The scientists found resident southern and Bigg’s killer whales with 4-nonylphenol in their livers and skeletal muscles.
4NP is associated with the production of toilet paper.
The scientists also discovered PFAS, known as forever chemicals, in the bodies of the killer whales.
Orcas are some of the most polluted marine mammals in the world.
Species are full of chemicals, from “highly toxic and carcinogenic” PCBs to the infamous DDT insecticide.
Now, a group of scientists has discovered another worrying chemical, and it’s associated with toilet paper.
Scientists from the University of British Columbia, the British Columbia Ministry of Agriculture and Food, and Fisheries and Oceans Canada found a chemical known as 4-nonylphenol, along with dozens of other chemicals, in liver and bone tissue. of 12 southerners killed and Bigg’s orcas.
The chemical 4NP belongs to a group of chemicals known as alkylphenols, which UBC researcher Juan José Alava described to Insider as “very toxic.”
Although Alava and other researchers who spoke to Insider noted that it’s too soon to conclusively conclude how orcas are affected by 4NP, their discovery raises some alarm.
The amount of 4NP found in killer whales, which tended to be higher in blood-rich liver tissues, reached an exceptionally higher level in one calf.
“These contaminants can basically affect reproduction, development, and we know, based on the weight of evidence, that they affect cognitive function and also the nervous system,” Álava said. “So we are talking here about pollution that is harmful to the environment and harmful to this species of orcas.”
Alava said the exact source of 4NP affecting whales is unknown, the chemical can be found mainly in sewage sludge and sewage treatment plants. It is also used in detergents and cosmetic products.
In addition to 4NP, more than half of the contaminants discovered in killer whales belonged to a category of chemicals known as PFASs, commonly known as forever chemicals due to their difficulty breaking down in the environment. PFASs can be found in drinking water, fish, and in trace amounts in human blood, and can increase the risk of diseases such as cancer and liver disease in humans.
The study authors noted that it was the first time 7:3-fluorotelomer carboxylic acid, a type of PFA, had been found in a Pacific Northwest killer whale. Alava noted that FTCA 7:3 has never been found in British Columbia before and could indicate the contaminant is making its way through food systems.
‘They’re just being killed by 1,000 cuts’
Although Biggs and the southerners are threatened by the possibility of extinction, the southerners, whose numbers are not growing, have scientists especially concerned.
In addition to habitat loss, climate change, and entanglement in fishing gear, southern resident orcas struggle with their food supply.
Overfishing means there isn’t enough food. And pollutants in the environment mean that when food is around, it very well could be full of chemicals. Because killer whales eat so much, they typically have a higher concentration of chemicals compared to their smaller marine counterparts.
Southern residents rely on Chinook salmon to supplement their diet. The discovery of chemicals in their system means that Chinook salmon also have contaminants in their system, a warning to people who also eat salmon.
But more than that, the lack of a good food supply is affecting orca reproduction, Deborah Giles, a scientist and director of research at the nonprofit organization Wild Orca, told Insider.
Giles’ own research found that 69% of southern resident orca pregnancies were unsuccessful, with 33% failing late in pregnancy or immediately after birth.
“And those females that are losing their young are deprived of nutrition, which of course works to increase the impacts of the chemicals,” Giles said.
Chemicals are also transferred between mothers and fetuses. The UBC study, which looked at a southern resident known as J32, found that all of the chemicals found in her were transferred to her fetus. J32 died in 2014 while trying to deliver her fetus, Giles noted.
“They’re really getting killed by 1,000 cuts,” Giles said.
‘This is just the tip of the iceberg’
“Very few” orcas were examined to determine the extent of 4NP contamination in orcas, the study authors noted, but even obtaining this amount of data on orcas, which are typically studied after death, is a daunting task.
Alava told Insider that due to limited access to orca organs, he doesn’t think he or the team he worked with will be able to perform a necropsy study like this again any time soon.
The lack of data means that there are still many unanswered questions: Why are some species less affected by certain chemicals than others? What role do these chemicals play in endangering this species? How many chemicals will researchers continue to find? And which of the dozens of harmful chemicals found in the environment should scientists and regulators focus on when trying to save the species?
Irvin Schultz, manager of NOAA’s Environmental Chemistry Program, who spoke to Insider about the research, also said that because these particular chemicals haven’t been examined before, more needs to be done to determine their true impact on the species.
“It’s definitely more than trace levels,” Schultz said. “So it’s something that gets their attention, and maybe it’s definitely something to continue to measure and track.”
Schultz, whose lab focuses on measuring other pollutants, such as polyaromatic hydrocarbons that occur naturally after burning fossil fuels, says it’s also important to note that killer whales are exposed to many more pollutants.
“The real value of this study is to provide some data for compounds that haven’t been as frequently monitored or measured,” Schultz said.
And scientists like Giles continue to pay attention to which other orcas may have other unknown chemicals in their bodies.
“My guess is that the more we look, the more we’re going to find regarding chemicals, man-made chemicals that find their way through the food web and into our top predators like whales,” Giles said. “And I think that’s the scary part for me, is that I think this is just the tip of the iceberg as far as what we’re going to find.”
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