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Science Wednesday: Biodiversity, Mosquitoes, and Health, Oh My!

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Each week we write about the science behind environmental protection. Previous Science Wednesdays.

It was 0630 and although the sun was beginning to rise, it was still very dark within the tropical forest. Following a 20 minute ride in a small boat, we had arrived at a remote trail on the island and were now navigating the trail to check the CO2/light traps set the night before. The illuminated traps were beacons in the sea of dark forest, and we hoped they’d be filled with mosquitoes. The forest was peaceful in the early morning light, except for the occasional bouts of grunting from the howler monkeys or an agouti crossing the trail.

I never imagined working at EPA would lead me to Barro Colorado Island (BCI), a former mountain top that became an island when the Panama Canal was created in the early 1900s. Now a natural monument, it was the setting of the inaugural sampling event for a joint project between EPA and the Smithsonian Tropical Research Institute (STRI).

The project explores the link between biodiversity, insect vectors (those capable of passing a pathogen one animal to another), and disease. The connection between biodiversity (the number and abundance of difference species) and disease is complicated, but we know that sometimes changes in biodiversity (specifically, the loss of structural diversity) can increase the abundance of certain disease-carrying vectors. In turn, this can increase the risk of humans coming into contact with the disease-transmitting vector. Human activities, such as encroaching into new areas to build houses or clear land for farming, can change local biodiversity.

The STRI-EPA project focuses on mosquitoes and how changing biodiversity in “natural” and anthropogenic landscapes affects vectors of public health importance.

Back at the lab, we began the monumental task of sorting through the traps’ contents. Thankfully, I was surrounded by insect experts who were able to show me exactly what to look for among the tiny copious critters. Microscope and forceps in hand, I started sorting and sorting…. Hours later, sorting complete, we separated mosquitoes and sandflies (another vector important to public health) by species into groups of 50 or fewer. Specimens were placed into vials and frozen. The samples will be analyzed later to see what kinds of pathogens the insects were carrying, if any.

image of author wearing orange lifejacket Over this next year, sampling will continue at BCI. We plan to expand sampling into nearby, land-disturbed areas inhabited by people so that mosquito diversity and disease risk can be compared with that of BCI.

About the Author: Meghan Radtke, Ph.D. is an AAAS Science and Technology Policy Fellow at EPA. Her fascination with biodiversity and tropical forests inspired her to join the Biodiversity and Human Health research effort.

Editor's Note: The opinions expressed herein are those of the author alone. EPA does not verify the accuracy or science of the contents of the blog, nor does EPA endorse the opinions or positions expressed. You may share this post. However, please do not change the title or the content. If you do make changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

EPA and the Smithsonian: Partnering in a Land Use and Biodiversity Study

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Each week we write about the science behind environmental protection. Previous Science Wednesdays.

In March 2007, an agency-wide Memorandum of Understanding (MOU) with the Smithsonian Institution (SI) was signed, recognizing a shared interest in collaborating to promote intellectual exchange and the advancement of education and outreach on a wide range of scientific topics.

One of the areas in which we have been working in partnership with the Smithsonian is in studying the relationship between land use, biodiversity, and human health. Smithsonian Tropical Research Institute’s (STRI) network of tropical forest plots is being developed into a system of Smithsonian Institution Global Earth Observatories (SIGEO), which has and will continue to provide critical scientific data about how tree biomass and biodiversity are responding and adapting to increases in atmospheric CO2 and global warming. In addition to modeling the global carbon budget, we recognized that SIGEO serves as an excellent platform to explore the dynamics and mechanisms underlying the relationship between anthropogenic stressors, changes in biodiversity, and disease transmission to humans because the sites have been so well characterized ecologically. EPA and STRI are working together to inventory and monitor important animal groups such as vertebrates and arthropods that can play important roles in human disease transmission.

Why is this a timely research opportunity? Mosquitoes are medically the most important group of Diptera, both in the numbers of disease agents they transmit and the magnitude of health problems these diseases cause worldwide, and climate change is predicted to expand vector range and exacerbate disease.

Our collaboration will use appropriate temperate and tropical plots that are part of the SIGEO network to assess the status and trends of mosquito species populations over time and evaluate whether infectious disease transmission risk is being altered in response to changes in climate and surrounding land-use. CDC has also joined as a partner to evaluate collected mosquitoes for the presence of arboviruses of public health importance and identification of the vector species they are utilizing in distinct habitats. Comparison of the findings from this study with an ongoing CDC study of arbovirus presence in nearby Guatemala will provide a better estimate of the risk of human and animal epidemics due to movement of zoonotic arboviruses throughout Central America. Mosquito monitoring will also add new information to Smithsonian’s MosquitoMap, a new web-based, geospatially referenced clearinghouse for mosquito species collection records and distribution models.

EPA is working with STRI, CDC, Smithsonian Museum Support Center, and the Gorgas Memorial Lab in Panama.

For more information on EPA’s Biodiversity and Human Health activities, see:
http://www.epa.gov/ncer/biodiversity

About the author: Montira Pongsiri, PhD, MPH, is an Environmental Health Scientist in EPA’s Office of the Science Advisor.

Editor's Note: The opinions expressed herein are those of the author alone. EPA does not verify the accuracy or science of the contents of the blog, nor does EPA endorse the opinions or positions expressed. You may share this post. However, please do not change the title or the content. If you do make changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.