Sustaining a thriving lobster fishery through science and community.
Service Learning in Action
In recent years several Bowdoin professors have been using service learning in their classes. Service learning combines academic learning of a subject with community service. Students work with a community partner and are given a real-world problem to tackle. This allows them to apply their theoretical knowledge to a project that will benefit a community group. The geology department has used service learning as part of the curriculum since the spring of 2000. This semester students worked on 12 projects with five community partners.
This article discusses one of these groups. To find out more about all of the projects, attend the Service Learning Poster Session in the Druckenmiller Atrium from 2 to 4 p.m., Friday, December 7.
It's 2:24 p.m. when four students and a scientist begin carefully making their way down the pebbleewn beach and into the shallow water of Lowell's cove. Low tide is at about 5 o'clock, so it's a bit early to find lobsters, but they're hopeful.
The students have been collecting and analyzing data to help Lobster Conservancy scientists determine what characteristics make a good lobster nursery. (Lobsters start out in a larval form and take years to grow to the size people are accustomed to seeing. They need a place to develop before heading out to sea as a larger lobster). As a reward for the hard work on the project this group of students got a trip to the hottest lobster nursery around, Lowell's Cove. Diane Cowan from the Lobster Conservancy joined them to talk lobsters - and track down a few as well.
This Harpswell cove, about 15 minutes from the College, is the best lobster habitat the Conservancy has found in Maine, Massachusetts or New Hampshire. Normally when Cowan visits a lobster habitat, she is searching for young lobsters to measure and record; this data is analyzed to inform scientists about the lobster fishery. Today, though, she'll help Jamie Holte '03, Ricardo Simmonds '04, Elizabeth Norton '05 and Chrissy Assad '05 gain a visual appreciation for lobster nurseries and their importance to Maine and to the lobster fishery. (Assad normally works with another group, but each group takes one member from another project group along to do field work, so that students are exposed to a number of projects.) Cowan is constantly instructing as she wades through the water: she explains the importance of not moving rocks on beaches, especially big ones, because they may be serving as shelter for a myriad of sea creatures; demonstrates how to tell a carnivorous snail from an herbivore, she talks about the habits of hermit crabs. She also promises that they will see some lobsters.
Scientists know that Lowell's cove is a great lobster nursery, and they know of others. What they aren't sure of is what characteristics determine that a particular spot will be a good nursery. Among the data students are examining are water temperature, the direction of incoming waves, exposure to open water, sediment, and distance to a depth of 30 meters (because that's the depth that lobsters will eventually want to migrate out to). The project will also help scientists to develop maps of the states nurseries and know better how to regulate and protect them.
At Lowell's cove, the mouth of the cove is far out and open to the ocean without the barrier of any small islands, which is helpful to lobsters in their larval stages since they travel with the waves away from the females in the ocean into the cove. A lobster starts out as an egg about 1 millimeter in diameter, and during the first larval stage looks more like a shrimp. They don't swim well at this stage and for the most part travel with the currents. When a lobster finally leaves its larval stage and reaches the first juvenile stage, it looks much like an adult, but is not yet male or female - at this point the lobster will fit on the end of a person's finger.
At first there are more snails and crabs to be found than lobsters. Cowan turns over rocks (and carefully replaces them) but there are no lobsters to be found. After tromping over seaweed and boulders to another side of the cove, the search is finally rewarded - a juvenile lobster, about 4.5 inches long. Diane, who is licensed to handle underage lobsters, measures it and lets the students get a good look before returning the lobster safely to his (or her) home.
The next lobster is much harder to find. Cowan is just about to replace a rock, when one of the students spots movement in the water. Finding lobsters often means watching for their antenna to surface or move the surface of the water, since the lobsters stay safely hidden close to the mud. This lobster is quite young and only about an inch long, yet a perfect image of an adult. The final lobster Cowan uncovers is much closer to legal size (and much more annoyed at being found). It manages to stay out of sight, seeming to know it is being watched, taunting Cowan with its waving antennae. When Cowan manages to pick it up, the lobster raises his claws up at her in anger - it's what they do when they feel threatened, Cowan says. After he's been measured and studied a bit, he too returns to his home beneath the large, flat rocks of the cove.
The tide has already receded another 10 feet or more, when the students prepare to leave. The next week they'll be back in the lab, but with memories of a face to face encounter with the residents of the nurseries they're studying.