Climate change will continue to challenge survival of our marine fish and fishing industry |22 September 2017

The results of the first analysis of how vulnerable the world’s freshwater and marine fishes are to warming water temperatures caused by climate change have recently been published by researchers of the University of Washington (UW).The fisheries sector in Seychelles is the second major pillar of the economy and contributes significantly to food security. Consequently, the fishing industry is particularly vulnerable to the effects of climate change, making the results of UW’s study of particular interest to Seychelles.

The lab experiments conducted by the UW’s School of Aquatic and Fishery Sciences measured the highest temperatures that fish are able to tolerate before they die and showed that generally marine fish in the tropics and freshwater fish in higher latitudes of the Northern Hemisphere were the most at risk when water temperatures warmed.

The researchers explained that “fish in tropical oceans are already living in water that is approaching the upper range of their tolerance, so they might not have much wiggle room when temperatures increase slightly. On the other hand, fish in freshwater streams in the far north are accustomed to cooler water temperatures and have much less tolerance for warming waters. Since the effects of climate change are acutely felt in high latitudes, this does not bode well for fish in those streams that have a small window for survivable temperatures.”

“Fish will either migrate, adapt or die off as temperatures continue to warm,” the researchers explained. “It is unlikely that fish will be able to keep up with the rate at which temperatures are increasing. The ability to move, then, is imperative for fish that live in the most critical areas identified in this analysis.”

The findings of this study can be linked as far back as 1998 when the ‘El Nino’ phenomenon caused sea surface temperatures to rise around the Indian Ocean and led to significant economic losses. Fishing and agriculture accounted for more than half of the total figure according to the International Monetary Fund (IMF).

In Seychelles, the strong climate oscillations impacted on the industrial purse-seine tuna fishery. According to the 2009 Seychelles National Climate Change Strategy (SNCCS), fluctuations in the climate caused modifications of tuna habitat and consequently this affected catch-ability. The direct, indirect and induced economic effects of the tuna industry was said to have declined by 58%, 34% and 60% respectively. It was additionally mentioned in the SNCCS, that “climate change impact on coral reefs and fisheries, through warming of the ocean and ocean acidification are threats that would undermine food security and livelihood in Small Island Developing States.”

Local fishermen in Seychelles affirm the economic burden on the fishing industry, explaining that rising sea surface temperatures cause fish to move deeper into the ocean. This affects their work as they are out fishing for longer periods of time and at greater distances. Consequently, they report to spend more money on food supply, fuel and fishing materials, which ultimately cause an increase in the price of fish on the market.

Ronny Jumeau, New York-based ambassador for Climate Change and Small Island Developing State Issues, has previously highlighted that rising sea temperatures are of even greater importance in the Indian Ocean. “Many people do not know that the Indian Ocean is warming up quicker than the Atlantic and the Pacific. One of the reasons is that the Atlantic and the Pacific are opened up to both polar regions. You have the North Pole and the South Pole. In the case of the Indian Ocean, we only open up to the South Pole. In the north, you hit against the land mass of India and the Gulf, so the hot water circulates there. When you get the warming of oceans, it tends to warm up in the Indian Ocean more than in others,” he remarked.

Seychelles’ fishing industry is greatly susceptible to warming of the ocean as a result of climate change so to ensure the viability of our economy and food security for the future, climate change remains at the centre of Seychelles’ Sustainable Development Strategy.

References:

University of Washington; Seychelles National Climate Change Strategy 2009; National Public Radio; Many Strong Voices

Photo source: Huffington Post