Invasive Mediterranean Parrotfish Threaten Croatian Fishing Industry

The delicate balance of the Adriatic’s ecosystem hangs in the balance, calling for concerted efforts to protect its biodiversity and sustain local livelihoods

For decades, Croatian fisherman Marko Kristic has ventured into the pristine waters of the Adriatic Sea, casting his nets in search of traditional catches. However, Kristic now finds his livelihood under threat as an invasion of the Mediterranean parrotfish jeopardizes both his catch and his income.

Kristic, hailing from the village of Molunat in southern Croatia, laments the encroachment of the parrotfish, a species previously unseen in these waters. He notes that the parrotfish, along with approximately 50 other new species, has infiltrated the Adriatic due to climate change and increased maritime traffic.

“The Mediterranean parrotfish was first spotted in the southern Adriatic about 15 years ago, but it has since become a common bycatch in my nets,” Kristic explains, emphasizing the challenges it poses to his traditional fishing practices.

Despite being enjoyed as a delicacy in its native habitats, the parrotfish fails to appeal to the local palate in Kristic’s village. “I can’t sell it to anyone. The local population won’t eat this new fish,” he laments, highlighting the economic repercussions of the invasion.

Nenad Antolovic, a researcher at the Institute for Marine and Coastal Research in Dubrovnik, underscores the broader ecological implications of the invasion. Antolovic attributes the decline in fish stocks in the Adriatic to overfishing, climate change, and the influx of new species.

“The Adriatic is changing, it is getting warmer. Because of that, new organisms appear. By that, I mean fish and planktons and algae,” Antolovic elucidates, drawing attention to the multifaceted nature of the environmental challenge.

According to data from the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), the Mediterranean Sea is experiencing unprecedented warming, making it the fastest-warming sea on the planet. This warming trend facilitates the migration of new fish species from the Red Sea through the Suez Canal, further imperiling the survival of native species.

In neighboring Montenegro, scientists at the Institute of Marine Biology in Kotor highlight the blue crab as a prominent example of an invasive species wreaking havoc on local ecosystems. Olivera Markovic, a scientist at the institute, describes the blue crab’s arrival approximately 20 years ago as a significant threat to biodiversity.

“Since the appearance of the blue crab, the population of the green crab has been drastically reduced, and in some areas, wiped out altogether,” Markovic reveals, emphasizing the cascading effects of invasive species on native fauna.

Ilija Cetkovic, another researcher at the institute, points to the proliferation of other invasive species, including the rabbitfish, pufferfish, and lionfish, in the warmer waters along the Montenegrin coast. Of particular concern is the lionfish, which Cetkovic describes as a voracious predator causing considerable harm to marine ecosystems.

As Croatian fishermen like Marko Kristic grapple with the challenges posed by invasive species, scientists and policymakers face the urgent task of mitigating the environmental and economic impacts of these intruders. The delicate balance of the Adriatic’s ecosystem hangs in the balance, calling for concerted efforts to protect its biodiversity and sustain local livelihoods.