A research team led by the University of Minnesota at Twin Cities has completed the world’s first population estimation of the Weddell seal in Antarctica. This shows that the number of seals is significantly lower than previously thought. Recording seal population trends over time helps scientists better understand the impacts of climate change and commercial fishing.
The study is published at Science Advances, A peer-reviewed scientific journal by the American Association for the Advancement of Science (AAAS).
Researchers, along with more than 330,000 international volunteer citizen scientists, completed the count with hundreds of high-resolution satellite images covering the vast region of the Antarctic. This is the first direct population estimate ever made for the global distribution of various wildlife species on Earth.
According to their research, Antarctica is home to approximately 202,000 sub-adult and adult female Weddell seals. When the satellite imagery was taken in November, the male seals are not shown in the image because they are mainly in the water under the ice and protect their territory. Earlier estimates of female seals were about 800,000.
Michelle LaRue, a researcher at the University of Minnesota, said, “This does not necessarily mean that Weddell’s seals have dropped significantly in recent years, but instead it determines changes over time. It’s likely to be a more accurate count that can be used as a baseline to do. ” An assistant to the Faculty of Global Environmental Sciences and the lead author of research. “We have also developed an efficient process for monitoring them to see if their population has changed from this baseline. Tracking seal populations against this benchmark is for conservation efforts. It is important.”
Weddell seals are one of the most iconic species in Antarctica. In addition to being undeniably charismatic, they live in the southernmost part of any mammal in the world and can live up to 30 years in some of the harshest conditions on earth. They are seasonal residents of the coastal sea ice that surrounds Antarctica. Scientists want to know more about how climate change and fishing in the Antarctic Ocean affect seal numbers and the entire ecosystem over time by counting seals on satellite images.
“Weddell seals are so important because they are an important indicator of the Antarctic Ocean,” said Larou, a senior lecturer at the University of Canterbury’s Faculty of Global Environmental Studies. “Weddell seals live on ice that attaches to Antarctica, the same habitat as emperor penguins. As the climate continues to change, its fast ice may be expected to change. And their numbers tell us how the ecosystem is changing. “
According to Laroux, the Weddell seal is important because it preys on the Antarctic Patagonian toothfish, which is commercially caught and ultimately comes to our table as a Chilean sea bass.
“That is, not only does it provide ideas for climate change, but how the entire ecosystem works because the Antarctic toothfish, the Chilean seabass, is a very important part of the Antarctic ecosystem. We also provide ideas about. ”LaRue has been added.
In addition to this first count, researchers have gained new insights into the Weddell seal habitat. Seals prefer to be near the deep sea as well as near the continental coast, probably due to the location of predators and the fish they eat. Perhaps most interesting is that seals seem to prefer to be near emperor penguins, but only if not too many.
“There seems to be a trade-off. It’s good to be near the emperor penguins, but only if the penguins colonies don’t grow too large and there isn’t much competition for food,” Larou said.
Weddell seals are very important to the Antarctic ecosystem and have been studied since the early 1960s, but due to the harsh Antarctic weather and remote areas where seals live, seals cannot be counted comprehensively. bottom. Researchers can now count seals using high-resolution satellite imagery. The downside, however, is that there are too many images for scientists to process alone. That’s why they turned to citizen scientists.
“There is absolutely no other way to count the exact number of Weddell seals,” said Leosaras, co-author of the study and senior scientist in Point Blue Conservation Science. “Our team includes skilled researchers who know how to count seals in images, but it took years for a small team to find all the images, and humans. The eyes are even more accurate than any computer algorithm. ”
But Mr Saras said it might change soon. With the help of citizen scientists, researchers now have data to train computers to help automate future counts that give them more information about this important species. increase.
In addition to knowledge of seal ecology, this feat required a variety of skills.This includes new technologies for very large-scale processing and publishing. Satellite image Volunteer, promotion of volunteer recruitment projects, knowledge of geophysics of sea ice formation on the Antarctic coast, advanced statistical methods. LaRue has brought together a team of researchers and engineers to make that possible.
Insights from Michelle LaRue et al., First World Population Estimates of Weddell Seals in Antarctica, Science Advances (2021). DOI: 10.1126 / sciadv.abh3674
University of Minnesota
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Researchers and citizen scientists have completed the first ever number of global Weddell seals
Source link Researchers and citizen scientists have completed the first ever number of global Weddell seals