Fish populations in the Lastovo archipelago are threatened by overfishing and climate change, show preliminary findings of a research conducted this week by the World Wide Fund for Nature (WWF).

WWF researchers note that the number of fish species and their size have declined in relation to those in some other protected Mediterranean areas, where research was conducted this summer. Overfishing has been identified as yet another factor contributing to the poorer status of fish stocks, the organisation said in a statement.

The findings of the research were presented to the management of the Lastovo Archipelago Nature Park, southernmost Croatia.

“They prove that areas treated as reservations have a much greater resilience,” said Patrik Krstinic of the WWF Adria, adding that this means that reducing human pressure on marine species and habitats facilitates protection against the consequences of climate change.

Fish stocks recover relatively quickly if the pressure of fishing is reduced, and regulated, no-fishing zones, such as the Jabuka Pit in the Croatian Adriatic, have shown the best results, he said.

A WWF round table on the protection of the Adriatic Sea and the latest research show that without quality monitoring of fisheries management measures it is not possible to achieve the recovery of biodiversity in protected areas.

“In the areas that have quality monitoring, the recovery of fish stocks is visible within a period of several years. The migration of fish from protected to neighbouring areas positively affects the biodiversity of the sea and fisheries in general,” Krstinic said.

Invasive fish species like the parrotfish, previously inhabiting only the eastern part of the Mediterranean, have been spotted in the sea off Lastovo as well, and now the parrotfish is one of the dominant species in the Lastovo Archipelago Nature Park. At the same time, researchers have expressed concern about the absence of some species such as the brown meagre, which is present in similar habitats of the Mediterranean Sea.

The WWF had already researched fish populations in the Lastovo archipelago in 2018, and the latest research will show if there are significant changes in relation to that year.

The final findings of the research will be available in early 2024.