Should Neonicotinoids Be Used On Washington Tidal Flats?
Recently, in the Pacific Northwest, oyster farmers were granted a permit to use the water soluble toxic chemical imidacloprid in Willapa Bay and Grays Harbor.
This five year permit covers all burrowing shrimp management activities that result in a discharge of aquatic pesticides containing active ingredient imidacloprid to treat commercial oyster and clam beds (excluding geoduck culture).
Imidacloprid is a systemic pesticide belonging to the neonicotinoid family. It is currently the most widely used insecticide in the world and is primarily produced by Bayer. This neonicotinoid is used in agriculture, arboriculture, gardening, as a flea medication for pets, and in the home environment.
Tom Theobald: Listeners should understand that one of the things that distinguishes imidacloprid is that some of the breakdown products are even MORE toxic than the parent compound.
The Pacific Oyster Industry
Commercial shellfish is an important occupation in some parts of Washington state. My understanding is nearly a quarter of all commercial oysters come out of these two bays. -Rich Doenges,Water Quality Manager from the Southwest Regional Office, Department of Ecology, State of Washington .
Impact of Imidacloprid
June Stoyer: Where there any concerns about the use of this particular chemical because it is so pervasive? The reason that I ask is because imidacloprid was found in the drinking water on Long Island. Has there been any concern that this is going into open water?
Rich Doenges: The concern about impacts to non-target species, the concern about persistence is something we did consider before we issued the permit. One of the monitoring requirements we have is that there needs to be and will be done some pretty intensive sediment monitoring of the benthic invertebrates. What we are looking for is to ensure that there is a recovery of the benthic invertebrates at least within two weeks after an application of imidacloprid.
Tom Theobald: Can you tell the listeners how a half pound per acre would compare with how it might be applied to farm ground, for example?
Rich Doenges: That’s a good question. I do not know the answer to that.
I don’t know if it is related, I know obviously a lot of your listeners are familiar with the association of neonicotinoids and bee colony collapse and at least what we understand from the work that USEPA did in 2013 during the registration that the concentration of a half a pound per acre would be below concentrations that would impact honeybees. I’m not an expert on that but that’s my understanding of what EPA has determined.
Rich Andrews: There are a number of things that really just jump out at me about the use of pesticides in open waters which are considered waters of the state and waters of the United States.
In fact, how can one legally even issue a permit to pollute these waters under the Clean Water Act of the United States, let alone the companion act within the state of Washington. It just does not compute to me to be sensible or legal.
June Stoyer: You used to work for the EPA, correct?
Rich Andrews: Yes, I did. I worked in the National Pollutant Discharge Elimination System Enforcement Activity which is the very kind of permit that this is. I authorized a lot of permits myself.
Another thing in reading and studying up on what’s going on in Washington on this, the other Rich (Doenges) mentions the permit for Carbaryl which in my reading of the information off of the State of Department Ecology’s website, that permit is still legitimate so in fact, oyster producers can use both Carbaryl and imidacloprid and still not be violating anything. So there really is something that’s been silent and hasn’t been discussed. The one was not rescinded when the new one was issued.
There is actually no monitoring of the harvested species themselves, the clams and the oysters. They’re only looking at the other things, in sediment concentrations and water concentrations but they’re not saying about what they’re actually harvesting and feeding to people that are buying these oysters.
It is interesting that this description for local oysters appears on ExploringClarkCounty.com in an article titled, For the love of Willapa Bay Oysters – Eco-smart Shellfish.
The question remains, will consumers still purchase these oysters regardless of the unknown human health impact?
Benthic Invertebrates: Indicators of Water Quality
Benthic invertebrates are organisms that live on the bottom of a water body (or in the sediment) and have no backbone. Benthic invertebrates are extremely important indicators of environmental change.
According to the National Oceanic and Atmospheric Administration, benthic invertebrate communities are generally separated into two major size classes. The meiofauna are organisms (metazoans plus foraminiferans) that typically range from 63 to 500 mm in size, and the macrofauna are all of the larger organisms greater than 500 mm in size. Both groups include species that are considered to be either epifauna because they reside primarily on the surface of the sediments and other substrata, or infauna because they burrow or live beneath the surface of the sediment-water interface.
Because all of the major structural and functional attributes of benthic communities are affected by sediment quality in generally predictable ways, benthic community structure assessment is a valuable tool for evaluating sediment quality and its effects on a major biological component of marine, estuarine and freshwater ecosystems. (Source: Sediment classification methods compendium)
Benthic invertebrates are to water quality what bees are to the health of the environment. Considering the vast number of studies on the impact of imidacloprid on pollinators (eg: Menzel, Tennekes, Mineau, Palmer) it is preposterous that this chemical was selected.
Should Oyster Farmers Use Neonicotinoids?
In this special series called “The Neonicotinoid View”, which is the only radio show focusing on the impact of neonicotinoids, host June Stoyer and special guest co-host, Colorado beekeeper, Tom Theobald talk to Rich Doenges, Water Quality Manager from the Southwest Regional Office, Department of Ecology, State of Washington about this decision. Please click the play button below to hear the entire interview.