Blog post by Steffen Oppel, Senior Conservation Scientist, RSPB Centre for Conservation Science.
Seabirds are exposed to several threats at sea, and there is a variety of options to protect them, but policy makers and conservation practitioners need to understand which approach is most suitable for which species.
New research is providing insights into this question based on miniature technology that records how far seabirds fly to find food during the breeding season.
Seabirds can travel hundreds of kilometres - but there are huge differences between species such as these frigatebirds and terns
Technology turning the tide
Seabirds breeding on islands or along our coastline are some of the most spectacular creatures to see when you visit the sea. They nest on land, but find all their food at sea, whether it is fish, squid, crabs or shrimps.
For humans stuck on land it is difficult to know how far these birds go out to sea to find their food, because they quickly disappear beyond the horizon or amidst towering waves. But technology has turned the tide and we are now able to follow seabirds during their feeding trips using electronic gadgets.
Researchers attaching a small GPS tracking device to the tail of a breeding seabird
Over the last 20 years, researchers have equipped over 100 species of seabirds with increasingly small tracking devices to follow their movements at sea.
Many of these data have been contributed to the BirdLife Seabird Tracking Database and can be used for conservation planning or research, for example to identify areas at sea that are important foraging grounds for particular seabirds.
In a new study published in the journal Marine Policy, researchers have now summarised the tracking data of 52 species from 10 families across the Atlantic Ocean to highlight the differences in the spatial scale of their movements during the breeding season.
The average foraging distance of adult seabirds during the breeding season varies substantially among the 10 families for which there are sufficient data.
The new study
This summary, based on more than 12,000 foraging trips from over 5,000 breeding birds, highlights the enormous differences between seabird families: while cormorants and shags often only travel 5-10 km out to sea, albatrosses, petrels, and frigatebirds routinely travel more than 200 km to find food during the breeding season.
There are obviously large differences even within families, and sometimes even within species, for example because birds from large colonies have to fly further than those nesting in small colonies because high competition in large colonies leads to food depletion.
What does it mean for conservation?
The information summarised in this paper offers useful guidance for policy makers and conservation practitioners. Birds that travel very far and exploit vast areas at sea may require conservation measures at a much larger scale than birds that travel only a short distance and remain in a smaller area.
Measures to reduce seabird bycatch such as these 'tori' (or 'streamer') lines behind a boat in Alaska can be implemented across the entire ocean and therefore benefit even wide-ranging seabirds
Most birdwatchers and seabird scientists would have intuitively known that some species travel much farther than others, but being able to quantify the foraging range of so many species based on data contributed by >70 scientists is a great testament to what we can achieve if we work together
Seabirds face many threats,” Maria Dias, Senior Marine Science Officer at BirdLife International, and a co-author of the study, said. “At sea, they are vulnerable to pollution, overfishing, and being killed in fishing equipment, a problem known as bycatch”.
For the ailing seabird populations in the UK, marine protected areas are a useful tool. “This new paper shows that for species such as kittiwakes, puffins and razorbills, protected areas are vital to safeguard foraging sites” says Gareth Cunningham, Senior Policy Officer of the RSPB. “But to date all four UK Governments have failed to protect adequate foraging areas for any of our international important populations of cliff-nesting seabirds.”
While creating and managing effective protected areas may be appropriate for some species that do not travel very far, globe-trotting species such as albatrosses and petrels can encounter threats almost anywhere in the ocean. They therefore require a combination of conservation solutions, such as measures that eliminate the incidental bycatch in fishing equipment anywhere within their vast foraging range.
Impressive work everyone. Keep it up and we may yet save something from the wreck of planet earth.
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