Progress to Date


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Tagging and Recapture:
Approximately 100 lobsters with freshly extruded eggs have been tagged and released in 3 different years. If and when these lobsters are recaptured their temperature loggers can be read while still attached to the lobster and she can be re-released. While the temperature loggers can log data for 4 years, the loggers will be lost when the lobster molts, likely in the early summer. This is okay, however, because we are most interested in information about movement and temperature exposure in the winter. This is the first year of two year project, so more lobsters will be tagged next fall.

Berried female lobster. Lobsters extrude eggs from a pair of oviducts at the base of their ventral abdomen. Eggs are fertilized with sperm that the female has stored in a specialized pouch located between her walking legs. Once the eggs are fertilized they flow down the tail and stick onto the swimerettes. Eggs grow here for 6-13 months before they are released as pelagic larvae.

Logging Data:
When a berried female lobster is caught participants log data into a datasheet that is later sent to us.

Downloading data to the computer. Once data is retrieved from the temperature loggers onto the shuttle it can be downloaded to the computer. To download to the computer the data is transferred from the shuttle to an optical basestation which is connected to a computer. Data can then be visualized using BoxCar software.

Sample output of temperature logger data displayed in BoxCar software. Participants save this data with the number assigned to the lobster and date and send these files to us via email.

Examination of the Eggs:
Staging guide for lobster egg development. Using a mathematical equation developed by Perkins (1972) the incubation time (time of extrusion to hatch) can be predicted for certain water temperatures as long as the size of the eye spot of the eggs is known.

Example of eggs collected for this project. Currently we are photographing and measuring the eyespots of eggs collected during initial tagging of berried females.