A new census covering over 10,000 sites reveals 11 of 25 seabird species that breed in Britain, Ireland, Isle of Man and the Channel Isles have declined over the past 20 years.
Britain and Ireland hold most of the world’s nesting Manx shearwaters, northern gannets and great skuas. The islands are also a vital stronghold for other species of seabird, such as lesser black-backed gulls, common guillemots, European storm-petrels and roseate terns. Yet a new study released today found that almost half of the seabird species in Britain, Ireland, Isle of Man and the Channel Isles have declined in the past 20 years.
The Seabirds Count census, led by the Joint Nature Conservation Committee (JNCC), surveyed over 10,000 sites between 2015 and 2021. Experts suggest that the causes of decline are linked to adverse weather conditions (which may be a result of climate change), a lack of food as a result of both climate change and fisheries, and predation.
The census, which provides population estimates for the region’s 25 regularly breeding species, found that some species have increased at some sites, thanks to successful conservation interventions such as predator eradication programmes and site protection.
Seabirds in decline
The census results show that 11 of the 21 seabird species, where there is confidence in their trends, have declined since the last census in 1998-2002.
Scotland has the greatest number of species in decline, with 14 out of 20 seabird species falling.
The main drivers for declining populations vary between species and location. Predation of eggs, chicks and adults by native and invasive predators is one of the most common problems. As is climate change, with adverse weather conditions causing nest sites to be swept away, and increased water temperatures reducing the availability of important food sources.
“Loss of biodiversity is weakening the ability of the marine environment to withstand disturbance, adapt to and mitigate against the impacts of climate change, and is affecting the ability of our seas to supply critical services for society,” said Dr Gemma Harper OBE, Chief Executive of JNCC.
Fish stock depletion by commercial fisheries is another likely contributor to seabird declines.
Hope for seabirds
Five species have remained stable whilst five have increased, with some of those increases linked to targeted conservation work. Four of the 25 species surveyed have up to date breeding population estimates but due to survey method changes and improvements these cannot be confidently compared with previous estimates.
“Seabirds are sentinels for the health of marine ecosystems, highlighting action that needs to be taken to recover the marine environment. The results of Seabirds Count help us understand the main drivers of seabird population change, providing the building blocks for decades of future seabird conservation and recovery,” said Dr Gemma Harper OBE.
Beccy Speight of the RSPB, added: “Seabirds Count couldn’t have come at a more crucial time. For decades, our seabird populations have been battered by the impact of humans, from the introduction of predators to islands that destroy nests and chicks, to the increasing effects of climate change that are impacting the availability of their food such as sandeels. The evidence shows that conservation efforts and smart policies do work, and help increase the resilience of our seabirds to better weather whatever new storm is on the horizon. It is now up to us to protect these amazing birds for future generations.”
Seabirds Count
The Seabirds Count survey took place between 2015 and 2021 and was led by the Joint Nature Conservation Committee (JNCC) with over 20 steering group partners, including Birdwatch Ireland, the National Parks and Wildlife Service (Ireland) and the RSPB.
The 25 seabird species included in the study were the Arctics Skua, Arctic tern, Atlantic puffin, black-headed gull, black guillemot, common guillemot, common gull, common tern, European storm-petrel, northern fulmar, great black-backed gull, great cormorant, great skua, herring gull, black-legged kittiwake, leach’s storm-petrel, lesser black-backed gull, little tern, Manx shearwater, Mediterranean gull, northern gannet, razorbill, roseate tern, sandwich tern, European shag, and also rare breeding species, such as yellow-legged gull.
Find out more about the Seabirds Count