By Nestor Arellano
A recent study of global climate change foresees a massive decrease in fish farm production coastal areas of British Columbia and other parts of the world. The report published in the journal Global Change Biology said climate change will impact marine aquaculture diversity for 85 of the currently most commonly farmed fish in the world’s coastal and open ocean areas and cause an average of 10 per cent to 40 per cent decline in the number of species suitable for farming in tropical regions.
To counter the effects, the study recommended several measures including the development of new fish species and the continued improvement of technologies for land-based fish farming.
The study looked into global patterns of 85 species identified as some of the currently most commonly farmed marine species in coastal and/or open ocean areas. The study projects future trends and patterns under climate change. Specifically, the study estimates a “mariculture diversity index” for a given location and determine how it would change by the middle and end of the 21st century under strong mitigation and “no mitigation policy scenarios,” according to Muhammed A. Oyinlola and William W. L. Cheung who conceptualized the study. The study defines mariculture as a form of aquaculture taking place in seawater, such as fjords, inshore and open waters, and inland seas or inland facilities like recirculating aquaculture systems (RAS).
The study is a contribution by the Nippon Foundation‐the University of British Columbia Nereus Program, an interdisciplinary ocean research program. Funding support was also received from the Natural Sciences and Engineering Research Council of Canada.
While the change in climate could be bad news for raising some species, it could be good for others, according to the study.
For instance, while the coast of BC could lose 60 to 84 per cent of the marine area suitable for raising Atlantic salmon, the region would gain 46 per cent more area ideal for farming oysters.
“By the mid ‐ 21st century, Australia and Canada’s Pacific coast, for example, were projected to lose about 32 per cent and 60 per cent respectively, of potentially suitable marine area for farming Atlantic salmon,” the study said. “..In contrast, for the same timeframe, the area potentially suitable for farming Atlantic salmon in Norway was projected to increase by about 29 per cent and 48 per cent…and by 100 per cent under both scenarios for Sweden.
The study recommended a review of marine aquaculture zoning and site selection factoring in climate change.
“In addition, hybridization and development of new species strains that have better survival rates at higher temperatures and lower oxygen levels should be encouraged through research and development,” the study said. “Future increases and improvements in cost‐effective technology should also improve land‐based operations.”