Why did so many fish die at St. Ouen's Pond?

Hundreds of fish, including endangered European eels, died at St. Ouen's Pond last summer due to exceptionally dry conditions and high temperatures, which depleted oxygen levels.

What is being done to protect Jersey's wetlands from climate change?

Jersey is strengthening monitoring and wetland management, creating buffer ponds and reed beds to filter pollutants, and adapting measures to make sites more resilient to climate change and extreme weather.

What endangered species were affected by the St. Ouen's Pond incident?

Nearly 300 of the dead fish were European eels, identified as one of the most endangered species in Jersey.

Home / Environment / Endangered Eels Among Hundreds Dead at St. Ouen's Pond

Endangered Eels Among Hundreds Dead at St. Ouen's Pond

31 Jan

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Summary

Hundreds of fish, including endangered European eels, died at St. Ouen's Pond.
Dry conditions and high temperatures led to low oxygen levels in the pond.
Efforts are underway to enhance wetland resilience against climate change impacts.

Endangered Eels Among Hundreds Dead at St. Ouen's Pond

Last summer, St. Ouen's Pond, Jersey's largest freshwater lake and a protected Site of Special Interest, saw over 700 fish die, including hundreds of critically endangered European eels. Ecologists attribute the mass die-off to exceptionally dry conditions in 2025 and record high temperatures, which caused water levels to drop and become warm. These conditions encouraged cyanobacteria to proliferate, consuming dissolved oxygen and leaving insufficient levels for fish survival.

In response, Jersey's Environment Minister announced strengthened monitoring and wetland management to improve resilience against climate change. Efforts will include creating buffer ponds and reed beds to filter pollutants from agricultural runoff. Environmental experts emphasize the need to adapt to erratic weather patterns, a growing concern amplified by rising global temperatures. The aim is to make natural spaces more resilient to climate change impacts.