In the vastness of the Southern Ocean, not only whales are in search of food. Numerous seabirds, including the largest seabird in the world, the wandering albatross, are also constantly on the move there. But this brings them into conflict with another species, humans, who hunt for fish, squid and krill in the sub-Antarctic waters. In recent decades, this has led to a massive decline in wandering albatrosses due to bycatch. A study has now looked into the details in more detail, discovering the areas at risk for the birds and possible main fisheries.
Wandering albatrosses from South Georgia like fishing vessels, especially South Korean longline fishing vessels and Argentine trawlers in the area between 40 and 60 degrees south latitude and between Patagonia and South Georgia. And that also puts them in the greatest danger area there of ending up as bycatch. This summarizes the results of the study by Ana Carneiro of BirdLife International and Dr. Richard Phillips of the British Antarctic Survey, who conducted this work together with four other researchers. The study was published a few days ago in the journal Biological Conservation.
Thanks to satellite data from 251 transmittered wandering albatrosses at various stages (young to adult), Carneiro and the team were able to identify the areas where the birds spend the most time in search of food. Simultaneous AIS (Automatic Identification System) analysis of the various vessels showed that almost half of the surveyed albatrosses had stayed within 5 kilometers of the vessels. South Korean longliners, Argentine trawlers, and Chinese squid jiggers received the most “visits” in this regard. It was with the former type of vessel that the birds stayed the longest, which is consistent with the previous data that was had.
The research team also examined where wandering albatrosses most often forage during their various life stages and whether they are at increased risk of ending up as bycatch there. It was found that especially adults during the breeding season and later the newly fledged young birds are most often on the move in the shelf area between Patagonia and South Georgia. Because at that time the conditions for successful squid hunting are greatest there. But the fishing vessels, which are also underway there and thus pose a potential threat especially to inexperienced young albatrosses, are also aware of this.
The team of authors does point out in their paper the dangers posed in the areas by the identified vessels. “Now that we have identified the fleets that represent the greatest risk to albatrosses from South Georgia, it’s important that advocacy focuses on those particular fishing nations and the vessel operators,” Richard Phillips explains. But at least in the area around South Georgia and the Falkland Islands, the numbers of wandering albatrosses losing their lives as bycatch are slowly declining, thanks to simple and effective deterrent measures by fishing vessels and stronger controls. But wandering albatrosses live up to their name and are able to travel long distances in a relatively short time in search of food, which brings them to regions where ships do not care about protective measures. “We know that deaths or injuries of seabirds in fisheries can be avoided using simple but highly effective techniques,” says Ana Carneiro. “The problem is that there is no checking of compliance with those measures in many fisheries.” And this increases the risk that the majestic seabirds end up drowning without a sound instead of gliding across the vastness of the ocean.
Dr Michael Wenger, PolarJournal
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