Can clams help clean oil-filled waters?

WASHINGTON - Researchers at Southeastern Louisiana University are studying the lowly Rangia clam, common in the waters of Lake Pontchartrain, Lake Maurepas and other brackish bodies of water, to determine whether they can help in cleaning oil-polluted waters.

The research is an outgrowth of the work that Phillip Voegel, assistant professor of chemistry, and one of his students Caitlyn Guice performed last summer when they analysed water samples from the lakes as well as the clams themselves to determine if they absorbed any oil.

In the wake of the British Petroleum oil spill, they and several other Southeastern scientists performed a number of studies, evaluating water quality, assessing the health of several species of plants and animals, and conducting visual surveillance of the wetlands for oil contamination.

Guice has received a 2,300-dollars Louisiana Sea Grant Undergraduate Research Opportunities Grant to study the ability of the clam to remove hydrocarbon pollutants from natural water.

Voegel explained that clams are bottom-dwelling filter feeders, obtaining nutrients by filtering the water around them.

Although a food source for a number of aquatic species such as drum fish and crabs, the Rangia clams are generally small and not typically eaten by humans in the U.S.

“As filter feeders, these clams help to maintain water clarity and quality,” said Guice.

“We began studying them last summer as a possible marker for water contamination by the oil spill because they can concentrate hydrocarbons in their flesh,” she added.

The scientists’ thinking then turned to the possibility of the clams serving as a natural cleaning mechanism of waters polluted by oil or other possible contaminants.

“Looking at bio concentration of hydrocarbons by shellfish in this manner is a complete shift in thinking from the typical focus on food safety,” said Voegel.

“Successful completion of this project will provide new knowledge on the abilities of the Rangia clam to concentrate pollutants from the water and determine if and under what environmental conditions, this ability could be applied to the bioremediation of oil-contaminated sites,” he added.

He envisions the possibility of moving large caged pallets of the clams into oil-affected waters to assist in the collection of oil. The cage would prevent other species that feed on the claims from getting to them.

Guice will be looking at the effects of various environmental factors, such as the salinity levels of water, on the process of oil bio concentration in the clams.

Voegel said the information obtained in the study could lead to environmentally friendly methods that would use clams to clean lakes and wetlands that have been contaminated by oil.

“It is exciting to consider the use of existing biological resources that could help alleviate the damage that occurs when petroleum products are accidentally released into the environment,” he said.

Guice hopes to complete the project by December. (ANI)