Killer whales in the North East Pacific are the most contaminated marine mammals in the world, so says Peter Ross, scientist for the Department of Fisheries and Oceans, Canada (DFO).
I don't know what concerned me most when I heard Peter speak recently. His testimony, or the fact that his position is to phased out. Who will speak on behalf of the orca on this crucial matter when he cannot?
Here are some of the horrific facts from Peter's presentation:
- There are 88,000 chemicals on the Canadian market.
- By way of small-scale spills, Puget Sound experiences the equivalent of 4 Exxon Valdez spills per year
- DDT in the form of DDE still persists in the marine environment
- PCBs are the bigger threat to killer whales, due to the way they mimic hormones. In a necropsy they were associated with 11 different hormone receptors, including estrogen and thyroid.
- Salmon - the food of choice of the southern residents, bring persistent organic pollutants (POP) from the open ocean
There were some good indicators also, however, in that levels are dropping for concentrations of PCBs, DDT and PBDE (flame retardant - thanks to the ban in 2004).
PCB levels in harbor seals are down ten fold, which is good news for the transients who venture into Puget Sound for a meal, where harbor seals are storing the highest known levels of PCB.
Killer whales, proposed Peter, are sentinels of global pollution. A giant black and white canary in the coal mine (he didn't say that, I did!)
Chemical regulations are based on the impact on short living species, and not long-lived, like ourselves and orca. One wonders why the low bar when a third of the world relies on the ocean as the sole source of protein.
