Dead fish at Chadwick Lakes are alien species unsuitable to warm climate

Dead fish at Chadwick Lakes are alien species introduced illegally and unable to survive the hot summer weather, the environment watchdog said.

Photos of dead fish on the banks in Chadwick Lakes, a valley system in the outskirts of Rabat, surfaced on social media over the past few days.

However, the Environment and Resources Authority said that from the initial assessment it is likely the fish died due to “warm evaporating waters”.

ERA is investigating the matter but noted this happens every year in the dry season and mostly affects alien fish and freshwater animals introduced in the valley ponds.

“This is most often the case as such animals are not native to the dry Mediterranean summer and as a result cannot survive the hot and dry summer conditions,” the authority said.

It reiterated that people are not to release any aquarium fish and other animals in local freshwater systems since they are not adapted to Maltese climate and end up affecting native species of importance.

Chadwick Lakes has seen non-native goldfish and crayfish being introduced illegally by people to the detriment of the local ecology.

Nature Trust Malta and the Energy and Water Agency that are responsible for the valley’s rehabilitation reiterated their appeal to the public to avoid releasing exotic species at Chadwick Lakes that may also threaten the endemic frog.

The two organisations said that before the summer they already implemented an exercise and caught a quite amount of fish from the valley, which was released during winter.

“However, it seems that other fish was released in the valley during the last weeks,” they said.