Co-occurrence of Pacific sleeper sharks Somniosus pacificus and harbor seals Phoca vitulina in Glacier Bay

Alaska Fishery Research Bulletin
By: , and 

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Abstract

We present evidence that Pacific sleeper sharks Somniosus pacificus co-occur with harbor seals Phoca vitulina in Glacier Bay, Alaska, and that these sharks scavenge or prey on marine mammals. In 2002, 415 stations were fished throughout Glacier Bay on a systematic sampling grid. Pacific sleeper sharks were caught at 3 of the 415 stations, and at one station a Pacific halibut Hippoglossus stenolepis was caught with a fresh bite, identified as the bite of a sleeper shark. All 3 sharks and the shark-bitten halibut were caught at stations near the mouth of Johns Hopkins Inlet, a glacial fjord with the highest concentration of seals in Glacier Bay. Using a bootstrap technique, we estimated the probability of sampling the sharks (and the shark-bitten halibut) in the vicinity of Johns Hopkins Inlet. If sharks were randomly distributed in Glacier Bay, the probability of sampling all 4 pots at the mouth of Johns Hopkins Inlet was very low (P = 0.00002). The highly non-random distribution of the sleeper sharks located near the largest harbor seal pupping and breeding colony in Glacier Bay suggests that these 2 species co-occur and may interact ecologically in or near Johns Hopkins Inlet.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Co-occurrence of Pacific sleeper sharks Somniosus pacificus and harbor seals Phoca vitulina in Glacier Bay
Series title Alaska Fishery Research Bulletin
Volume 11
Issue 2
Year Published 2005
Language English
Publisher Alaska Department of Fish and Game
Contributing office(s) Alaska Science Center
Description 5 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Alaska Fishery Research Bulletin
First page 113
Last page 117
Online Only (Y/N) N
Additional Online Files (Y/N) N