Illegal trawling ravages Tunisian seagrass meadows crucial for fish

Illegal trawling ravages Tunisian seagrass meadows crucial for fish
  • The largest remaining seagrass meadows in the Mediterranean are in Tunisia’s Gulf of Gabès, a hotspot for biodiversity and fishing.
  • But illegal bottom trawling and industrial pollution are destroying this unique habitat, a natural nursery to numerous species of fish and other marine fauna.
  • Hundreds of trawlers ply their trade overtly with little consequence, and most of the catch makes its way to Europe, skirting laws designed to prevent the entry of illegally caught seafood.

KERKENNAH ISLANDS, Tunisia — It’s a rainy afternoon in the port of Kraten, and all the fishing boats are docked, waiting for a winter storm to pass. Some fishers have gathered at the port anyway, to have a chat and share a tea while arranging nets and octopus traps for the coming days. Boulbeba Souissi and Najib used to catch and sell marine sponges, but after these became scarce, Souissi moved on to snorkeling tourism and Najib focused on octopus fishing with traditional clay traps.

“We need to give nature the time to regenerate,” Najib tells Mongabay. “That is how it works. I always say to other fishers, using bottom trawling, that they need to stop destroying the marine flora near the coast. But they are deaf.” (Mongabay is withholding Najib’s surname to protect his livelihood.)

The archipelago of Kerkennah lies in the Gulf of Gabès, in eastern Tunisia. The country has the largest population engaged in fishing activities in the Mediterranean Basin, with about 45,000 people employed in the sector. About three in four are dedicated to small-scale fishing, although industrial fishing generates 62% of overall earnings due to the large volume of seafood exported, mainly to EU countries.

Data on registered fishing vessels in this region come from the General Fisheries Commission for the Mediterranean, a U.N. organization. The 22 coastal countries supply the data to the commission, but they often exclude unreported catches, as is the case for many small vessels roaming the Kerkennah Islands.

“There are hundreds of kys boats that every night are trawling the seabed. They trawl juvenile octopus too, so it became more difficult for me to catch,” Najib says, sipping his tea near the wet dock. “These fishers are aware that, in this way, the flora will be destroyed, but they go after the money. It’s easy money in the end.”

Boulbeba Souissi holds an artisanal fish trap commonly used in the Kerkennah archipelago, Tunisia. Image by Davide Mancini.
Traditional octopus traps used in Tunisia.
Traditional octopus traps used in Tunisia. Image by Davide Mancini.

In Arabic, the word kiss or kys means bag, and people here use it to refer to the shape of the nets deployed by the small artisanal vessels that illegally trawl the gulf’s seabed, especially around the Kerkennah Islands.

Bottom trawling, in which a vessel drags a weighted net across the seabed, capturing or uprooting anything in its path, is against Tunisian law in shallow areas of the Gulf of Gabès. Here, the largest seagrass meadow in the Mediterranean creates an important nursery for juvenile marine species, making it a hotspot for traditional fishers since ancient times.

About 15 years ago, large trawlers started illegally entering the shallows at night. It happened sporadically, but small-scale fishers quickly understood the potential of mounting the gear needed to trawl the rich seabed: drag nets with heavy plates to keep them open, and more powerful engines. Some of them adopted the destructive kys trawling technique because they saw the high profitability of trawling and didn’t want to leave it to industrial vessels. Others continued with their traditional fishing methods.

Due to a degradation of Tunisian state institutions following the Arab Spring in 2011, a culture of tolerance toward illegal fishing spread across the Gulf of Gabès, and the number of kys trawlers surged. Local observers with the German NGO FishAct counted 576 kys trawlers last December in the governorate of Sfax, which has jurisdiction over the Kerkennah Islands, representing an increase of 38% since 2018, when FishAct made the last count.

A fish vessel mounting an illegal kys (or kiss) trawling gear docked in the port of Kraten
A fishing vessel mounting illegal kys (or kiss) trawling gear while docked in the port of Kraten, Kerkennah Islands. Image courtesy of FishAct.

As kys trawlers are officially registered as artisanal fishing boats, they can access state-subsidized fuel. According to FishAct’s report, published in March, “[i]n 2018, the regional fisheries commission of Sfax implemented a mandatory inspection of the vessels prior to the delivery of fueling receipts for subsidized fuel, to ensure that the vessel doesn’t contain illegal fishing gear. But this measure was undermined, by removing the obvious trawling gear from the vessels prior to the inspection, and putting it back after fueling.”

Authorities’ failed attempts to tackle illegal trawling have generated frustration among real artisanal fishers, who are witnessing a depletion of fish stocks and the destruction of the shallow-water seagrass meadows. Artisanal fishers find themselves in a difficult dilemma: whether to join the destructive kys trawlers or keep practicing artisanal fishing, knowing that stocks are declining and they can’t compete with the kys vessels’ efficiency.

Posidonia oceanica is the Mediterranean’s most important endemic seagrass species and constitutes strictly protected habitats under the Bern and Barcelona conventions, to which Tunisia is a contracting party. Seagrass is an important stabilizer for the country’s coastlines, which are experiencing some of the highest rates of coastal retreat in the world. The marine meadows play critical climate-related and ecological functions, sequestering CO2 and enhancing water quality through oxygenation. For this reason they are sometimes collectively called the Mediterranean’s lung. P. oceanica meadows are a biodiversity hotspot, housing nearly 20% of all Mediterranean species while making up only 1.1% of the sea’s total surface area.

Despite their recognized environmental importance, seagrass meadows in the Mediterranean have regressed an estimated 34% over the past 50 years, according to a 2015 paper, mimicking global seagrass declines. “Full recovery of P. oceanica meadows is usually considered irreversible in human time-scale, because it is a slow-growing species with a low recovery rate,” the paper warns.

A kys (or kiss) trawling vessel leaving the port
A kys (or kiss) trawling vessel leaving the port of Sidi Mansour, Kerkennah Islands. Image courtesy of FishAct.
The seagrass Posidonia oceanica, an important habitat for marine life and stabilizer of Tunisia’s coastlines, which are experiencing some of the highest rates of coastal retreat in the world. Image by Melina Marcou via Wikimedia Commons (CC BY-SA 4.0).

Lobna Boudaya, a life science researcher at the University of Sfax, is coordinating a research project on the island of Djerba, at the southern end of the Gulf of Gabès, moving seagrass from areas where it’s still abundant into areas where it has disappeared to study the optimal conditions for transplantation and its impact on coastal restoration. The project is an attempt to reverse the loss of the seagrass meadows. Boudaya told Mongabay trawling and phosphogypsum pollution from industrial sites are the main reasons for the gulf’s loss of seagrass.

Phosphate plants belonging to Groupe Chimique Tunisien discharge 14,400 metric tons per day of untreated phosphogypsum waste directly into the Gulf of Gabès, research shows. This byproduct is highly destructive to marine flora and fauna. The phosphate product itself is a fundamental component of agricultural fertilizers, and it constitutes a major export for Tunisia, the world’s fourth-largest producer, which sends its phosphate mainly to Europe.

Although export of phosphate and seafood to Europe is an important pillar of southern Tunisia’s economy, legal standards created to prevent environmental damage are regularly skirted along the supply chain. Tens of white refrigerated vans run back and forth on the road connecting the three main Kerkennah Islands all day long. The middlemen managing the white vans collect fish products coming either from kys trawlers or artisanal fishers, like Najib. The vans bring the seafood to the ferry connecting with the commercial port of Sfax, where many seafood exporters are based. Although illegally caught, seafood like octopus, squid, blue crab and rose shrimp can easily find a way to European markets, the main destination of Tunisian fish exports.

“In theory, the middlemen should not be able to sell to exporters, because they need a catch certificate that proves the fish was caught respecting the rules, which is not the case for kys trawling,” a management-level employee of a major exporting company in Sfax, who requested anonymity for safety reasons, told Mongabay. “In practice, they present all the certification needed to be exported. It does not make sense.”

A fish shop
A fish shop at the ferry arrival in Sidi Youssef. Image by Davide Mancini.
The port of Kraten. Image by Davide Mancini.

The employee said high levels of corruption among some Tunisian authorities in the Gulf of Gabès are enabling systematic falsification of the documents EU importing countries require as a means of preventing fish products caught by illegal, unreported and unregulated (or IUU) fisheries from crossing their borders.

Interviews by Mongabay with employees of exporting companies, fishers and middlemen indicate that IUU catches regularly reach the EU market, bypassing the paper-based catch certificate scheme.

A recent report on kys trawling in Tunisia by FishAct and London-based NGO Environmental Justice Foundation (EJF) confirmed that IUU catches may be entering the EU, especially Italy and Spain, while underscoring the environmental harm the illegal trawling causes. “This also emphasises the importance of fisheries transparency,” Steve Trent, EJF’s CEO and founder, told Mongabay by email. “Without it, consumers in the EU may unknowingly be contributing to the destruction of this precious ecosystem and the erosion of the livelihoods which depend on it.”

The storm will continue all day long, Najib says as he leaves the dock at Kraten for his house. He adds that he feels lucky to have one after many years of work. That’s not the case for many young fishers today given Tunisia’s current economic instability, he says.

Boulbeba says that when summer comes he’ll resume his snorkeling classes to teach his passion for the ocean to local kids and to show them the beauty of untrawled seabed. Recently, he and other local snorkelers came up with the idea of a “kys trap,” a series of concrete blocks with strong steel hooks. They’ve been placing the traps on the shallow seabed around Kraten Island to damage the nets of any kys boat that attempts to trawl the seagrass. Both Najib and Boulbeba hope the new generations will be aware of the habitat the trawlers are destroying, and see the marine ecosystem as something to respect, to restore and to protect in the future

Boulbeba Souissi stands in front of an anti-trawling mural in the port of Kraten. Image by Davide Mancini.

This story was produced with support from

Illegal bottom trawling widespread inside Mediterranean marine protected areas


FishAct. (2023). Illegal shallow water bottom trawling, i.e. “Kiss” trawling in the Gulf of Gabes, Tunisia. Retrieved from

Boudouresque, C.F. (2004). Marine biodiversity in the Mediterranean: status of species, populations and communities. Travaux scientifiques du Parc national de Port-Cros, 20, 97-146. Retrieved from

Pergent-Martini, C., Pergent, G., Monnier, B., Boudouresque, C. F., Mori, C., & Valette-Sansevin, A. (2021). Contribution of Posidonia oceanica meadows in the context of climate change mitigation in the Mediterranean Sea. Marine Environmental Research, 165, 105236. doi:10.1016/j.marenvres.2020.105236

Telesca, L., Belluscio, A., Criscoli, A., Ardizzone, G., Apostolaki, E. T., Fraschetti, S., … Salomidi, M. (2015). Seagrass meadows (Posidonia oceanica) distribution and trajectories of change. Scientific Reports, 5(1). doi:10.1038/srep12505

El Zrelli, R., Rabaoui, L., Abda, H., Daghbouj, N., Pérez-López, R., Castet, S., … Courjault-Radé, P. (2019). Characterization of the role of phosphogypsum foam in the transport of metals and radionuclides in the Southern Mediterranean Sea. Journal of Hazardous Materials, 363, 258-267. doi:10.1016/j.jhazmat.2018.09.083

FishAct, Environmental Justice Foundation. (2023). Kiss of Death: How illegal bottom trawling threatens ecosystems and livelihoods in Tunisia. Retrieved from

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