The Cres-Lošinj archipelago is the northern most group of islands in the Croatian Adriatic. The coastline is extremely diverse, consisting of many large and small coves and underwater caves. Due to warm ocean currents passing around Lošinj, the island has a relatively temperate climate with mild winters and summers. The marine environment around Lošinj is one of the most pristine in the northern Adriatic Sea with underwater visibility almost always exceeding twenty meters. The dense vegetation, mild weather and clean sea make Lošinj a very attractive place and it is a frequent destination for the rehabilitation of patients with pulmonary and allergic diseases.

Our field base is located on the east coast of the island. Some 95 fish species are found in these waters – nearly a quarter of the total fish species found in the Adriatic Sea – together with large predators such as the bottlenose dolphin. Sharks, tuna fish and loggerhead sea turtles inhabit this area as well. Some of these fish stocks have been severely depleted, among them the dusky grouper (Epinephelus marginatus). There are large meadows of seagrass (Posidonia oceanica) throughout the area, which are known to be important for fish spawning. They have not yet been mapped.

Seagrass meadows in shallow water

The area around Ćutin Veli and Ćutin Mali is dominated by coralligenous communities, with a diversity of algae, corals and sponges. These coral communities live only in areas of high water purity with minor suspension of solid particles; many rare coral species are found here, some of which are protected, in particular the sea fan (Paramuricea chamaeleon) and the red coral (Corallium rubrum). However, the constant activity of diver groups endangers them. There are numerous valuable shellfish (Lithophaga lithophaga, Pholas dactylus), which despite legal protection are exposed to overfishing leading to a decline in their numbers, but more importantly, also contributes to the destruction of the coastal habitat.

Mali Lošinj (Foto: Marcin Osadzin)

The Adriatic Dolphin Project began in the Cres-Lošinj archipelago in 1987 and is the longest systematic study of resident coastal bottlenose dolphins (Tursiops truncatus) community in the Mediterranean and one of the longest in Europe, depicting a comprehensive picture of the social, ecological and conservation status of these iconic marine mammals. The research area covers most of Kvarnerić Channel and stretches along the eastern coast of Lošinj, with its many beautiful bays and smaller islands – Trstenik, Ćutin, Palacol, and Orjule –and their exceptionally rich marine flora and fauna towards Cres Island. Over the last few years, we have expanded this area to include a part of Vir Sea towards the south (connecting the survey area with our Murter field base), the western coast of Lošinj, Kvarner Gulf and a part of the Velebit Channel. Based on recent ADP results, the Cres-Lošinj resident dolphin community is estimated at 180 individuals. However, between 1995 and 2003, a significant decrease in the estimated population size (39%) had occurred. The increasing pressure from human activities is the most likely explanation for this. We found that especially in the summer, dolphins avoid their key habitats, due to the increase of underwater noise caused by nautical traffic and physical harassment from boats. Also, a notable decline in fish prey was registered, adding to the anthropogenic stress. Lately the local resident community seems to have recovered, but the size is fluctuating yearly, requiring continuous monitoring.

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