To imagine the coastline without the calls of seabirds ringing out above the waves as they search for prey and protect their young would be to imagine a true climate disaster. Though this extinction scenario seems far-fetched, seabirds face more threats than any other group of birds. Dangers include competition from invasive species, commercial fishing, and especially climate change because they rely both on delicate coastal habitat (for breeding) and the open ocean (for food). Changes in either habitat can threaten their survival.
Many seabird species also rely on arctic habitats, which are some of the most threatened by climate change. Some birds have long migrations that can be made more difficult by unpredictable weather events. The IUCN (International Union for Conservation of Nature) now lists 31% of seabirds as vulnerable, endangered, or critically endangered. Several seabird species—including kittiwakes, petrels, puffins, and terns—face particular threats from climate change.
Kittiwakes
The black-legged kittiwake (Rissa tridactyla), known in the United Kingdom simply as "kittiwakes," are a species of gull reminiscent of the more common ring-billed gull, except it is smaller, with a large head in proportion to its body and black legs and feet. Its name comes from its characteristic call that sounds like “kitti-weeeik.”
Kittiwakes use several cliffside sites in the UK, such as the Bempton Cliffs in Yorkshire, as their breeding grounds. They typically rear one to three fluffy, grey chicks each year. Since a 2018 assessment by BirdLife, the kittiwake has been listed as “vulnerable to extinction” on the IUCN Red List of Threatened Species, which was a stark change from their 2016 assessment that placed them at “least concern.” According to the Royal Society for the Protection of Birds (RBSP), overfishing and changes in ocean temperatures have eroded the populations of sand eels, which form a large part of these nesting birds’ diets.
Kittiwakes also face threats to their breeding grounds. In February 2024, the kittiwakes suffered a crushing blow to their habitat when a cliff face holding 383 kittiwake nests fell into the sea in Sussex, England. The Sussex Ornithological Society had already observed a decline in kittiwake nests on the cliff face, with numbers at their lowest since 2011. This cliff face was the only known nesting site for the kittiwakes in Sussex, and it’s unclear if they will be able to adapt and return to the area.
Petrels
The decline of the kittiwake population is part of a larger trend in the population decline of seabirds. A long-term study that followed Wilson’s Storm Petrels in Antarctica showed a massive 90% decline in population over a forty-year period for two colonies.
Like the kittiwakes, petrels are pelagic seabirds and spend most of their lives in the open ocean. They only return to land for breeding and rely on specific nesting sites for nesting. Petrels are also facing loss of food due to warming oceans. The melting of sea ice reduces the number of Antarctic krill that the birds rely on. (To learn more about krill, see the E&I article “Antarctic Krill: An Ecosystem Powerhouse Caught Between Humans and Nature.”)
Cloudier seas may also make it difficult for pelagic seabirds to find food. Researchers at University College Cork (UCC) in Ireland observed Manx shearwaters, a seabird in the petrel family with gray color and white bellies, to understand how the cloudy ocean waters affected hunting conditions. The UCC researchers found that when sunlight penetrated the water, the shearwaters were able to dive deeper and collect more prey. The study suggests that as the oceans get cloudier due to climate change, it will be more difficult for pelagic seabirds to find food.
Puffins
In 2016 and 2017, researchers estimated that thousands of birds, many of them tufted puffins, died of starvation in the Bering Sea. The research team suggested that warming seas impacted the availability of the birds’ traditional food sources in the molting season, a stressful season during which the birds need extra energy and lose some of their ability to fly and dive. The puffins, which are colorful seabirds with upright penguin-like postures, were not able to find enough fish to sustain themselves, and the bodies of emaciated puffins washed up on the northwestern coast of North America, including St. Paul’s Island in Alaska.
More recently, the tufted puffin’s cousin, the Atlantic puffin, suffered from the effects of warming seas and heavy rains in the Gulf of Maine. A study noted that the sea surface in the gulf was warming 99% faster than the global ocean. This has led to changes in available fish for the puffins to feed their chicks. This, plus heavy rainfalls, contributed to a disastrous 2021 for the puffin population—90% of the nesting puffins on the Island of Petit Manan, a ten-acre island refuge for nesting seabirds, failed to raise chicks to adulthood. Fortunately, by 2023, these puffins saw a second year of population rebound, Popular Science reported.
Terns
Even subtle changes in weather and climate can have negative impacts on seabirds with long migratory routes. Arctic terns fly to both the North Pole and South Pole, the longest migration of any animal at 100,000 kilometers (over 62,100 miles). Terns rely on wind support to help with their migration, but changes in windspeeds due to climate change could negatively impact their journey. A 2023 study found that climate change could affect prevailing winds along the terns’ migration route, which may require them to change course. Due to the length of the journey, even minor wind pattern changes can have negative impacts for these long-distance avian athletes.
In addition to changes in weather, disappearing sea ice may influence the arctic tern’s breeding and foraging grounds. The terns rely on Antarctic sea ice for raising their chicks, and the loss of sea ice has likely led to devastating effects on other arctic seabirds such as the Ivory gull, which has lost 70% of its Canadian population since 1980. “[C]ontaminants and illegal harvesting in Greenland during migration” are likely contributing factors.
Beacuse of their sensitivity to the effects of climate change, seabirds can indicate the general health and well-being of the ecosystems they inhabit. For that reason, it’s important to protect seabirds, not just for their own sake but for the sake of marine ecosystems.
A 2019 study found that 380 million seabirds would benefit if the top three threats to seabirds could be controlled: the proliferation of invasive species, bycatch (unintentional trapping as a result of commercial fishing), and climate change.
Countering these threats is an intimidating, long-term task, but researchers are also working to save several individual seabird species. In 2023, conservationists made an international effort to create a new colony of threatened black-footed albatrosses on the Mexican island of Guadalupe. And Audubon’s Seabird Institute is working to restore seabird populations worldwide, including seven in the Gulf of Maine. There is hope for seabirds as long as commitment to their conservation continues.
*Mal Cole is a freelance science and nature writer based in Massachusetts.
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