10-day-old autopsy Orca Launched in Norway in 2017, it became clear that these iconic whales, despite being calves, are full of harmful chemicals.
Young killer whaleOrca orca) Was one of the eight dead killer whales investigated by Norwegian researchers.Of these, seven (including calves) had banned levels Flame retardants Researchers have discovered polychlorinated biphenyls (PCBs) that are high enough to cause health problems in animals. And all had some new pollutants at lower levels, most of which are unknown and not yet banned.
“Probably the most striking finding was that newborn killer whales were as contaminated as adults,” said Eve Jordi, a research collaborator and founder and principal investigator of the Norwegian killer whale study. Tells Live Science by email. “This means that these new contaminants are inherited from the mother to the calf (placenta and milking movement of the mother).”
The team conducted animal autopsies to learn more about Orca health in Norwegian waters. Killer whales (not really whales, but the largest species of dolphins) are at the top of the food chain, meaning they are vulnerable to high levels of pollutant accumulation, Jourdain said. It was. The team collected fat and possibly muscle and organ samples from eight whales that died after being stranded or caught in a net in Norway between 2015 and 2017, and then artificial chemistry of whale tissue. I started to analyze the substance.
Overall, the team “is still found at a high level in Norwegian killer whales, despite the fact that PCBs were banned long ago,” Jourdain said. Researchers have also screened for new, unregulated chemicals, such as brominated flame retardants (BFRs), and low-level retarders pentabromotoluene (PBT) and hexabromobenzene on the fat of all eight whales. Researchers write that they have discovered (HBB). the study.
These chemicals were created as alternatives to PCBs, but they provide little comfort to whales. The study reveals that “these alternative chemicals have the same accumulation properties as PCBs in killer whale tissue,” Jourdain said.
Researchers also saw Perfluoroalkyl Substances (PFAS)It is known as an “eternal chemical” because it does not decompose like other chemicals in a normal environment. Mercury level. Still concerned, researchers say that PFAS and mercury levels are lower in killer whale calves than in adults, “suggesting less efficient transfer of these substances to the mother’s body.” Pointed out in the study.
Some of the chemicals investigated in the study (BFR, PBT, HBB, PFAS) are widely used in countless products such as cosmetics, ski wax, textiles, leather, paper and foam-based fire extinguishers. Mr. says. “These can flow into the sea through local streams, sewage, etc. [and] Then climb high and accumulate until you reach the food chain [their] The highest level of apex predators like killer whales. “
Previous studies also found PCBs in killer whales, including Lulu, an adult killer whale whose corpse was found on an island off Scotland in 2016. Lulu’s fat PCB levels were 100 times higher than scientists consider safe for marine mammals. That is, she had some of the highest level PCBs ever recorded on whales. Live science previously reported..
Scientists don’t know how harmful these chemicals are to killer whales, but research has shown legacy pollutants such as PCBs. Immune and reproductive system With a whale, she said. “This means that killer whales are more vulnerable to pathogens and diseases and may be less likely to breed.”
The fact that both new alternative chemicals appear to behave like traditional pollutants in the sense that they both accumulate in whale tissue was also relevant to researchers. “This is a concern because they are not yet regulated and we know very little about how harmful they are to wildlife,” Jourdain said.
Originally published in Live Science.
Dead killer whales reveal harmful chemical levels in killer whales
Source link Dead killer whales reveal harmful chemical levels in killer whales