MEPs condemn new lice treatment: who’s right?

Last night, the European Parliament passed a motion condemning use of the chemical agent on which Benchmark’s CleanTreat® delousing treatment is based. So, is CleanTreat a threat to the marine environment or a game-changer in the salmon farmers’ war against sea lice?

The point at issue is not the CleanTreat system itself, but the chemical that it uses. CleanTreat itself is a water purification system that allows fish to be treated with types of medicine – or pesticide, if you will – that cannot be used in open water.

Benchmark has been trialling the system in conjunction with its new sea lice treatment, BMK08, which it says has been shown to be highly effective against lice, without causing any ill effects for the fish. The treatment was originally marketed as Ectosan and, now, as BMK08. It is based, however, on an established, effective and once commonly used insecticide: imidacloprid.

The trouble is, imidacloprid is one of the substances classed as neonicotinoids, which became infamous when campaigners linked widespread use of these pesticides to a collapse in bee populations.

Anti-fish farming campaigner Don Staniford, of Scottish Salmon Watch, said in a complaint to the European Parliament’s Environment Committee: “Benchmark has patently failed to inform shareholders, investors, the public, the stock exchange and the media that BMK08/Ectosan is in fact the banned neonicotinoid imidacloprid.”

Imidacloprid has indeed been banned – but not completely. At one time it was the most widely used insecticide in the world. Like other neonicotinoids, it is a systemic toxin that acts on the central nervous system of insects and arthropods.

Dave Goulson, a biology professor at Sussex University, talking to the Guardian (27 May 2021) put it this way: “These chemicals are incredibly poisonous – the novichok for insects. It takes a billionth of a gram to harm aquatic life, so even tiny traces would have major impacts on marine life.”

Bad for bees, but what about fish?

In April 2018 the European Union resolved to ban outdoor use of the three main neonicotinoids, including imidacloprid. They continue to be used, quite lawfully, in enclosed greenhouses and also as flea and tick treatments for cats and dogs. As the latter suggests, neonicotinoids are deemed to be quite safe up to a certain dose for vertebrates, including humans and our pets.

A spokesperson for Benchmark told Fish Farmer: “BMK08 has been proven to be safe for salmonids and the medicine will always be administered in a closed contained system; and will be exclusively used with the award-winning and validated CleanTreat® purification system to remove the medicine before release of purified water back into the sea”.

The company’s confidence that the treatment is safe for salmonids is, it says, based on extensive field trials carried out in Norway.

The spokesperson added: “We have made significant progress towards commercialisation of our new sea lice solution, BMK08 and CleanTreat®, our first customer agreements for CleanTreat® have been signed and EU ratification of the Maximum Residue Limit (MRL) opinion was achieved in April. The MRL confirms the safety of Benchmark’s sea lice solution for consumers.

“The commercial launch of BMK08 and CleanTreat® remains subject to the grant of a Marketing Authorisation from the Norwegian Medicines Agency”.

The MEPs on the Environment Committee were not convinced, however, and they voted at their May meeting in favour of a lengthy motion that, among other things, stated: “…hazardous chemicals that are applied under veterinary prescription and used to treat infections of sea lice are ultimately released into the aquatic environment; their effects not only have the potential to negatively impact sensitive non-target organisms, the release of those compounds has been identified as a major environmental concern due to the high mobility of imidacloprid in soil and the resulting contamination of ground and surface water…”

The motion argued that the European Commission should withdraw its MRL for imidacloprid in animal products for human consumption – in other words, they believe there should be no acceptable level of the substance in the fish we eat. Given the importance of the EU market for salmon producers in Norway and Scotland, this would represent a major setback for Benchmark.

Last night, the motion was endorsed by the European Parliament at its plenary session, by 441 in favour to 232 against.

Grace O’Sullivan, a Green party MEP from the Republic of Ireland, had strongly supported the motion. Speaking prior to the vote, she said: “”We need to put a stop to the use of dangerous neonicotinoids in fish farming. We know that this chemical has devastating impacts on the environment and biodiversity. For this very reason the EU already banned its use on certain crops, a decision more recently upheld by the European Court of Justice. We won’t accept the use of Imidacloprid on crops, and we won’t accept it in our marine environment either.”

She tweeted afterwards: “My resolution calling on @EU_Commission to block use of a toxic pesticide in EU’s fish farms has passed!

“Imidacloprid is linked to biodiversity loss + already banned for certain agri uses on land. I pursued based on evidence it’s bad for both terrestrial and marine-life.”

Grace O’Sullivan MEP

The Parliament’s vote will be advisory, not binding, for the Commission and current MRL for imidacloprid remains in effect. The vote does place the Commission under political pressure to comply, however, or at least to revisit its policy on the issue.

The Scottish dimension

Earlier this year The Ferret, an independent news source in Scotland, reported that emails from Marine Scotland appeared to show that the agency was sympathetic to promoting BMK08 for trials in the UK.

Both the Scottish Government and Benchmark have made it clear, however, that there is no plan to trial the new treatment in Scotland, at least in the short term.

The company told Fish Farmer: “We are currently focused on launching our new sea lice solution, BMK08, which is used together with CleanTreat, in Norway. At this time we do not have any scheduled trials for BMK08 in Scotland”.

The company stresses: “BMK08 has been developed to work exclusively in a wellboat which is a closed treatment system, so the medicine is not exposed to the environment. After treatment with BMK08, fish are removed from the treatment water and rinsed to remove external residues before being returned to their pens. The rinse water and treatment water remains on board the wellboat and is transferred to the CleanTreat vessel via a system of secured pipes. The medicine is then removed by CleanTreat through a series of steps, monitored closely by our on-board laboratory to confirm the medicine has been removed before returning purified water back to the sea”.

In terms of its passage through the regulatory process, Benchmark says: “The commercial launch of BMK08 and CleanTreat remains subject to the grant of a Marketing Authorisation from the Norwegian Medicines Agency.

“The MRL (Maximum Residue Limit) for BMK08 (imidacloprid) has been ratified under European Law and confirms the safety of Benchmark’s sea lice solution for consumers. For an MRL to be granted the Committee for Medicinal Products for Veterinary Use (CVMP) review all toxicology and safety data for the substance.

“Used together with CleanTreat, this medicine and treatment system is a breakthrough development for the salmon industry in effectively managing sea lice levels and improving fish welfare whilst protecting the environment.”

There is no doubt that simply releasing imidacloprid into the marine environment in order to kill sea lice would be highly reckless; equally, it is clear that is not what Benchmark is intending to do.

The question for regulators will be twofold, therefore: is the treatment safe for the fish (and for consumers); and is CleanTreat effective in ensuring that no active imidacloprid is left in the residue that enters the sea?

Failing to address this properly could be bad for the environment, but an overly cautious approach could also risk losing out on an opportunity to tackle one of the biggest issues for fish health.

This article is an updated version of the feature that appeared in the June 2021 issue of Fish Farmer