Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NOAA scientists find mosquito control pesticide low risk to juvenile oysters, hard clams

10.06.2014

Climate stressors, however, increase risk to shellfish

Four of the most common mosquito pesticides used along the east and Gulf coasts show little risk to juvenile hard clams and oysters, according to a NOAA study.


The study showed low risk of impacts from four common mosquito pesticides on juvenile hard clams -- but that risk increased with climate stressors such as hypoxia.

Credit: NOAA

However, the study, published in the on-line journal Archives of Environmental Contamination and Toxicology, also determined that lower oxygen levels in the water, known as hypoxia, and increased acidification actually increased how toxic some of the pesticides were. Such climate variables should be considered when using these pesticides in the coastal zone, the study concluded.

"What we found is that larval oysters and hard clams can withstand low levels of pesticide use, but they are more sensitive to pesticides if their ecosystem is suffering from local climate stressors like hypoxia and acidification," said the study's lead author, Marie DeLorenzo, Ph.D., NOAA environmental physiology and microbiology program lead with NOAA's Centers for Coastal Ocean Science. "Hopefully these data will benefit both shellfish mariculture operations and environmental resource agencies as they manage the use of mosquito control pesticides near their coastal ecosystems."

Commercial shellfishing has a large economic national impact. NOAA Fisheries estimated that U.S. oyster and hard clam landings for 2010 were worth nearly $118 million and $41 million, respectively. Shellfish growers, however, are concerned that pesticide spraying near the coastlines may contaminate both their hatcheries and source waters. This is compounded by a lack of data on the toxicity of mosquito insecticides for these shellfish.

These ecologically and economically important species inhabit tidal marsh habitats along the U.S. Atlantic and Gulf of Mexico coastlines. Clams and oysters are also important for the coastal ecosystem because they filter water, improving water quality, and serve as habitat and food sources for other estuarine species.

Approximately 200 mosquito species live in the United States. In addition to causing painful itchy bumps to people, mosquito bites can transmit serious diseases such as malaria, dengue fever, and West Nile virus. One approach to controlling mosquitoes is to apply pesticides by spraying from planes or trucks over a large area. However, to effectively control mosquitoes, the pesticides must target species which live in aquatic habitats that are also home to sensitive estuarine species. This may pose a risk to coastal environments. Also, since many residential communities where the pesticides may be used are near these coastal aquatic habitats, the potential for direct overspray or unintentional drift into these waters is increased.

The study sought to address a lack of toxicity data for mosquito control pesticide effects on shellfish early life stages. The research team examined the toxicity of four mosquito control pesticides (naled, resmethrin, permethrin, and methoprene) to larval and juvenile life stages of hard clams (Mercenaria mercenaria) and Eastern oysters (Crassostrea virginica).

Lethal thresholds were determined for the four pesticides, and differences in sensitivity were found between chemicals, species, and life stages tested. Overall, clams were more susceptible to mosquito control pesticides than oysters. Naled, an organophosphate chemical, was the most toxic compound in oyster larvae, while resmethrin was the most toxic compound in clam larvae. Decreased swimming activity was observed after four days in larval oysters and decreased growth was found in juvenile clams and oysters after 21 days.

Using a hazard assessment, which compared the toxicity thresholds to concentrations expected in the environment, the researchers calculated a low-level of risk to clams and oysters from application of these pesticides for mosquito control.

The researchers also tested the pesticides' toxicity under climate stress conditions. The more extreme climate conditions caused increased pesticide toxicity.

The study did not address the impacts of the pesticides on other shellfish such as shrimp or lobsters.

###

NOAA's mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter, Instagram and our other social media channels.

Ben Sherman | Eurek Alert!

Further reports about: NOAA larvae mosquito oysters pesticide pesticides shellfish species toxic toxicity

More articles from Agricultural and Forestry Science:

nachricht Microjet generator for highly viscous fluids
13.02.2018 | Tokyo University of Agriculture and Technology

nachricht Sweet route to greater yields
08.02.2018 | Rothamsted Research

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

'Lipid asymmetry' plays key role in activating immune cells

20.02.2018 | Life Sciences

MRI technique differentiates benign breast lesions from malignancies

20.02.2018 | Medical Engineering

Major discovery in controlling quantum states of single atoms

20.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>