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

2009 September 16

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 here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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4 Responses leave one →
  1. Brenda-EPA permalink
    September 16, 2009

    Sounds really interesting!

  2. Michael E. Bailey permalink
    September 17, 2009

    This is important work that will have major public health benefits. The rain forest is a fragile organism and human interferance can cause serious damage including the proliferation of insect vectors that can spread contagian from animals to people. What we are doing in North America with greenhouse gas production is having a negative impact on the south and central American rain forests like the Amazon at the very time the forests are needed most to provide natural carbon sequestration. The GHG problem is probably as important as the slash and burn agriculture and the illegal logging, and narcotics manufacturing being done by local populations. Best wishes, Michael E. Bailey.

  3. Anonymous permalink
    September 24, 2009


    Thanks for your reply. I agree that green house gases, slash and burn agriculture, and many other local and not-so-local human activities are affecting the world’s rain forests. The fun (and challenging) part about ecology is figuring out the relationships among all the “players”. As you stated, the work is incredibly important and necessary if we are going to protect both the environment and humans.


  4. Naples Dentist permalink
    August 15, 2011

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