Science.-Albatrosses can dive to more than 19 meters deep – Publimetro México

MADRID, 20 (EUROPE PRESS)

Prey-chasing albatrosses dive to depths that can exceed 19 meters, double what was previously estimated, according to a new study published in Current Biology.

Thalassarche (small to medium sized albatrosses such as the black-browed albatross) are known to dive shallow, reaching a maximum diving depth of 6 to 9 meters. New data compiled by a team led by the University of Oxford revealed that 50% of birds dived deeper than 10 meters and that dives could reach 19 meters deep, more than twice as deep as I thought previously.

GPS devices, depth recorders and accelerometers documented the voyages of the albatross population from Goicoechea Island in the Falklands as they traveled to the South American coast and dived to unexpected depths to pursue prey.

Dr Oliver Padget, Junior Research Fellow at Oxford University’s Department of Zoology, said in a statement: “A better understanding of the unobserved behavior of albatrosses and other endangered seabirds is essential to conservation efforts.

“That black-browed albatrosses are physically capable of such deep dives will now need to be taken into account when thinking about the effectiveness of mitigation strategies that rely on species being restricted to the surface.”

Recorded diving activities among the population took place during the day, suggesting that albatrosses rely on their vision to pursue prey in schools of fish on deeper dives.

“We found that deep diving was restricted to daylight hours, so a possible mitigation could be pelagic longlines setting at night, when albatrosses are less likely or able to chase baits and get caught,” he continued. Dr Padget.

The albatross, the protector of sailors’ souls, is facing a conservation crisis. The precipitous decline in populations in recent decades has left the albatross among the most endangered species in the world. 15 of the 22 species of the albatross family are in danger of extinction.

A major factor in the decline has been modern commercial fishing methods. Seabirds are caught incidentally by vessels targeting large offshore fish, such as tuna, using pelagic longlines.

Generally observed as surface eaters, with a powerful sense of smell and shallow diving ability, hungry albatrosses are at particular risk when lines are set and baited hooks are still close to the surface.

Bycatch mitigation measures can reduce potential hazards by limiting hook availability to birds as lines sink from the surface (using weights to sink lines faster or hooks that cover the barb).

These techniques focus on the danger of lines near the surface because albatrosses are not (generally) documented diving to depths where hooks are deployed for target capture.