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Characterization of large basking shark Cetorhinus maximus aggregations in the western North Atlantic Ocean |
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| Authors: | L M Crowe O O'Brien T H Curtis S M Leiter R D Kenney P Duley S D Kraus |
| Institution: | 1. Center for Coastal Studies, 5 Holway Avenue, Provincetown, Massachusetts, U.S.A.Present address: Integrated Statistics under contract to the Northeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 166 Water Street, Woods Hole, Massachusetts 02543, U.S.A.;2. Anderson Cabot Center for Ocean Life, New England Aquarium, 1 Central Wharf, Boston, Massachusetts, U.S.A.;3. Atlantic Highly Migratory Species Management Division, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 55 Great Republic Drive, Gloucester, Massachusetts, U.S.A.;4. University of Rhode Island, Graduate School of Oceanography, 215 South Ferry Road, Narragansett, Rhode Island, U.S.A.;5. Northeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 166 Water Street, Woods Hole, Massachusetts, U.S.A. |
| Abstract: | Cetorhinus maximus aggregations recorded during extensive aerial survey efforts off the north‐eastern United States between 1980 and 2013 included aggregations centring on sightings with group sizes of at least 30 individuals. These aggregations occurred in summer and autumn months and included aggregation sizes of up to 1398 individuals, the largest aggregation ever reported for this species. The aggregations were associated with sea surface temperatures of 13–24° C and chlorophyll‐a concentrations of 0·4–2·6 mg m?3 and during one aggregation, a high abundance of zooplankton prey was present. Photogrammetric tools allowed for the estimation of total body lengths ranging between 4 and 8 m. Characterization of these events provides new insight into the potential biological function of large aggregations in this species. |
| Keywords: | basking shark behaviour courtship elasmobranch foraging shoaling |