New England lobstermen have gone high tech by adding low-cost instruments to their lobster pots that record bottom temperature and provide data that could help improve ocean circulation models in the Gulf of Maine.
Environmental Monitors on Lobster Traps, or eMOLT, is a partnership involving NOAA, the Maine, Massachusetts, Downeast and Atlantic Offshore Lobstermen's Associations, the Gulf of Maine Lobster Foundation, and the Marine Science Department at Southern Maine Community College (SMCC) in Portland, Maine.
The data collected from temperature sensors on the lobster pots and from GPS surface drifters deployed as part of the eMOLT program help ocean circulation modelers better understand processes in the Gulf of Maine, such as how lobster larvae and other planktonic animals and plants, including those that cause harmful algal blooms, drift and settle. This information may also help determine how ocean currents disperse, condense and transport pollutants, invasive species, and food for whales in portions of the Gulf of Maine.
“Local fishermen already spend their days at sea, have the biggest stake in preserving our coastal marine resources, and are the most knowledgeable of the local waters,” said Jim Manning, an oceanographer at the Woods Hole Laboratory of the Northeast Fisheries Science Center (NEFSC), part of NOAA's Fisheries Service. “They are interested, curious and enthusiastic to learn more about lobster science and the environment. It seemed like a natural fit, a win-win situation.”
The devices, which cost about $150 each, internally record temperature every hour around the clock while the pots are in the water. At the end of the season when the pots are hauled out, the instruments are removed and shipped back to Mr Manning in an envelope he provides. He downloads and processes the data and then puts the temperature information on the eMOLT website. Each lobsterman has his/her own personal web page to see the data from their own pots, while everyone including the general public can see the overall data collected each year.
One of the program’s successes has been low-cost surface drifters equipped with Global Positioning System (GPS) chips, developed by Mr Manning and since 2004 built by students in the marine science program at Southern Maine Community College (SMCC). The students build about 50 drifters a year, each costing about one third that of commercially-made instruments.
Close to 100 lobstermen have provided sensor data since the program started, and about 60 lobstermen have been long-term active participants. Mr Manning says he is a bit surprised but very pleased so many lobstermen are interested in the project. The eMOLT partners have contributed to a database with more than three million hourly temperature records, 80,000 salinity records, and 260,000 satellite drifter fixes (locations).
What’s next? Mr Manning says the partners are working on a real-time bottom temperature sensor attached to the traps that would wirelessly transmit data via satellite once the trap is hauled on deck. They are also working on a combined tilt metre-bottom current metre with digital compass to measure both bottom currents and the angle at which the trap rests on the seafloor. The information collected should provide insight in whether bottom currents affect how lobsters move, and whether currents influence lobsters to enter a trap. In the near future, Mr Manning would like to add sensors to measure oxygen, nutrients, and pH to determine ocean acidification levels in the region.
