Environmental Monitors on Lobster Traps

Annual Report

June 2003

PI contact information:

NOAA Northeast Fisheries Science Center, Woods Hole

Jim Manning, 508-495-2211, james.manning@noaa.gov

Atlantic Offshore Lobstermen

Association Representative:

    Bonnie Spinazzola, 603-483-3030, bonnie@offshorelobster.org

Industry Representative:

    Marc Palombo, 508-888-5714, calico@cape.com

Massachusetts Lobstermen

Association Representative:

  Dave Casoni, 508-224-3038, lobsterteacher@hotmail.com

Industry Representative:

Bernie Fenney, 781-447-0750

Maine Lobstermen

Association Representative and Gulf of Maine Lobster Foundation Director:

  Patrice Farrey, 207-985-4544, patrice@mainelobstermen.org

Industry Representatives:

 Art Vuilleumier, vuilleum@maine.rr.com,

 Jill Goldthwait, jillgold@acadia.net

Downeast Lobstermen

Association Representatives:

  Clare Grindal, 207-359-8025, dela@hypernet.com

Industry Representative:

  Jeremy and Charlene Cates, 207-259-3647, admissions@washingtonacademy.org


List of project participants:

 (as of June 2003)

3- "has probe(s)" and 4- "has probe(s) and has returned data":


4 Bennett Paul Newport RI

4 Campanale RobRoy Pt. Judith

4 Christopher Scott Pt. Judith

4 Colbert Bob Sandwich

4 Colbert Denny Sandwich Ma

4 Cote Bro Hyannis Ma

3 Handrigan Tim Pt. Judith

4 Mataronas Gary Tiverton RI

4 Moore Grant Westport Ma.

4 Palombo Marc Sandwich

3 Palombo William Newport, RI

4 Peabody John Pt. Judith

4 Shafmaster Jonathan Newington NH

4 Spencer David Newport

4 Stribley Russell New Bedford

4 Violet Jim Newport RI


4 Backman Ralph Beals Island

3 Bragdon Robert Winter Harbor Me.

4 Bridges Leroy Deer Isle

4 Cates Brian Cutler

4 Cates Jeremy Cutler

4 Chipman Roger Birch Harbor Me.

4 Chipman John Sr. Birch Harbor Me.

4 Dassatt Mike Belfast Me

3 Day Walter Vinalhaven

3 Farrin Clive BoothbayHarbor

4 Faulkingham Michael Winter Harbor Me.

4 Lemieux Norbert Cutler Me

4 Lemieux Nick Cutler

4 Robbins Stevie Stonington Me. 04681




4 Baines Bob Spruce Head Me.

0 Burch John Rockland Me


4 Carter Shane Bar Harbor Me

4 Carver Dwight Jonesport Me


3 Fernald Bruce Isleford Me

3 GOLTER JOE Greenland, NH

4 Gamage Arnold Jr. S. Bristol Me.

3 Hutchins Ed Cape Porpoise Me


4 Johnson David Long Island Me.


4 MacVane Tom Long Island, Me


3 Miller Dan Tenants Harbor Me

2 Morowski Robert Saco Me

4 NuddJr Bob Hampton NH

4 Smith Jay Nobleboro Me.

4 Thomson Mattie Monhegan Island Me

4 Tripp Jim Spruce Head Me.

3 Wells Mark Phippsburg

3 White Jeff York Me


3 Baldwin Lew Humarock

3 Barrett John Cohasset Ma

4 Brown Alex Provincetown Ma.

4 Carroll Emmett Chilmark Ma

3 Carver John Green Harbor Ma.

3 Carver Steve Green Harbor Ma.

4 Dauphinee Fred Scituate

4 Doherty Bill Hingham

4 Haviland John Green Harbor

4 Jesse Todd Plymouth Ma

4 Kandrick David Sandwich

4 Keane Stephen Marshfield Ma.

3 Mahoney Chad Hull Ma.

3 Manning Chris Hull

4 Marcella Bob Hull Ma

4 Martin Bobby/Rob Plymouth Ma

3 Mason Phil Marshfield

4 Oehme Kurt Sandwich

4 Ryan Skip/Chris Squantum Ma

3 Sauvageau Therese Beverly

4 Sawyer Arthur/Sook Gloucester Ma. 01930

4 Souza Billy Provincetown Ma.

3 Trowbridge Larry Scituate Ma.

4 Tufts Mike Glouchester

4 Tupper Mike Rockport Ma

2 Tooley Marybeth Camden

Project objectives:

With some modifications during the first few phases of eMOLT, our objectives have now stabilized. Taken directly from the phase III proposal,  by monitoring the temperature and salinity at dozens of fixed sites around the Gulf of Maine region, we hope to quantify the scales of variability.  One of the long-term scientific goals is to distinguish between advective and locally driven events that influence the bottom water conditions.  Given multiple time series along the coast and within different basins, we expect to track the influx and transport of remote source waters.

In subsequent years, with enough empirical information, one may build confidence in predictive models.  We envision a time in the future when eMOLT data will be used by local numerical circulation modelers to both initialize and validate their simulations.  As we approach the "drifter" phase of measuring circulation patterns along the coast (see phase IV proposal), we have become more committed in this respect by providing numerical modellers with observations of not only temperature and salinity but current velocity.

If interannual variations in temperature and salinity are limited to a few degrees and PPTs, can we document these changes with scientific accuracy?  What is the source of error in comparing the conditions at one site with the same site the following year? What constitutes a "site" and how precise must one be in reoccupying that site/depth?

Do changes in bottom water temperature and salinity explain the migration patterns and activity of Homarus americanus?   Many of our colleagues are interested in a correlation of lobster abundance and large scale climate signals such as the North Atlantic Oscillation.  As depicted in the records thus far (see figures in appended section), there are several episodic events over the course of the year but the dominant feature in this series is the longer trend.  After further investigation of historical temperature records,  it has become clear that the interannual and even decadal changes in temperature may be the more significant influence on lobster populations given that  the temperature effects may be most important during reproductive and larval stages of development. While episodic events may certainly be important in understanding the displacements and redistribution of lobster abundance,  the coverage of data necessary to resolve these  smaller scale phenomenon  would be cost prohibitive.  We are now committed to maintaining the eMOLT sampling and have consequently adjusted the focus of our investigation to both longer time scales and a larger region.

It should be clear, however, that we are still committed to documenting small time and space scales as well. Given the hourly records of temperature in a variety of places, we have already documented a large degree of temperature variability due to the semi-diurnal tides, for example. How does the tidal variation in temperature affect the lobster? Do they search for frontal features in the temperature and salinity field rather than an absolute value of a particular variable? This is a particularly interesting question that has come up regularly in discussions of the data collected thus far.   The lobstermen have evidently often focused fishing activity on thermal fronts as regions of high abundance and  capture.  As shown, for example, in Figure 3 of last years annual report the variations due to the tide can be depicted at any one site and the degree of variation changes due to a combination of the lunar cycle and weather events occurring at the time.  Is there something associated with a thermocline (food and prey availability) that attracts the animals to that zone?

Assessment of success at meeting the objectives:

The two most important conclusions at the time of this writing are that 1) the interannual variations in bottom waters of central and northern New England are apparently governed by large scale weather pattern such that the entire region responds in a coherent way and 2) the degree of interannual temperature change can be several degrees C. The signal in temperature change therefore is a few orders of magnitude larger than the noise/error associated with the instrumentation's accuracy. Now that three years of data are available at several sites within the Gulf of Maine (Figure 1), we can confidently conclude, for example, that conditions in early 2003 were significantly colder the same time in 2002. Most of the difference is apparently due to local heat flux rather than the changes in the influx of remote source waters. Given that the winter of 2002 was the warmest year on record (air-temperature wise) in New England and that 2003 was one of the coldest, it is no surprise that the subsequent springs resulted in warm and cold bottom temperatures, respectively. Given the large spatial coverage of eMOLT temperature records and the this coherent nature of their variability, it will be possible to make general statements on the gulf wide bottom temperature fields.

It is now possible, as demonstrated with computer animated graphics at annual forums this past spring, to visualize the hour-by-hour evolution of bottom water distributions in certain regions of our coast. These movie loops provide a revealing illustration of the power of the local wind in upwelling/downwelling cycles. The collection of over a dozen eMOLT records in Mass Bay, for example, together with the state of Massachusett's Division of Marine Fisheries records, demonstrated the episodic mixing and overturning that occurs in that area when the climatological summer wind is interrupted by periods of strong wind from the north. The abrupt warming of the bottom waters in early fall is evidently an annual occurrence but the timing of that event and the intensity of the change can vary from year to year.

What are the two most important sources of error associated with our data? How have we addressed each?