Restoring Lobsters

A trained observer v-notches a female lobster while on a commercial vessel.

In order to bring back lobsters lost from the oil spill, the responsible party (RP) funded a large-scale program to restore lobster populations by marking their tails with a v-shaped notch. By a consent decree, the RP was required to v-notch and release 1.248 million legal size female lobsters. Once v-notched, these lobsters are protected by law until they molt, or change their shell, and the v-notch disappears. By this method, the reproductive lives of the lobsters will produce an estimated 17 billion eggs which will yield the 9 million lobsters lost by the spill.

During the first year in 2000, approximately 300,000 lobsters were released. Female lobsters were purchased from dealers, v-notched and released from a research vessel within a ten-mile radius of Point Judith, RI.

Restoration was expanded 60 miles offshore and 30 miles east. (Click to enlarge)

It was soon discovered, however, that within the immediate area of restoration, the catch rate of v-notch lobsters was increasing too rapidly; there were too many v-notched lobsters in too small of an area. In 2001, the RP started a new approach using trained observers and commercial fishermen to capture and release v-notch lobsters. With this new method, lobster fishermen that were involved in the program were paid for each lobster they v-notched and returned to the ocean. Restoration was conducted as far as 60 miles offshore and 30 miles east towards Martha's Vineyard. The v-notching area was expanded to increase lobster restoration efforts, attract new fishermen to the restoration program, and disperse the abundance of v-notched lobsters throughout the restoration area. From 2001 to 2005 the number of lobsters notched and returned to the ocean each year was approximately 38,000; 212,000; 123,000; 241,000 and 412,000, respectively. In 2006, just under 43,000 lobsters were notched, and the final 1.248 millionth lobster was notched by early summer.

Methods
Trained observers were assigned to lobster boats to accompany fishermen on their trips. As female lobsters were captured, they were inspected to determine eligibility, v-notched and released at their capture location. While onboard, observers also recorded recapture information of previously v-notched lobsters, including whether or not recaptured v-notches were carrying eggs or not. The success of the v-notch program is evident by the number of previously v-notched lobsters that were bearing eggs upon recapture.

A lobster is captured and given a unique identification number. When the lobster is recaptured, biologists can track the movement of the lobster, as well as gain other valuable data. The green rubber bands are removed before release.

To track movement of the v-notched lobsters, RP representatives and NOAA cooperated to complete a successful tagging project that was conducted in conjunction with the v-notch program. A percentage of the lobsters notched were also equipped with a special tag which identified that individual lobster. Over 35,000 individual lobsters were equipped with tags from 2003 to 2006. When the lobster was released, the location and date of capture were recorded. When a tagged lobster is recaptured, the date, the location of recapture, size of the lobster, shell condition and whether or not that lobster is carrying eggs or not is recorded. This recapture information gives scientists and marine managers valuable information such as migration patterns and survival of the animal. This type of information will aid marine managers in lobster management, to help ensure a strong lobster fishery in the future.

Assessing Restoration Success
In February 2007, the RC signed a contract agreement with University of Massachusetts, School of Marine Science and Technology to analyze the data obtained via these projects. The major objective of the analysis is to evaluate the success of the v-notch program in terms of increased egg-production provided due to v-notching. The final report of this work is due in August of 2008, with publication of results in a scientific journal anticipated. Also, during the v-notch program, an independent, 2-year tank study was designed and conducted by project participants to analyze the impacts of v-notching on the American lobsters. Those results have been submitted for publication in a scientific journal in April, 2008 and the manuscript is currently in review.

Recapture Analysis of American Lobster in Rhode Island Sound resulting from North Cape Oil Spill Lobster Restoration Project.

Information
For more information, please contact Bryan DeAngelis.