Dead fish were found floating in the water recently at Lagoa dos Salgados, considered to be one of the best spots in the Algarve for bird watching and aquatic life.
David Stross, a local resident, told the Algarve Resident: “I was walking with family and friends to see the turtles but all we saw were dozens of dead fish floating on the water’s surface and no sign of any turtles at all.
“We had visited the lagoon some days earlier and had seen literally dozens of turtles, although they were all covered in green algae. You can imagine how distressing it was to be confronted with dozens of dead fish and very few birds and definitely no turtles.”
Biologist Élio Vicente told the Algarve Resident that the cause of this phenomenon could have various origins.
“The cause may have been from the heating of the water during the summer, which leads to the reduction of oxygen in the water, and thus anything living in the lagoon dying of asphyxiation.
“There is also the likelihood of the existence of toxins that accumulate in water, which can poison the fish, causing their death. This toxicity can be caused by human waste or general waste, which often ends up in lagoons because of the carelessness of people.
“Finally, it may also be a viral disease, which is also common.”
David Stross returned to the lagoon a few days later. He told the Algarve Resident: “I have again visited Lagoa dos Salgados and was delighted to see that the turtles are back and there were no dead floating fish but many herons.”