Poison Is Only A Short Term Solution
The likely use of chemicals to control a Eurasian milfoil outbreak in Capitol Lake is the regrettable result of the damming of the Deschutes River fifty years ago. “No one knowingly wants to spread poison, but to control the milfoil outbreak, poisons probably will be put into Capitol Lake,” said Jeff Dickison, policy analyst with the Squaxin Island Tribe. “The real problem isn’t milfoil; the problem is Capitol Lake’s shallow and warm water that creates prime growing conditions for milfoil and other invasive species. The only way to eliminate the problem, and permanently remove milfoil, is to restore the Deschutes estuary.”
If saltwater were allowed to return to the lower Deschutes River, the current milfoil outbreak would be controlled almost immediately. Milfoil is only found in freshwater lakes, spreading from lake to lake via boat hulls, fishing tackle, etc. “Milfoil cannot survive in saltwater, and does not spread to estuaries, which Capitol Lake once was,” said Dickison. “Restoring the Deschutes estuary is the only sure-fire way to eradicate milfoil.”
“These kinds of things are going to happen because we’re trying to make an estuary into something that it can’t be in the long term – a lake,” said Dickison. Capitol Lake is shallow, heats up in the summer and has low dissolved oxygen, which makes it attractive to plants like milfoil. If untreated, floating mats of milfoil build up in the lake, damaging fish and wildlife habitat, and decreasing recreational opportunities.
The state department of General Administration is currently considering using a chemical called “fluridone” to control the outbreak. Fluridone has a label restriction that it is not to be used in brackish or saltwater. There are fears that fluridone is “bio-cumulative,” or builds up, in marine species such as shellfish and other invertebrates that are a food supply for salmon. There hasn’t been much research into these dangers because fluridone isn’t usually applied in saltwater habitats. “The problem with applying fluridone in Capitol Lake is that the lake drains into Budd Inlet,” said Dickison. “If the label on the chemical warns for it not to be used in saltwater, then why are they using it in a body of water that drains immediately into saltwater?” Another chemical being considered, 2,4-D, is classified by the World Health Organization as a “’moderately hazardous” herbicide and was a main component of Agent Orange.
In addition to milfoil, Capitol Lake is also infested with purple loosestrife, a noxious weed that displaces native vegetation. Loosestrife, because it displaces native food sources, also drives away waterfowl and other animals. It can grow to be nine feet tall and has spread from Europe in the past few centuries to throughout North America.
Contrary to the intentions of the original designers of the Capitol Campus, Capitol Lake was created in 1951 when an earthen dam was built between the banks of the lower Deschutes River. Freshwater backed up by the dam flooded what had been a rich tidal estuary. Today the lake is a warm, shallow reservoir that is constantly filling with sediment and faces a host of environmental problems. In addition to an invasion of non-native weeds, problems include water quality and low levels of dissolved oxygen.
“By continuing to attempt to make a lake work, rather than exploring alternatives, we’re dedicating ourselves to dumping poison into the water,” said Dickison. “The only way to solve the problem of invasive plants – and many other water quality issues in Capitol Lake – is to return it to an estuary.”