A kettle lake surrounded by homes in west Anchorage, Sand Lake has become a battleground in the war on invasive species. Opposing forces concur that Elodea, an aquatic plant commonly used in aquariums, is present in the lake. However, both sides are far from agreement on whether Elodea is a non-native, invasive weed in Alaska.
A recently released plan drafted by the Anchorage Soil and Water Conservation District concludes that Elodea is native to Alaska, or at least that evidence to the contrary isn't persuasive. The document, entitled "Sand Lake Aquatic Vegetation Management & Lake Restoration Plan," recommends controlling, not eradicating, the plant and offers several management options.
Weapons of mass destruction
The plan purports to be an objective, scientific assessment of all alternatives. However, the agency admits that early in the planning process "several property owners immediately served us with verbal notice that if herbicide was put forward as the only alternative the ASWCD would be sued." Not surprisingly, the plan then goes to great lengths to justify why herbicides won't be necessary.
While using herbicides to control weeds on public lands and waters is controversial, many homeowners apply them on suburban lawns. Due to their widespread use herbicides could be considered weapons of mass destruction, especially if applied improperly.
Nevertheless, it's obvious that the agency's consideration of herbicides, in particular Fluridone, was forestalled by the threat of a lawsuit. That's a poor way to assess viable alternatives.
Without freedom to consider all options, how do you know an official will make the most informed decision? As former Secretary of Defense Donald Rumsfeld once said in a press conference on the likelihood of finding even more destructive weapons of mass destruction in Iraq, "There are things we do not know we don't know."
Public agencies should be allowed to evaluate the pros and cons of all reasonable alternatives. The time to sue or threaten a lawsuit is when an appointed official chooses the alternative you don't like.
Native or non-native
In this instance, a lot hinges on whether Elodea is a native or non-native plant. Because of the threatened lawsuit, the agency downplayed scientific evidence that Elodea is a non-native invasive. Instead, the plan bent over backward to convince us the plant is native.
One of its oft-repeated arguments for native origin is blatantly unscientific. The agency has "secured affidavits of several long-time property owners of Sand Lake who state they observed Elodea in Sand Lake prior to 1960 with absolute clarity." Elodea is notoriously difficult to identify. Were any of the homeowners aquatic plant specialists? That's unlikely given that in 1952, according to a topographic map, only eight homes were on the lake. None of the property owners were named in the plan, so there's no way of knowing what they know. Which raises another concern. Were any of these homeowners among those who threatened to sue?
Key elements of propaganda are repetition and telling people what they want to hear. According to the plan, not only is Elodea a long-time resident of the lake, it's actually one of the most beneficial aquatic plants known to humankind. Its purpose is "to produce oxygen better than any other aquatic plant on earth." It removes heavy metals, radiation and other contaminants from the water. Because moose eat Elodea, according to lakeside residents, the plan implies that eradicating the plant will "degrade moose habitat and forage."
Despite referring to a "Science Team," "collaboration with a varied team of scientists and experts," and "peer review," no scientist's name is on the plan. When a reputable expert contributes to a scientific report it is customary and desirable to include his or her name.
In 137 pages of speculation, half-truths, and digressions posing as scientific inquiry, the plan fails to cite a single document that contradicts its narrative. The agency is certainly aware that the Alaska Natural Heritage Program has classified Elodea as a non-native invasive species. It also knows that Tricia Wurtz, the invasive plant program manager for the U.S. Forest Service in Fairbanks, and her colleague Nick Lisuzzo reviewed over 140 scientific articles and other documents and found nine reasons to support the non-native origin of Elodea in Alaska. No mention of those in the plan.
But the most astounding "oversight" was the plan's failure to acknowledge that two weeks prior to its release the Alaska Department of Natural Resources, its sponsoring agency, quarantined both species of Elodea found in Alaska to keep the infestation from spreading any farther.
The plan accurately depicts eutrophication of the lake as a contributing factor in the burgeoning Elodea population. Eutrophication is a natural process that is accelerated by urbanization, where nutrients such as lawn fertilizers are flushed into the lake by runoff from impermeable surfaces like roofs, roads and driveways.
Adding the "unquestionable proof" that eutrophication has been accelerated by volcanic ash and "dummy bombs" dropped into the lake over 50 years ago by the military is unnecessary and a little unbalanced.
Because the agency believes Elodea is a native species, it fails to acknowledge any necessity to eradicate it. Instead the plan advocates a variety of half-measures to reduce the extent of the infestation. It recommends suction dredging, which hasn't worked so well in Fairbanks. It took four months for an eight-person crew to remove Elodea from 13 acres of Chena Slough. At that rate it would take six years to suction-dredge Sand Lake.
Another recommendation is to draw down the lake water approximately six feet in autumn to freeze the weeds. That could kill Elodea in the heavily infested band along the shoreline, but the weed will survive in the remaining submerged area. Fragments of the plant will quickly re-colonize the shoreline once the lake refills.
The plan also proposes covering the 75-acre lake with geotextile fabric, at least in "small areas with infestation." This might kill Elodea by cutting off photosynthesis, but there was no indication of how long the fabric would need to be on the lake, and covering small areas would not eradicate the weed.
The agency proposes conducting an experiment in the lake using microbes, "a product that we feel is effective, 100% natural, and with no negative impacts." Dumping barrels of a non-native microbe into the lake may cause more problems than an approved herbicide.
Another experimental approach suggested by the plan would be to suspend bags of cypress sawdust from buoys in the lake – like large teabags – based on a "hypothesis" from an unspecified study.
Not only is the Sand Lake plan selectively myopic regarding facts, the agency refuses to recognize invasive species experts as stakeholders. Because property owners were a "core concern," the plan defined stakeholders as people who have platted properties adjacent to the lake and other Anchorage residents "to the degree they actively use the lake."
What about the rest of us?
The presence of an invasive aquatic plant in a lake is comparable to an infestation of rats. Just because Nome is overrun by rats and is dealing with the problem doesn't mean the rest of the state wants them. Elodea is an aggressive aquatic weed, easily dispersed by boats and floatplanes. It chokes out fish habitat and makes it difficult for people to use lakes and slow-moving streams.
It's time for the Department of Natural Resources to pull the plug and employ professionals who know what they are doing, who won't be intimidated by threats of lawsuits, and who will objectively evaluate all reasonable alternatives before recommending the best one for eradicating Elodea in Sand Lake.
Let the experts tell us what needs to be done. If an herbicide is deemed the best solution, then it's up to the political appointees to make the decision to use it or not.
Rick Sinnott is a former Alaska Department of Fish and Game wildlife biologist. Contact him at firstname.lastname@example.org.
The views expressed here are the writer's own and are not necessarily endorsed by Alaska Dispatch, which welcomes a broad range of viewpoints. To submit a piece for consideration, e-mail commentary(at)alaskadispatch.com.