New DMC researchers aim for better understanding of lobster lives, water quality

Carl Huntsberger and Whitley Gilbert are two new graduate students at the Darling Marine Center who would like their research to support better management of two of Maine’s most valuable natural resources—clean water and lobsters.

Huntsberger was 9 years old when he got his lobster license. He knew that a legal-sized lobster, also known as “a keeper,” is one whose main shell measures between 3-1/4 and 5 inches in length. Anything else, including egg-bearing females of any size, must be thrown back.

These days, Huntsberger, who grew up in Belfast and received his B.S. from Roger Williams University in Rhode Island, is no longer catching lobsters. He’s studying them, trying to find a more accurate way to determine a lobster’s age than size alone.

“I want to be able to provide data that will go into management decisions,” said Huntsberger. “But I don’t want to be in the fishery management office all the time, and I don’t want to be at sea as a commercial fisherman all the time. I want the mix.”

As a master’s student in the University of Maine’s School of Marine Sciences, he is conducting research on juvenile and adult lobsters in Professor Rick Wahle’s lab at the DMC to see if the number of rings that form on a part of a stomach called the gastric mill relates to their age.

“Our goal is to hold them for at least a year and be able to determine if rings are annual, molt-induced or caused by some other factor,” said Huntsberger. “Hopefully it will improve stock assessments for lobster.”

Gilbert is a graduate student in UMaine’s School of Earth and Climate Sciences. She is working toward a better understanding of water quality by studying nutrient loading in Casco Bay.

Nutrient loading is caused when upstream pollutants, such as fertilizers from lawns and farms, run downstream and eventually settle on the sea floor. In places like the Gulf of Mexico and Chesapeake Bay, massive amounts of nitrogen and phosphorus have caused bright green algal blooms that block sunlight, depriving the water of oxygen. These areas, called dead zones, can lead to large die-offs of fish and shellfish.

While the problem may not be as extreme in Maine, Gilbert pointed out that Casco Bay is next to Portland, one of the fastest growing cities in New England. Currently, the only model for determining nutrient loading in the bay is based on land use upstream. Gilbert’s master’s research, which is funded by the Casco Bay Estuary Partnership, takes a closer look at other possible factors, such as rainfall, drought and storms by sampling the water at the bay’s fall lines—where fresh water meets salt water—and comparing her findings with those based on the land-use model.

“If we get a better handle on the causes and effects of nutrient loading in Casco Bay, it can help land-use managers make decisions that will keep the water clean,” said Gilbert.

She believes another way to keep water clean is through better communication. While an undergraduate student at Iowa State, Gilbert worked with farmers who didn’t see the harmful downstream effects their farms had on the Gulf of Mexico’s shrimp fisheries. As a consequence, they didn’t see the need to change their farming methods to prevent that pollution.

“In the future, I’d like to be an intermediary between science and the farmer,” said Gilbert. “As a scientist you’re not supposed to be an advocate, but more and more scientists have to better communicate their results or they become misunderstood.”