Date

2009

Document Type

Master's Thesis

Degree Name

Master of Science (M.S.)

Department

Moss Landing Marine Laboratories

Abstract

The Bering skate, Bathyraja interrupta, is one of the most common skate species in Alaskan waters. Skates are a regular bycatch in Alaskan commercial long line and bottom trawl fisheries, and there is increasing interest in directed fishing of skates in the region. Until recently, little was known about the life histories of Alaskan species. This is the first study to examine the age, growth and age at maturity of B. interrupta, and one of the few studies to compare life history characteristics of a skate species among management regions. No significant difference between sexes was detected in either region. However, a slight but significant difference was found between regions. The parameters of the von Bertalanffy growth function were L∞ = 112.5 cm TL and k-1yr = 0.06 for the eastern Bering Sea and L∞ = 119.2 cm TL and k-1yr = 0.06 for the Gulf of Alaska. Age estimates provided a minimum longevity of 19 years and 21 years for the eastern Bering Sea and Gulf of Alaska respectively. In the Gulf of Alaska, the size at maturity was estimated as 69 cm TL for males and 71 cm TL for females, while the age at maturity was estimated as 11.6 years and 12.0 years respectively. In the eastern Bering Sea, the size at maturity was estimated as 70 cm TL for males and 72 cm TL for females, which corresponded to 13.1 years and 11.2 years respectively.

Comments

Thesis (M.S.) Division of Science and Environmental Policy. Moss Landing Marine Laboratories

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