One of the consequences of climate change in our seas is the swift emergence and spread of the lionfish, whose natural habitat is the Indian and Pacific Oceans, across the Aegean and Mediterranean seas. With its large fins and striking pattern of reddish black scales, this species has brought with it a series of problems for marine species and fishing, due to its excessive feeding and breeding habits.
What’s the global situation like?
The species was observed for the first time in the Mediterranean basin in Israel in 1991, however, this was a fruitless attempt at expansion on the lionfish’s part. During the 20 years that have since elapsed, it spread quickly across the Eastern Mediterranean region. Being a species that has its origins in the Pacific and Indian oceans, it travelled to the Mediterranean through the Suez channel, as well as becoming an issue for the Atlantic ocean by making it onto the shore in Columbia due to a damaged aquarium during Hurricane Andrew in the USA in 1992. Today, the lionfish can be seen on the shores of more than 40 countries.
Just as in Turkey, other countries on the Mediterranean and Atlantic Ocean coasts are making various attempts to mitigate the problems caused by this species for marine ecosystems and fishing. The species’ behaviour, distribution, and population size are being researched; special vessels are developed for its catching, and in some countries fishing regulations are amended. There are various campaigns to inform the public on how to avoid being harmed by the lionfish’s spikes and to encourage its consumption.
How did it arrive in Turkey?
Increasing seawater temperatures due to climate change make the Mediterranean Basin more habitable each day for species from different ecosystems such as the Red Sea and the Indian Ocean. These new species travel through the Gibraltar Strait and the Suez Channel, as well as being transported in ships’ ballast water; they quickly adapt to foreign seas and multiply, while at the same time causing problems for local fish species and small scale fishing economies. Like Randall’s threadfin bream, redcoat, and the brushtooth lizardfish, the lionfish has been inhabiting and quickly multiplying in our waters in recent years.
Two species: The lionfish is presumed to have reached Turkey via the Suez channel, and two species currently live in our seas; the first, Pterois miles, was recorded for the first time in 2014 in İskenderun. The second, Pterois volitans, was observed in 2016.
Effects on our seas: The lionfish can produce two million eggs a year; its stomach can enlarge up to four times its size which allows it to feed extensively. The lionfish generally eats juvenile members of fish and crustacean species such as crabs, octopi, and scorpion fish. The species can be found in the Aegean and Mediterranean seas in Turkey, and as these seas lack predators of the lionfish, meaning that there aren’t other fish to eat the lionfish, this allows the species to spread quickly. Studies conducted in the Caribbean show that adult lionfish feed on young grouper fish, while adult grouper fish feed on young lionfish. There are no studies to confirm the same behaviour in Turkish waters yet, however, research is ongoing.
Effects on fishing: The lionfish has caused new problems for small scale shore fishing, since it feeds on local and economically valuable species. Valuable species that fishers used to catch have begun to be replaced by lionfish and other invasive species, thus adding the presence of invasive species to the list of problems already faced by those who make a living from fishing, including a decrease in marine biodiversity and increased costs. One of the reasons that the fishing economy is affected is the fact that consumers avoid lionfish and other new species despite their delicious taste, because they don’t recognise them as edible.
Effects on human health: The lionfish is a delicious species whose tissue does not contain any toxins. It has spikes on its back, abdomen, and tail fin, which contain venom that can cause health problems if touched during cleaning the fish or if a diver comes into contact with them while underwater. Cutting these spikes off with a pair of scissors and wearing gloves while doing so alleviates the problem by eliminating the possibility of contact.
What is the Mediterranean Conservation Society doing?
It may not be possible to halt climate change entirely, but it is possible to lessen its effects. To this end, the MCS has been working with Ege University and fishery cooperatives to monitor invasive new fish species since 2013. The Marine Ranger Scheme has been implemented in No Fishing Zones in order to preserve important territorial species such as the dusky grouper and the white grouper and to increase their population. We’re working together with volunteer chefs from all around Turkey to include lionfish and other new species in our dishes, and lionfish has already begun to appear on menus in İstanbul, İzmir, Ankara, Bodrum, and Kaş in various different recipes. We’re conducting a stock analysis with Ege University to determine the speed of the lionfish’s spread and to get more information about its population, and we’re working together with Katip Çelebi University to ascertain the species’ feeding habits.
Author: Esra Kartal, MCS
Photo: Zafer Kızılkaya
Source: Aposto! March 31, 2021
Instagram: @yenibaliklar