Why does this matter? As the report outlines, fisheries are both vulnerable to climate change impacts and also contribute to it, through direct vessel emissions and fishing equipment disrupting the seabed. Protecting the ocean and its marine habitats – which can sequester more carbon per unit area than forests – is critical to mitigating climate change. In the UK, saltmarsh and seagrass meadows store around 220 million tonnes of blue carbon, 93% of which is sequestered in marine sediments.
The report highlights three key areas to be addressed. First, tackling direct emissions from fishing vessels. UK fishing fleets generate an estimated 914.4 kilotons of CO2 annually – the equivalent of the annual energy usage of over 110,000 US households. WWF, the MCS and RSPB highlight that over half of the UK’s fleet still in operation is over 30 years old. Most vessels in this ageing fleet are powered by carbon-intensive heavy fuel oils, while half relies heavily on diesel.
Second, marine biodiversity should be improved by minimising and potentially reversing damage from poor practices and destructive fishing gear. Around 87% of fish caught by UK vessels use a combination of demersal and beam trawl, and seine nets, which damage muddy sediments and seagrass. When disturbed from the seabed carbon re-mineralises into the ocean and can be released back into the atmosphere, increasing greenhouse gas levels.
Third, the UK’s marine habitats require increased protection to improve their ability to act as a carbon sink, the report states, as blue carbon is further extracted when fish stocks are depleted. The first UK fish stock audit post-Brexit, published earlier this year, found only three of the UK’s top ten fish populations are fished at or under their maximum sustainability yield. Alongside fish and shellfish, larger species are also considered carbon stores, with species such as tuna estimated to be 10% to 15% carbon. This leaves the ocean system when they are fished.
Adopting a climate-smart approach would support the UK’s Fisheries Act, passed last year, which recognises climate impacts in fisheries but has yet to take action in addressing the issue.
Companies are developing solutions to decarbonise vessels, with some exploring alternative fuels such as hydrogen and ammonia to cut carbon from larger, long-range maritime transport. On a smaller scale, electrification is being looked at by several figures in the maritime industry, such as Bio Feeder, which announced plans to charter Norway’s first electric fish feed vessel this summer. Others are experimenting with sail-powered cargo fleets, such as Timbercoast, while SailCargo’s Ceiba vessel combines traditional timber sailing masts with solar-powered engines to achieve commercial-scale zero-carbon shipping.
For smaller fishing vessels, returning to traditional methods could be more appropriate. Cornwall-based Fal Oysters fishery is rooted in low-emission fishing practices, using just sail power and a lower impact approach to harvesting seafood.
To better protect the UK’s blue carbon-storing habitats, bottom trawling is set to be banned within Marine Protected Area (MPA) networks and increased limitations are due to be enforced outside of MPAs.
Less-destructive alternatives such as bottom longlines will require incentives to encourage positive action. Certain initiatives are aiming to reinvent less disruptive fishing gear, such as the Cyprus-based project SEALIVE, which is developing bio-based fishing nets made with natural materials including micro-algae. The nets are also compostable on an industrial scale.