The International Union for Conservation of Nature (IUCN) Red List of Threatened Species collates the extinction risk of animal, plant and fungi species. It is used to gain an insight into biodiversity health and aid conservation decisions. The assessment lists species into one of the below categories:
Not Evaluated
Data Deficient
Least Concern
Near Threatened
Vulnerable
Endangered
Critically Endangered
Extinct in the wild
Extinct
157,190 species have been assessed to date with over 44,000 species threatened with extinction.
As the COP28 UN climate conference takes place in Dubai, the IUCN released an update to the list on Monday 11 December 2023 in the hopes of bringing attention to the link between biodiversity and climate change.
The update included the first global freshwater fish assessment which found that one quarter of the assessed species are at risk of extinction. Freshwater fish are crucial to ecosystem function, human food provision and livelihoods. Threats to freshwater fish species are summarised in the table below.
Threat
% Freshwater Fish Species affected
Climate change
Pollution
Dams & water extraction
Overfishing
Invasive species & disease
17
57
45
25
33
An example of a species which has changed from Least Concern to Near Threatened is the Atlantic Salmon (Salmo salar). Between 2006 and 2020, the Atlantic Salmon population has declined by 23%. Many of the above threats affect the global population, with salmon farming causing a significant threat. Breeding with escaped farmed fish can affect the gene pool alongside wild salmon dying due to salmon lice and diseases caused by salmon farming.
An interesting quote from the IUCN press release regarding the importance of the findings of the freshwater fish assessment:
“Freshwater fishes make up more than half of the world’s known fish species, an incomprehensible diversity given that freshwater ecosystems comprise only 1% of aquatic habitat. These diverse species are integral to the ecosystem, and vital to its resilience. This is essential to the billions of people who rely upon freshwater ecosystems, and the millions of people who rely on their fisheries. Ensuring freshwater ecosystems are well managed, remain free-flowing with sufficient water, and good water quality is essential to stop species declines and maintain food security, livelihoods and economies in a climate resilient world,” said Kathy Hughes, Co-Chair of the IUCN SSC Freshwater Fish Specialist Group.
A positive outcome from the update is the scimitar-horned oryx (Oryx dammah). Thanks to an international breeding and rewilding programme, the species is now listed as Endangered instead of Extinct in the Wild on the IUCN red list. Chad is now home to a herd of 600 oryx which have been considered extinct in the wild since around the year 2000. There is still a long way to go to ensure that the work continues in the midst of a biodiversity crisis, however, it does offer some hope for conservation programmes and the future.