Characteristics and stomach contents of Greenland sharks (Somniosus microcephalus) caught in Svalbard during June 2008-2009, supplement to: Leclerc, Lisa-Marie E; Lydersen, Christian; Haug, Tore; Bachmann, Lutz; Fisk, Aaron T; Kovacs, Kit Maureen (2012): A missing piece in the Arctic food web puzzle? Stomach contents of Greenland sharks sampled in Svalbard, Norway. Polar Biology, 35(8), 1197-1208

Harbour seals in Svalbard have short longevity, despite being protected from human hunting and having limited terrestrial predation at their haulout sites, low contaminant burdens and no fishery by-catch issues. This led us to explore the diet of Greenland sharks (Somniosus microcephalus) in this re...

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Bibliographic Details
Main Authors: Leclerc, Lisa-Marie E, Lydersen, Christian, Haug, Tore, Bachmann, Lutz, Fisk, Aaron T, Kovacs, Kit Maureen
Format: Article in Journal/Newspaper
Language:English
Published: PANGAEA - Data Publisher for Earth & Environmental Science 2012
Subjects:
Biological sample
International Polar Year 2007-2008 IPY
Arctic
Svalbard
Greenland
Norway
Haug
atlantic cod
bearded seal
Cystophora cristata
Erignathus barbatus
Gadus morhua
hooded seal
International Polar Year
IPY
minke whale
Pusa hispida
ringed seal
Somniosus microcephalus
Online Access:https://dx.doi.org/10.1594/pangaea.815268
https://doi.pangaea.de/10.1594/PANGAEA.815268
Description
Summary:Harbour seals in Svalbard have short longevity, despite being protected from human hunting and having limited terrestrial predation at their haulout sites, low contaminant burdens and no fishery by-catch issues. This led us to explore the diet of Greenland sharks (Somniosus microcephalus) in this region as a potential seal predator. We examined gastrointestinal tracts (GITs) from 45 Greenland sharks in this study. These sharks ranged from 229 to 381 cm in fork length and 136-700 kg in body mass; all were sexually immature. Seal and whale tissues were found in 36.4 and 18.2%, respectively, of the GITs that had contents (n = 33). Based on genetic analyses, the dominant seal prey species was the ringed seal (Pusa hispida); bearded seal (Erignathus barbatus) and hooded seal (Cystophora cristata) tissues were each found in a single shark. The sharks had eaten ringed seal pups and adults based on the presence of lanugo-covered prey (pups) and age determinations based on growth rings on claws (<1 year and adults). All of the whale tissue was from minke whale (Balenoptera acutorostrata) offal, from animals that had been harvested in the whale fishery near Svalbard. Fish dominated the sharks' diet, with Atlantic cod (Gadus morhua), Atlantic wolffish (Anarhichas lupus) and haddock (Melanogrammus aeglefinus) being the most important fish species. Circumstantial evidence suggests that these sharks actively prey on seals and fishes, in addition to eating carrion such as the whale tissue. Our study suggests that Greenland sharks may play a significant predatory role in Arctic food webs. : Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150

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