Saving Seabirds: Why Addressing Bycatch Can’t Wait

Seabirds are in serious trouble. In Scotland, about 70% of the species breeding on our shores are in decline, facing multiple challenges that are often complex and inter-connected. Every year, thousands of birds die after being accidentally caught in fishing lines and nets. This is called bycatch. 

Because seabirds spend most of their life at sea, ranging across vast areas of the ocean, they often encounter fishing vessels, putting them at risk of getting hooked or entangled in fishing lines and nets. In fact, research identifies bycatch as one the top three drivers for seabird  decline worldwide (Dias et al., 2019). The Scottish Seabird Centre is calling on the Scottish Government to take action now to stop seabirds being killed in this way.

(c) Jamie McDermaid

How are seabirds killed by fishing lines and nets?

Seabirds can be accidentally killed on fishing lines and in nets when they are foraging for food and are attracted to bait or offal (fish wastes such as heads or guts) discarded from fishing boats. Seabirds can dive for bait, get hooked on the fishing lines and drown as the lines sink. They can also become entangled and trapped in fishing nets when diving for prey. The fishing methods identified as the highest risk for seabird bycatch are gillnet and longline fishing (Ramirez et al. 2024). Gillnets are a type of fishing, using a wall of net that hangs vertically in the water. Fish swim through the gillnet and get caught.

Seabirds are fascinating, vulnerable group of birds. Most of them are long-lived, reach sexual maturity late in life and are slow to reproduce, meaning that the death of adult individuals may have severe consequences on entire population dynamics (Richard et al. 2025).

(c) Jamie McDermaid

Bycatch in the UK and Scotland

Evidence indicates that bycatch from fishing boats in UK waters, especially those that use longlines and gillnets, may account for the death of thousands of birds each year (Northridge et al., 2020). 

We also know that seabird bycatch is a big issue across Europe, with recent research suggesting that 195,000 individuals are killed in fishing lines and nets every year in European waters. This study found that the region with the highest levels of bycatch is the Northeast Atlantic, which includes the longline fleet operating off the Northwest of Scotland (Ramirez et al, 2024). 

The seabird species most impacted by bycatch in the UK and Scottish seas, where the offshore longline fleet operates, is Fulmar (Northridge et al., 2023). Evidence indicates that thousands of fulmars might be killed every year in off the north and west parts of our waters. Fulmars are particularly sensitive to bycatch in longline fisheries and are highly attracted to fishing vessels, often gathering behind boats to scavenge bait, offal, and discarded fish. Their sharp sense of smell allows them to detect food from long distances, making fishing operations particularly enticing. Because fulmars feed mainly at the ocean’s surface, they are more likely to encounter baited hooks before they sink, increasing the chance of accidental capture. Their wide-ranging movements across heavily fished northern waters also mean they frequently overlap with commercial fisheries.

In their research, Northridge et al (2020) also identify guillemots and cormorants as species that are vulnerable to bycatch. Guillemots and cormorants are pursuit divers, meaning they dive underwater to catch their prey, making them highly vulnerable to entanglement in nets and trawls.

It’s important to note though, that estimates relating to the number of seabirds killed on fishing hooks and in nets is likely to be an underestimate, because – incredibly -  seabird bycatch is not reported or monitored. This means the true scale of the problem is likely to be much worse than the figures suggest.

The Scottish Seabird Centre’s position on reducing and eliminating seabird bycatch 

Seabird bycatch is internationally recognised as a major issue for marine wildlife. Scotland and the wider UK, like many countries in the world, are committed to addressing this threat. The UK Fisheries Act 2020, which is the legal framework related to fisheries since the UK left the EU, includes a priority objective to “reduce and where possible eliminate bycatch”. Yet even the basic actions needed to achieve this are not yet in place.

The Scottish Seabird Centre is calling for urgent action to monitor and reduce seabird bycatch, with the goal of eventually eliminating it entirely. We have therefore asked that the Scottish Government: 

1. Introduce a requirement to report seabird bycatch. Currently, there is no requirement to report on the number of seabirds killed on fishing hooks and in nets, which means the problem is basically ignored. We want to see all fishing vessels operating in Scottish waters reporting on seabird bycatch, and we want to see this system backed up by monitoring and enforcement so that everyone can have trust in it.
2. Roll-out Remote Electronic Monitoring (REM) to all vessels operating in Scottish waters, including those under 10 metres. REM is a powerful and cost-effective way of monitoring and documenting fishing activities in real time. It provides a simple way of monitoring what is being caught, as well as problems like seabird bycatch. The Scottish Government have introduced REM to some types of fishing boats, and because longline fishing vessels pose such a high risk of bycatch, we believe they should be the priority as REM is rolled out further.
3. Take action now to reduce seabird bycatch. While we need more data on how many and which seabirds are being killed, we already know enough to take action for some of the highest-risk fishing gear such as longlines. And the good news is that there is plenty of research and experience from around the world we can draw on, which shows that the most effective approach is to require using a combination of measures including bird-scaring lines, night setting and weighted hooks to ensure hooks sink quickly out of the seabirds’ diving depth. Measures such as managing fish waste and discards to avoid seabirds being attracted by vessels or minimising the time the net is on the water surface can also reduce entanglement risk in trawls and nets. 

The Scottish Government is consulting on proposals to make fishing in Scottish waters more selective, reducing the capture of non-target species of fish, shellfish and sensitive marine species. We have made all of these points and more in our response to the consultation, which you can access HERE.