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

Nearly one hundred New England lobstermen have installed temperature sensor's 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 nter-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 degrees 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.