Low oxygen levels in Spittal Pond may have caused a number of fish to die at the site in recent weeks.

A spokesman for the Department of Environment and Natural Resources said dead juvenile snappers were collected from the shoreline at the eastern end of Spittal Pond, Smiths, on May 30.

He said: “We could not determine a cause of death, possibly low oxygen levels in pond, which may occur as water temperature rises.

“Also, we had over five inches of rain in May and this will decrease the salinity of the pond water, which is very stressful for marine fishes. The combination of stresses may have caused their demise.

“Spittal Pond will remain a challenging environment for fishes because of the large fluctuations of oxygen levels and salinity.”

The spokesman said the department was not aware of any such changes in other coastal ponds, such as Mangrove Lake.

He added that there is “no capacity” to control or change the conditions in Spittal Pond.

“It is a marginal environment for marine fishes that are introduced and trapped in there,” he said.

It is unusual for ocean fish to be in the pond.

The spokesman added: “Survey work done in Spittal Pond by Dr Martin Thomas in the later 1980s found only the small mosquito fish to be very abundant and a few American eels.

“He also recorded that mullets had been seen on one occasion. He thought that storm events can wash small fishes into the pond from the south shore and this may have happened last fall, with Hurricane Paulette.

“This is an unusual and noteworthy event if the factors that introduced the fishes to the pond are correct and the assumptions about their demise are true.”

Members of the public who see large numbers of dead fish should report them via https://environment.bm/contacts-for-strandings, or call the Bermuda Aquarium Museum and Zoo on 293-2727.