SEA TURTLES The most common sea turtles in Atlantic Canada are leatherback and loggerhead turtles. Both species are migratory, moving between beaches, nearshore coastal waters, and the open ocean in different life stages. Leatherbacks typically occupy Atlantic Canada, one of their most important foraging habitats, from June to December (Figure 40). They inhabit the sunbathed zone of the ocean, spending most of their time in near-surface waters. This makes them vulnerable to fishing activity as bycatch. Young loggerheads are mainly seen during summer and fall in warm offshore waters. Most loggerhead turtle strandings have occurred in late autumn. The strandings were linked to cooling ambient ocean temperature and the onset of hypothermia. Sea turtle eggs and hatchlings are subjected to high levels of predation in aquatic and terrestrial environments by a broad range of marine predators, including birds and fish. As such, sea turtles transport nutrients and energy between marine and terrestrial ecosystems. Leatherbacks also contribute to ecosystem balance in some areas by consuming jellyfish, which are a major predator of zooplankton and larval fish. Leatherback sea turtle eating jellyfish. Credit: Gene Herzberg, 2009.
Leatherback turtles have been observed in high-use foraging areas off Nova Scotia every year since 2002. In-water sampling, application of identification tags, and telemetry studies have all provided insight into the population characteristics, movements, foraging behaviour, and habitat use of leatherback and loggerhead turtles.
STATUS AND TRENDS •
Leatherback turtles and loggerhead turtles are listed as endangered under Canada’s Species at Risk Act.
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Leatherback sightings from marine investigations or by fisheries observers suggest their population in Canadian Atlantic waters is stable.
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The distribution of juvenile loggerhead sea turtles in the Northwest Atlantic is limited by ocean temperature. Most sightings occur during the summer and fall in warm, offshore waters, especially those influenced by the northern edge of the Gulf Stream.
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Seasonal sea turtle population density in Canadian waters remains unknown for all species.
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Between 1996 and 2006, an estimated 9,592 juvenile loggerheads were incidentally captured by the surface long-line fishery.
CANADA’S OCEANS NOW: ATLANTIC ECOSYSTEMS
2018
LEATHERBACK SEA TURTLE ANNUAL MOVEMENTS
Satellite tracks from 1999 to 2016
High use areas (where turtles spend more than 50% of their time)
Figure 40 : Seasonal movement of leatherback sea turtles through Canadian waters from 1999 to 2016 from satellite tags. The areas circled in orange represent high use areas (>50% of their time).
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