The International Union for Conservation of Nature (IUCN) updated the assessments of two of the world’s largest eel populations – European eel and Japanese eel. The new assessments show no significant improvements.
Both species are on the Red List of threatened species managed by the International Union for Conservation of Nature (IUCN). The status of European eel (Anguilla anguilla) is “Critically Endangered” and the status of Japanese eel (Anguilla japonica) is “Endangered”. The assessments were carried out by the IUCN Anguillid Eel Specialist Group (AESG). According to the group, both species have a life cycle that makes application of the Red List criteria challenging.
In the case of European eel, assessment of the different life stages confirms that the population remains Critically Endangered and that the population trend is “decreasing” for mature individuals. All the life stages, from the larval Leptocephali to the mature silver eels have shown tremendous decline. Although some improvements in European glass eel numbers have been reported over recent years, these were not sufficient to make a difference in the assessment, which is applied to a three generations/decadal scale. The assessment also shows a “continuing decline in the area, extent and/or quality of habitat” – one of the main threats to European eel.
The overall negative trends of “decreasing” population and “continuing decline” in suitable habitat types are confirmed in the context of numerous “Conservation Actions” that have been put in place, including research and monitoring, area-based regional management plans, harvest management plans, some international legislation and trade controls. But despite many good efforts, there is currently no framework of conservation actions that is applied throughout its wide geographical range.
The confirmation of the population’s “Critically Endangered” status should not come as a surprise to anyone, since the International Council for the Exploration of the Seas (ICES) advice in November 2019 stated that the condition of the eel remains critical and that all anthropogenic mortalities should be reduced to as close to zero as possible.
– The new IUCN assessment confirms the need for urgent action to protect and support the recovery of European eel, says Niki Sporrong at the Fisheries Secretariat. The efforts within the EU to help its recovery since the 2007 Eel Regulation was adopted have been patchy and insufficient. European eel recovery is going to take a long time and we now need much more consistent efforts to protect the species throughout its geographical range.
The IUCN Anguillid Eel Specialist Group is also in the process of re-assessing American eel (Anguilla rostrata), but due to COVID-19 the completion of this assessment has been delayed and may not be finalised until early next year.
For more information:
European eel: https://www.iucnredlist.org/species/60344/152845178
Japanese eel: https://www.iucnredlist.org/ja/species/166184/152764855