Puget Sound orcas face toxic situation
By LeiLani Hector - Staff Reporter
The endangered Puget Sound orcas have the highest levels of polychlorinated biphenyls of any marine mammal in the world, a biology professor said here last week.
Highline Professor Woody Moses gave his presentation on Our Toxic Orcas on Nov. 2 for Green Week.
Green Week was a week-long series of events, presentations and programs on all things from climate change to learning about the endangered Puget Sound Orcas.
Orcas are "one of the most magnificent animals in the planet," Moses said.
But things aren't that great for the Puget Sound orcas. One of the big problems is food in the sense that they aren't eating enough, Moses said, which leads to two issues:
• They are starving.
• The starvation is making the final problem worse – which are toxics, he said.
"They are highly, highly contaminated," Moses said.
These Puget Sound orcas have the highest levels in their blubber, about 150 parts per million of polychlorinated bi- phenyls (PCBs) of any marine mammals in the world, while the average is 15 parts per mil- lion, he said.
"Polychlorinated biphenyls are a man-made thing-- these
did not exist in nature up until the 20th century," Moses said.
Polychlorinated biphenyls are chlorine compounds that have been used in things such as coolant fluids and heat transfer fluids.
They are highly stable-- they do not break down and because of this, it has been banned in the U.S. since 1977, he said.
So how does polychlorinated biphenyl get in the orcas? Moses asked.
Because this chemical does not break down, they have not gone away, and everything that has been dumped into the environment is still there, he said.
PCB gets into the orca's system due to the organisms interacting with the environment that contains the chemical, as well as through the food chain moving from one organism to the next.
For example, the phytoplankton, the bottom of the food chain, eats the bacteria from the ocean, which contains the polychlorinated biphenyl. Then the zooplankton, the second to the bottom of the food chain, eats the phytoplankton.
Then the salmon, the second from the top of the food chain, eats the zooplankton. Finally, the orcas, the top of the food chain, eats the salmon which is how the polychlorinated biphenyl level are so high, and which is why the orcas are toxic.
Due to the short supply of salmon, it forces orcas to metabolize more blubber in order for them to survive, which in turn, releases more polychlorinated biphenyls into their blood, destroying the immune system, and the starvation is what is causing the lethality of the pollutant within the orcas,