My PhD is focused on examining parasites and contaminants in marine birds, but the types of contaminants that can affect marine birds can number into the hundreds. To narrow it down a bit I am focusing my work on mercury. Recently I got my first PhD chapter published in the journal Environmental Reviews (free access courtesy of Environmental Reviews here), which is a review of mercury in marine birds in Arctic Canada. Here I give you a taste about what the paper is about.
Mercury is a known neuro-toxin that affects animals. This is why all those silver liquid filled (mercury) thermometers are no longer found in classrooms. Although liquid mercury is fun to play with as it sticks together, and many have memories of rolling those silver dollops around, long term exposure can have detrimental effects.
Recently, the need to limit and monitor global mercury was recognized with a new international convention, called the Minamata Convention. This convention is named for the small Japanese village where acute mercury poisoning was first intensively recognized and studied. The goal of the convention is to limit the production of mercury, and its release into the environments.
Mercury is a natural element but its release into the environment has been greatly increased since industrialization and fossil fuel combustion has occurred on a large scale. A major problem with mercury is that it doesn’t stay where it is released. Mercury can travel for thousands of kilometers through both water and air currents around the globe. Mercury pollution may be from some very specific sources and regions, but it is a global traveler, making it a concern for everyone.
What is troubling beyond the current production is that shifts in climate, such as melting permafrost and glaciers, is also releasing mercury that has been stored or caught in the ice. Understanding how these changing factors affect mercury release is key to predicting and monitoring mercury in the environment.
Not all birds have the same levels of mercury either. While ducks have some of the lowest levels in the Arctic, gulls have some of the highest. So high that some gull species have been listed among those species that may be impacted by their current levels of mercury pollution. This has to do primarily with their diets. While most sea ducks eat benthic prey (mussels, urchins), gulls often eat higher up the food chain and can be regularly found nesting within larger colonies of seabirds where they feed on seabird eggs and chicks whenever they can get them.
A – a common eider pair nesting on East Bay Island; B – a glaucous gull nesting in the thick-billed murre colony on Coats Island.
With such changes taking place not only is the health of ecosystems and birds important, but keep in mind that for many people birds are food. Studying contaminants burdens in birds is about understanding how these chemicals move through the environment and ecosystem, which includes humans. So with increasing levels, change global patterns, and the human health implications, mercury in marine birds is an important way we can study these changes. Fortunately, Canada has been a leader in mercury in marine birds studies. Now the task is too make sure that we stay a leader!
This article has been selected by Environmental Reviews as an Editor’s Choice award, and thus is free to all to download. You can access the full article here complimentary of Environmental Reviews.