2024-03-14 11:37:11
A new study by Australian ocean scientists has documented the serious impact of entanglement in fishing gear on the survival of North Atlantic right whales, Xinhua reports.
The North Atlantic right whale (Eubalaena glacialis), also called the Biscay whale, is listed by the International Union for Conservation of Nature (IUCN) as critically endangered.
In their study, published in the journal Proceedings of the Royal Society B, the researchers analyzed 40 years of data on 199 female right whales, along with known cases of entanglement in fishing gear. In this way, they calculated the impact of these encounters on the reproduction of the whales.
Modeling of data from whale sightings shows that when female whales become entangled for a time in the lines of lobster and crab fishing gear, they are less likely to give birth afterwards, potentially leading to the extinction of the species.
“Low fertility is one of the main factors in the decline of the North Atlantic right whale population, and until now the reason for the inability of these whales to give birth was not clear,” explains Joshua Reid, the study’s lead researcher and a PhD student at Macquarie University.
“This study clearly shows that all types of entanglement in fishing gear affect the ability of females to give birth subsequently, helping to address one of the big, unsolved questions in saving North Atlantic right whales,” Reed said in a statement Wednesday.
There are currently fewer than 350 North Atlantic right whales left alive in the world, making them the second most endangered large whale species. Entanglement in fishing gear is considered a major threat to their survival.
Previous studies have shown that 89% of females have experienced at least one entanglement in their lifetime, with almost two-thirds of them experiencing two or more.
According to the new study, females that experienced mild or severe entanglement in a given year had a lower chance of passing into the breeding population than those that were not entangled or had moderate entanglement.
Surprisingly, those with light entanglements had the lowest probability of breeding, on average 47% less than females that were not entangled.
“This study clearly shows that using grading terms such as ‘mild’, ‘moderate’ and ‘severe’ to describe the relative severity of entanglement scars is inappropriate,” said co-author Rob Harcourt, professor emeritus in the university’s Faculty of Life Sciences. Macquarie.
“These terms lead to the unconscious assumption that ‘minor’ injuries are not important, when in fact they are significant,” he adds.
The research team concluded that management actions are needed to address the fatal consequences of all entanglements, regardless of severity classification, BTA writes.