Scotland’s salmon farmers tackle sea lice scourge
Campaign groups cite 70% fall in wild fish returns over past 25 years
Mure Dickie in Edinburgh, Apr. 2, 2018
To anti-fish farm activist Don Staniford, the Scottish salmon sector is facing “Aquacalypse Now”: a “horror show” of environmental damage, sea lice infection and sick fish.
Salmon farmers in Scotland, who rear fish in offshore pens, have in the past often shrugged off such criticism.
In just four decades, the sector has become a pillar of the rural economy and a major UK food export. It accounted for a record £600m in UK exports in 2017, up 35 per cent from 2016.
But the industry’s opponents have been bolstered in recent weeks by the publication of a report by the Scottish parliament’s environment committee that raising serious concerns about its expansion plans. The sector hopes to double its annual contribution to the Scottish economy to £3.6bn between 2016 and 2030.
The committee said salmon farms suffered “unacceptable” fish mortality and there was a lack of understanding of how they affect the wider ecosystem.
In some recent years, less than three-quarters of the young salmon, or smolts, put in pens are eventually harvested. Environmentalists have raised concerns about the impact of medicinal chemicals on other sea life.
“If the current issues are not addressed this expansion will be unsustainable and may cause irrecoverable damage to the environment,” the committee said.
The Scottish parliament’s rural economy committee will carry out its own inquiry in the coming months.
Sea lice — small crustaceans that eat the mucus, skin and blood of salmon — are a central focus of dispute between campaigners and the industry. The lice can thrive in the cramped conditions of fish pens and environmentalists and anglers believe that they latch on to passing wild fish, contributing to a collapse of stocks.
Salmon and Trout Conservation Scotland, which campaigns for wild fish, has cited research showing that in areas of intensive salmon farming, sea lice are having a “general and pervasive negative effect” on wild fish populations.
According to Atlantic Salmon Trust, another campaign group, there has been a 70 per cent fall in wild salmon returns to Scotland over the past quarter century, though conservationists accept that fish farms are not solely to blame.
While the environment committee said industry efforts had proven “largely insufficient” to control sea lice, producers insist they have made huge strides in recent years.
Ben Hadfield of Oslo-listed Marine Harvest, Scotland’s biggest fish farmer, said that while the sector had previously over-used chemical treatments to kill sea lice, Marine Harvest had since found new ways to secure a six-fold reduction in lice infestations at its Scottish farms.
“Now we have a more holistic strategy,” Mr Hadfield said, pointing to “cleaner” fish that eat the lice off the salmon, “hydrolicer” machines that wash them off and “thermolicers” that pump the fish through heated water to remove the lice.
In February, Norwegian-owned Scottish Sea Farms, the country’s second-largest salmon producer, said it had invested £800,000 in anti-sea lice shields of permeable fabric to wrap around its salmon pens to a depth of 6m.
But Jim Gallagher, managing director of Scottish Sea Farms, said sea lice were hardly a problem for the company last year. He said climate change and warmer waters that have affected local salmons’ gill health are a much bigger challenge for the industry.
Following the environment committee’s report, the Scottish Salmon Producers Organisation said growth had to be sustainable and the sector’s progress in reducing its environmental impact “must be better demonstrated”.
In an effort to shore up public confidence, the SSPO will publish sea lice data on a farm-by-farm basis from April — a move long demanded by activists.
Mr Hadfield said such disclosures should have been made long ago, adding that farmed salmon has a much smaller impact on climate than other sources of protein such as beef or chicken, and is highly popular with consumers.
“The way to change perceptions is to be more open than people expect and to accept that this is farming in a wild environment and there are challenges,” he said.
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