Quantcast

Mosquito Spraying Ineffective and Toxic to Wildlife and Humans

Xerces Society

Scientists at the Xerces Society for Invertebrate Conservation sent a letter yesterday to the U.S. Fish and Wildlife Service asking that the agency abandon a proposed mosquito control project at the Bandon Marsh National Wildlife Refuge in Oregon. Although no public health emergency has been declared, and no existence of mosquito-transmitted disease has been found, a decision was made to spray about 10,000 acres in and around the refuge with two insecticides, Dibrom and MetaLarv S-PT. Both of these insecticides are toxic to a broad variety of wildlife.

Dibrom is intended to kill adult mosquitoes. The active ingredient is naled, an organophosphate nerve agent that is highly toxic to humans as well as to a wide range of wildlife. Drift from spraying can negatively impact pollinators such as honey bees, native bees and butterflies. This type of spraying is widely recognized as being an ultimately ineffective form of mosquito management, especially for a species such as the salt marsh mosquito (Aedes dorsalis), which is being targeted at Bandon, because it can fly 10 miles or more from its emergence site and will recolonize the treated area.

MetaLarv S-PT is a slow-release formulation of methoprene, a compound that mimics the naturally-occurring juvenile hormone in insects. Although much less toxic to humans than Dibrom, MetaLarv is highly toxic to aquatic invertebrates including dragonfly nymphs, aquatic beetles, mayflies, non-biting midges and crustaceans from copepods to crabs, and may be linked to developmental defects in amphibians.

“The Xerces Society has grave concerns with the chemical controls proposed for salt marsh mosquitoes at Bandon Marsh NWR and the Bandon area,” said Celeste Mazzacano, aquatic conservation director of the Xerces Society and lead author of the report Ecologically Sound Mosquito Management in Wetlands. “To say that the spraying will not harm animals is misunderstanding the true impact of these chemicals. There are much better ways to control mosquitoes.”

The current plan calls for spraying about 10,000 acres of marshland and forests around Bandon, including residential and recreational areas, despite the fact that there are no reports of mosquitoes infesting the beach or the town. This plan runs counter to the Fish and Wildlife Service’s own draft mosquito control policy which states: “we will allow populations of native mosquito species to function unimpeded unless they cause a human and/or wildlife health threat” (emphasis added).

It is also contrary to the widely adopted tenets of Integrated Pest Management, in which a thorough process of surveillance is conducted to determine the “hotspots” of mosquito larval development and those sites are spot-treated with the least toxic insecticide possible, when and as needed.
 
The plan has also not addressed the potential impact that spraying could have on shorebirds and song birds that use invertebrates as food as they migrate southward in September and October, or on the federally endangered western snowy plovers that inhabit coastal beaches year-round. Because of disruption of food webs waterfowl that migrate later in the fall could also be affected.

In addition, there is apparently no consideration of how this could affect fisheries. Both organophosphates and methoprene are directly toxic to fish, and many young fish feed on the invertebrates that would be killed under this treatment plan. MetaLarv is also highly toxic to young crabs as well as other crustaceans, and can cause abnormalities in development and reproduction at sublethal doses.

“This spraying project is not a solution and has long-term impacts and we call on the U.S. Fish and Wildlife Service to halt it,” said Scott Black, executive director of the Xerces Society and co-author of the report. “We urge the Oregon Coast National Wildlife Refuge Complex to develop a rational, environmentally sound and effective mosquito management plan for the Bandon Marsh area in accord with the tenets of Integrated Pest Management.”

Visit EcoWatch’s BIODIVERSITY page for more related news on this topic.

EcoWatch Daily Newsletter

Climate activists protest Chase Bank's continued funding of the fossil fuel industry on May 16, 2019 by setting up a tripod-blockade in midtown Manhattan, clogging traffic for over an hour. Michael Nigro / Pacific Press / LightRocket / Getty Images

By Julia Conley

Climate campaigners on Friday expressed hope that policymakers who are stalling on taking decisive climate action would reconsider their stance in light of new warnings from an unlikely source: two economists at J.P. Morgan Chase.

Read More
Protesters holding signs in solidarity with the Wet'suwet'en Nation outside the Canadian Consulate in NYC. The Indigenous Peoples Day NYC Committee (IPDNYC), a coalition of 13 Indigenous Peoples and indigenous-led organizations gathered outside the Canadian Consulate and Permanent Mission to the UN to support the Wet'suwet'en Nation in their opposition to a Coastal GasLink pipeline scheduled to enter their traditional territory in British Columbia, Canada. Erik McGregor / LightRocket / Getty Images

Tensions are continuing to rise in Canada over a controversial pipeline project as protesters enter their 12th day blockading railways, demonstrating on streets and highways, and paralyzing the nation's rail system

Read More
Sponsored
padnpen / iStock / Getty Images

Yet another reason to avoid the typical western diet: eating high-fat, highly processed junk food filled with added sugars can impair brain function and lead to overeating in just one week.

Read More
Horseshoe Bend (seen above) is a horseshoe-shaped meander of the Colorado River in Page, Arizona. didier.camus / Flickr / public domain

Millions of people rely on the Colorado River, but the climate crisis is causing the river to dry up, putting many at risk of "severe water shortages," according to new research, as The Guardian reported.

Read More
An alarming sign of an impending drought is the decreased snowpack in the Sierra Nevada Mountain range, as seen here in Christmas Valley, South Lake Tahoe, California on Feb. 15, 2020. jcookfisher / CC BY 2.0

California is headed toward drought conditions as February, typically the state's wettest month, passes without a drop of rain. The lack of rainfall could lead to early fire conditions. With no rain predicted for the next week, it looks as if this month will be only the second time in 170 years that San Francisco has not had a drop of rain in February, according to The Weather Channel.

The last time San Francisco did not record a drop of rain in February was in 1864 as the Civil War raged.

"This hasn't happened in 150 years or more," said Daniel Swain, a climate scientist at UCLA's Institute of the Environment and Sustainability to The Guardian. "There have even been a couple [of] wildfires – which is definitely not something you typically hear about in the middle of winter."

While the Pacific Northwest has flooded from heavy rains, the southern part of the West Coast has seen one storm after another pass by. Last week, the U.S. Drought Monitor said more Californians are in drought conditions than at any time during 2019, as The Weather Channel reported.

On Thursday, the U.S. Drought Monitor said nearly 60 percent of the state was abnormally dry, up from 46 percent just last week, according to The Mercury News in San Jose.

The dry winter has included areas that have seen devastating fires recently, including Sonoma, Napa, Lake and Mendocino counties. If the dry conditions continue, those areas will once again have dangerously high fire conditions, according to The Mercury News.

"Given what we've seen so far this year and the forecast for the next few weeks, I do think it's pretty likely we'll end up in some degree of drought by this summer," said Swain, as The Mercury News reported.

Another alarming sign of an impending drought is the decreased snowpack in the Sierra Nevada Mountain range. The National Weather Service posted to Twitter a side-by-side comparison of snowpack from February 2019 and from this year, illustrating the puny snowpack this year. The snow accumulated in the Sierra Nevadas provides water to roughly 30 percent of the state, according to NBC Los Angeles.

Right now, the snowpack is at 53 percent of its normal volume after two warm and dry months to start the year. It is a remarkable decline, considering that the snowpack started 2020 at 90 percent of its historical average, as The Guardian reported.

"Those numbers are going to continue to go down," said Swain. "I would guess that the 1 March number is going to be less than 50 percent."

The National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center forecast that the drier-than-average conditions may last through April.

NOAA said Northern California will continue deeper into drought through the end of April, citing that the "persistent high pressure over the North Pacific Ocean is expected to continue, diverting storm systems to the north and south and away from California and parts of the Southwest," as The Weather Channel reported.

As the climate crisis escalates and the world continues to heat up, California should expect to see water drawn out of its ecosystem, making the state warmer and drier. Increased heat will lead to further loss of snow, both as less falls and as more of it melts quickly, according to The Guardian.

"We aren't going to necessarily see less rain, it's just that that rain goes less far. That's a future where the flood risk extends, with bigger wetter storms in a warming world," said Swain, as The Guardian reported.

The Guardian noted that while California's reservoirs are currently near capacity, the more immediate impact of the warm, dry winter will be how it raises the fire danger as trees and grasslands dry out.

"The plants and the forests don't benefit from the water storage reservoirs," said Swain, as The Mercury News reported. "If conditions remain very dry heading into summer, the landscape and vegetation is definitely going to feel it this year. From a wildfire perspective, the dry years do tend to be the bad fire years, especially in Northern California."