Environmental monitors on lobster traps (eMOLT): long-term observations of New England’s bottom-water temperatures

Abstract

Nearly one hundred New England lobstermen have installed temperature sensors on their traps to record hourly values at fixed locations since 2001. These moorings are distributed primarily along the shelf edge in the northern Mid-Atlantic Bight and along the entire western edge of the Gulf of Maine in a range of water depths (1–300m). Variability associated with tidal, wind, seasonal, and inter-annual processes can be depicted at nearly all sites. Tidal variation, for example, at certain times of the year in many locations can be significant (>10°C). Wind forcing is shown to significantly modify the seasonal cycle at many locations such as in Massachusetts Bay where a dramatic turnover occurs in the Fall. Inter-annual anomalies are derived by removing seasonal cycles. Comparisons between sites and between years are made. The years 2002 and 2006, for example, are documented as warmer in general than other years at nearly all sites. While a direct correlation between temperature variability and lobster catch is difficult to quantify in the data collected thus far, preliminary investigations document the relationships on a seasonal time scale.

The possibility of incorporating this network of moored sensors into a regional ocean observing system is addressed and the limitations are discussed. Given the minimum cost required to deploy the instrumentation and the sustained interest of the fishermen, the initiative provides a means to collect data continuously and a strategy for monitoring environmental change on climatic time scales.

Additional information

Notes on contributors

J Manning

James P Manning has been employed as an oceanographer for the NOAA’s Northeast Fisheries Science Center for more than 20 years. After receiving his masters degree in oceanography from the University of Rhode Island in 1987, he has been investigating physical processes on New England’s shelf and their relationship to fisheries. In addition to working with local fishermen, he is particularly interested in providing data to local coastal ocean circulation modellers to help initialise, assimilate, and validate numerical simulations.

E Pelletier

Erin Pelletier has worked on eMOLT and a variety of other collaborative research projects for the last decade. As executive director of the Gulf of Maine Lobster Foundation, she coordinates, for example, extensive ‘ventless trap’ and ‘rope exchange’ programs with fishermen throughout New England. Trained in environmental education, she specialises in outreach to fishermen and helps them sustain their resource.