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


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 Covering the bases with cover crops
01.10.2015 | American Society of Agronomy

nachricht Innovative seeding machine to speed up kenaf planting
23.09.2015 | Universiti Putra Malaysia (UPM)

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: Secure data transfer thanks to a single photon

Physicists of TU Berlin and mathematicians of MATHEON are so successful that even the prestigious journal “Nature Communications” reported on their project.

Security in data transfer is an important issue, and not only since the NSA scandal. Sometimes, however, the need for speed conflicts to a certain degree with...

Im Focus: A Light Touch May Help Animals and Robots Move on Sand and Snow

Having a light touch can make a hefty difference in how well animals and robots move across challenging granular surfaces such as snow, sand and leaf litter. Research reported October 9 in the journal Bioinspiration & Biomimetics shows how the design of appendages – whether legs or wheels – affects the ability of both robots and animals to cross weak and flowing surfaces.

Using an air fluidized bed trackway filled with poppy seeds or glass spheres, researchers at the Georgia Institute of Technology systematically varied the...

Im Focus: Reliable in-line inspections of high-strength automotive body parts within seconds

Nondestructive material testing (NDT) is a fast and effective way to analyze the quality of a product during the manufacturing process. Because defective materials can lead to malfunctioning finished products, NDT is an essential quality assurance measure, especially in the manufacture of safety-critical components such as automotive B-pillars. NDT examines the quality without damaging the component or modifying the surface of the material. At this year's Blechexpo trade fair in Stuttgart, Fraunhofer IZFP will have an exhibit that demonstrates the nondestructive testing of high-strength automotive body parts using 3MA. The measurement results are available in a matter of seconds.

To minimize vehicle weight and fuel consumption while providing the highest level of crash safety, automotive bodies are reinforced with elements made from...

Im Focus: Kick-off for a new era of precision astronomy

The MICADO camera, a first light instrument for the European Extremely Large Telescope (E-ELT), has entered a new phase in the project: by agreeing to a Memorandum of Understanding, the partners in Germany, France, the Netherlands, Austria, and Italy, have all confirmed their participation. Following this milestone, the project's transition into its preliminary design phase was approved at a kick-off meeting held in Vienna. Two weeks earlier, on September 18, the consortium and the European Southern Observatory (ESO), which is building the telescope, have signed the corresponding collaboration agreement.

As the first dedicated camera for the E-ELT, MICADO will equip the giant telescope with a capability for diffraction-limited imaging at near-infrared...

Im Focus: Locusts at the wheel: University of Graz investigates collision detector inspired by insect eyes

Self-driving cars will be on our streets in the foreseeable future. In Graz, research is currently dedicated to an innovative driver assistance system that takes over control if there is a danger of collision. It was nature that inspired Dr Manfred Hartbauer from the Institute of Zoology at the University of Graz: in dangerous traffic situations, migratory locusts react around ten times faster than humans. Working together with an interdisciplinary team, Hartbauer is investigating an affordable collision detector that is equipped with artificial locust eyes and can recognise potential crashes in time, during both day and night.

Inspired by insects

All Focus news of the innovation-report >>>



Event News

EHFG 2015: Securing healthcare and sustainably strengthening healthcare systems

01.10.2015 | Event News

Conference in Brussels: Tracking and Tracing the Smallest Marine Life Forms

30.09.2015 | Event News

World Alzheimer`s Day – Professor Willnow: Clearer Insights into the Development of the Disease

17.09.2015 | Event News

Latest News

New Oregon approach for 'nanohoops' could energize future devices

13.10.2015 | Life Sciences

Supercoiled DNA is far more dynamic than the 'Watson-Crick' double helix

13.10.2015 | Life Sciences

Breast cancer drug beats superbug

13.10.2015 | Health and Medicine

More VideoLinks >>>