Climate change could alter tuna migration patterns in the Pacific island. This redistribution threatens to severely disrupt the economies of the Small Island Developing States (SIDS). It will also disrupt the sustainable management of the largest tuna fishing grounds on earth.
Tuna fishing plays a key role in food security and also the economic development of a majority of the 22 Pacific Island nations and territories. And among these, 10 of the Pacific SIDS are overwhelmingly dependent on the contribution of tuna to their economy and are referred to as ‘tuna-dependent.’
Over 95% of all tuna caught in that area come from the exclusive economic zones of these 10 SIDS. 37% of their government revenue comes from access fees paid by industrial fishing boats.
By 2050, a high greenhouse gas emission rate of RCP 805 could cause a 13% decline in the biomass of 3 species of tuna. This would be due to tuna migration to the high seas.
Every species of fish have their water temperature preference. This temperature is suited to their physiology and provides the ideal conditions for reproduction and growth, according to Johann Bell.
Bell is the senior director, tuna fisheries at the Center for Oceans. It is part of Conservation International, a non-profit devoted to the protection of the benefits of nature through science, fieldwork, and partnership.
Lack Of Food Will Force Tuna Migration To Deep Seas
Changes in water temperature affect the availability of prey. The rise in ocean temperatures brings changes to the availability of prey and this affects tuna migration patterns. Such fish would starve if they do not follow the movement of their prey.
Conservation International discovered that the ideal conditions for yellowfin and skipjack tuna are migrating eastwards as the ocean temperatures rise. These two species are considered ‘target species’ in this Pacific Island waters for the purse-seine fishery.
Tuna migration caused by warm waters will lead to a majority of the fish being netted in high-seas zones that are in the east and fall outside the jurisdiction of the SIDS, according to Bell.
The UN Convention on the Law of Sea defines that all coastal nations of the world have automatic jurisdiction over natural resources within their Exclusive Economic Zone. This is within a 200-mile radius from their shores. The coastal nations have exclusive rights to regulate, enforce, and ban the exploitation of fisheries and other marine resources.
The water beyond is known as high seas and is considered virtually ungoverned territory. They function as an open zone for fishing. As the tuna migration takes them beyond the EEZ of the Pacific Islands, this could scuttle their efforts to retain a sustainable zone. Moreover, fishing in the high seas by fishing fleets could lead to overfishing arising from lack of enforcement, according to representatives of Conservation International.
The study undertaken by Conservation International covered the 10 SIDS in the Pacific who are likely to be the most affected by tuna migration to the high seas.
These SIDS will face a decline of 20% in productivity by 2050 if ocean temperatures continue to rise at present rates. All the 10 island nations of Micronesia, Cook Islands, Marshal Islands, Kiribati, Palau, Nauru, Solomon Islands, Papua New Guinea, Tuvalu, and Tokelau will suffer economically from this tuna migration.
A major loss will be the denial of access fees earned by these SIDS earn from fishing fleets from the US, EU, China, Japan, Taiwan, and South Korea. Their annual revenue could decline by anywhere between 8 and 17% as a result of this migration.
The island nations have few alternative options of revenue and this fall will reduce the ability to support communities in adapting to unrelenting climate change. Investment in health, infrastructure, and education will also languish.
Another Blow Of Climate Change
Climate change is already affecting small nations the worst though their contribution to global warming is quite low when compared to developed nations. And nations that contribute to 60% of greenhouse gases will benefit instead from tuna migration where they will be exempt from paying any fees.
Only a drastic cut in the emission of fossil fuels that limiting global warming to 1.5C could thwart tuna migration. Another way to guarantee that Pacific SIDS continues to benefit would be to ensure that they receive revenues from tuna fishing despite foreign fishing fleets moving to high seas.