Impact of Ocean Acidification on Recruitment and Yield of Bristol Bay Red King Crab

• Main Author: Poljak, Dusanka
• Other Authors: Punt, André E
• Format: Thesis
• Language: English
• Published: 2013
• Subjects: Bristol Bay Red king crab; Discounted profit; Ocean acidification; Recruitment; Yield; Fisheries and aquatic sciences; fisheries; Bering Sea; Pacific; Red king crab; Alaska; Aleutian Islands
• Online Access: http://hdl.handle.net/1773/22815

Thesis (Master's)--University of Washington, 2013 The excess of anthropogenic carbon dioxide (CO2) produced since the industrial revolution is being absorbed by the oceans through the carbon cycle. Atmospheric carbon dioxide has increased about 40% since the preindustrial era, and the oceans have absorbed more than a third of these emissions. This has led to the release of H+ ions via seawater carbonate chemistry, and hence to a reduction in ocean pH, that is, ocean acidification. Ocean pH has been reduced by roughly 0.1 units, which is equivalent to an increase in H+ of roughly 30%, and about a 16% decrease in . Corrosive waters, the waters below the CaCO3 saturation horizon, are predicted to reach shallower depths more in the Northeast Pacific Ocean than in any other ocean basin. The saturation horizon is projected to reach the surface of the North Pacific Ocean during this century, and some regions of the Bering Sea are predicted to become carbon shell corrosive seasonally by the middle of this century, which will expose a wide range of North Pacific species, including Bristol Bay Red king crab, to corrosive waters. Bristol Bay Red king crab has been one of the most valuable fished stocks in the US. It is managed by the State of Alaska under federal guidelines defined in the Fishery Management Plan (FMP) for crab in the Bering Sea and Aleutian Islands. Current management rules are designed to handle short-term fluctuations in stock abundance mainly due to exploitation. The impact of ocean acidification on red king crab is predicted to lead to long-term changes to stock abundance, and for which management is currently unprepared. This thesis explores the impact of ocean acidification on recruitment and yield of Bristol Bay red king crab under a range of ocean acidification scenarios and management strategies. The management strategies include setting the exploitation rate for the directed fishery to that under the overfishing limit (OFL) rule, applying constant exploitation rates, and setting exploitation ...