The Weather Network – Tuna see optimistic rise in numbers 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 the illegal fishing.

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

That’s according to the International Union for Conservation of Nature (IUCN), which updated its Red List of Threatened Species on Saturday to highlight the successes of conservation action for some ocean species while others need to. still be improved.

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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 countries implementing more sustainable catch quotas while successfully tackling illegal fishing.

Atlantic bluefin tuna (Thunnus thynnus) moved from endangered to less concern, while southern bluefin tuna (Thunnus maccoyii) was moved from critically endangered to endangered. Albacore (Thunnus alalunga) and yellowfin tuna (Thunnus albacares) both statuses also changed – from Near Threatened to Least 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 to the IUCN Red List is a powerful sign that, despite growing pressures on our oceans, species can recover if states genuinely commit to sustainable practices,” said Bruno Oberle, Director General of IUCN, in a press release.

“States and others now gathered at the IUCN World Conservation Congress in Marseille must seize the opportunity to raise ambition on biodiversity conservation and work towards binding targets based on sound science. These Red List assessments demonstrate how our lives and livelihoods are intertwined with biodiversity.


With news of the rise in the numbers of several tuna species, not all of them are rebounding. According to the IUCN, many regional tuna stocks are still seriously depleted.

For example, the largest eastern population of Atlantic bluefin tuna, located in the Mediterranean Sea, has increased by at least 22% over the past 40 years. However, its smaller native community in the western Atlantic, which breeds in the Gulf of Mexico, has more than halved over 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 over thousands of kilometres, so it is 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 this statistic shows that effective management measures are “lacking” in most of the world’s oceans.

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

Great white shark/Sharkdiver68/Wikipedia

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

The Komodo dragon, the largest living lizard in the world, has been moved from the endangered category of vulnerable on the IUCN Red List. Native to Indonesia and found only in the World Heritage-listed Komodo National Park and surrounding Flores, it is increasingly threatened by the impacts of climate change. Acceptable habitat for 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 the protected areas of Flores are also threatened by significant habitat loss due to activities. continuous humans.

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