Fisheries

Seabirds depend on both land and sea to survive – and so they are also affected by threats in both environments. Incidental mortality in fisheries (‘bycatch’) is the main threat to seabirds at sea, affecting 100 species and estimated to kill more than 1 million birds each year.

Overfishing

Bycatch

Pollution

Energy Development

Hunting & Trapping

Disturbance

Invasive Species

Light Pollution

Climate Change

Overfishing - Depletion of a birds’ food supply through fishing

Purse seine fishing in Chile
@Patricio Ortiz

Growing problem for seabirds, with more than 50 species currently impacted
Number of threatened species affected more than doubled during the last 10 years
More than 100 million individual seabirds are exposed to this threat

Overfishing is the main cause of decline of at least 24 species and is also often associated with other threats at sea, such as bycatch and decrease in prey abundance due to changing oceanographic conditions near the colonies.

BirdLife is working towards the creation of well-managed Marine Protected Areas to help address overfishing. It is also promoting the effective implementation of ecosystem-based management of forage-fisheries within the context of wider, multi-stakeholder Marine Spatial Planning.

Bycatch - The incidental catch of non-target species

Bycatch - Black-browed Albatross
@Leo Tamini

Affects 100 seabird species worldwide
Some groups particularly affected are: albatrosses, shearwaters and large petrels, penguins, auks, sea ducks and cormorants
Almost 200 million seabirds worldwide are exposed to this threat

BirdLife is working hard to address bycatch in fisheries. The Seabird Tracking Database (initially known as the “Global Procellariform Tracking Database”) was created to inform our conservation efforts to address this issue, via the Albatross Task Force and our policy work with the Regional Management Fisheries Organizations (RFMOs).

Tracking data compiled in the Seabird Tracking Database have been used to analyse the areas of highest bycatch risk across the oceans and inform numerous governmental and inter-governmental bodies on how and where to implement mitigation measures.

Pollution - Harmful substances in the environment

Oil pollution in the oceans is improving and now less threatened species are affected
Still, almost 70 species globally are impacted by pollution
Plastics is not (yet) a cause of major populations declines on seabirds. However…

Plastic pollution is an emerging threat that is increasingly affecting seabirds in every ocean basin. We still know very little about the potential lethal effects of plastic contamination in seabirds, and the population-level effects it may cause.

BirdLife is working to improve our understanding of plastic exposure in small petrels, in a study using seabird tracking data and plastic distribution - read more here.

Energy development - Oil and gas extraction, or offshore renewable energy

Oil & gas platforms can pose a serious threat to seabirds, particularly to small petrels – which are attracted by the lights of the flares
Offshore windfarms can also impact seabirds via collision or displacement

Offshore wind farming is a fast-growing issue with potentially large impacts on seabirds, but we still have limited information on the consequences for seabirds at the population level. This threat is expected to affect mostly coastal species such as divers, scoters, terns and shags.

Hunting/Trapping - The harvest of seabirds or eggs for commercial, recreation or subsistence purposes

Almost 100 species of seabirds globally are harvested for their eggs or meat
Along with disturbance, this is the top threat to coastal globally threatened species, affecting half of these species

Hunting/trapping at colonies is the second major threat on land in terms of number of species affected. Seabird hunting and egg collection are still common practices in many seabird colonies around the world, from the Arctic to tropical regions. Seabirds are also hunted at-sea, although the scope and severity of this issue is far less known.

Disturbance - Human activities (including recreational) that alter seabirds' normal behaviour or their habitats

More than 70 seabird species are affected by disturbance
Along with hunting/trapping, it is a major threat to coastal globally threatened species
Penguins are also particularly affected, due to increasing tourism in remote areas

Disturbance of seabirds at their colonies can lead to reduced breeding success or even to permanent abandonment of their nests. The increase in ecotourism can pose an additional challenge, which can be mitigated by implementing regulations to control access to important seabird colonies.

Invasive Alien Species - Predation or habitat degradation caused by non-native species

Affects almost half of all seabird species globally
Most groups of seabirds, including the most threatened ones, are affected by invasive predators
Rats and cats are particularly problematic

Invasive alien species are the major threat to seabird species globally, affecting 165 species (73 of which are threatened with extinction). Seabirds breeding on isolated islands are particularly vulnerable – predation by introduced rats and cats is an extra source of mortality (especially in eggs and chicks, but often also in adults), and is the main cause of decline for more than 100 species.

Light pollution - Excess artificial light at night

Light pollution affects many seabird species, in particular petrels and shearwaters
Artificial lights near the colonies are particularly problematic for fledgling seabirds

Light pollution is a known threat to many fledgling seabirds around the world – when they leave the nest for the first time, they are often attracted to artificial light sources (such as streetlights or lighthouses), and become disoriented, resulting in injury or death.

The problem of light pollution at sea (including collision with ships or oil platforms) is still poorly known.

Climate change - Effects of long-term climatic changes, including severe weather events

Climate change impacts almost 100 species globally
Almost 200 million individual seabirds are exposed to the adverse effects of climate change
Penguins are particularly affected by this problem

Climate change impacts seabirds in many ways – via habitat shifting and alteration (e.g. changes in oceanographic processes and prey distribution around colonies), sea level rise and floods (resulting in inundation of colonies), increased frequency of extreme weather events (such as extreme temperatures and storms), and increased occurrence and virulence of avian pathogens. Translocations of nests and colonies can alleviate the negative impacts of climate change in some cases.

BirdLife is addressing this serious problem via a dedicated programmatic area of work – read more here.

Many seabirds forage over vast distances and are attracted to fishing vessels by bait, discarded fish and offal. This behaviour exposes them to the risk of bycatch during fishing operations. In longline fisheries, birds may swallow baited hooks and become hooked or entangled, subsequently drowning as the lines sink underwater. In trawl fisheries, birds attracted to discards may collide with the cables supporting or monitoring the trawl nets, resulting in injury or death. Capture in gillnet fisheries is due mostly to entanglement while diving for prey. While some fisheries have already reduced seabird bycatch by more than 80% by adopting mitigation measures, bycatch is still causing declines in many seabird populations.

Please view this page on a desktop computer to see our interactive Threats to Seabirds feature.

Using tracking data to address bycatch

Understanding where and when animals are under threat is crucial for directing conservation efforts to where they are most needed. This is particularly true for addressing the bycatch of seabirds in fisheries.

Over the last few decades, researchers have used electronic tracking devices attached to a wide range of seabird species to record bird movements, providing unprecedented insight into the lives of birds at sea. BirdLife has been working in close collaboration with researchers to compile this data to help address the threat of bycatch – we established the Global Procellariiform Tracking Database in 2004, which then evolved to hold data for all seabird species – the current Seabird Tracking Database. Since 2021, we have also established a research partnership with Global Fishing Watch to strengthen the use of fishing activity data in seabird conservation. By combining seabird tracking data with information on fishing activity, we can predict hotspots of risk – information that is vital for stakeholders and policy makers to target bycatch mitigation work and protect seabirds from unnecessary deaths in fisheries.

BirdLife researchers have developed a framework that integrates multiple sources of data to identify seabird hotspots at sea. Working with collaborators around the world, we used tracking data from over 4,000 individual birds to map the at-sea distributions of 22 seabird species of global conservation concern and quantify overlaps with fisheries. While many tracking studies focus solely on breeding adults, we showed that including data from juvenile, immature, and non-breeding adult birds is vital for estimating the full extent of risk from fisheries. Building on this work, BirdLife is also working with regional partners and researchers to identify priority areas for seabird bycatch mitigation in the Humboldt Current Large Marine Ecosystem, off Ecuador, Peru and Chile, and adjacent high seas. This regional approach aims to provide evidence to guide targeted conservation action and support efforts to reduce seabird bycatch in one of the world’s most productive marine ecosystems.