A new study has revealed that at least 25% of marine mammals could be at the risk of extinction as climate change, fisheries, bycatch, pollution and maritime development continue to adversely impact their lives. A University of Exeter team investigated the status of 126 species, including whales, dolphins, seals, sea lions, manatees, dugongs, sea otters and polar bears, and concluded that at least 1/4th of them were threatened.
Besides, the factors mentioned above pose some level of risk to nearly 98% of the marine mammal species, mainly in coastal waters.
Among the species in grave danger are vaquita porpoise and the North Atlantic right whale, both nearly extinct, reported Daily Mail.
Dr Sarah Nelms from the Center for Ecology and Conservation on Exeter's Penryn Campus in Cornwall, says humans have reached a crucial point when it comes to marine mammal conservation.
Even though, she says, very few marine mammal species have gone extinct in modern times, human activities are "putting many of them under increasing pressure".
Among the conservation measures and steps, Sarah says the paper discusses Marine Protected Areas (MPAs), bycatch reduction methods and community engagement. Apart from this, it also underlines some of the species that are in urgent need of focus, she says.
Their survival depends on specific habitats that have come under severe threat due to climate change. Polar bears and walruses, to cite a couple of examples, depend on sea ice.
Another study, published in 2020, painted a grim picture of the future of polar bears. It warned this species could be wiped out as early as 2021. The reason?
Their habitats are diminishing every passing day. The Arctic, for example, shelters these animals and it has become warmer by two times, causing ice they heavily rely on to melt away.
"Marine mammal bycatch, i.e. the incidental capture or entanglement of animals in active fishing gear, is a critical yet seemingly intractable problem and is currently the threat affecting the greatest number of marine mammal species worldwide (101 species recorded, but likely more)," the study reveals.
Pollution is said to be the next reason behind driving the extinction of some of these species. And it's not just chemicals and plastic that's harming their ecosystem but also noise, says the study.
Researchers say anthropogenic underwater noise pollutes and affects marine mammals globally. This noise pollution traumatises marine mammals' responses, leading to stress and sometimes resulting in animals injuring themselves.
About pollution, the study concludes that about 40% of the marine species were found to have either digested or entangled with plastic in the ocean
Another disheartening fact is that about 21% of marine mammal species have been listed as 'data deficient' in the IUCN Red List. This means enough is known to assess their status and steps needed to protect them from going extinct.