| Contributors | Affiliation | Role |
|---|---|---|
| Cowan, Diane | Principal Investigator |
Project Leader: Diane Cowan, The Lobster Conservancy
Additional Participants: Mathew Thomson, F/V Shearwater
Win Watson, University of New Hampshire
Matthew Weber
Andrew Solow, Woods Hole Oceanographic Institution
Mark Wallace, F/V Pamela B
Tim Thompson, F/V Haley & Amy
Bill Rourke, F/V A-Bill
Michael Reny
Richard Nelson, F/V Pescadero
Peter Murphy
Jon Murphy, F/V Redeemed
Steve Lash, F/V Streaker II
Troy Hayes, F/V Gray Ghost
Mark Havener, F/V Sarah Ashley
Philip Genthner, F/V Melinda Kay
Darrell Brazier, F/V Amy Sue
Nick Caloyianis, Caloyianis Productions, Inc.
Clarita Berger, Caloyianis Productions, Inc.
Richard Barter, F/V Tammy Jeane II
Kevin Benner, F/V Wanda Marie
Rex Benner, F/V Sydni & Erik
Denny Benner, F/V Maureen R
Jim Bolen, F/V Finest Kind
Philip Bramhall, F/V Amanda Kate
The Lobster Sonar Tracking Project was launched in late summer 2002, and was implemented for 2 tracking seasons. In September and October of the first season (2002) a total of 191 egg-bearing females were tagged: lobster IDs: 001 - 193. These lobsters were then tracked over the subsequent 13 months. In August and September of 2004 - the second season of the project - 45 egg-bearing females AND 41 males were tagged, a total of 86 lobsters: lobster IDs: 300 - 400.
Each lobster was tagged with three pieces of equipment: a sonar transmitter that emits a unique frequency/code combination, a temperature datalogger ("Tidbit") that records the ambient water temperature every hour, and a ribbon tag with the lobster's ID and The Lobster Conservancy (TLC) phone number to identify the lobster in the event of recapture. Participants were equipped with vessel-based hydrophones to periodically "listen" for sonar signals throughout their fishing territory. Frequency and code were recorded from each observed signal and the lobster ID was subsequently looked up. Hence, the tagged lobsters could be tracked any one of three ways: via hydrophone, trap recapture, or SCUBA dive recapture (using an underwater dive receiver). Information on lobster egg state could only be collected upon recapture. Likewise, temperature data collected by the Tidbit was only useful if the logger was recovered upon recapture and the information downloaded. Temperature data on 30 lobsters from the 2002-2003 season and 18 lobsters from the 2003-2004 season were downloaded as well as data from stationery loggers. Each lobster ID in that data object corresponds to lobster IDs in the associated data objects.
Project website: http://www.lobsters.org
Associated data: water temperature, lobster tracking data, and lobster recapture data
Lobster Tag Data:
South missing
4=dbl crusher
5=dbl seizer 0 if lobster is missing no appendages;
If appendages are missing (other than antennae), this is the number of missing claws,
plus legs, plus maxillipeds, plus uropods.
(see 'comments' for which appendages are missing) 4= hatching explanation of the use of this code)
Validity code:
There is obviously room for human error in the collection of these data, and potential equipment errors as well. Incorrect sonar codes can be recorded, data can be incorrectly entered into the database, and sonar tags can and have fallen off lobsters without the investigators' knowledge (they will continue beeping away on the ocean floor). Therefore, the most confident tracking data was collected on a lobster that was subsequently recaptured (with the sonar tag still visibly attached). Slightly less confidence was awarded to tracking data on a lobster that showed movement, but has not been subsequently recaptured to verify sonar tag presence. Least confidence and most suspicion exists for tracking data that indicates a sonar tag has not moved for some time, and the lobster has not been subsequently recaptured. This indicates a good possibility that the tag has fallen off. Furthermore, through spatial analysis of most of the individual lobster tracks in GIS mapping software, a number of specific data points were noted that were either highly suspicious or downright impossibilities.
If a recapture showed that the sonar tag was missing, then every prior tracking record for that lobster received a "transmitter detached" reflecting uncertainty as to when the tag was lost. "Disappeared" means the lobster was never tracked or recaptured. Based upon spatial analysis we were able to determine that some of the tracking entries were "invalid", while others were "suspect". These validity descriptions are complete for every lobster tracked during the first year of the project, but not yet complete for the second year.
Revised Sept 05, 2006; gfh
It was found that although small female lobsters were abundant in Muscongus Bay, most were not ovigerous. Small ovigerous lobsters tended to spawn and remain inside the bay where they brooded at lower winter, but higher spring and summer temperatures than large ovigerous lobsters. In contrast, large ovigerous lobsters (>size at 50% maturity) were relatively rare, but most were ovigerous. They tended to spawn at greater distances from shore and while many stayed near where they spawned, others achieved a maximum displacement of up to 240 km. Large ovigerous lobsters were at more moderate temperatures throughout the year regardless of how far they traveled. Both small and large ovigerous lobsters experienced (1) sufficiently low winter temperatures for successful ovarian maturation, and (2) approximately the same number of degree days for egg development. These findings suggest that known thermal requirements of optimal cold temperature for successful ovarian maturation are balanced with sufficient numbers of degree-days for egg development via two distinct behaviors. Small ovigerous lobsters remain in shallow water where they experience colder winter but warmer spring and summer temperatures than large ovigerous lobsters that move to deeper water with warmer winter but colder spring and summer temperatures."
"The purpose of this study was to investigate the relationship between temperature, movements, and body size for ovigerous (egg-bearing) lobsters tagged recently after spawning and tracked throughout the 9-13 month brooding period. We made predictions about where and under what temperature conditions small (< size at 50% maturity) versus large (> size at 50% maturity) lobsters would brood.
| File |
|---|
lobster_recap.csv (Comma Separated Values (.csv), 44.63 KB) MD5:febeb465c850fc7b48ffc93ce7e71251 Primary data file for dataset ID 2782 |
| Parameter | Description | Units |
| year | year in which lobster was recaptured | |
| yrday_local | day of the year, Julian Day, local time | |
| day_local | day of the month, local time | |
| month_local | month of the year, local time | |
| lob_id | lobster identification number; this number is on ID tag and TidbiT; | |
| lat | latitude where lobster was captured | |
| lon | longitude where lobster was captured, negative = West | |
| depth_w | depth of the water where lobster was captured | |
| bottom_type | brief description of bottom | |
| location_desc | information about where lobsters were recaptured | |
| sex | Male; Female; Unknown; | |
| eggs_present | Is the lobster brooding eggs? Yes or no | |
| num_eggs | none; very few; few; 1/2 gone; full; | |
| egg_color | clear; green; opaque; black; brown; light; eyed; orange/red; | |
| egg_stage | 0 = none | |
| num_claws | 0 = no claws; pistol | |
| sonar_tag_cond | none | |
| tidbit_cond | released = lobster released with tag still attached | |
| tidbit_download | False = A temperature data logger (TidbiT) was recovered,but failed for some reason. | |
| id_cond | yes = fine | |
| data_source |
| |
| validity_code | NSR = not subsequently recaptured; | |
| comments | Comments by trackers or comments related to the signal reception |
| Dataset-specific Instrument Name | Lobster Trap |
| Generic Instrument Name | Lobster Trap |
| Generic Instrument Description | A lobster trap (often called a lobster pot) is a baited trap which traps lobsters or crayfish and is used in lobster fishing. A lobster trap can catch multiple lobsters at once and can be a various sizes. An opening permits the lobster to enter a tunnel of netting and proceed into a "chamber" or "kitchen", where there is bait, and then into the "parlor" from which it cannot escape. |
| Website | |
| Platform | F/V Maureen R |
| Report | |
| Start Date | 2002-09-05 |
| End Date | 2005-05-20 |
| Description | Many fishing vessels were used for this dataset. Others include: F/V Finest Kind, F/V Amanda Kate, F/V Sarah Ashley, F/V Steacker, F/V Redeemed, F/V A-Bill, F/V Haley & Amy, F/V Pamela B. Most of these are based in Friendship, Maine, with the exception of F/V Maureen R, which is based in Waldoboro.
See Deployment Report for details. Methods & Sampling It was found that although small female lobsters were abundant in Muscongus Bay, most were not ovigerous. Small ovigerous lobsters tended to spawn and remain inside the bay where they brooded at lower winter, but higher spring and summer temperatures than large ovigerous lobsters. In contrast, large ovigerous lobsters (>size at 50% maturity) were relatively rare, but most were ovigerous. They tended to spawn at greater distances from shore and while many stayed near where they spawned, others achieved a maximum displacement of up to 240 km. Large ovigerous lobsters were at more moderate temperatures throughout the year regardless of how far they traveled. Both small and large ovigerous lobsters experienced (1) sufficiently low winter temperatures for successful ovarian maturation, and (2) approximately the same number of degree days for egg development. These findings suggest that known thermal requirements of optimal cold temperature for successful ovarian maturation are balanced with sufficient numbers of degree-days for egg development via two distinct behaviors. Small ovigerous lobsters remain in shallow water where they experience colder winter but warmer spring and summer temperatures than large ovigerous lobsters that move to deeper water with warmer winter but colder spring and summer temperatures." Processing Description "The purpose of this study was to investigate the relationship between temperature, movements, and body size for ovigerous (egg-bearing) lobsters tagged recently after spawning and tracked throughout the 9-13 month brooding period. We made predictions about where and under what temperature conditions small (< size at 50% maturity) versus large (> size at 50% maturity) lobsters would brood. |
The Northeast Consortium encourages and funds cooperative research and monitoring projects in the Gulf of Maine and Georges Bank that have effective, equal partnerships among fishermen, scientists, educators, and marine resource managers.
The Northeast Consortium seeks to fund projects that will be conducted in a responsible manner. Cooperative research projects are designed to minimize any negative impacts to ecosystems or marine organisms, and be consistent with accepted ethical research practices, including the use of animals and human subjects in research, scrutiny of research protocols by an institutional board of review, etc.
At the 2008 Maine Fisheremen's Forum, the Northeast Consortium organized a session on data collection and availability. Participants included several key organizations in the Gulf of Maine area, sharing what data are out there and how you can find them.
The Northeast Consortium has joined the Gulf of Maine Ocean Data Partnership. The purpose of the GoMODP is to promote and coordinate the sharing, linking, electronic dissemination, and use of data on the Gulf of Maine region.
The Northeast Consortium was created in 1999 to encourage and fund effective, equal partnerships among commercial fishermen, scientists, and other stakeholders to engage in cooperative research and monitoring projects in the Gulf of Maine and Georges Bank. The Northeast Consortium consists of four research institutions (University of New Hampshire, University of Maine, Massachusetts Institute of Technology, and Woods Hole Oceanographic Institution), which are working together to foster this initiative.
The Northeast Consortium administers nearly $5M annually from the National Oceanic and Atmospheric Administration for cooperative research on a broad range of topics including gear selectivity, fish habitat, stock assessments, and socioeconomics. The funding is appropriated to the National Marine Fisheries Service and administered by the University of New Hampshire on behalf of the Northeast Consortium. Funds are distributed through an annual open competition, which is announced via a Request for Proposals (RFP). All projects must involve partnership between commercial fishermen and scientists.
The Northeast Consortium seeks to fund projects that will be conducted in a responsible manner. Cooperative research projects should be designed to minimize any negative impacts to ecosystems or marine organisms, and be consistent with accepted ethical research practices, including the use of animals and human subjects in research, scrutiny of research protocols by an institutional board of review, etc.