Environmental Monitors on Lobster Traps (eMOLT)

Since the  summer of 1996,  thanks to the cooperation of three offshore lobster catchers, bottom water temperatures have been recorded on the southern edge of Georges Bank over periods of several months.  By simply tie-wrapping temperature probes (cigar size) to lobster traps,  hourly temperatures  were recorded at several sites.  The purpose of the pilot experiment was to access the interest of the catchers and test the feasibility of such a monitoring strategy. The initial results are encouraging. Examples of the types of variability are depicted in the three panels of  Figure 1, each from a different catcher. While little if any scientific conclusions can be drawn from the limited data set thus far, the concept of a cost effective partnership with local lobster catchers and application of small  temperature probe technology has been demonstrated.

Earlier this year we submitted a proposal to the Northeast Consortium (a group of academics from UNH and MIT who allocate NOAA funds) to expand this project throughout the Gulf of Maine.  The proposal was accepted.  The grant money (~$60k) will be evenly distributed among the four participating associations (Atlantic Offshore, Mass, Maine, and Downeast) and is expected to arrive sometime this fall.  The Gulf of Maine Lobster Foundation will manage the funds. The  executive directors of each association will purchase the equipment  (Figure 2) and distribute it to interested members.  The  scientific party (Jim Manning, NMFS Woods Hole) will be responsible for training a few individuals from each association, compiling the database, and maintaining the web site.  The association members will be responsible for installing the software, initializing the probe, downloading the data from the probe, documenting the deployments, and emailing the data to the scientific party.  After conducting their first successful deployment, they will  also be responsible for training at least one other member.  The complete procedure for conducting the computer operations is provided in a webserved document.

Probes can be left recording on any trap for nearly a year or, if the member wishes, can be detached and read  with every haul.   The deployment sites must be maintained for at least two months in order to provide adequate time series  for scientific purposes.  Additional sensors for salinity and pressure (depth) will be purchased and deployed by each association but temperature will be the primary variable to be recorded.  The biological variables recorded with each haul  (as part of "documenting the deployment") include  total weight of lobsters kept,  total weight of eggers, and total weight of shorts.   The temperature time series will be publicly available on the project website with associated graphics,  but site-specific catch information will NOT be disclosed.

The long-term scientific goal of our work is two-fold. First, a network of strategically-located bottom temperature records in the Georges Bank/Gulf of Maine region would make an important contribution to operational oceanography. Recent numerical modeling efforts to characterize the important physical processes of our coastal ocean are limited by near-bottom data in both initializing and validating simulations.  The oceanographic community  is now diverting a lot of effort to real-time forecasting of our coastal oceans similar to the weather service operations.  We are most interested in documenting episodic  "events" . In the case of Georges Bank, these events are often related to the presence of Gulf Stream rings. In the case of the Maine coast, they are often related to episodes of upwelling/downwelling, river runoff, and an influx of water Canadian source water.  Secondly, we want to understand the relationship of bottom water temperature and behavior of  Homarus americanus off the coast of New England  What are the scales of variability and what degree of variability can initiate a migration of the lobster population? We hypothesize that there is an annual migration of lobsters that is triggered by oceanographic events.

For detailed information on this project you can visit  emolt.html.  Note that much of the protocol is yet to be finalized.  Please check this site for frequent updates/changes in the coming months.

For further information contact: James.Manning@noaa.gov

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