Many Dutch trawlers catch bottom-dwelling fish with bursts of low-voltage electricity, sparking fears from other fishing nations and some environmental groups.

Ton Koene/picture-alliance/dpa/AP Images

Tensions flare over electric fishing in European waters

In a surprise outcome, the European Parliament voted today to ban a type of electric fishing that has demonstrated environmental benefits, as part of legislation to reform Europe’s fisheries.

The proposed end to “pulse trawling”—in which short bursts of electricity get flatfish out of the sediment and into nets—is a major disappointment to Dutch fishing companies, which have invested heavily in the technology; they claim it’s less damaging to marine ecosystems than traditional bottom trawling and saves energy. But some environmental groups applaud the parliament’s decision.

Many observers had predicted European Parliament would only recommend scaling back pulse trawling. “I’m baffled, to be honest,” says Marloes Kraan, an anthropologist at Wageningen Marine Research in IJmuiden, the Netherlands. “We had prepared ourselves for a bad outcome, but a ban was totally unexpected,” says Pim Visser, director of VisNed, a trawling trade group in Urk, the Netherlands. 

BLOOM Association, an environmental group in Paris that has led a campaign to stop pulse trawling, declared the vote “a tremendous victory for the ocean, for artisanal fishers and Europe.” BLOOM worries that pulse trawling harms nontarget marine life; fishing groups in other EU countries, meanwhile, are increasingly angry about competition from the Dutch pulse trawlers. Other nongovernmental organizations, however, including Greenpeace Netherlands, say pulse trawling has promise to increase sustainability and that ending it now would penalize the fishing industry for innovating. “We call upon the fishermen not to be discouraged to embrace further innovation,” the North Sea Foundation said in a statement about the “unfortunate” outcome.

The vote is just the first step in negotiations with the European Commission and member states over the large package of fisheries reforms. 

We call upon the fishermen not to be discouraged to embrace further innovation.

North Sea Foundation

Most bottom trawlers drag a net, held open by a wide metal beam, across the bottom to catch shrimp or fish. Trawlers targeting flatfish, such as sole or plaice, also use dangling iron chains to scare them out of the sediment. The beam and chains disturb or kill many bottom-dwelling organisms, the nets catch unwanted species, and all the tugging requires a lot of diesel.

Pulse trawlers, by contrast, barely touch the bottom because they use bursts of low-voltage electricity to catch flatfish, particularly Dover sole. After the current briefly cramps their muscles, they try to flee, and many end up in the net. Because sole are more susceptible to electricity than other species, pulse trawling reduces bycatch. And the gear is lighter and can be towed slower, so the boats burn half as much fuel and impact less area. “We catch with a lesser environmental impact and greater economic returns,” Visser says. He credits the gear with saving many fishing companies from bankruptcy.

Sea bed A charged approachMany Dutch fishing vessels have adopted electric pulse trawling, but competitors and some environmentalgroups object. In pulse trawling, a wingshaped beam glides above the sea bed trailing strings ofelectrodes that are located above the mouth of the net. Electricitycauses flatfishto leave thesediment. Net doesn’ttouch the seabed, causingless damage.
V. ALTOUNIAN/SCIENCE

Encouraged by initial studies, the Dutch government in 2006 successfully lobbied the European Commission to allow 5% of each country’s fleet to use pulse trawling, exempting them from the European Union’s 1988 general ban on electrical fishing. By 2009, Dutch companies had embraced the opportunity. As demand grew, they received additional licenses for reducing bycatch or research with the condition that they provide detailed data on their catches. Now, 75 vessels, about 28% of Dutch trawlers, use pulse gear. Fishing companies outside the Netherlands fish for sole, too, but don’t specialize in it; as a result, few have invested in the expensive technology.

BLOOM argues that the research and bycatch licenses are illegal and a guise for commercial fishing, and that pulse trawling puts small-scale fishing at an even bigger disadvantage than conventional trawling does. BLOOM advocates catching flatfish with gillnets, stationary curtains of netting that have a much lower bycatch rate than either kind of trawling and do less damage to the sea floor. “There shouldn’t be any use of electric current,” says Director Claire Nouvian. “We’ve got enough evidence to know this is nonsense.”

Scientists have so far found little evidence that the electrical currents cause serious harm. Last year, a working group with the International Council for the Exploration of the Sea (ICES) highlighted harm to large cod and whiting as the only known irreversible effect. Although not many cod are accidentally caught by pulse trawlers, about 10% of them suffer vertebral fractures and hemorrhages when their muscles overcontract from the shocks. Initial laboratory research on other organisms has not shown lasting, serious effects, but the ICES group says questions remain, for instance about the effects on sharks and rays. 

Nevertheless, “We know enough to continue with pulse trawling in the present context,” says Adriaan Rijnsdorp, a fisheries biologist at Wageningen Marine Research and a co-chair of the ICES working group. But he says a decision on the future of pulse trawling should wait until 2019, when a 4-year, EU-funded research program on ecological impacts, which he coordinates, is due to wrap up.

There shouldn’t be any use of electric current. We’ve got enough evidence to know this is nonsense.

Claire Nouvian, BLOOM Association

Any decision will have to be agreed on by the European Parliament, the commission, and member states, in this case represented by their fisheries ministers. The commission has proposed removing the cap on licenses in the southern North Sea, where pulse trawling now occurs; other areas could follow after further studies. The ministers, by contrast, would de facto remove licenses beyond the 5% limit of a country’s fleet, which would force most Dutch vessels to give up pulse trawling.

A compromise in which the technique is greatly curtailed is the most likely outcome, says Irene Kingma, director of the Dutch Elasmobranch Society in Amsterdam, which promotes the study and conservation of sharks and rays. “There might be carnage within the Dutch fishing sector,” Kingma says. “And if they change back to beam trawling, we have all the environmental problems from that.”