Effects of climate change on coastal aquaculture in British Columbia: an examination of anticipated impacts in the Strait of Georgia
Date
2012-11-27
Authors
José, Edson Anselmo
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Abstract
Climate change is one of the factors that pose new challenges to the sustainability of the capture fishery and aquaculture sector around the world. As concerns over the impacts of climate change on ecosystems have been increasing over the last few decades, this study investigated how anticipated changes in climatic conditions would affect Manila Clams and Pacific Oysters bottom culture in British Columbia (BC) and assessed the extent to which the environmental databases that have been assembled by various agencies and institutions in BC could support this type of analysis.
This study examined changes in sea surface salinity (SSS) and sea surface temperature (SST) developed scenarios of these changes and analyzed the trends based on projections of SST and SSS of open ocean adjacent waters of BC’s coast. In addition, this study quantified beach exposure/inundation as result of sea level rise (SLR). Moreover, this study identified areas along the Strait of Georgia (SoG) that have capability for shellfish culture and defined capability indices for Manila Clams and Pacific Oysters bottom culture based on the physical conditions that characterize existing commercial aquaculture operations. Finally, this study assessed how bottom shellfish culture sites’ capability in the SoG will be affected by changes in SST, SSS and beach exposure/inundation associated with SLR.
Results of the analysis indicate that the annual average projections of SST of open ocean adjacent waters of BC’s coast will increase approximately 10C between 2012 and 2050 at a rate of 0.1110C/year, and between 2051 and 2100 the SST will increase approximately 20C at a rate of 0.0330C/year. The annual average projections of SSS of open ocean adjacent waters of BC’s coast will decrease approximately 0.2 ppt between 2012 and 2050 at a rate of 0.0055 ppt/year. Furthermore, projections from 2051 to 2100 indicate that SST will decrease approximately 0.5 ppt at a rate of 0.0088 ppt/year.
In addition to the performed analysis, this study selected and simulated SLR on three sites (Buckley Bay and Fanny Bay in Baynes Sound, and Henry Bay on Texada Island). The results indicate that an increase of 1.2 m in sea level will inundate 121 ha of Buckley Bay and Fanny Bay combined and 37 ha of Henry Bay. An increase of 2 m in sea level will inundate 195.2 ha of Buckley Bay and Fanny Bay, and, 51.4 ha of Henry Bay. Capability indices’ classes defined and mapped in this study for Manila Clams bottom culture are: Not advisable, Poor, Medium and Good; and Not Advisable, Medium and Good for Pacific Oysters.
This study concluded that the existing datasets provided by various agencies and institutions are accessible, and can be used to investigate the impacts of climate change on coastal aquaculture in BC, although there is lack of some datasets as well as there is a need to improve some available datasets. This study also demonstrated and concluded that site capabilities to support Manila Clams and Pacific Oysters culture in the SoG will not be affected by the expected changes of SST, SSS. Changes in SST and SSS associated with SLR will not adversely affect shellfish bottom culture in the SoG. In contrary, SLR will have a negative impact on shellfish bottom culture.
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Keywords
climatic changes, shellfish, aquaculture, sea level