Pevensey residents said they first saw the ‘dozens’ of dead fish at the sluice by Fence Bridge yesterday (Tuesday, September 19).
Images show a number of dead fish by the water, but a resident said they have now been cleared by the Environment Agency.
An Environment Agency spokesperson said: "We are investigating an incident of a number of dead fish found near Fence Bridge in Pevensey. Our officers have been to the site to take water samples to help identify the cause.
“Members of the public who spot fish in distress should report it to our 24/7 incident hotline [via] 0800 80 70 60 so that we can investigate.”
Responding to fish in distress and fish kills is part of the Environment Agency’s service to protect fish stocks and the fisheries it supports.