Overfishing and destructive fishing practices are straining marine ecosystems across Europe, weakening the ocean's ability to store carbon and sustain biodiversity. In Greece, a new initiative from WWF Greece and local chefs is turning attention to an unlikely solution: invasive species.
The World Wide Fund for Nature's (WWF) free seafood guides, tailored to each country, help consumers choose fish that are caught or farmed sustainably. The latest edition for Greece, known as the Fish Guide, includes a traffic-light system: green for species with healthy stocks or low-impact fishing, yellow for those to consume in moderation, and red for species to avoid due to overfishing or harmful practices.
For the first time, the guide features a dedicated section on alien species—non-native fish that have entered Greek waters through human activities, including climate change and shipping. More than 240 such species have been recorded in Greece, and their rapid proliferation threatens native fish populations and damages fishing gear.
From Fear to Fork: Changing Perceptions
“When you're not familiar with something and you hear the word 'alien,' unfortunately there is a phobia,” says Elias Margaritis, fisheries officer at WWF Greece. He points out that many alien species, such as sardines, non-native mullet, and trumpet fish, are tasty and nutritious. “In the southern regions they are now in abundance—they have slowly gone to the Peloponnese and the Ionian Sea.”
The guide includes information on which alien species are suitable for consumption, highlighting their distinctive taste and high nutritional value. It also provides details on seasonality, minimum legal sizes, and first spawning maturity, empowering consumers to make informed choices.
Chef George Koutlis, who contributed recipes to the guide, argues that the restaurant industry must adapt. “We should not give people what they ask for, because we cannot have octopus all year round, we cannot have mullet, squid and all that all year round,” he says. “So we have to adapt our menu with foreign species and slowly the whole world will get to know them.”
This shift aligns with broader European efforts to promote sustainable seafood. For instance, top European chefs have boycotted endangered eel as EU policy lags behind science, highlighting the need for proactive measures.
Nutrition and Recipes for Everyday Use
The Fish Guide goes beyond simple recommendations. It details the nutritional content of each species, including protein, omega-3 fats, and vitamins, and highlights the ten species with the highest nutritional value. Recipes from Greek chef Giorgos Tsoulis, gastronomist Ilias Mamalakis, and other international cooks make the guide a practical tool for home cooks and professionals alike.
Margaritis emphasizes the broader environmental stakes: “We have to think that in two years we might not even have fish to sell in our shops. So we have to slowly integrate foreign fish species into the menus, so that people gradually learn about them.”
A nationwide survey conducted by WWF Greece found that about one in two Greeks consumes fish or seafood once a week. The guide aims to steer those choices toward sustainability, especially as climate change accelerates the spread of invasive species across the Mediterranean.
This approach is part of a wider European trend. In Portugal, for example, invasive species like the lionfish are being promoted as a culinary delicacy. The EU's Common Fisheries Policy also encourages member states to manage invasive species, though implementation varies. The Greek initiative offers a model for other Mediterranean countries facing similar challenges.
By embracing alien species, Greek chefs and conservationists hope to reduce pressure on native stocks, protect biodiversity, and adapt to a changing climate. As Margaritis puts it, “We have to leave the sea at least in the same condition or better.”
