Question to the Department for Environment, Food and Rural Affairs:

To ask Her Majesty's Government what assessment they have made of the reasons for the decline in fish populations, in particular eels, in UK rivers.

Freshwater fisheries and aquaculture policy are devolved in the UK.

In England, the status of fish populations, and reasons for any declines, are assessed through an extensive monitoring programme covering a wide range of species, undertaken by the Environment Agency.

The reasons for the eel's decline are complex and not fully understood but human impacts and oceanic factors are assumed to have major impacts on the stock. These factors will likely affect local production differently throughout the eel's continental range. Human factors may include fisheries (legal and illegal), habitat loss and blockage to migratory pathways, mortalities at hydropower turbines and water pumps, contaminants, non-natives and various climate change factors.

The state of the European eel stock across the UK and the level of man-made impacts are assessed every three years, with a UK report prepared and reported to the International Council for the Exploration of the Sea (ICES) for international assessment of this stock. The next report for 2018-2020 is expected later this year.