Sea History 127 - Summer 2009

Page 39

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ne day, over 175 years ago, a yo ung C harles Darwin peered over the sid e of his sailing ship, HMS Beagle. The ship was sailing off Tierra de! Fuego, the blustery southern tip of Argentina. Darwin's eyes widened when h e saw long bands of some so rt of crimson-colored so up covering the surface of the sea. He wrote later in his acco unt of the voyage:

Darwin's shipmates were indeed correct when they said that the creatures were I food for whales. Even THOl?.P..ClC L.E:6S though individual Antc:f cP..~ y~ot:>vc E >?..5' 1 000 fol".. ft:f.W-l (:, E:G6S !ti ON£ YEt>.,~ arc tic krill, the largest of their kind, do not grow larger than an average person's pinky, the whales of the South- rigid outer skeleto n, so they need to shed ern Ocean-notably the blue, fin, and right or molt their shells in order to grow. They wh ale-dine on them almost exclusively. can shed these exoskeletons on the spot I have seen narrow lines of water ofa Whales swim open-mouthed through fields when they need to distract predators. bright red colour, from the number of of these critters, gulping millions at one Because Antarctic krill live in such crustacea, which somewhat resemble pass. massive groups, they not only provide in form large prawns. The sealers call In the Southern Ocean mariners have food for whales, seals, fish, squid, and them whalejood. Whether whales feed sailed through dense swarms of kri ll so vast birds, but humans have also developed a on them I do not know; but terns, corthat they covered the area of 280 square large industrial fishery to net them by the morants, and immense herds of great miles. Thar's larger than the entire city of ton. Krill are occasionally served as food in unwieldy seals derive, on some parts of C hicago! Ocean currents move these little countries such as Japan , but, more comthe coast, their chief sustenance from animals around, but krill also m anage to monly, catches are sold to feed farm anithese swimming crabs. swim together like schooling fish, perhaps mals or fish raised in aquaculture. By som e So, what was he looking at? Darwin was because it helps more individuals survive estimates, co nsidering the total weight of likely sailing through a patch of krill, or eu- when predators approach, and maybe it all the living m embers of their species, phausiids, which look similar to crabs and helps them when finding their own food, Antarctic krill are the most populous animals on Earth. Certainly that wo uld have shrimps (prawns), but are recognized today which is mostly microscopic plants. as their own kind of animal. 1he Antarctic In winter, krill eat algae and other tiny impressed C harles Darwin, who wo uld be krill is the species most commonly found in organisms that live under the ice. When celebrating his 200th birthday this year. In the next issue's Sea H istory for Kids, the area where D arwin sail ed, but the word swimming in the open ocean, they collect "krill" wasn't in common English usage both near the surface and also hundreds we'll examine the mys terious fish in back then . It's ac tually a Norwegian word, of feet below. Krill use their forward sets-· one of New England's most famous meaning "very small fry of fish ," and, ac- of legs to feed and their back limbs to . _ {_~)~ \paintings. If you're interested in ~l Qi , pas t entries of"Animals in Sea cording to the krill expert William Ham- swim, adjusting their tail fins like a /f~ ~ ·~ History," check out www. ner, once also meant "tiny creepy-crawly rudder to steer. Like other crusta1 things." ~ ceans, such as lobsteh'-hill have a I · seahistory.o rg.














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