KOCHI: Keith Brander, fisheries biologist and an authority on the impact of global warming on fisheries, has called for cutting down on marine fishing to mitigate the impact of climate change and to maintain a sustainable level of fish stocks.
Mr. Brander, who was the lead author of the fisheries section of the 2007 report of the Intergovernmental Panel on Climate Change (IPCC), said overexploitation was already a major cause for the depletion of the fish stocks. Worsening the situation, the rise in seawater temperature caused by global warming would make the sea inhospitable for many marine ecosystems.
“The frequency and intensity of extreme climate events is likely to have a major impact on future fisheries production in both inland and marine systems,” Mr. Brander said.
Fish mortality
“Reducing fish mortality in the majority of fisheries, which are currently fully exploited or overexploited, is the principal feasible means of reducing the impacts of climate change.”
Mr. Brander said that over-fishing should be checked in such a way that it would not hurt the livelihoods of fishing communities. Already, fish stocks were under heavy pressure from habitat degradation, pollution and introduction of new species, apart from over-fishing.
“Climate change will now be an added factor,” he told The Hindu. “Climate change can act directly on productivity of commercial fish species by altering growth and reproduction.” Indirectly, climate change would act by enhancing or suppressing prey, predators and pests with consequences for the structure and resilience of the whole marine ecosystem.
Global warming
He admitted that scientists still had no exact clues to how global warming would impact the oceans and their ecosystems, unlike the terrestrial impacts. Humans depended on the oceans for many ecosystem services and there was a cause for concern that these services would be damaged and degraded by climate change. There was no single global response to these impacts. “Local and regional responses, depending on local realities, are necessary to handle the situation.” In terms of fish stock depletion, curtailing fishing was an important response.
Mr. Brander, who until recently had been the coordinator of the International Council for the Exploration of the Sea, was here to give a presentation on the “Impacts of climate change on marine ecosystems and fisheries” at a symposium on “Marine ecosystems: challenges and opportunities.”
The symposium was organised by the Marine Biological Association of India and the Central Marine Fisheries Research Institute.
