Populations of Freshwater Migratory Fish Have Plummeted in Last 50 Years

Bonn, 30 July 2020 - The World Fish Migration Foundation and the Zoological Society of London have issued a new report on the status of freshwater migratory fish. The Living Planet Index (LPI) for Migratory Freshwater Fish is the first comprehensive global report on the conservation status of these species. It analyzes data from 1,406 populations of 247 species using the Living Planet Database. Species were identified as those listed on the Global Register of Migratory Species (GROMS), an initiative launched under CMS in the late ‘90s.

The report reveals an alarming 76 per cent average decline in populations for the period of 1970 to 2016. Habitat degradation, alteration, and loss account for approximately half of the threats to migratory fish. Besides loss of wetlands, a significant role in population decline is played by dams and other river barriers that constitute obstacles to migration and prevent the fish from reaching their mating or feeding grounds, disrupting their life cycles.

Over-exploitation, such as unsustainable fishing and accidental bycatch account for around one third of the threats to these populations. Furthermore, populations are threatened by the impacts of the climate crisis as changes in temperature can alter the timing of migration and reproduction, causing these events to happen at the wrong time, and therefore misalign reproduction and the period of greater food availability in a specific habitat.

CMS has the mandate and the instruments to address many of these threats.  Currently twenty-six species of freshwater fish are listed on CMS Appendices, including the European Eel, the Giant Catfish, sawfish and a number of species of sturgeon and paddlefish.  The findings of the report suggest that a significant higher number of species might meet the criteria for being listed.

Migratory fish are invaluable to human health and the global economy. Fish and fish by-products represent some of the world’s most traded products within the food sector. The recreational fishing industry alone is worth billions of dollars and supports tens of thousands of jobs. Overall, the figures represent the need for more protective measures for migratory and freshwater fish worldwide.

The press release issued by the authors of the report can be found here.

Last updated on 16 September 2020

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News item
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Fish