(Beyond Pesticides, April 29, 2015) Much to the dismay of activists and concerned local residents, the Washington Department of Ecology (Ecology) approved a permit for the use of imidacloprid (a neonicotinoid) to combat a growing native population of burrowing shrimp that threatens valuable shellfish (oyster) beds in Willapa Bay and Grays Harbor in Washington state. Imidacloprid is known to be toxic to bees but is also toxic to aquatic organisms, raising questions on the impacts of its use on the long-term ecological health of the bays.
The shellfish industry is important to the Pacific Northwest, injecting an estimated $270 million or more into the regionâs economy, and providing jobs for many. Washingtonâs tidelands, especially those in Willapa Bay, have been particularly productive for more than 100 years. However, according to shellfish growers, the burrowing shrimp (ghost shrimp, Neotrypaea californiensis,Â and mud shrimp, Upogebia pugettensis) undermines the industry. The creatures burrow into shellfish beds, making the beds too soft for shellfish cultivation. Their burrowing churns the tidelands into a sticky muck, smothering the oysters. After several years of deliberations and studies, Ecology identified imidacloprid as itsÂ preferred choice for eradicating the shrimp. According to the agency, imidacloprid disrupts the burrowing shrimpsâ ability to maintain their burrows. A risk assessment conducted by Ecology concludes that, âThe proposed use of imidacloprid to treat burrowing shrimp in shellfish beds located in Willapa Bay and Grays Harbor is expected to have little or no impact on the local estuarine and marine speciesâŚ.. , and will not significantly impact human health.â
However, in comments submitted by the Xerces Society, supported by Beyond Pesticides, and others, Ecology failed to consider existing published research that demonstrates the potential for wide-range ecological damage from imidacloprid. The groups say that theÂ risks, coupled with the lack of data on how imidacloprid will impact sensitive marine environments like Willapa Bay and Grays Harbor, warrant greater caution. The comments urged the agency to review existing data which shows imidaclorpidâs potential to damage the rich marine ecosystems of Willapa Bay and Grays Harbor. Imidaclorpid is water soluble and highly toxic to aquatic invertebrates. Its persistence and largely irreversible mode of action in invertebrates make it particularly dangerous in these ecosystems. Further, the comments note, imidaclopridâs impact on these key species can also cause a cascading trophic effect, harming the fish, birds, and other organisms that rely on them for sustenance.
But environmental organizations were not the only ones to raise concern for the use of imidacloprid. The National Oceanic and Atmospheric Administrationâs National Marine Fisheries Service (NMFS) voiced many concerns over the application of imidacloprid to the bays. Among them include concerns surrounding the large size of the area to be treated. NMFS believes that the proposed acreage should be reduced because of many unknowns regarding impact to other aquatic and terrestrial biota. Further, NMFS states that the burrowing shrimp are native to the region and play an important role in the natural ecosystem. The agency also voiced concern for the green sturgeon â a âspecies of concernâ under the Endangered Species Act (ESA), and the potential direct and indirect impacts to its food sources in the designated critical habitat. The agency believes that effects and damages will not be limited to the treatment sites. Similarly, the U.S. Fish and Wildlife Service (FWS) also expressed reservations over imidacloprid use. FWS wrote Ecology expressing its opposition to the imidacloprid permit, citing a lack of scientific information regarding fate and transport, efficacy, persistence, and effects to non-target organisms. It went on to dispute claims that shrimp control improves biodiversity, citing the possibility of significant alterations occurring to the bayâs ecosystem without burrowing shrimp control, disagreeing with Ecologyâs conclusion that âno significant adverse impactsâ would be expected. Read Ecology’s EIS.
The permitÂ -a National Pollutant Discharge Elimination System (NPDES) permit under the Clean Water Act- to use imidacloprid to control burrowing shrimp came at the request of the Willapa/Grays Harbor Oyster Growers Association. Ecology and members of the shellfish industry believe the neonicotinoid, imidacloprid, is a âsaferâ choice compared with other, older pesticides classes like the carbamate, carbaryl. Carbaryl is still currently used as a control option, despite many objections to its use based on its toxicity. However, aÂ 2015 scientific review by Christy Morrissey, PhD, Pierre Mineau, PhD, and others, on the impacts of neonicotinoids in surface waters from 29 studies in 9 countries finds that these chemicals adversely affect survival, growth, emergence, mobility, and behavior of many sensitive aquatic invertebrate taxa, even at low concentrations. Neonicotinoids, including imidacloprid, were also recently evaluated by a large panel of international experts chartered under the International Union for the Conservation of Nature (IUCN), which found that neonicotinoids have âwide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.â
The U.S. Environmental Protection Agency (EPA), which oversees the registration and use of imidacloprid and other pesticides, is currently reviewing the human and environmental health impacts of imidacloprid and other neonicotinoids pesticides. EPA has stated that it will not be completed before 2018/19. According to agency documents, in 2012 Willipa-Grays Harbor Oyster Growers Association petitioned for imidacloprid use for intertidal oyster beds to control burrowing shrimp. This represented a new use for imidacloprid. As such, the agency established tolerances for residues, in or on fish at 0.05 parts per million (ppm), and fish-shellfish, mollusk at 0.05 ppm. The petition for new use was issued a conditional registration on June 6, 2013 for the imidacloprid products, Protector 0.5G and Protector 2F, which can only be used in Willipa Bay/Grays Harbor, according to the product labels. The label for Protector notes, âThis product is toxic to wildlife and highly toxic to aquatic invertebrates.â The risk assessment conducted by EPA for this new use states that âthe proposed use of imidacloprid on oyster beds in WA can result in residential exposure via potential contact with residues in oyster bed water or sediment during recreational swimming,â including Native American tribes and subsistence farmers.
Earlier this month, EPA announced a moratorium on new uses and products of neonicotinoid insecticides, however, imidaclopridâs use in Willipa/Grays Harbor precedes this new moratorium, and so will be allowed. Advocates have been calling a suspension of neonicotinoids due to their association with bee and pollinator decline across the country. This call includes an expansion of the moratorium to include products already on the market. Learn more at Bee Protective.
Under the new permit, the Willapa-Grays Harbor Oyster Growers Association must submit an annual operations plan for Ecology to approve before any use of the pesticide. Growers will be able to use pesticide on up to 1,500 acres of commercial tidelands in Willapa Bay and on up to 500 acres in Grays Harbor. It can be applied no more than once a year and only in low-wind conditions. Throughout the five-year term of the permit, Ecology will require growers to conduct water and sediment monitoring through a partnership with the Washington State University Long Beach extension research facility. For more on the permit see here.
But local residents are concerned that shellfish growers will apply imidacloprid irresponsibly and contaminate not just the oyster beds but surrounding areas as well. For instance, the permit will allow for aerial spraying so long as wind speeds do not exceed 10 miles per hour. However, pesticide drift -a concern with any aerial application, is worrying residents on the potential impacts to non-target organisms like pollinators and others. Other concerns include the contamination of oysters, fish, and other aquatic organisms in the Bay, as well as those consuming contaminated organisms.
For more information on the environmental impacts of neonicotinoids, visit What the Science Shows.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Chinook ObserverÂ
Photo Source: The Oregonian