How Much Fish Do You Eat?
As we all know too well, the same water in which fish live is the same water in which we dump waste products, and unfortunately, fish can concentrate these chemicals in their flesh. Eat the fish and you might get a side dish of toxins, so to speak. Under the Clean Water Act, states are supposed to set limits on the amount of toxins dumped in the water so that the fish are safe to eat.
There’s a set of calculations that has to be done that depend on the nature of the toxin and how much more of a risk the government agencies are willing to run with the endpoint, namely, the health of the citizens.
The government does it this way because it will not simply say “do not discharge these harmful chemicals” (that was supposed to happen by 1985 but that’s going to have to be another story), because there are a lot of businesses that would have to shut down rather than install the equipment needed to meet a “zero discharge for toxics” standard. The discharge permits for some industries already have very low limits for most toxins because those toxins end up in fish flesh (and then in ours).
So some calculations have to be done to get to an answer and the “risk to health” piece has a couple of components of its own, including how much fish a person eats. The US Environmental Protection Agency published guidelines on this some time ago and those were adopted by the state of Washington. The “fish consumption rates” have been criticized for some time as not being protective enough of certain groups of fish consumers. That’s understandable, as the current fish consumption rates are 6.5 grams per day (when used in a discharge permit scenario) and 54 grams per day (when used in a contaminated sediment clean-up scenario). Tribes, in particular, have been critical of those numbers saying that their members eat lots of fish. Some non-tribal ethic groups eat much fish also. Most likely some sport anglers and commercial fishers eat more fish than the population at large. It’s clear to us that the fish consumption rates need to be set so that all of these groups that eat a lot of fish are protected. Period.
Washington is looking at the fish consumption rates and may be making changes to them, but one fish consumer does not seem to factor into the discussion. The southern resident killer whales (SRKW) consume huge numbers of fish and are affected similarly to human fish consumers. In 2005, NOAA Fisheries mentioned that pollution from DDT and PCB’s adversely affects SRKW. In the mid 1990’s, states bordering the Great Lakes enacted “wildlife criteria” in place to protect avian and mammalian wildlife. Why hasn’t there been a similar effort to enact water quality criteria to protect Puget Sound’s wildlife?
Stay tuned; Wild Fish Conservancy is keeping tabs on this effort.
Mark Hersh, Water Quality Specialist, Wild Fish Conservancy