I.â€™s. If so, it is likely you encountered a diurnal thermocline, which only forms when the sun is out and break down at night as the water column mixes. Deeper, permanent thermoclines do exist, and these support a lot of marine life. The boundary between the two layers is so strong that sinking food almost becomes neutrally bouyant here. A lot of fish come here to feed since it is so rich in potential food. 3
Temperature is also important in the regulation of enzyme reation rates such as food digestion and energy production. As a rule, reaction rates double every 10OC increase in temperature. However, like light, high temperatures can be lethal as delicate enzymes perish at about 40OC (104OF). Water has a high heat capacity, meaning it takes a lot of energy to increase temperature. In an ocean, these high temperatures are unheard of, however some shallow lagoons or intertidal rock pool may have temperatures that get close to this danger level.
C. Oxygen and Carbon Dioxide Sea water involves a large amount of dissolved gas, the most important being carbon dioxide (used by primary producers for photosynthesis) and oxygen (used by most other organisms for respriation). Oxygen is distributed unevenly in the world’s oceans, mainly as a result of variation in temperature, as dissolved oxygen is dependent upon temperature, although many factors may effect oxygen. As temperature increases, the amount of dissolved oxygen decreases, meaning the surface of warm Caribbean waters will always have less oxygen than cold deep ocean waters. •
Where does dissolved oxygen come from?
Waves breaking on the shore cause a lot of oxygen to be dissolved, so coastal waters are often highly saturated as a result. Primary producers create oxygen during photosenthesis. Where they grow abundantly the water may become super saturated. •
Where does the oxygen go?
Aerobic organisms use oxygen for biological processes. The decay of dead organisms also results in the use of a large amount of oxygen. When an organsism dies, it sinks and can be caught at a permanent thermocline. Due to the large amount of oxygen used in these areas, they can create oxygen minimum zones, which is characteristic of the permanent thermocline on a global scale.
The Origin of Life In the next section we will look at the theory of evolution but before that we are with the chicken and egg problem. Before any animal or plant can evolve, there must be something there for it to have evolved from!
Well, there are many theories concerning the origin of life and the possible ways in which species have originated. A brief outline of the main theories on the origin of life are presented here. Much of the evidence on which these theories are based would be impossible to prove or disprove so let your imagination run wild!
A. Special Creation This theory is believed by most of the worldâ€™s major religions and attributes the origin of life to a supernatural event at a particular time in the past. Archbishop Usher of Armagh calculated that God created the world in October 4004 BCE and finished with Man at 9:00 am on the morning of the 23rd. He achieved this figure by adding up the ages of all related people in the bible from Adam to Christ. Whilst the arithmetic is sound, it places Adam as having lived at a time when archaeological evidence has shown that there was a well-established urban civilization in Egypt! Since the process of special creation occurred only once and presumably will never have again, it cannot be proven or disproved. Faith is therefore a major part of this theory.
B. Spontaneous Generation This theory has always been used as an alternative to special creation and dates back to the time of Aristotle (384-322 BCE), who believed that life arose spontaneously. Aristotle’s hypothesis of spontaneous generation assumed that certain particles of matter contained an ‘active principle’ which could produce a living organism when conditions were suitable. One scientist though he had proved this theory in 1577, when we found that a dirty shirt and a handful of wheat grains placed in a dark cupboard would spontaneously generate mice in around three weeks! The active principle in this process was through to be human sweat. As you can imagine, it wasn’t too long before others had proved this to be wrong, and it was in 1860 that Louis Pasteur finally proved that only life could give rise to life (biogenesis), thereby disproving the theory of spontaneous generation. This, however, raised another problem. Since it was now clear that a living organism was require in order to produce another living organism, where did the first one come from? Did this, in fact, actually prove the theory of spontaneous generation? HELP!!!
C. Steady-State This theory states that the Earth had no origin and has always been able to support life and has changed remarkably little, if at all. This theory also proposes that species have no origin, that they have always existed and that in the history of a species the only alternatives are for its numbers to vary, or for it to become extinct. Believers of this theory do not even accept the presence or absence of fossils as evidence.
D. Cosmozoan This theory is based on the idea that life has an extraterrestrial origin. It does not therefore, constitute as a theory of origin as such but merely moves the problem to somewhere else in the Universe.
E. Biochemical Evolution Many biologists believe that the original state of the Earth bore little resemblance to its present day form. It was thought to have been very hot (4000-8000OC) and as it cooled, carbon and the less volatile metals condensed and formed the Earth’s core, the surface was probably barren and rugged as volcanic activity caused folding and fracturing. It is suggested that the atmosphere of this primeval Earth was also very different to todays. The lighter gases (hydrogen, helium, nitrogen, oxygen, and argon) would have escaped into space because the gravitational field at this time was low. The simple heavier compounds, however, (water, ammonia, carbon dioxide, and methane) would have been retained. On theoretical grounds, organic compounds (probably hydrocarbons) could have formed in the oceans from more simple compounds using the energy from the strong sun. Scientists argue that is was 6
conceivable that, over time, the oceans would gradually accumulate organic molecules to produce a primeval soup from which life could have risen.
The Theory of Evolution (The development of more complex organisms from pre-existing simpler organisms over the course time) There are several million species of animals and plants living today, but where did they all come from? This is the question which al biologists try to answer, and one that has by no means been answered yet.
A. Darwin and the Theory of Evolution
The man who dedicated his life to answering this question is Charles Darwin (1809-1882). Darwin had always been an keen naturalist, but his real opportunity came in 1832 when he was offered a berth on HMS Beagle, a man-of-war which was to sail around the world on a mapmaking survey. The journey took nearly five years and the many long stops in port gave Darwin the opportunity to explore the plants and animals in many different parts of the world. What Darwin Saw forced him towards the conclusion that animals and plants have evolved by a process of slow change over successive generations. This, he suggested, was brought about by a process called natural selection or survival of the fittest. Darwin studied the evidence he had collected for more than twenty years after returning from his voyage and in 1859 published his famous book called ‘The Origin of Species by means of Natural Selection.’
B. Darwin’s Evidence Darwin had collected a lot of evidence to support the idea that species have changed through time. Much of this was based on the fact that different animals and plants exist in different areas of the world. He then realized that if a species, like man, had arisen by gradual change, it should be possible to discover something about our past by comparing our modern day form 8
with ancient fossils. Darwin did exactly that, tracing the ancient history of organisms back through time. Darwin was also able to describe how species are able to change in form over millions of years. He was very impressed by the way that animals and plants seemed to have adapted to their surroundings. Darwin’s explanation is that no two individuals of any species are identical, even though we all look the same. Some are always better suited to a particular environment than others. For example, your skin may take longer to burn than your friends meaning that you are better suited to be outdoors! Darwin argued that in some cases the poorly suited organisms would perish whereas the well adapted ones would survive to hand on their beneficial characteristics to their offspring. This is what is meant by natural selection. Nature, as it were, selecting the ‘fit’ and rejecting the ‘unfit’. Although Darwin’s theory explained how organisms could slowly change over time, questions were raised as to how some of the animals on different continents could still be identical. Look to the Palaeoceanography section to learn more about continental drift!
Bibliography Biology (a functional approach)
Tides and Currents “The tides are the heartbeat of the ocean, a pulse that can be felt all over the world” –Defant
A. Tides The tide is the slow up and down movement of sea level that occurs every day with amazing regularity. It is very easy just to accept this phenomena without question, however have you ever stopped to ask what causes tides? Tides are caused by differences in the gravitational pull of the sun and the moon on the rotating earth. Newton’s Law states that two bodies (such as planets) exert a gravitational pull on each other, the strength of which is dependent on their size and their distance away from each other. In this case there are three bodies, the earth, the moon, and the sun. The moon is much closer to the earth than the sun, hence its gravitational pull is much stronger. This is why the moon is the regulator of the earth’s tides. As the earth spins, the ocean water which directly faces the moon is pulled upwards, away from the earth causing tidal bulge. Unlike tides, this is caused by the centrifugal force as a result of the rotation of the earth. This tends to create high tides on the earth’s sides both nearest and furthest from the moon at the same time.
Although the gravitational pull of the sun is less than that of the moon, it still has an effect which can be felt strongest at a new and full moon. This occurs every 14 days and the result is an especially high or low tide called a spring tide. This is because the pull of the sun and the moon are working in unison and the effects become magnified.
The opposite of the spring tide is the neap tide, which is the lowest and weakest tide. Neap tides occur halfway between new and full moons when the moon and the sun are 90 degrees to each other, resulting in opposite forces pulling on the tides that flatten the tidal bulge.
Most areas of the world experience two high and low tides per day. This is referred to as twicedaily or semi-diurnal tides. However, changes in the moonâ€™s declination (angle relative to the earth) will cause this to vary so that some areas only receive one high and low tide per day. This is called daily or diurnal tides. Although the tide-producing forces are distributed over the earth fairly even, the sizes and shapes of ocean basins in addition to interference from land masses prevent the oceanâ€™s tides from forming a simple regular pattern. The tides are typically 2 to 10 feet high, but in a restricted waterway such as the Bay of Fundy in Canada, tides can reach up to 50 feet! On the other hand, some areas of the world may experience almost no tide at all, like the Mediterranean Sea in Europe.
B. Ocean Circulation Even when the sea appears to be perfectly calm and flat, the water at all depths is continually moving. This movement is known as an ocean current and is responsible for the constant mixing and swirling of ocean water. There are two main types of current in the water: surface (only extending down a few feet) and subsurface. Subsurface currents are much harder to observe and require special equipment to study. •
What actually causes a current?
Ocean currents are produced and maintained by the interaction of three dominant physical mechanisms: wind stress (friction), pressure gradients (differences in atmospheric pressure) and Coriolis effect (deflection of air and water as a result of earth’s rotation). A wind current is created by strong, steady winds, similar to those that we get in the B.V.I.’s, called Trade Winds. •
Where does wind come from?
These Trade Winds are a result of differential heating in the earth’s surface (it is hotter in the Caribbean than in Minnesota). The hot air rises causing a vacuum which pulls the colder air in, creating wind. These winds are permanent, however they do not blow in straight lines due to the rotation of the earth (Coriolis Effect). These permanent winds are called zonal winds. Some examples are the easterly Trade Winds in the subtropics and the mid-latitude Westerlies.
These zonal winds propel the major ocean circulation systems, however similar to the wind, these currents are deflected by earth’s rotation. The amount of deflection increases with latitude, meaning that in high latitudes the current may be 45 degrees from the wind direction while there is little variation between wind and current on the equator. Again, land masses interrupt continuous flow of ocean currents and create circular gyres. The North Atlantic Gyre includes a current that should be familiar to you: the Gulf Stream (see the red arrow in the map below). The Gulf Stream brings warm subtropical waters up the east coast of North America
then curves east towards Great Britain. This is why Bermuda, an island just off the coast of Boston, MA can support coral reefs.
C. Upwelling and Downwelling As the wind moves surface water, the water is replaces by upwelling from below. Upwelling water is important as it is high in nutrients needed by primary producers. This means areas of upwelling are generally high in primary productivity. The coast of Oregon is an example of an area of upwelling (remember the West coast of the US has high levels of primary productivity?).
Downwelling is caused when winds move surface currents towards areas with high elevation, creating pressure on subsurface currents. Downwelling is also caused when cooled surface waters descend and are replaced by rising warmer water. Downwelling areas are usually poor in primary productivity. Areas of upwelling and downwelling are often affected by ocean currents and gyres. 13
Palaeoceanography (The study of ancient oceans) A. Pangaea Think back to Darwin’s theory of evolution and remember one of the questions raised was how do two very similar species live in two different continents? If you look at a map of the world, it can be imagined that the continents could fit together like jigsaw pieces. This single large landmass is called Pangaea. Pangaea was surrounded by a very large, very shallow ocean called Panthalassa and had small gulf called Palaeotethys. It is proposed that Panthalassa became what is today the Pacific Ocean, making it the oldest of today’s oceans. Pangaea split in half creating two continents: Lurasia and Gondwanaland. The new sea was called the Tethyan Seaway.
B. Continental Drift While the theory was first proposed in 1912, it wasn’t until 1965, a scientist named Sir Edward Bullard constructed a computer model to test the theory. He found that the continents fit together with minimal gaps or overlaps when continents were outlined at 2000m depth contours. Since the 1960’s, even more evidence has come to light suggesting that the continents have indeed moved and ‘drifted’ to their current locations. This is the theory of plate tectonics which states that the plates are moved by the convection of heat which is produced at the earth’s core. 14
Massive volcanic eruptions and earthquakes throughout central Pangaea resulted in the shifting of the continents through a series of steps:
1. Rising magma caused cracks in the rigid continental crust (land) 2. As the crust pulled apart, large pieces of rock and land sink, creating a rift valley 3. Further spreading creates a narrow sea
This process, consisting of rifting and drifting (seafloor spreading), occurred about 120 million years ago. To learn more about plate tectonics, look for the next section!
C. Evidence Some sediments contain natural magnetic rock like iron ore magnetite (Fe3O4). When floating in water, these magnetic particles point towards the poles, however once buried, they maintain this direction and do not change. The magnetic pole has not always been the same, this is called apparent polar wandering. Rocks from the same era, about 70 million years, in North America are oriented further west than those in Europe, suggesting that both continents have since changed position relative to each other. There is more evidence from magnetic poles that support the continental drift theory. Once or twice in a million years, the pole reverse, and have done so for the past 76 million years. The study of paleomagnetism have found magnetic anomalies, or magnetic properties that differ from those currently forming. These represent a time when the polarity was reversed! A scientist named Frederick Vine found that at an oceanic ridge, there is an identical pattern of reversals on either side! This finding also confirmed that at certain points, the oceanic crust was actually spreading apart as the youngest crust is found at the ridge with the crust increasing with age as distance increases from the ridge.
Plate Tectonics 15
In 1965, J.T. Wilson, a professor at the University of Toronto, combined the ideas of continental drift with those of seafloor spreading to produce the currently accepted theory of plate tectonics. Movements of the lithosphere (the solid crust and mantle) produce both drifting continents and seafloor spreading.
The lithosphere comprises of several lithospheric plates, each 80-100 km thick, capped by continental crust, oceanic crust, or both. Major plates include the Pacific, Eurasian, African, Australian, North American, South American, and Antarctic. Minor plates include the Cocos, Caribbean, Nazca, Philippine, Arabian, and Indian plates. These plates move independently of each other and can diverge, converge or move side by side. Earthquakes are concentrated around plate boundaries.
Divergent (or constructive) plate boundaries occur when plates move apart and the lithosphere splits as new crust material fills the crack. This occurs mainly as mid-ocean ridges such as in the Atlantic, but they can happen on land too. 16
Convergent (destructive) plate boundaries happen when two plates are moving towards each other. An oceanic trench will from when an oceanic lithosphere converges either with another oceanic lithosphere or a continental lithosphere. When two oceanic lithospheres converge (A), one subducts (pushed underneath the other crust), creating the trench at the subduction zone. An island arc is created at the leading edge of the non-subducting lithosphere. Oceanic crust is heavier than continental crust, which results in continental crust rising over oceanic crust in a convergent zone (B). Again, this will result in the formation of an oceanic trench and create a continental volcanic arc. When two continental crusts converge (C), trenches do not form because sediments are too light to be subducted. The earthâ€™s crust folds and becomes mountain ranges like the Alps or the Himalayas.
Transform (shear) plate boundaries occur when two plates move parallel to each other along the fault line. These parallel movements may cause earthquakes from snaps under pressure. An example of this is San Andreas Fault in California. 17
The B.V.I.’s are located on the Caribbean Plate. Look at the surrounding plates and their interactions. From your new knowledge, what can you interpret about the Caribbean Plate?
The Puerto Rico Trench is an oceanic trench created as the North American Plate is subducted by the Caribbean Plate. This is why there are still active volcanoes and earthquakes in the Caribbean. Although there are no active volcanoes in the B.V.I.’s, they are the result of ancient volcanic activity. The only non-volcanic island in the B.V.I.’s is Anegada, which is a coral island formed by years and years of coral growth. That’s why it’s so flat! Some rocks and land are obviously not volcanic. Think of the giant boulders at the Baths on Virgin Gorda. These were created about 50 million years ago as magma formed huge buildups of granite called granite. These granite accumulations were exposed above the waterline around 15 to 25 million years ago as the tectonic plate was lifted, revealing the granite. Erosion from rain and wind eventually smoothed the boulders into the beauties they are today.
Weather A. Hurricanes Hurricanes, along with Typhoons and Cyclones, are some of the most violent storms in the world. It wasn’t until WWII that the naming system we use today came into being (previously they had been named they their latitude and longitude). Until 1979, hurricanes were given women’s names until a feminist group forced a change in the US. The current system has 6 sets of alternating male/female names that rotate on a yearly basis. •
How do hurricanes form?
Hurricanes begin by forming in warm waters off the west coast of Africa when warm, moist air rises. As it cools, it condenses into clouds and heavy rain. This rise of air creatures a low pressure zone at the water surface and cooler air rushes in to fill the vacuum (remember the section on upwellings?). Air around this low pressure zone will begin to spiral in an anticlockwise direction in the northern hemisphere (it will be clockwise in the southern hemisphere-remember Coriolis?!). As the air rises, it can reach heights up to 15 km before falling away from the center or eye of the low pressure system. This reduces the pressure over the eye, causing wind speeds to increase. A stable eye will not form until it reaches wind speeds of at least 35 mph (tropical storm). The eye of a storm is calm and cloudless. Lower pressure in the center cause faster winds, which again increases the strength of the storm. The trade winds lead the forming hurricane across the Atlantic Ocean towards Central and North America. Sometimes storms get caught in the Gulf Stream and are moved up the eastern coast of the US. As the hurricane moves into cooler water or over land, it begins to loose strength and dissipate.
Hurricanes need a few things to survive. Warm water to drive the upward motion of warm air. Moist air, so movement over land prevents this uptake of moisture. Light winds to allow for the formation of the storm, too strong of winds outside the system will simply break it apart.
Before a storm can be declared a hurricane, it must go through several other classifications based on wind speed. Tropical Depression: less than 33 knots/38 mph Tropical Storm: 34-63 knots/39-73 mph Category 1 Hurricane: 64-82 knots/74-95 mph Category 2: 83-95 knots/96-110 mph Category 3: 96-112 knots/111-129 mph Category 4: 113-136 knots/130-156 mph Category 5: more than 137 knots/157 mph Hurricane season officially begins on June 1st lasting until November 30th, however the formation of tropical cyclones is possible at any time of year. As wind speed doubles, the pressure quadruples. This means that a 160 knot wind has 256 times the force of a 10 knot wind while only being 16 times as fast! Hurricanes are can be 100-500 miles wide and move only 1015 mph, which means some areas can be exposed for up to 24 hours. Meteorologists say they are able to track a hurricane with increasing accuracy, although they are so unpredictable, most likely you will only know where a storm is going a little as a day ahead of time. This is why it is always important to be prepared! •
How do you survive a hurricane on a boat?
The most important part of surviving a hurricane, or any storm for that matter, on a boat is having a good weather report. Weather updates are extremely easy to get ahold of these days and staying on top of the weather is part of being a prudent mariner. Staying out of open water and getting away from the path of the storm is always the best option. When that is not an option, however, there are several other things you can do to help you and your boat survive to see the calm after the storm. Heading for port may be many people’s next move, however choosing the right ‘safe harbor’ is very important. It must have good holding for an anchor and ideally has high cliffs or mountains to shelter you from direct winds. Being on the dock may not be the best idea, as rolls from waves can batter a ship against the side of the dock. Use heavy and extra anchors with a large amount of scope (length of anchor chain or line), usually about 10:1, to account for waves. Hurricane holes, or narrow coves or inlets, surrounded by strong trees can provide another save option to place your boat during a storm. Just make sure the trees are strong enough to tie up to and the cove is far enough inland to avoid the strongest winds. Make sure everything on deck is tied down, including sails as high winds can cause large amounts of damage.
If you cannot get to safe harbor and are out in open sea, there are a few things you can do to avoid the worst of a storm. First, it is always important to know where you are relative to the center of the storm. This is easily done with a little understanding of physics. Stand with your back to the wind (essentially at a right angle to the wind) and point your left arm out to the side. This is the direction of the eye of the storm (in the Northern Hemisphere). This is called Buyâ€™s Ballot. This can also be done with instruments onboard. Look at the direction of the wind and they center should be about 100 â€“ 110 degrees to that.
The safest part of the storm is southeastern (bottom right) side of the storm, if you are facing the storm. Here the forward velocity of the storm is subtracted from the wind speed. If the storm is moving towards you, place the wind on your head southwest and sail through the navigable semicircle. It is called the navigable semicircle because you will be moving with the wind out of the path of the storm. If you are on the right hand side of the storm, you are in the dangerous semicircle, where winds are strongest and usually in the path of the storm. The most dangerous position to be in a storm in the dangerous quadrant, or the right front. This is in the direct path of the storm and will have the strongest winds and largest waves.
B. Storm Surge Before we can talk about storm surges, first we must understand how waves work. Waves are essentially a product of wind, usually a wind coming from offshore, although onshore winds can produce waves too. Offshore winds can start the initial motion of wave hundreds of miles from where it will eventually break. The friction between the wind and the water molecules creates energy that travels through water molecules (remember our section on currents?). The longer and stronger a wind blows, the more energy transferred and the larger the wave. The energy is transferred from water molecule to water molecule rather than the actual movement of water as would happen in a current. This energy dissipates at a depth of Â˝ of the wavelength. 23
A wave is formed when this energy meets an obstacle, such as a reef or land and the rotation of energy is broken. This is when a wave begins to break and the water molecules are moved forward. The larger the wave height, the further out a wave will begin to break.
Storm surge is essentially a very large wave created as a result of the strong and long fetch (length of water which wind blows). The low pressure associated with the eye of a tropical storm creates a false high tide. In certain places, the effects from Coriolis can also amplify storm surges. Storm surges are often some of the most destructive forces of a storm or hurricane.
The Evolution and Ecology of Coral Reefs Coral reefs are the marine equivalent of tropical rain forests. Both are complex tropical ecosystems (abiotic and biotic factors of an environment and their interactions) which support a large and diverse amount of life.
A. Evolution of Coral Reefs Corals are one of the oldest forms of life, dating back to at least 500 million years. During this time there were various basic solitary corals forming, however, scientists believe that true reefforming corals evolved only in the Triassic period, about 250 million years ago. In 1842, Charles Darwin (again!!) was the first to accurately describe how coral reefs formed. He recognized the three main types of reef which can still be found today: fringing, barrier, and atoll.
The Fringing Reef A fringing reef occurs close to land and follows the contours of the shoreline. Stony corals require a hard substrate base on which to settle. The major zone of the coral is usually separated from the shore by a shallow reef flat. Fringing reefs can only grow out towards the ocean as they are limited in vertical growth by the tidal range, as corals cannot survive out of water. These areas are usually fairly turbid due to suspended sediment which can reduce light levels, essential to coral growth. The Barrier Reef Darwin suggested that vertical growth of a fringing reef may happen as a result of isostatic (local) or eustatic (global) changes in sea level. These changes happen over a long period of time, such as after an ice age when glaciers melt. This causes the sea level to rise, with the release of previously ice-locked water. Darwinâ€™s theory depended on the subsidence (sinking) of volcanic islands, meaning that as the dormant volcano slowly sank, the fringing reef would grow vertically to stay close to the surface to maintain a steady source of sunlight. This would then produce a barrier reef with a lagoon of calm waters between the reef and the land mass. This can also happen with a subsiding continental shelf (think Great Barrier Reef in Australia).
Atoll As the dormant volcano continues to sink, the reef will continue to grow until eventually the volcano disappears below the surface. The largest amount of atolls occur in the equatorial Pacific.
B. Coral Reef Zonation The degree of exposure and the amount of wave action play an important role in determining reef structure. The surface of the reef is called the terrace (reef flat), which exists just below the water line and is occasionally exposed during low tide events. Just seaward of the terrace is the algal ridge, which takes most of the force of breaking waves as it is slightly higher than the terrace. After the algal ridge is the buttress zone, which is usually made up of branching corals that help slow waves before they break on the algal ridge. Just below is the buttress zone is the reef face. The reef face will continue to descend up until about 70 m in depth, depending on turbidity. The most amount of coral growth and live exists closer to land on the reef flat, algal ridge, and buttress zone.
It is important to understand that this is a generalization of reef zones commonly found. There can be many differences between reefs, however most follow this general system. For example, windward vs. leeward reefs are exposed to different amounts of wave action and depth contours which will result in varying structural features. Windward reefs tend to be dominated by branching corals which are fast growing and able to withstand the high energy waves. These reefs also tend to have spur and groove formations. Why these patterns have formed is unknown, although it is hypothesized it is the result of erosion. These help to dissipate the energy of the waves. Have you noticed any spur and groove formations on any of your dives? On leeward reefs, spur and groove formation and the algal ridge are usually absent, due to the decrease in wave action. Instead, the outer reef flat gradually blends with the upper reef. Corals 26
tend to be grouped into patches or mounds with sand between them. In some leeward reefs, a gradual change in coral growth forms can be observed. This is less obvious in the Caribbean where coral species are less diverse than in the Indo-Pacific.
C. Coral Growth Forms Corals can grow in five main growth forms. Different species of coral can grow in several different growth forms while others only grow in one form. Massive corals are usually circular, however they are usually not very big. Encrusting corals grow following the contour of the substrate. Branching coral are exactly that, branching! They tend to look like trees. Columnar (pillar) corals are again as the name states, shaped like columns. Plate-like corals grow horizontally and are flat like plates. Foliaceous grow in flat, spiraling colonies. Free living corals are single cell corals that do not live in a colony, like mushroom coral. These are not common in the Caribbean.
D. Ecology of Coral Reefs Corals are actually an invertebrate, not a plant! They are part of the phylum Cnidaria and part of the class Anthozoa. A coral is actually a colony of many, many coral polyps which secrete a calcium carbonate skeleton that builds the reef structure and give protection to the polyp. These skeletons are very slow growing, about 5 mm a year (although branching corals are the fastest growing corals, growing up to 10 cm a year!). These skeletons are left over when the coral dies or breaks off. Next time you are walking on the beach, find for a piece of dead coral and look at home complex some of the skeletons are. Corals are suspension feeders (they capture food particles suspended in the water column) and most are nocturnal. Look for exposed polyps on your next night dive! Just like all Cnidarian, corals have nematocysts (stinging cells) that they can use to help capture their prey. Corals, 27
however, also have photosynthetic algae called zooxanthellae living within their tissues. These algae provide the corals with both their color (the polyps are mostly transparent) and extra energy as a result of the primary production. In return, the zooxanthellae are given protection by living within the polyp tissue. A relationship like this is called a symbiotic relationship. A symbiotic relationship in which both parties is called mutualism. Can you think of any other mutualistic relationships on the reef?
Since these zooxanthellae require sunlight, depth is a limiting factor for corals, as they can only grow in shallow waters that receive adequate sunlight (refer back to the chapter on light). In addition to light, zooxanthellae are sensitive to several other environmental factors such as temperature and pH. Most corals cannot survive over 28OC. If temperatures do rise over this threshold, as they have been known to do in El NiĂąo years, an event called coral bleaching can occur. Coral bleaching is when the zooxanthellae become environmentally stressed and leave the coral. Since it is the zooxanthellae that provide the pigment to the coral, the corals then become white or bleached. These are not dead corals, however they are not healthy corals. Coral bleaching can be lethal if they are not recolonized relatively soon after a bleaching event. The worst coral bleaching event to happen in recent history was in 1983 when nearly 70% of corals died in the Pacific Ocean and Caribbean Sea.
Coral reefs are an extremely important habitat. They are the most diverse marine ecosystem that supports a large assemblage of life. Even animals which do not live directly on coral reefs, such as pelagic creatures, rely on coral reefs as a source of food. Corals are also important to maintaining the water quality as they help recycle nutrients back into the ecosystem (remember we said clear, tropical waters in which corals are usually found are generally nutrient poor?). The only other area in the ocean that has as much life are areas of upwelling.
Marine Habitats A. Coral Reefs (see the chapter on the evolution and ecology of coral reefs) B. Seagrass Beds Seagrasses are a terrestrial plant that has returned to the ocean, becoming extremely specialized making up only about 50 species. Just like terrestrial plants, seagrasses photosynthesize, which limits them to very shallow waters. Unlike terrestrial plants, however, their root systems differ in that rather than each plant having its own root system, the seagrass meadows form a large linked network of roots just under the sand. By creating this weaving blanket of roots, seagrasses are able to withstand much the turbulent waters that come with shallow water life.
Seagrass beds are ecologically important for several reasons. With their lush leaves reaching constantly towards the surface, seagrasses provide a wonderful and protected environment for many different type of marine species. They are an important nursery ground for juvenile fish as well as a sanctuary for many different invertebrates. Seagrass beds are also a great food source for many lager mega fauna such as sea turtles and manatees. Seagrass beds are under threat of destruction from human impact. Coastal development and trawling (a type of fishing that drags heavy nets behind a boat along the seafloor) can tear up seagrass beds and it is estimated that over 29% of the earthâ€™s seagrass beds have already been lost. Animals you are likely to find: Sea turtles, manatees, crabs, oysters, sea cucumbers, sea urchins, star fish, copepods.
C. Mangrove Forests Mangroves, like seagrasses, are plants that have returned to the sea. It is not, however, without extreme adaptations that these angiosperms (flowering plants) are able to live in their unique niche. There are several different species of mangrove found worldwide, though like corals, their range is limited to the tropics. All species of mangroves have developed ways of withstanding both high salinity and low oxygen levels of coastal estuaries. The key to these issues is their massive aerial root system (roots that extend upwards out of the water and soil). Though mangroves can remove up to 90% of salt through filters in their roots, the true masterpiece of these amazing plants are hidden in their leaves. Some species collect salt in older leaves that will later be shed (sacrificial leaves), most mangroves have developed complex system of salt excretion through their waxy leaves. With the help of specialized cells called lenticels these trees can â€œbreathe airâ€? or absorb oxygen from the air.
Mangroves play a massively important role to the health of the worldâ€™s oceans as well as to life on land. With their complex maze root systems, mangroves are able to retain large amounts of sediment, or dirt, that would otherwise be washed out to sea from rains and heavy wave action. This benefits the land living creatures in that the forests protect again land erosion while also keeping the sediment from smothering corals and seagrass beds that exist just off the shore. Mangroves, like seagrass beds, are also important nursery grounds for many juvenile reef species. From crabs to sea cucumbers, from butterfly fish to barracuda, many species of reef creatures can be found in their smaller versions tucked nestled between the maze of mangrove roots. In the BVI we find three species of mangrove, Red, Black, and White, all named for the color of their roots. Red mangroves grow closest to the waterâ€™s edge where life is the hardest. Next the Black mangrove follows along the tidal ranges. This means that unlike the Reds, Black mangroves alternate between being exposed and slightly submerged in the tides. White mangroves grow the furthest distance from shore. Unlike the first two species, White mangroves roots are not exposed and are able to withstand the coldest temperatures. Animals you are likely to find: juvenile reef fish, sponges, urchins, sea cucumbers, horse shoe crabs.
D. Kelp Forests The type of kelp that composes these famous underwater forests is brown algae that grows at an extremely fast rate, up to 18 inches a day! Because of this amazing growing speed, kelp forms dense, towering forests that resemble those you may picture on land. Kelp forests are sustain a large variety of life providing plenty of shelter and food for a wide diversity of fish, inverts and mammals. Kelp forests, like coral reefs, tend to grow in the shallow waters close to shore as the algae is dependent on the light from the sun for photosynthesis to maintain is growing capacity. This limits the kelp to shallow waters. Unlike coral reefs, however, kelp forests are found in cold, nutrient rich waters. Though kelp may look and act like a plant similar 31
to seagrass, the two are not closely related. Kelp instead of roots, has a holdfast that grips rock or substrate. A stem or trunk is replaced with a stipe and leaves with blades. Because the stipe does not contain the xylem and phloem that give land based plants their structure, kelp has gas bladders to lift the algae towards the surface and strongest sunlight. Animals you are likely to find: sea stars, urchins, sea otters, sharks, rockfish, sea bass.
E. Pelagic Zone The pelagic zone or open ocean is the largest realm of the ocean. It can be split into four zones: epipelagic (0-650 ft), mesopelagic (650-3,300 ft), and bathypelagic (3,300-13,000 ft), and the abyssopelagic (13,000 and deeper), though sunlight only reaches the first layer. The pelagic ocean is constantly flowing, shifting, changing, and mixing through ocean currents, upwellings, and downwellings. The epipelagic ocean is the only portion that absorbs a significant amount of sunlight. It is here that phytoplankton, or photosynthetic plankton, exist. These tiny organisms are the basis for the majority of food webs in the marine realm. Animals you are likely to find: whales, sharks, tuna, plankton, zooplankton.
F. Deep Ocean The deep sea is considered any pelagic region which light does not penetrate, essentially any area from the mesopelagic region at 650 ft and below and consists of nearly 95 percent of all space on earth. In this deep, dark world, those who inhabit it have had to overcome not only the darkness, but intense pressure and cold. These creatures that exist here look like they come straight out of an alien movie! Large fang filled mouths, huge eyes, translucent bodies, nearly every form imaginable can be found here. With the deep ocean consisting of such a large area, food sources are a rare occurrence so many species have evolved to be able to eat nearly anything (hence the fish that are mostly mouth so they can swallow any prey regardless of size). Many fish simply wait for debris from above to fall into their world. A whale carcass can feed a symphony of creatures for only a matter of weeks! Hydrothermal vents are a relatively recent discovery, found in 1977. These essentially underwater volcanoes exist along continental plate boundaries releasing minerals and magma into the surrounding seawater reaching temperatures of 700Â°F! Surprisingly, these deep sea vents support an oasis of life unique as their habitat. Rather than converting carbon for energy use like those on the surface that undergo photosynthesis, the life on hydrothermal vents has evolved to convert metals such as hydrogen sulfide as an energy source. Animals you are likely to find: jellyfish, squid, plankton, fish, octopus, crabs, tube worms.
G. Ice Worlds (Arctic and Antarctic Life) Life in the polar regions of the world have always seemed like wild, frozen tundra unable to support life. It may be surprising just how much life can be found in these strange worlds! The Arctic Ocean surrounds the North Pole and the Arctic Circle. Many species of birds, dolphins, whales, and fish call these northern frozen seas home as the cold water is nutrient rich, supporting a large amount of smaller plankton to feed the larger animals. The Antarctic is surrounded by the largest current in the world, the Antarctic Circumpolar Current, which moves from the Southern Ocean east into other oceans. The Southern Ocean is also home to some of the most violent storms on the planet with temperatures ranging from 2850Â°F the dramatic change in temperature between ice and land causing large weather shifts. Invertebrates thrive in the frozen waters of the Antarctic, especially crustaceans. The cold, nutrient rich waters support a host of small shrimp, krill, and many other species that form the basis of many food chains. Animals you are likely to find: penguins, whales, seals, crabs, shrimp, plankton, krill, sea stars.
H. Salt Marsh 33
Salt marshes form in temperate intertidal zones and are typically filled with halophyte (salt loving) grasses and shrubs. These plants have adapted similarly to mangroves to deal with the salty environments with salt glands and sacrificial leaves. The complex root systems of these halophytes trap sediments which cause salt marshes to become a complex mix of lagoons and channels as the tides rise and fall. Just as there is zonation in coral reefs, there is also zonation in salt marshes. High marsh is the area that is furthest from the water and is only submerged during severe storms or highest high tides. Midshore ranges between high marsh and low marsh. It is here where salt contents are at their highest due to constant changes in tidal cover. Low marsh is the only zone consistently submerged, even during low tide. Plants that live here also have to struggle with the lowest amount of dissolved oxygen. They overcome this just as mangroves do by sending roots back to the surface to collect oxygen through the air. Salt marshes are home to many insects and aves groups (such as geese), though there are few herbivores that reside in salt marshes. Because of this, there is a large amount of decaying plant matter, which is a great niche for anaerobic bacteria. Animals you are likely to find: periwinkles, blue crabs, herons, fiddler crabs, and raccoons.
Bibliography Oceanography and Marine Biology
Marine Creatures A. Scientific Classification The classification, or taxonomy, of living things is a way of organizing all living things into categories. These categories are broken down into increasingly more specific and small categories. There seven levels of classification. Kingdom Phylum Class Order Family Genus Species Every level is titled using the Latin names. This because the scientific community encompasses many languages and cultures worldwide, each with their own local common name. By using a standardized Latin naming system, it ensures that two scientists on opposite sides of the world can talk about the same organism, despite potential differences in common name. Most organisms are referred to by the two lowest categories of classification, this is called binomial nomenclature. For example, the Foureye butterflyfish, sometimes called the Mock Eye butterfly fish, is reffered to Chaetodon capistratus, where Chaetodon is the genus and capistratus is the species name. This classification system also allows for one to compare how closely related two species are. Today the classification of organisms is done by advanced genetic testing which can determine how evolved one species is from another. Groups are depicted in a family tree called a cladogram. Following the cladogram, one can determine if the great hammerhead shark (Sphyrna mokarran) or the blue fin tuna (Thunnus thynnus) are more recently evolved from humans (Homo sapiens).
B. Phylum: Porifora (sponges) Sponges are some of the most simplistic animals on earth. They have only a cellular level of organization meaning that their bodies are completely made up of only specialized cells. They have no tissues or organs. Some sponges exhibit radial symmetry (circular) though most are asymmetrical (no symmetry). Sponges are sessile creatures, meaning they are attached to the bottom and cannot move. They are filter feeders, which means they get their food from small particles in the surrounding water. To do so, water is drawn in through small openings in the walls or sides of the sponge and drawn through the body by specialized cells called choanocytes and out through a larger opening at the top of the sponge (the osculum). Choanocytes have flagella (a tail like appendage) that creates a current of water flow). Sponges can be further classified into classes based on the level of complexity of this internal water current. Sponges do not have a skeleton so they get their structural support from small proteins called spicules. These can be made of either silicon dioxide or calcium carbonate. These spicules come in many shapes and sizes and are unique to each species of sponge. This means that sponge species can be identified by looking a ground up sample of a sponge under a microscope to look at the spicules. Sponges can reproduce asexually, by budding, or sexually, by releasing gametes (sperm and egg) into the water column.
Sponge spicules under a microscope
C. Phylum: Cnidaria (jellyfish, corals, anemones, and hydroids) Cnidarians (the â€œCâ€? is silent) are slightly more evolved than Porifora as these creatures have developed tissues. All cnidarians have radial (circular) symmetry and all exist in two forms at least once during their life, though each has a preferred form. The first of these is called a polyp, a tube attached to the bottom with the mouth facing upwards (think of an anemone). The second is called the medusa, a free swimming, bell shaped phase with the mouth facing down (think of a jellyfish). Cnidarians also have specialized organelles called nematocysts. These are used for defense and catching food. Within the nematocysts are a specialized cell called a cnidocyte, a stinging cell usually found on the tentacles (these cells are why it hurts when you touch fire coral or a jellyfish). Cnidarians donâ€™t have spicules like sponges but instead rely on the surrounding water for their hydrostatic skeleton.
Hydrozoa (fire coral and Man O’war jellyfish) Scyphozoa (jellyfish) Cubozoa (comb jellyfish) Anthozoa (corals, anemones, and sea fans)
D. Phylum: Platyhelminthes (flatworms) Platyhelminthes are bilaterally symmetrical (two equal sides) organisms. They are free swimming, have very primitive organs, and are some of the first to exhibit cephalization (the concentration of sensory organs at the front of the body). Some of these newly developed organs are the oceli or eye spots. While these oceli can detect differences in light intensity, they cannot “see” in the sense of the word that you or I are used to. Platyhelminthes also uses auricles, or sensory pits, to find food or detect dangers. This is also the first phylum to develop a nervous system and the initial beginnings of a brain called paired ganglia, one set on each side of the body.
E. Phylum: Mollusca (snails, octopus, clams) Mollusca means “soft body,” and all organisms included in mollusca contain a fleshy body most have a shell of some sort which is secreted by the mantle. This phylum contains several classes that have developed distinct differences from one another.
Class Bivalvia (clams, oysters, and scallops) These are usually sedentary animals that use their foot to anchor themselves to the substrate. Bivalves all contain two shells (hence bi (two) valvia (valve)) that are can be closed with a very strong adductor muscle. Bivalves are filter feeders and filter the water through a network of gills which traps small food particles that are then internally digested.
Class Gastropoda (snails, conchs, nudibranch, flamingo tongue) Gastropod, or stomach foot, are molluscs that have only a singular shell rather than two as in seen in bivalves, though in some subclasses this shell has been lost (as in nudibranchs). The opening of the solitary shell can be guarded with an operculum, a door like structure on the dorsal side of the shell. Gastropoda is the largest class within mollusca, containing over 80% of all molluscs. The coiling of the shell that is unique to gastropods aids in the protection of the animal by reducing the amount of exposure.
Class Cephalopoda (octopus, squid, cuttlefish, nautilus) Cephalopoda, “head foot”, are some of the most evolutionarily evolved of all invertebrates. These molluscs all exhibit an enlarged anterior (front end of the body) section of the body and the internalization of the shell (with the exception of nautiloids which still have an external shell). In squids and octopi this shell is reduced to a very thin pen. The enlarged head region of 37
these cephalopods is most likely due to the complexity of sense organs and the very developed brains. Octopus have the most developed brains of all invertebrates and even have working eyes. These eyes, however, have developed independently of vertebrate eyes and are therefore slightly different. This means that the octopus and vertebrates have overcome an issue in different ways and arrived at a similar solution. This is called an analogy (similar structures from different ancestors). These animals all swim the majority of the time with their heads and are aided by the use of tentacles or arms. They also possess a beak, or jaw, for catching prey. Cephalopods have also developed specialized skin cells called chromatophores which allow the individual to purposefully alter the colors shown on the skin. This can be used for mating purposes, camouflage, or intimidation.
F. Phylum: Annelida (segmented worms-feather duster worms, Christmas tree worms, leeches) Annelids have a segmented body plan called metameric segments with a high cephalization of the anterior region. These segments are usually visible on the outside of the body and continue through the tissues to internal segments. Annelids are evolutionarily important in that they are the first to develop a coelom, a fluid filled cavity surrounding the gut.
G. Phylum: Arthropoda (crabs, lobsters, insects, spiders) The phylum arthoropoda is the largest of all the phylums, containing about 80% of all organisms in the animal kingdom. Because of this large phylum, there is a large diversity within the phylum, though there are still features that are shared throughout all classes of arthropods. The first of these is the segmented body, or tagmata, though the number of segments varies between classes. All arthropods also have paired, jointed appendages. These appendages are specialized for specific functions depending on the segment of the body they are attached to. This process is called tagmosis. Arthropods also exhibit an exoskeleton, or an external hard covering composed of chitin (or the same material that makes up your finger nails). This exoskeleton is used mostly for protection, though the skeleton does not grow with the arthropod and therefore must be shed from time to time when the animal gets too large. This is called ecdysis. Subphylum Crustacea (crabs, lobsters, shrimp, isopods) Subphylum Chelicerata (spiders, horseshoe crabs, scorpions) Subphylum Myriapoda (millipedes, centipedes) Subphylum Hexapoda (insects) â€“The largest subphylum in Arthropoda
H. Phylum: Echinodermata (sea stars, urchins, sand dollars, sea cucumbers) 38
Echinoderms staying true to their name, â€œspiney skin,â€? all possess endoskeletal ossicles, or a form of spines formed from their outer most tissue layer. These are more evident in some organisms, like urchins, than in other, like sand dollars. All echinoderms also have pentaradial symmetry, or five equal body portions, even sea cucumbers. The locomotive process shared by all echinoderms is quite the evolutionary feat. The water vascular system is a current flow of water through a series of internal canals into tube feet. These tube feet are a very important part of the system as they are what allows for the suctioning abilities of echinoderms, or how they can hold onto their substrate. Echinoderms are also famous for their regenerative abilities. If the arm of a star fish is lost to a hungry crab, then the star fish possess the ability to regrow the missing limb. If a portion of the central ring canal (part of the water vascular system) is also lost with the arm, then an entirely new star fish can grow off the severed limb as part of asexual reproduction. Class Asteroidea (sea stars) Class Ophiuroidea (brittle stars) Class Echinoidea (urchins and sand dollars) Class Holothuroidea (sea cucumbers)
I. Phylum: Chordata Chordates are the most evolutionarily advanced of all the phyla in the animal kingdom. This phyla includes many subphylum, though the two most important are the Urochodata, or tunicates, and the subphylum Vertebrata (vertebrates). All chordates share several evolutionarily important features. These include a notochord, a dorsal nerve chord, internal digestion, gill slits and a post anal tail (though these may be reduced in the adult form of a species).
Subphylum: Vertebrata Vertebrates all have common features though the classes and subclasses may appear to extremely different from one another. An internal skeletal system is found in all vertebrates. Each vertebrate also has a closed circulatory system and an oxygen transporting cell.. In addition to these advancement in body circulation, vertebrates have developed a chambered heart. The inner ear of all vertebrates has also developed so that these individuals are more suited towards their 3-D world. In all previous phyla, the individuals were only able to determine directions based on a two dimensional plane: right and left, and up and down. By developing a fluid filled inner ear called the semicircular canal, vertebrates can determine their position in space using pitch, roll, and yaw.
Class: Agnatha (hagfish, lampreys) Agnatha is a class of jawless fish, the most primitive of all vertebrates. Hagfish and lampreys are some of the only remaining species of this mostly extant class. They have no backbone, though scientists believe this to be lost secondarily; that is their ancestors possessed one which 39
was once again lost in evolutionary development. Hagfish and lampreys are scavengers that grip their prey with their circular mouths and twist their body into a knot to rip off pieces of flesh (gross!!).
Class Chondrichthyes (sharks and rays) Chondrichthyes are a class composed of all marine organisms. This class has a cartilaginous skeleton, like the type of tissue that makes up your ears or tip of your nose. Their bodies are entirely covered in scales that have evolved specifically for speed. These are called placoid scales and are shaped like sharks teeth. This triangular shape allows for the water to flow smoothly past the scales creating very little drag. Chondrichthyes are generally a very large animal, and while the water provides some buoyancy assistance, these muscular creatures still require some aid in staying neutrally buoyant. Sharks have overcome this issue by developing a very large and oily liver. It is the largest organ in their body second only to skin. Sharks and rays reproduce sexually and are considered to be either oviparous (produce eggs rather than live birth) or some species are even ovoviviparous (keep eggs inside uterus until they hatch, this differs from live birth in that there is no umbilical chord providing nutrients to the juvenile). Chondrichthyes also have a couple of senses that we do not. The first of these is called the lateral line, which is a series of gel filled cells with a singular hair that allows for the detection of changes in water vibrations. The second new sense can detect electromagnetic changes in the water, meaning that they can almost â€œseeâ€? a fish struggling in the distance. The sense organs are concentrated on the rostrum (snout) of sharks called the Ampullae of Lorenzini. Ampullae of Lorenzini
Class Osteichthyes (bony fish) Similar to chondrichthyes, osteichthyes is a class containing entirely all marine individuals. There are several key advancements osteichthyes has evolved. The first of these is the ossification of the skeleton. This advancement provides extra structural support. (Without this evolution the transition to terrestrial organisms would not have been possible as the water 40
provides some support of the body. This is why the largest creature on earth, the blue whale, can only exist in the ocean.)
Osteichthyes also have different scales than chondrichthyes. Rather than triangular scales, fish have circular scales called ctenoid scales or cycloid scales.
Rather than using an enlarged organ to aid and buoyancy, osteichthyes have developed a swim bladder, an internal air sac which they can intentionally add or remove air from to remain neutral in the water column, kind of like an internal BCD. (Again, without this evolution the transition to land would not have been possible as most scientists believe that lungs were originally evolved from the swim bladder). Ostichthyes are only oviparious, that they lay eggs, and do not care for their young (with the exception of the paternal (male) care given by seahorses). Ostichthyes also have a lateral line, which aids in the schooling abilities of many fish like sardines, though they lack the Ampullae of Lorenzini. This class has developed an 41
operculum, or hard covering over the gills which allows for the forceful pumping of water over the gills for oxygen transfer. This is why fish can sit in a single spot and still breathe and is called ram ventilation. Sharks do not have an operculum so they do not breathe through ram ventilation. However, it is a myth that all sharks have to continuously swim to keep a flow of water over their gills to breathe. Instead they use buccal pumping, which is similar to ram ventilation. Can you think of a shark that might use buccal pumping we see in the B.V.I.?
*For more information on fish, check out the Fish-y Facts section!
Class Reptilomorpha This is one of the first classes in the transition from aquatic to terrestrial life, though the first tetrapod (4 legged animal) was aquatic, thanks to the development of both the pelvic and pectoral girdles. From this class on, any aquatic animals have secondarily returned to the sea. This is evident in that they will still exhibit several terrestrial specific traits. The first of these are the development of lungs. Without water, animals required another way for oxygen transfer. Reptiles all lay eggs (oviparous), have scaled skin, and are cold blooded (need the sun for body temperature regulation). Most reptiles have a two chambered heart, though crocodiles have a three chambered heart. Subclass Aves (birds-albatross, sea gulls, penguins) Subclass Sauropsida (dinosaurs) Subclass Testudines (turtles/tortoises)----check out the chapter on sea turtles for more info! Subclass Crocodylomorpha (crocodiles and alligators)
Class Mammalia (mammals) Here we find the most familiar class of organisms. Mammals are some of the only viviparous (live birth) animals and some of the only to provide maternal care. This includes the development of milk in female individuals. All mammals, even the aquatic ones, also have hair. This is derived from deeper tissue layers in the skin cells than the feather in aves (which is derived from the keratinization of the external or outer most layer of skin). Mammals has have a 42
four chambered heart and the most advanced digestive system which is capable even of monitoring hormone levels within the body. Mammals are also warm blooded, meaning that the body can regulate its internal temperature on its own. The process of maintaining internal balance of all systems (temperature, hormones, etc.) is called homeostasis. Subclass Monotremata (platypus and echidna) Subclass Metatheria (marsupials-kangaroo) Subclass Eutheria (placental mammals-whales, humans, ect)
Fish-y Facts The ocean is a weird and wonderful place! A. Shape Body Shape The shape of a fish is essential for the specific life style it may lead and habitat it lives in. Fusiform: These fish are ususall streamline, fast swimmers. The are generally pelagic, predatory species. They swim by moving tail side to side. (Barracuda or tuna)
Attenuated: Fish with an attenuated body form tend to be slow swimming, as they swim by undulating (moving) their entire body. Because of this they tend to live under rocks or in the sand. (Eels)
Dorsoventrally Flattened: These fish are compressed and tend to live on or under the sand. (Flounder)
Compressed: These fish can easily manouver through corals or crevaces in rocks. (Anglefish)
Tail Shape The tail shape (caudal fin) explains the type of swimming a fish can do.
Forked tails are for burst swimmers and the best for acceleration (Barracuda) Lunate (homocercal) tails are for for long distance swimming because they have low drag ang good acceleration (Swordfish) Truncate tails have good manouvability give short bursts of energy (Butterflyfish) Rounded tails also offer good manourability, however they have high drag (Cowfish) Eel-like tails offer very little acceleration, however they are very good for balance and manouvering (eels) Heterocercal tails are ideal for long distance swimming. The larger upper lobe adds vertical lift, making it easier to maintain position whiel swimming (sharks)
The combination of fins (pectoral, dorsal, anal, pelvic, and caudal) allow fish to control their movevents and position in the water. This means controlling pitch, roll, and yaw.
Mouth Shape and Location 45
The location and shape of the mouth dictates what a fish can eat.
Superior mouth: A fish with a superior mouth is most likely a benthic fish which preys on fish that swim above it. Terminal mouth: Fish with terminal mouths are often generalists which feed in midwater. Inferior mouth: Fish with an inferior mouth usually feed on invertebrates or detritus in the sand. Tubular mouth: This is common of corallivores (fish that eat coral).
B. Coloration Fish come in nearly every color of the rainbow or sometimes they donâ€™t have any color at all! Some fish have spots, some have bars, and some can change their colors. Color can be used as warnings, mating signals, or camouflage. Letâ€™s look into some of the most common coloration patterns on fish. Countershading: This is when a fish is dark on top and light on the bottom. This is a type of camouflage that allows it to blend with the dark, deep ocean from above or the sunlit surface from below. This is common in pelagic species.
Bars: Again another camouflaging technique, vertical bars allows fish to blend into backgrounds. Stripes: stripes are horizontal and often found in fish that school. The stripes allow the fish to blend together and make it harder for predators to pick out an individual.
False Eye: Most predators attack the head end of a fish, which stops it from escaping. Some fish have developed a false eye spot on their posterior end (tail end) which gives them a chance to evade a hungry predatory.
Red Coloration: Most fish with red coloration are either nocturnal or live below the depth of red light penetration. This allows them to blend with dark better. Bioluminescence: Some deep sea fish communicate or attract prey through flashes of light! Bioluminescence is created as a chemical reaction or bacteria. Some organisms can gain bioluminescence ability by consuming other animals that emit their own luminescent chemical. Cryptic Coloration: Some fish have chromophores in their skin which allow them to change the color, pattern, or texture of their skin to match the background, allow them to blend in. Some fish even had odd shapes or appendages which allow them look like just another part of the reef.
Bright Colors: Bright coloration usually warns predators of poison or can be used to attract a mate. Transparency: Many deep sea fish and creatures lack pigmentation altogether. With no light penetrating at those depths, it would be a waste of energy!
C. Defense As weâ€™ve just seen, coloration can be used as a defense mechanism, however some fish go one step further. Barbs or Spines: Some fish have spines or barbs which make them harder to swallow. In some species, these can even have poison tips.
Change in size: Some fish can change their size, making them appear too large to eat. Armor: Some fish have ‘body armor’ or tough scale which help to protect them from sharp teeth. Schooling: Several species of fish swim in school to avoid predation. Safety in numbers! Mucus sac: Parrotfish secrete a mucus sac at night when they are asleep to help mask their smell.
D. Hunting Help With all of these adaptations to help fish avoid being eaten, predators have had to evolve their own techniques. Barbels: Some fish, like goatfish, have developed barbels, or sensing appendages under their jaw to ‘taste’ the sand in search of prey. Large mouths: Many fish have developed a large mouth in order to eat larger prey. This is very common in the deep where food is always readily available and a fish must be able to eat whatever it happens upon, no mater what the size!
Bioluminescence: Again, light comes into play in the deep. Probably the most famous of these is the Angler fish, which ‘fishes’ for prey in the dark as prey are attracted to the light. Ambush: Some predators take the lazy route. They cover themselves in sediment or camouflage with the reef and simply wait for unsuspecting prey to swim by.
E. Weird Fish The Anglerfish, apart from fishing for fish, is unique in that males and females have a VERY unique relationship. In the deep ocean, meeting another anglerfish of the opposite sex can be hard to do, thanks to the vastness of the deep. To overcome, when a female anglerfish comes 48
across a male, the male attaches himself to the female…permanently. Eventually the blood vessels of the female will fuse with the male, giving nutrients to him. In return, the male provides sperm whenever the female requires it. This is called sexual parasitism. The Mola mola, or sunfish, is a larger, pelagic, dorsoventrally flattened fish that swims using its dorsal and anal fins. They can grow up to 14 long and weigh up to 5,000 pounds!
The ocellated icefish lives in the Southern Ocean, where it is so cold, oxygen is more easily dissolved into the blood stream. Except these fish don’t really have a blood stream per se. They lack hemoglobin which carries oxygen to muscles and organs and gives blood the red color. This means this fish has CLEAR BLOOD! Parrotfish, though common on the reef, are very strange when you have a closer look. Their mouths have formed into a ‘beak’ (hence the name) to help them feed. Parrotfish do not eat coral, instead they eat the algae that grows on top of rock or coral. As they graze on this algae, they often ingest pieces of coral or rock. During digestion, these pieces are broken down until released, in the form of sand! If you listen closely you can hear one munching away! Some fish can change sex, meaning they are hermaphroditic and have both male and female reproductive organs, if there are no mates to be found. There are two types of hermaphroditic fish, protandrous and protogynous. Protandrous fish live in a community with two large fish and many smaller fish. Only the two larger fish are sexually active. If the breeding female is removed, the breeding male will become female and the next largest small fish will become the new breeding male. An example of a protandrous fish are clown fish. Protogynous fish consist of one large male with a group of females or a harem. If the breeding male is removed the largest female will become male and take his place. Blue head blennies are an example of protandrous fish.
Caribbean Sea Turtles A. Classification KINGDOM-Animalia PHYLUM-Chordata CLASS-Reptilia ORDER-Testudines SUBORDER-Cryptodira turtles, and sea turtles.
Includes freshwater turtles, snapping turtles, tortoises, soft-shelled
FAMILY-Cheloniidae or Dermochelidae Chaeloniidae includes sea turtles which have shells covered with scutes. Most sea turtles are part of Cheloniidae. Dermochelidae includes only one modern species of sea turtle, the leatherback, which has leathery skin rather than scutes.
B. Overview Sea turtles are large air-breathing reptiles found in most tropical and subtropical waters throughout the worldâ€™s oceans. The part of their shell which covers their back is called the carapace, while the flat part on their underside is called the plastron. Hard scales known as scutes are a distinctive feature of all but the leatherback. There are 7 living species of sea turtle ranging from the small Olive Ridley (usually less than 100 lbs) to the very large leatherback (can weigh between 650-1300 lbs!). Turtles are relatively easily identifiable by their species distinguishable arrangement of scutes along with differences in carapace shape, length, and color. While turtles lack true teeth, they do have a modified beak which is suited to the species individual diet. Turtlesâ€™ ears are not noticeable on any species, rather eardrums are covered by skin which allows them to hear best at low frequencies. They have an excellent sense of smell. Underwater, sea turtles have great vision, however they are very near sighted on land. Years of evolution have enables turtles to adapt extremely well to the water life, with streamlined bodies and large flippers, yet they still maintain close ties to land. Females come ashore to lay their eggs in the sand. Many thousands of sea turtles have been tagged around the world in various conservation programs which has helped scientists to collect vast amounts of information regarding turtle growth rates, reproductive cycles and migratory routes.
C. Reproduction and Nesting Behaviour Copulation takes place in the water, either on the surface or underwater. Often several males will compete for the attention of one female, leading to some fairly aggressive fights. Females may mate with several males prior to the start of nesting season and store the sperm for several months. This means that once eggs are finally fertilized, they will have been done so by a variety of males helping to maintain a high genetic diversity amongst populations. While males rarely return to land having crawled into the sea as hatchlings, females come ashore to nest. Interestingly most females return to the beach on which they hatched, called their natal beach. Most females will nest at least twice during each mating season (some turtles nest up to 10 times a season!) but will not nest in consecutive years. Most turtle nests contain between 100-400 eggs!
Females usually nest at night and it is unlikely she will abandon the nest while in the process of laying eggs, but will do so if forced to by harassment or threat. Incubation of the eggs lasts for about 60 days but the temperature of the sand largely governs embryo development. Essentially the hotter the ambient temperature, the shorter the incubation period. Temperature also governs the sex of hatchlings, males will develop in cooler sand at the bottom of the nest while females develop in the warmer sand towards the top of the nest. This is common for many reptiles. 51
D. Growth and Development Hatchlings must emerge from the nest on their own, unlike alligators which are helped by their mother. This often happens at nigh tor during rain showers when temperatures are slightly cooler, however the process can last several days. Once out of the nest, the baby turtle will orient themselves to the brightest horizon and dash towards the sea. Having made the hazardous journey down the beach, they typically swim several miles out to sea where they are caught in strong ocean currents along with copious amounts of seaweed. They may stay in these currents for several years before they return to near shore to feed. There is very little known about these years in a sea turtles life and are often referred to as the ‘lost years’ as we do not know exactly where they go or what happens. The obstacles for hatchlings are so numerous that only 1 in 1000 turtles will reach adulthood. Once turtle reach the size of an average dinner plate, they will begin to appear at feeding grounds closer to shore. They do, however, grow extremely slow and can take between 15-50 years to reach sexual maturity depending on the species. It is impossible to determine the age of a turtle merely through physical observations but it is hypothesized that some may live over 100 years!
E. Navigation Out in the open ocean turtles will often encounter strong currents. Turtles can only lift their heads several inches out of the water, giving them limited visibility and often in areas with no land marks. Even with these limitations, turtles will regularly navigate vast distances to find the same tiny stretch of beach from which they emerged as hatchlings. •
How do turtles navigate back to their natal beaches?
One of the more recent theories is that turtles have the ability to accurately determine both the angle and the intensity of the earth’s magnetic field (read more about this in Palaeoceanography!). Using these pieces of information, they may have been aware of latitude and longitude, like a personal GPS, enabling them to navigate just about anywhere. In order to successfully protect Caribbean turtles, scientists must first understand the routes and habitats turtles use between returns to the beaches and breeding grounds. Female turtles spend about 90% of their life anywhere but their nesting beaches, although these nesting beaches usually receive the most amount of protection. In an effort to better understand the migrations of sea turtles, researches have used many methods from small identification tags to high tech satellite tracking chips. During these next 3 weeks we will be catching, measuring, and tagging sea turtles. Some turtles will be re-catches and we will be able to track their growth and movements since their previous captures by their ID tags.
F. Resident Sea Turtles In the Caribbean, there are 4 resident species: hawksbill, green, loggerhead, and leatherback. We will be tagging two of these species: the green and the hawksbill. Green Sea Turtle (Chelonia mydas) This turtle is called the â€œgreenâ€? turtle because its flesh has a green tint due to its diet which mainly consists of sea grasses and algae. Hawksbill Sea Turtle (Eretmochelys imbricate) The hawksbill gets its name from the bird-like shaped beak. This adaptation allow it to feast on sponges and crustaceans.
G. Threats Of the seven species of sea turtle, 4 are listed as threatened and 3 as critically threatened on the IUCN Red List. Sea turtles face natural threats such as predators like racoons, crabs, ants, and dogs, both as eggs and as hatchlings. Once in the ocean, they are generally much safer save for the occasional shark attack. Though seemingly abundant, it is not these natural threats which are driving sea turtles towards extinction. For those threats we focus on human caused threats. Human threats come in a wide variety and target turtles at nearly every life stage. Artificial lighting, pollution, consumption, illegal shell trade, beach dredging, oils spills, climate change, invasive species, and commercial fishing are just a few of these devastating threats. 53
Threats to our Oceans and Marine Management The world’s oceans are an important part of people’s daily lives. They provide food, protection, income, weather patterns, and even medications. It is estimated that nearly 30% of all the people in the world now living within 100 km of the ocean. That’s about 210,000,000 people! As the world population continues to grow, so does the amount of pressure placed on the world’s oceans. In fact, today the oceans are facing many threats.
A. Pollution Of course the most obvious source of pollution is the trash seen in the ocean. Even with waste management programs, a large amount of our daily use materials end up in the oceans. These can range from plastic bottles to cigarettes to fishing nets to that lost flip flop. The amount of time it takes to break down the trash depends on the materials it is made from. Organic materials, such as food, take only weeks to decompose where a plastic water bottle can take up to 450 years. Item
Time to Decompose
Glass bottle Monofilament fishing line
1 million years 600 years
Plastic bottle Aluminum can
450 years 60-200 years
Styrofoam cup Plastic bag
50 years 10-20 years
Plywood Paper towel
1-3 years 2-4 weeks (Ocean Conservancy, 2004)
Another major pollution issue is the improper disposal of waste. Just as fertilizers can cause algal blooms, untreated human waste can add an unhealthy amount of nutrients to the water, again causing algal blooms. This is why it is important for cities and villages, especially those close to the coast, to have water treatment facilities. In addition to fertilizing algae, untreated or ineffectively treated waste can also contain a large amount of medications. Fish then eat the alga that now contains drugs and experiencing the effects of the medications. In some places, an increase in the amount of birth controls entering the water systems is causing issues with the reproductive abilities of fish. Another type of pollution comes from oil and gas spills. These are usually caused by shipping accidents though they can also from oil drill accidents, like the spill in the Gulf of Mexico in 2010 which was estimated to have leaked over 210 million gallons of oil into the gulf.
B. Overfishing and Destructive Fishing Another major threat to the oceans is the amount and types of fishing occurring. With the world population constantly increasing, every year more and more fish are being pulled from the oceans. Over the years man has developed better and better technologies for fishing so that now fishing methods are more effective and a single boat can capture more fish in less time. This means that every year more and more fish are being taken from the oceans with less left to reproduce and replace those lost. This is how a fish stock becomes threatened and may eventually collapse. This happens when all the fish in an area have been fished out. Basically, man has become too good at catching fish. Trawling nets are now so large that they can hold up to 500 tons of fish or 13 jumbo jets. Scientists estimate that in the past 60 years, large fish stock have dropped by nearly 90%. If we continue to fish at these rates, it is predicted that all the fish stocks will collapse within the next 50 years. Not all fish caught in those large trawling nets or on long lines are the intended or desired species. Those species caught by accident that are not targeted are called bycatch. This bycatch is often simply through back into the ocean, even though most of the fish are already dead. Shrimp trawling boats have reported an average of 80-90% bycatch per every haul. This means that for every 1 lb of shrimp brought into market, 9 lbs were lost as waste. In an effort to support the growing demand for fish, aquaculture, or fish farming has become more and more popular. Though the idea on paper appears to be an answer to the ever declining fish stocks, it is not all good news. Fish farms often have a large production of excess nutrients which can increase algal growth on coral reefs. Many of the fish farmed are also carnivorous and require a large amount of smaller fisher for food. This means that many fish are still being caught, however they are going to feed larger fish rather than people. It is estimated that it takes about 5 lbs of food, or smaller fish, to generate 1 lbs of farmed fish. In addition to the amount of overfishing, it is the methods of fishing that are problematic. Trawling drags heavy nets across the ocean floor, destroying any benthic composition (bottom structure) in its wake. In this way many acres of seagrass beds have been lost. In some areas dynamite, or blast fishing, is still used by using dynamite to generate a shock wave to stun the fish. This destroys large areas of reef and creates a large amount of bycatch as one is not able to target specific fish. Another destructive fishing method uses cyanide, or chemical fishing. The cyanide is used by free divers to temporarily stun fish. This is a very common method to catch fish used in the aquarium trade as it does not kill the fish immediately. While this method limits the amount of bycatch as it is much easier to target specific fish, it still causes large amount of damage to reef and to the fishermen as well. Cyanide is a poison and after years of fishing with this method, it is not uncommon to lose a hand.
C. Coastal Development Coastal development and deforestation has changed the face of the coastlines, removing much of the vegetation that used to line the water lines in order to create white sand beaches. Without these plants, there is nothing to hold the sediment, or dirt, to the ground. When rain comes, all the sediment is washed into rivers and then out to the oceans. This is bad for several reasons. 55
The topsoil is usually the most nutrient rich soil as it has the most recent detritus layers (decomposed materials). Without these nutrients it becomes very hard to grow crops or trees in these areas. As the mud makes its way towards the oceans, the sediment begins to settle. If it settles on coral reefs, the fine particles begin to smoother the corals, which they are unable to remove. As the layer of mud builds, the zooxanthellae is unable to photosynthesis and the corals begin to suffocate and eventually die. This is called sedimentation. Fertilizers from agricultural farms are also washed into the oceans in addition to the sediment. Again, this can be problematic for corals as the fertilizers aid in algal growth. Just as the sediments can smoother corals, an algal bloom can also smoother and kill corals. Coastal development can also destroy reefs and important nursery zones such as seagrass beds and mangrove forests in order to build shipping lanes or a new ocean front city.
D. Invasive Species Invasive species are species that are non-native or not endemic to an area. They can introduced on purpose, as new crops or a way to manage a pest, or by accident, like species transported trans-ocean in the ballasts of ships. The majority of newly introduced species cannot find space to inhabit or the physical conditions might to be suitable and they quickly die off without a problem. Some invasive species can have positive effects, however sometimes invasive species can hard the natural balance of an ecosystem. Invasive species can bring new disease, out compete and prey on endemic species, and breed with native species creating hybridizations. Once a species has colonized a new area, it can be very hard to get rid of, as there are no natural predators. Recently in the Caribbean and Atlantic, Lionfish (Pterois), have become a problematic invasive species. Native to the Indo-Pacific, these beautiful and hardy fish are sold in the aquarium reef fish trade.
E. Marine Management So with all these issues, what can we do? One of the leading attempts to protect the ocean and its fish populations is the implementation of marine protected areas or MPAâ€™s. These are regions set aside in order to help replenish local fish stocks and to protect important ecosystems. Within an MPA there are several zones. These can range from no take zones (where no fishing is allowed) to limited take areas (with fishing limits and seasons) to tourism zones (open only to tourism use such as scuba diving and snorkeling). Recent studies have shown that by creating no take zones, the fish populations surrounding these areas also benefit. Without government support it is hard to manage and enforce fishing regulations, however without community support the boundaries and zones will be ignored. Education and community outreach programs are necessary to the success of marine management. In addition to MPAâ€™s, fishing regulations can play a large role in the maintenance of fish populations. By imposing fishing seasons for fish to only be caught during seasons which the fish are not spawning (reproducing) gives the fish species a chance to reproduce and replenish the fish stocks. Size limits are also important in fisheries regulations. Taking fish that are too small may mean that the fish has be caught before it has a chance to reproduce. Larger fish tend to be the most reproductively efficient, meaning that one larger fish can produce more offspring than several medium size fish combined. This is why it is important to protect the large fish as well as the small fish. Sustainable fishing is a term that includes any fishing method that both 56
limits the amount of bycatch and the destruction to the natural habitat. Fishing seasons and size limitations are all examples of sustainable fishing. Another simple example of a sustainable fishing method is the sea turtle excluding devise. This is a simple set of bars inside trawling nets that prevents the accidental capture of large animals such as sea turtles. Changes in policy, both at the national and international level, has also have a large impact on fisheries. CITES (Convention on International Trade of Endangered Species) is an international convention that monitors and regulates the trade of endangered species. Those species that are listed as threatened for extinction on the IUCN Red List (International Union on the Conservation of Nature), one of the most respected and referenced lists of status of vertebrate species, is strictly prohibited. There are many conventions and directives that focus on sustainable fisheries management around the world.
F. What can we do? Saving the world’s ocean is not going to happen overnight and will require everyone’s efforts. There are simple things you can do in your everyday life to help limit your pressure on the world’s oceans. • • • •
Limit your use of plastic bottles and instead use a reusable water bottle. The same goes for plastic bags. Bring a reusable bag to the grocery store. If you do use plastics or glass, recycle! Most countries these days have recycling programs. Limit the amount of seafood you consume. Try to only eat seafood on special occasions. Know where your fish comes from. The Monterey Bay Aquarium has designed a program called Seafood Watch which recommends sustainable caught or raised seafood. They have region specific printable cards that can easily fold up and fit into your wallet. There is even a free app available for download that can direct you to local seafood markets or restaurants which sustainable seafood. www.seafoodwatch.org Spread the word! The best thing you can do to help save the oceans is to help educate those around you. Many people do not know or fully understand the threats the ocean is currently facing. Be a good steward and set the example for your family and friends on how to be ocean friendly.
Science in Action and Group Projects A. Scientific Diving A team of competent divers can offer field work assistance to almost all areas of oceanographic and marine biological science. Underwater a diver can measure and observe a wide variety of physical, geological and biological process such as ice-age stalactites in a drowned cave to the most secrete and intimate behaviors of marine animals. Without the scientific diver many of these scientific areas would be more difficult, expensive, or impossible to observe. Scientific divers have worked all over the world in areas ranging from the middle of the Atlantic Ocean to the highest mountain lakes on the slopes of the Himalayas. Some scientific divers may be scientists that have been trained to dive, but some are simply divers who have been trained in scientific techniques. Divers are able to accurately position, deploy, maintain and later recover delicate instruments on the sea bed. Some tasks may require special skills, such as marine life identification, recognizing and mapping the sea bed or underwater construction. The development of scuba since the late 1950’s has expanded the scope of underwater scientific study. Marine scientists use scuba as a means of reaching their research sites. The freedom to work ‘untethered’ is of enormous value since the diver in situ can think and adapt to changing conditions. They can conduct work that is more complex and detailed than anything that can be achieved by modern day scientific equipment. As a result of their great use in research, an estimated 150,000 scientific dives take place world-wide each year.
B. Scientific Writing •
What is scientific writing?
Scientific writing is writing that is meant to for an audience of fellow scientists with background knowledge of the topic. This means you are writing for people who are expected to understand basic terms (such as a paper in Nature) rather writing for the general public (such as an article in National Geographic). •
Why is it important?
Scientists tend to have a reputation of being bad writers. By practicing, studying, and reading scientific journals you will improve your own writing abilities. Writing well is important because not only will it aid in the success of future publications but it will also allow for better communication of ideas, translation of data, and translation between scientist and the public community. •
How does scientific writing differ from writing an essay for my English class?
Scientific papers are much more concise than an English essay. Most papers have strict word counts or authors may be charged per word, making every word written important. This means additional words to add “fluff” or effect to the paper are usually left out. Scientific papers tend 58
to explain the study in as few words as possible. This can initially make reading some scientific papers hard to comprehend and can be downright intimidating. It is important as a scientist that you feel comfortable reading scientific papers and can understand them enough to grasp the information. A good way to practice reading and understanding scientific writing is to do this in a group and hold a discussion/critique. By discussing the paper in a group, you will be able to ask questions on sections you may be unclear on as well as be introduced to different interpretations of the paper. Critiquing scientific papers also holds value. By reading more papers, you become aware of many styles of writing and common pitfalls of scientific writers. Pin pointing what works and what doesn’t work in other papers gives you the opportunity to avoid making similar mistakes in your own writing. Tips for good scientific writing: • • • • • • • • • • •
Always write in past tense Write in third person Begin paragraphs with topic sentences Write from broad topics down towards more specific details (old information before new information) Be direct in you statements (avoid using unnecessary or filler words) Avoid long, run on sentences Place action verbs in the begging of sentences rather than at the end Avoid biased comments Use adjectives/adverbs seldom Do not tell your reader what they are about to read (they will find out when they read it!) Cite everything (if you gain information from a source outside of your studies data collection, cite where it came from-this gives your claims more credibility as well avoids any potential for plagiarism accusations) Proof read your work/Have someone else proof read your work.
Tips for data presentation: • • •
Never put raw data in a scientific paper Use a table or graph to display data visually The title and axis labels should explain what the data is showing without needing further explanation o Though a short 1-2 sentence summary of the data shown about should be placed below each table or graph Choose which data is displayed wisely (similar to words, authors are usually charged for each graph included in a single paper)
C. Group Project This group project is designed to give you experience with all stages of a research project and working with a group. You are expected to hand in a proposal, complete data collection, write a paper on your project, and present your findings. The purpose is for you to understand the processes and issues involved with scientific research, we are not expecting you to discover a new species or solve declining fisheries. Gear Available: Backpack lab: Alkalinity testing, dissolved oxygen, carbon dioxide, ammonia, ammonium, nitrates, nitrites, phosphates, phosphites, pH, salinity, temperature Secchi Disk Quadrats (1 m2) Transects (100 m or 50 m) Rulers Mirrors Pipets Slates Scuba Tanks Dive Kit Advice: Keep in mind that you only have 4-6 dives with only 20-30 minutes (depending on depth and air consumption) to collect your data. Keeping your project simple and straight forward is best. Be sure to have a solid plan for data collection with each team member confident in their role, this will avoid stress and confusion later during the dive. Also be aware that your first data collection dive may reveal that your methods are not going to work. This is ok, be willing to adapt. Be aware of how fast time moves down here. You will only have about 2 weeks from start to finish to complete your project, so begin thinking about what interests you early and start to keep mental notes of patterns you notice on dives. You can start your write up before all of your data is collected. Begin writing your introduction and methods early so you have more time to commit to results and conclusions (or enjoying a snorkel break). Working in a group can be challenging, but it is important to learn how to work well with others towards a common goal, as most research projects consist of several team members, volunteers, and advisors. Donâ€™t be the group member that simply coasts along on the back of others. They will grow frustrated with you and you will miss out on important work experience. Talk to your staff! We have placed experienced scientists onboard for a reason. They have all completed several research projects of their own and read countless scientific papers. They also have a great idea of the life common around our dive sites and can steer you in a better direction. Bounce ideas off of them and talk out any issues you find in your data collection, design, or write up. We love talking science so please give us another reason to get our nerd on!
D. Group Project Proposal Question:____________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ Why is this important: _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ Hypothesis:__________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ Methodology:________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ Materials____________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________
Dolphin Program Research Project As part of the dolphin program you will complete a formal write up of the research you and your group executed. All group members are expected to contribute equally and will be graded as a group using the following outline: GENERAL • • • • • • • • •
Does the title page include a title, date, and names of participants? Are there page numbers? Are there section headings? Are the margins consistent? Do the sentences make sense? Do the sentences flow? Are there spelling mistakes? Does each paragraph have a topic sentence, and do other sentences in the paragraph support the topic? Is the information presented in a logical and easy to follow manner. Is it written in past tense?
INTRODUCTION The purpose of the introduction is to provide relevant background and rationale for the study. To do this, emphasis needs to be placed on the use of literature to provide support for statements made in this section. Moreover, the introduction should be structured so that the ideas flow from general to specific, ending with a paragraph that contains a concise and specific ‘purpose statement’ and, in some cases, a series of predictions.
• • • •
Does the title reflect the research topic? [Check this before and after you read the introduction] Is there a logical flow of ideas from general to specific? Is the argument complete and the broader significance clear? Is there a clear understanding of why you are doing the study?
METHODS The purpose of the methods section is to provide details on where, when, and how. This section can be fairly succinct, as it should only include details that are relevant. A good question to ask yourself is “Does it matter if……?”. For example, “Does it matter if the data was written on a dive slate?” Would the data have been different if it were written on underwater paper? Likely not, so this type of detail is unnecessary. •
Is it clear how the methods relate to the purpose statement and predictions? 62
• Is there too much information? Are there irrelevant details? • Are enough details provided so that the study can be emulated? • Could diagrams be used to help depict methods used? Conversely, are there too many? • Are statements unbiased? • Could subheadings be used to provide more structure? • Are figures clearly labeled, easy to follow, and neatly presented? • Is correct terminology used? • No results or discussion should be included in this section RESULTS The purpose of the results section is to describe trends in the data. This section should be fairly succinct, and NOT include any interpretation of the results. Typically, the results section includes figures and tables. Note that maps, drawings, and graphs are all referred to as ‘figures’. Not all the results need to be regurgitated [“plot x had 15 bunnies, plot y had 13 bunnies, plot z had 16 bunnies”], but instead the patterns in the data described [“the number of bunnies among plots ranged from 13-16”]. • • • • • • • • • •
Have you thought carefully about which information to include? Are major trends in the data described? If statistics have been used, are they appropriate and does the significance of any statistical analyses seem to be understood? Are the visual representations used appropriate for the data? Are connections made from text to the appropriate figures? No interpretation of results should occur in this section. Are the raw data actually summarized or have you just included all their data? Are figures and tables professional/neat? Do all figures and tables have captions, and are the captions complete? Are figures properly labeled? Axis labels, scales, legend [if appropriate], discernable symbols?
Tips for Figures and Tables § When in doubt, look at articles in scientific journals for examples. § Figure captions belong below each figure, while table captions belong above each table. § Use separate sequences when numbering figures and tables, and number each according to when they are referenced in the text [i.e., the first figure you make reference to in the text should be Fig. 1, not Fig 5.]. § Keep figures simple and easy to read. 3-D bars, fine lines, and small symbols can significantly reduce the quality of you figures. § Tables are used to display large amounts of data, but NOT raw data. Raw data belongs in an Appendix at the very end of your paper. DISCUSSION The discussion is reserved for the interpretation of results as they pertain to the subject outlined in the introduction. As such, some of the background in the introduction should be expanded on in the 63
discussion, and the topics used as a foundation for interpreting the results, supporting or refuting predictions, and developing novel ideas to further the research. The interpretation of the results should be clear and arguments/claims supported heavily by the use of literature. • • • • • • • • •
Are the results summarized in the first paragraph and are they tightly related to the purpose statement in the introduction? Is it made clear whether predictions were supported or refuted? Is the data interpreted or are the trend simply repeated? Are interpretations supported by trends in the data AND by accounts from the literature? Are interpretations grander than what can be supported by the data? Has thought been given to address the question ‘WHY’? Does the discussion end with a general conclusion? Are results put into a wider context? Are suggestions for further research creative or interesting CITATION FORMAT
Is literature cited to provide support for stated facts? Are citations formatted correctly, both in the text and in the Literature Cited section?
Cite references in the text by author and year. For example “……..(Jackson, 1997)”, or “Jackson (1997) showed that……”. For more than two authors, used “et al.”. For example, “Jones et al. (1990) found that….”, or “………(Jones et al., 1990). For multiple citations supporting one sentence, list citations in alphabetical order NOT by year published. In the Literature Cited section, list all authors for papers with up to five authors, and list the first author followed by et al. for articles with six or more authors. All references included in the literature cited section must be cited in the text and vice versa. Citations are listed in alphabetical order by the last name of the first [or only] author. Use this style in the Literature Cited section: Jackson, G.C. 1997. Nassau grouper abundance in the Bahamas. Carib. J. Sci. 33:125-141.
Benthic Coverage Example:
Soft Quadrat Depth Massive Plate Branching Coral
Crustose Demospongea Coraline Brown/Green Rock/Sand
Benthic Coverage over Changing Depth 0.9 0.8
Sol Coral 0.4
0.1 0 14 m
Quadrat Depth 65
Roving Fish Survey
' Common'Name:'Banded'Butterflyfish______________________________________________________' Scientific'Name:'Chaetodon)striatus_______________________________________________________' Location:'Alice'in'Wonderland____________________________________________________________' Habitat:'Found'near'large'brain'coral______________________________________________________' Activity:'See'swimming'around'reef'occasionally'pecking'at'corals.'Very'active'and'fairly'tolerant'of____' divers._______________________________________________________________________________''' Depth:'25'ft___________________________________________________________________________' Notes:'Generally'seen'in'maleLfemale'pairs'since'they'are'monogamous.'They'can'usually'be'found'on__' hard'coral'reef'heads'as'they'feed'on'coral'polyps,'small'worms'and'crustaceans.'Only'found'in'tropical' Atlantic'waters.________________________________________________________________________' ' *Note:'Your'journal'should'include'10'fish,'5'invertebrates,'and'2'plants.'' '
Identification Journals 10 Vertebrates, 5 Invertebrates, 3 Plants ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ 71
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Dolphin Marine Biology/Oceanography Quiz Read the questions carefully and circle the correct answer on the sheet provided. All answers can be found in this manual or additional resources onboard. GOOD LUCK!!
1. Which of the following Phyla can be recognized because of their PENTA-RADIAL SYMMETRY? A. Porifera
2. Corals are a member of which Phyla and Class? A. Porifera, Hydrozoa C. Cnidaria, Hydrozoa
B. Mollusca, Anthozoa D. Cnidaria, Anthozoa
3. Mangrove and Seagrass areas are vitally important as marine habitats because they A. Provide food for marine animals B. Provide oxygen for marine animals C. Provide shelter for juvenile marine animals D. Both A & C 4. TRUE or FALSE. Sponges are considered animals despite the fact that they have no identifiable organs to preform respiration, digestion, or blood circulation. 5. Many Cnidarians contain stinging cells known as A. Nematocysts
D. Collar cells
6. If on one of your dives you came face to face with a Ctenophora, what would it be? A. Feather Duster Worm B. Green Algae C. A flat worm D. A comb jelly 7. The oldest ocean is the A. Atlantic Ocean
B. Southern Ocean
C. Pacific Ocean
D. Indian Ocean
8. Which is not a species of sea turtle local to the BVI? A. Green
B. Olive Ridley
9. TRUE or FALSE. A NEAP TIDE occurs when the sun and moon are working in unison and high tides are higher, low tides are lower. 10. TRUE OR FALSE. ZOOXANTHELLAE provide the pigmentation in corals. 11. According to Darwinâ€™s theory of coral reef formation, what is the correct order of reef formation? A. Volcano, fringing reef, barrier reef, atoll B. Volcano, atoll, fringing reef, barrier reef C. Atoll, volcano, barrier reef, fringing reef D. Barrier reef, fringing reef, atoll, volano 12. What is NOT required in the formation of a hurricane? A. Warm water B. Moist air C. High winds D. All of the above are required for hurricane formation 13. TRUE or FALSE. Invasive species are considered to be ENDEMIC to a region. 14. What type of scales would you expect to find on a nurse shark? A. Ctenoid
15. A boundary in water with different densities due to differences in TEMPERATURE are called A. Halocline
B. Phagocline C. Thermocline
16. Which of the following is not considered a major tectonic plate? A. Eurasian
17. Which Phyla were the first to develop CEPHALIZATION? A. Platyhelminthes
18. What is an example of animal with COUNTERSHADING? A. Sea turtle
B. Hammerhead shark
C. Bluefin tuna
D. All of the above
19. What are the odds that a sea turtle hatchling will reach adulthood? A. 1:1000
20. At what depths would you have to go to be in the mesopelagic (Twilight) zone?
A. 0-650 ft
B. 650-3300 ft C. 3300-13000 D. 13000+
21. If you happen to get stuck in a hurricane, what part of the storm is the safest to be in? A. Northwest B. Northeast
22. The majority of the islands in the BVI were created as a result of volcanos. What is the name of the fault line responsible for their creation? A. Eastern Caribbean Trench B. Puerto Rico Trench C. West Central Atlantic Fault D. None of the above 23. Variations in the salinity of sea water is mainly caused by A. Evaporation B. Rainfall and rivers C. The number of animals present D. Both A & B 24. Upwelling is an important process because it increases the A. Salinity B. Temperature C. Nutrient and oxygen content D. All of the above 25. TRUE of FALSE. Decaying marine animals can cause the surrounding water to become ANOXIC. 26. How much of the worldâ€™s oxygen is produced by marine photosynthetic algae? A. 80%
27. Ocean currents are caused by which of the following forces? A. Wind (causing friction) B. Atmospheric pressure C. Coriolis effect D. All of the above
28. Which origin of life theory suggests that life on earth has always existed with little change or variation? A. Steady-State 91
B. Cosmozoan C. Spontaneous Generation D. Biochemical Evolution 29. What are some adaptations mangroves have developed to survive in salty environments? A. Extra thick xylem B. Sacrificial leaves C. Lenticels D. Both B & C 30. TRUE or FALSE. Horseshoe crabs are part of the Phyla Arthopoda and are more closely related to spiders than to lobsters. 31. What is the ideal body shape for a fish living amongst coral reefs? A. Attenuated B. Fusiform C. Compressed D. Dorsoventrally flattened 32. What item will take the longest to decompose? A. Plastic bottle B. Styrofoam cup C. Aluminum Can D. Cigarette 33. TRUE or FALSE. Tides are caused by the effects of both the sun and the moon. 34. When sea water looks green, such as in California or England, it is probably because of A. Pollution B. Photosynthetic algae C. Species of animals present D. None of the above 35. All members of REPTILOMORPHA lay eggs, which means they are classified as being A. Viviparous B. Oviparous C. Oviviviparous D. None of the above
36. Who put forward the theory of evolution? A. Albert Einstein B. Charles Darwin C. Sir Isaac Newton 92
D. Bernard Moitessier 37. ‘Isostatic’ and ‘Eustatic’ refer to changes in A. Sea level
38. What type of organisms are zooxanthellae? A. Secondary producers B. Cnidarians C. Polyps D. Primary producers 39. After Pangea split, the landmass became two supercontinents: Lurasia and A. Gondwanaland
40. Wave energy dissipates at a depth ______ the wavelength. A. ½
D. equal to
41. Corals obtain energy through A. Suspension feeding B. Symbiotic relationship with zooxanthellae C. Both A and B D. None of the above 42. TRUE or FALSE. The fastest growing kelp in the world can grow up to 10 inches a day. 43. The theory of plate tectonics describes the way A. Continental crust moves on top of oceanic crust B. Oceanic crust moves on top of continental crust C. Oceanic and continental crusts move on top of magma D. Magma moves over continental and oceanic crusts 44. A halocline is caused by variation in A. Salinity
45. You would be likely to find halophytes in what kind of habitat? A. Deep ocean B. Kelp forest C. Salt Marsh D. Coral Reef 46. Members of the Phyla Porifora receive structural support from A. The water B. Silicon dioxide spicules C. Both A and B 93
D. None the Above 47. Characteristics of Chondrichthyes do NOT include A. Cartilaginous skeleton B. Apullae of Lorenzini C. Enlarged liver D. Operculum 48. What type of tail are you likely to find on pelagic fish? A. Truncate
49. Parrotfish secret a mucus sac at night for what reason? A. Camouflage B. Comfort C. Osmoregulation D. Mask their smell 50. What is not a problem that the first land animals did not have to evolve to overcome? A. Gravity (weight bearing) B. Respiration (gas exchange) C. Desiccation (drying out) D. All are problems 51. What percentage of Teleosts or bony fish have a swim bladder? A. 100%
52. TRUE or FALSE. Some corals may contain â€˜nematocystsâ€™. 53. What type of symbiotic relationship is there between Carapus bermudensis and Actinopyga agassizi an example of? A. Parasitism B. Mutualism C. Commensalism D. The do not have a symbiotic relationship
54. Sharks teeth are continuously lost and replaced throughout their lifetime. This is called A. Multidonty B. Polydonty C. Heterodonty D. Odenodonty 94
55. Which does NOT have an effect on where coral can grow? A. Depth B. Latitude C. Longitude D. Ocean currents 56. How many species of mangrove are found in the BVI? A. 3
57. How many stomachs do starfish have? A. 1
58. What is the largest class of MOLLUSCA? A. Bivalvia
59. What type of mouth would you expect to find on Bothus mancus? A. Inferior
60. Overfishing is a large problem today. What percentage of all fish stocks have been lost in the last 60 years according to scientists? A. 30%
61. Which of the following are ways that fish can protect themselves? A. Electricity B. Blowing air bubbles C. Squirting ink D. None of the above 62. TRUE or FALSE. Photosynthetic algae must remain in the photic zone to photosynthesize. 63. The Coriolis Effect states that permanent winds do not blow in straight lines but rather exist in permanent zones. At 18ON, which zonal wind are the BVIâ€™s located in? A. Westerlies B. Easterlies C. NE Trade Winds D. SE Trade Winds 64. TRUE or FALSE. Every thousand years, the magnetic poles reverse, a phenomenon called paleomagnetism. 65. Which zone on a coral reef is occasionally exposed at low tide? A. Terrace (reef flat) B. Algal ridge C. Buttress zone 95
D. Reef face 66. Which zone in the open ocean has the majority of marine life? A. Bathypelagic B. Abyssopelagic C. Mesopelagic D. Epipelagic 67. What color are most deep sea creatures likely to be? A. Black B. Red C. White D. Lime green 68. On a dive, where are you most likely to see a ‘box’ fish or ‘cow’ fish? A. On the bottom B. Under the boat C. On the surface D. Swimming mid-water 69. TRUE or FALSE. All fish fertilize their eggs externally. 70. What is the largest organ in a shark? A. Brain B. Liver C. Stomach D. Gonads 71. TRUE or FALSE. All Gastropod have a ‘shell’, either internally externally. 72. What is the only island in the BVI that does not have a volcanic origin? A. Tortola B. Jost van Dyke C. Anegada D. Marina Cay 73. A fairly symmetrical jaw placed in the center of the head describe the mouth of which type of feeder? A. Bottom feeder B. Surface feeder C. Mid-Water feeder D. Corallivore 74. Which is NOT a type of fin you would expect to find on Ostyichthyes? A. Caudal 96
B. Diurnal C. Anal D. Pectoral 75. Scutes are a distinctive feature on the shells of all sea turtle species except A. Olive Ridley B. Hawskbill C. Leatherback D. All of the above have scutes 76. How could you assess the effectiveness of an artificial reef? A. Compare the number of species present B. Compare the size C. Compare the depth D. It is impossible to measure effectiveness 77. If you want to survey the amount of coral coverage on a reef, which of the follow would you NOT need? A. Quadrat B. Transect C. Slate D. Secchi disc 78. Water can become â€˜supersaturatedâ€™ with oxygen because A. Plants form oxygen by photosynthesis B. Waves break on the shore C. Decaying marine organisms D. Both A and B
79. What type of lithosphere crust is the heaviest? A. Continental B. Oceanic C. Pie crust D. Both A and C 80. What is the faster growing coral growth form? A. Branching B. Massive C. Pillar 97
D. Encrusting 81. Which is not an important service provided by coral reefs? A. Storm protection B. Food source C. Habitat D. All are important 82. TRUE or FALSE. The largest current in the world exists in the Southern Ocean. 83. TRUE or FALSE. Birds are the only Reptilomorphs that are not cold blooded. 84. When a continental and an oceanic plate converge, what is formed? A. Trench B. Volcanic arc C. Island Arc D. Both A and B 85. In a hurricane, if winds are consistently blowing between 80-90 knots, what category storm would it be? A. Category 1 B. Category 2 C. Category 3 D. Tropical Depression 86. In the Southern hemisphere, ocean current circulate in which direction? A. Clockwise B. Counter-clockwise C. It depends on the zonal wind D. Circulation is dependent on east and western hemisphere, not north and south 87. TRUE or FALSE. Corals can recover after a bleaching event because they are not technically dead, they have simply lost their zooxanthellae. 88. TRUE or FALSE. The lateral line on fish and sharks serves a similar function to the hair on our arms.
89. What produces bioluminescence? A. Electrical pulses B. Chromatophores C. Chemcial reaction D. Extraterrestrial interaction 90. How long is the incubation period for sea turtle eggs? A. 60 days
B. 100 days
C. 30 Days
D. 120 days
91. Which of the following is not an acceptable method of marine management?
A. Marine protected area B. Policy change for endangered species C. Incentive programs for sustainable fishing D. None of the above 92. Which is a method used to age fish? A. Count rings on the otolith B. Count spines on dorsal fin C. Count rings on a scale D. Both A and C 93. The British Virgin Islands are fundamentally composed of which rock type? A. Calcium carbonate B. Granite C. Blackpool rock D. Bassalt 94. Transform faults occur when A. Plates move towards each other along subduction zones B. Plates move apart at divergent zones C. Plates move side by side relative to each other D. None of the above 95. Which naturally destructive process often occurs along transform faults? A. Earthquake B. Landslide C. Sink hole D. Quicksand pool
96. A Hawksbill turtle can easily be differentiated from the Green turtle as it possess A. 4 prefrontal scutes B. A carapace with winged peripheral scutes C. No over-lapping scutes D. Both A and B 97. TRUE or FALSE. An artificial reef can NOT supply the basis for a self-sustaining ecosystem and requires maintenance. 98. TRUE or FALSE. A scientific report should use plenty of adjectives and descriptive language to make the paper more interesting. 99
99. What invertebrate is most related to vertebrates? A. Tunicates B. Octopus C. Crab D. Brittle star 100. Which Subphyla was the first to develop the semicircular canal (fluid filled inner ear) to aid in balance? A. Urochodata B. Holothuroidea C. Vertebrata D. Cephalopoda BONUS: Acanthaster planci and Pterois pose a threat to Caribbean coral reefs how? A. B. C. D.
Bring white band disease that kills corals Cause excess nutrient accumulation on reefs Both are invasive Indo-Pacific species Both cause eutrophication on reefs
Student Answer Sheet
1. A B C D
27. A B C D
53. A B C D
79. A B C D
2. A B C D
28. A B C D
54. A B C D
80. A B C D
3. A B C D
29. A B C D
55. A B C D
81. A B C D
4. T F
30. T F
56. A B C D
82. T F
5. A B C D
31. A B C D
57. A B C D
83. T F
6. A B C D
32. A B C D
58. A B C D
84. A B C D
7. A B C D
33. T F
59. A B C D
85. A B C D
8. A B C D
34. A B C D
60. A B C D
86. A B C D
9. T F
35. A B C D
61. A B C D
87. T F
10. T F
36. A B C D
62. T F
88. T F
11. A B C D
37. A B C D
63. A B C D
89. A B C D
12. A B C D
38. A B C D
64. T F
90. A B C D
13. T F
39. A B C D
65. A B C D
91. A B C D
14. A B C D
40. A B C D
66. A B C D
92. A B C D
15. A B C D
41. A B C D
67. A B C D
93. A B C D
16. A B C D
42. T F
68. A B C D
94. A B C D
17. A B C D
43. A B C D
69. T F
95. A B C D
18. A B C D
44. A B C D
70. A B C D
96. A B C D
19. A B C D
45. A B C D
71. T F
97. T F
20. A B C D
46. A B C D
72. A B C D
98. T F
21. A B C D
47. A B C D
73. A B C D
99. A B C D
22. A B C D
48. A B C D
74. A B C D
100. A B C D
23. A B C D
49. A B C D
75. A B C D
BONUS: A B C D
24. A B C D
50. A B C D
76. A B C D
25. T F
51. A B C D
77. A B C D
26. A B C D
52. T F
78. A B C D
Fish ID Quiz
1.____________________________ 2. ______________________________