Environmental groups are calling on the Scottish fishing industry to take urgent steps to decarbonise the sector.
They say they have calculated that the UK fleet emits the same carbon dioxide as 110,000 homes every year.
A new report says fishing practices need to change to protect carbon stored in the sea bed.
The report has been co-written by WWF, the Marine Conservation Society and the RSPB.
It says that fishing methods like bottom trawling and dredging are a threat to so-called blue carbon which is stored in the sea bed. They report estimate that mitigating the amount of carbon lost from these fishing methods between 2016 and 2050 will cost the economy up to £9bn.
Mario Ray, policy and public affairs officer at WWF Scotland, said: “This report makes clear that governments across all four nations must help UK fisheries to re-think practices and modernise to meet the challenge of climate change and achieving net zero.
The report calls for bottom-towed fishing gear to be banned from use in protected areas, which make up more than a third of the UK’s waters. It also urges governments to mandate vessels to install monitoring such as cameras and GPS technology and calls for more research into the role of blue carbon.
With more than half of all vessels around 30 years old, skippers should be incentivised to switch to cleaner fuels like biodiesel or hydrogen, it adds.
In response to WWF, RSPB and Marine Conservation ‘report’ into fisheries, Elspeth Macdonald, chief executive of the SFF, said: “Wild-caught fish is already a climate smart choice, with our industry producing healthy protein food with a much lower carbon footprint than meat and most vegetables.
“Our industry’s carbon emissions are tiny in comparison to those from households and land-based transportation. Of course, as with all sectors, there is more work we can do, and indeed only today the UK Government has announced that it wants to accelerate the development of zero-emission vessels as part of its hydrogen strategy.
“This is an industry that has a proud record when it comes to innovation and the adoption of new technology, with skippers constantly evaluating how to do things better. We work with government to ensure we are protecting marine features including key carbon sinks such as maerl beds, based on a robust process underpinned by evidence.
“That is the main reason that, contrary to what the NGOs allege, fish stocks in our waters are in such a healthy state, with for example the overall whitefish biomass at record high levels and catching (mortality) at an all-time low.
“Our industry is committed to sustainability; indeed healthy stocks can be harvested in a much more carbon efficient way than unhealthy ones. We must not lose sight of the fact that we are producing food, and wild caught fish are a far better choice in terms of carbon footprint than other protein sources.”
The report prompted an immediate call from SFA executive officer Simon Collins for Scottish and UK government ministers and civil servants to resist the burgeoning and misguided campaign being waged by environmental NGOs on the fishing sector.
He said: “Whitefish stocks in Scotland’s waters have doubled in size over the last 20 years and are now at record levels, according to an analysis of data from the International Council for the Exploration of the Seas (ICES). At the same time the amount of these fish being caught (the fishing mortality rate) has declined markedly.”
“The analysis shows that, with inevitable fluctuations, the aggregate spawning stock biomasses (SSB) of the principal whitefish stocks have increased since the early 2000s, with some stocks increasing by much greater amounts.”
“Meanwhile, the average fishing mortality rates of these stocks have has more than halved over the same period and is at its lowest ever level.”
Mr Collins said: “There are more fish in the sea than ever, and our boats are catching less than they have ever done.”
“And yet if you listened to the headline seekers in the environmental NGOs, you would think that there was a crisis of over-fishing and climate impacts.”
“The simple truth is that like all sectors, we have work to do on reducing our impact on the climate, but we have come an incredibly long way and are already a climate-smart industry when it comes to the impact on stocks, as this research shows.”