Electric pulse fishing occurring extensively in Europe’s northern seas under guise of scientific research with little knowledge of impacts on commercial species and ecosystems

The pulse trawl: electrodes in the two direction of the gear cause an electric field above the seabed, which stimulate the flatfish so that come up and end up in the net.

Fishing in Europe with poisons, explosives and electricity is banned. But the commission has gradually been rescinding the ban on using electricity. It began with one or two boats, then in 2010, after ferocious lobbying by the government of the Netherlands, 5% of the Dutch trawler fleet was allowed to use this technique. In 2012 the proportion was raised to 10%. Eighty-five massive Dutch supertrawlers have now been equipped with electric pulse gear, at a cost of around £300,000 per ship. Over the past few months, the UK government has licensed a further 12 ships. These are registered in the UK and fly the Union flag, which means that they are allowed to fish within our 12-mile limit, but according to some in the fishing industry at least some of the boats have been financed and equipped by Dutch companies.

Pulse trawling, as the technique is known, uses electricity to flush flatfish or shrimp out of the sediments in which they hide. The electric shock makes them convulse and flip upwards, into the net. Electric fishing can greatly increase the catch of these species. The industry and the Dutch and British governments claim that this technique is less damaging than conventional beam trawling. There has so far been no serious effort to discover what the impacts of repeated electric shocks might be on any of the animal communities of the sea: those that live in the open water, on the seabed or under it. The tiny amount of research conducted so far has involved just a few species in fish tanks and, one poorly-designed and inconclusive study at sea.

Yet these 97 ships (85 Dutch, 12 British) have been licensed to operate across the entire southern North Sea: in other words, from Kent to Schleswig-Holstein, Edinburgh to Jutland. This includes the region’s Special Area of Conservation: Dogger Bank. Special Areas of Conservation are supposed to confer the highest level of protection of any European wildlife sites. Thanks to a veto by the Dutch government, every part of the Dogger Bank and its remarkable habitats remains open to beam trawling – and now electric fishing – and this area is ripped up on a daily basis.

By 2014, the pulse trawlers were already operating across the whole southern North Sea at greater intensity even than the traditional beam trawling fleet, with the exception of the seas within the 12-mile national limits around Britain, Germany and Denmark. With the licensing of the 12 British boats, our inshore waters will now also be exploited, including the two Special Areas of Conservation in England’s North Sea territorial waters: the North Norfolk sandbanks and the Haisborough, Hammond and Winterton reefs and banks, also off the coast of Norfolk.

So what possible justification does the commission give for permitting this mass deployment of an untested technology? Oh yes. It’s a “trial” for the purpose of “scientific research”. The commission tells me that the trial is “envisaged to last for five years.” The Dutch government explains that this “research programme” will study “the selectivity of the pulse trawl and the environmental benefits of leaving the seabed undamaged”. Note that it says nothing about the possible downsides. It already assumes that the technique is beneficial and undamaging.Given that the experimental area extends to the whole of the southern North Sea, what kind of an experiment is this? What’s the hypothesis? What’s the methodology? Where’s the control? How will the results be measured? When asked what conditions it had attached to its licensing of “British” vessels to use electric fishing, the UK’s environment department, Defra, these included “ensuring electric trawling is only allowed in certain areas” which are the entire southern North Sea, including the three Special Areas of Conservation.

The UK government went on to claim that permission would be rescinded if a scientific assessment established that harm was being done, but given that there is no credible means of assessment, it’s impossible to see how this could happen.The government then made a statement that the scientific papers are wrong:  “Currently studies indicate that pulse stimulation does not result in an increased mortality in sole, cod, brown shrimp and rag-worm. No mortality or spinal injury had been found in plaice, sole, cod, for example. There is plenty of evidence to suggest that this is incorrect. Among the few studies of the impacts of pulse trawling conducted so far is one showing tha tbetween 50 and 70% of large cod that come close to a passing electrode at realistic field strengths suffer fractured vertebrae. The cracking of their spinal columns through electric shocks also creates internal haemorrhages.

Between 50 and 70% of large cod that come close to a passing electrode at realistic field strengths suffer fractured vertebrae
Between 50 and 70% of large cod that come close to a passing electrode at realistic field strengths suffer fractured vertebrae.Photograph: Wageningen UR

Another trial showed that shrimp exposed to electric shocks have a significantly higher risk of subsequent infection with a virus. A further study showed a “statistically significant lower survival” rate for ragworm. As for flatfish like sole and plaice, we simply have no idea. In 2012, a small-scale fisherman in Kent told the Sunday Times that the areas through which the pulse trawlers have passed are “a graveyard. What they don’t catch, they annihilate. Virtually everything is dead.” And the rest of the ecosystem? Who knows? Some research finds that pulse trawlers have a lower bycatch (species they do not intend to take) than beam trawlers. This may be true, and it would scarcely be difficult, given the extraordinary amount of damage wreaked by conventional methods. But a study of pulse trawlers fishing for shrimp revealed “considerably higher bycatch rates for some species, compared to traditional beam trawls with sieve nets.”

Electric fishing allows boats to catch flatfish on muddy bottoms, which is difficult with conventional beam trawling, so it is likely to spread fishing damage into some of the few areas that were not previously being repeatedly wrecked. Pulse trawlers extracting flatfish still use a thick cable (the footrope) that drags across the bottom, so the physical damage they cause remains extremely high, while the electrical damage is unknown. Pulse trawling allows shrimp fishers to operate in clear water and during daylight, when shrimp are inaccessible to conventional fishing, so this could greatly increase the catch rate. Amazingly, there are no limits on the amount of shrimp that can be taken in the North Sea. When the same technologies were deployed in the East China Sea, they led to the collapse of the fishery, with the result that electric fishing is now banned in China.

As for the effects of repeated exposure to electric shocks on the animals of the sea, the impacts these might have on their ability to breed, implications for the survival of long-lived species, the long-term damage that might be done to species that detect their prey through electroreception (such as sharks and rays) and a host of other such questions, there is simply no data at all. Studies in freshwater suggest that electric shocks can be highly damaging to both fish eggs and fish embryos, but we have no idea whether the same effect occurs in salt water. Given that there are no controls on this “experiment”, no areas from which the fishing boats are excluded, no methodology and no obvious measurement parameters, the only way in which we are likely to discover whether or not the technique is damaging is through the collapse of the marine ecosystem across the entire fished area. How else could it be determined?

What this issue highlights is the absence of meaningful protection for the wildlife of the sea. Astonishingly, fishing, like farming, is entirely exempt from the environmental impact assessments that every other industry must undertake. The impact assessment for a large marine wind farm runs to about 20,000 pages, even though windfarms appear to have almost no impact on subsea life except a positive one, by providing places on which wildlife can anchor and offering some protection from trawlers. To conduct an experimental trawl to discover what lives on the seafloor where a wind farm is planned,  an exhaustive application must be submitted for a licence specifying where and when and for how long the trawl will be conducted.

Further information

Guardian news article, We should be outraged by Europe slaughtering sea life in the name of ‘science’
While we focus our anger on Japan using ‘scientific research’ as an excuse to kill marine life, Europe is doing the same thing under our noses with electric pulse trawling, with potentially disastrous effects