The Weather Network – Tuna numbers increase with optimism as other marine species decline


Monday, September 6, 2021, 3:37 p.m. – Four of the seven most commercially fished tuna species have shown signs of recovery thanks to countries that have instituted more sustainable catch quotas over the past decade while successfully combating illegal fishing .

While several tuna species are now on the road to recovery, the same cannot be said for other marine species, notably sharks and rays, due to ineffective population revitalization measures.

This is according to the International Union for the Conservation of Nature (IUCN), which has updated its Red List of Threatened Species Saturday to highlight the success of conservation measures for some ocean species while others still need improvement.

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In the latest review, IUCN presented the results of a reassessment of the seven most commercially fished tuna species. Four of them have shown signs of recovery over the past 10 years thanks to the introduction by countries of more sustainable catch quotas while successfully combating illegal fishing.

Atlantic bluefin tuna (Thunnus thynnus) changed from threatened to less concern while the southern bluefin tuna (Thunnus macoyii) changed from Critically Endangered to Endangered. Albacore (Thunnus alalunga) and yellowfin tuna (Thunnus albacares) both have also changed status – from near threatened to least of concern.

The IUCN Red List contains 138,374 species, of which 38,543 are threatened with extinction.

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“[Saturday’s] The update of the IUCN Red List is a powerful sign that, despite increasing pressures on our oceans, species can recover if states are truly committed to adopting sustainable practices, ”said Bruno Oberle, director general of IUCN, in a statement. Press release.

“States and others now gathered at the IUCN World Conservation Congress in Marseille must seize the opportunity to strengthen their ambition for biodiversity conservation and work towards binding targets based on sound science. . These Red List assessments show how closely our lives and livelihoods are linked to biodiversity. “


With the news of the increase in the number of several species of tuna, not all are rebounding. Many regional tuna stocks are still severely depleted, according to the IUCN.

For example, the largest eastern population of Atlantic bluefin tuna, located in the Mediterranean Sea, has increased by at least 22 percent over the past 40 years. However, its smallest native community in the western Atlantic, which breeds in the Gulf of Mexico, has declined by more than half during the same period. Yellowfin tuna, meanwhile, remains overexploited in the Indian Ocean.

“These Red List assessments are proof that sustainable fisheries approaches work, with huge long-term benefits for livelihoods and biodiversity. We must continue to enforce sustainable fishing quotas and fight illegal fishing, ”said Bruce B. Collette, chair of the IUCN SSC Tuna and Billfish Specialist Group, in the press release.

“Tuna species migrate thousands of kilometers, so it is also essential to coordinate their management on a global scale. “


The revised IUCN Red List also included a detailed reassessment of the global population of shark and ray species, revealing that 37% are now threatened with extinction. The group says the statistic shows that effective management measures are “lacking” in much of the world’s oceans.

According to its list, all endangered shark and ray species are overexploited, with 31% more affected by habitat loss and degradation, while 10% are in decline due to climate change.

Great white shark / Sharkdiver68 / Wikipedia
(Sharkdiver68 / Wikipedia)

It is not just marine species that are under pressure or threatened.

The Komodo dragon, the world’s largest living lizard, has been moved to endangered vulnerable on the IUCN Red List. Originally from Indonesia and only present in the Komodo National Park, a World Heritage Site, and in the vicinity of Flores, it is gradually threatened by the impacts of climate change. The acceptable habitat of the Komodo dragon could see a reduction of at least 30% over the next 45 years.

Additionally, although the Komodo National Park subpopulation is considered stable and well protected at this time, Komodo dragons outside of Flores protected areas are also threatened with significant habitat loss due to activities. continuous human.

Miniature courtesy of Videoblocks.

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