Lobster boat on Narragansett Bay. Photo courtesy of RIDEM.

The RI Department of Environmental Management (RIDEM) uses multiple monitoring strategies in the management of lobsters. Lobster harvests are tracked through the Commercial Harvester Catch and Effort Logbook program, which requires commercial license holders to record trips, areas fished, type and number of traps set, weight of catch, and intended use of the lobster. RIDEM also conducts trawls that collect data on adult lobsters, as well as other crustaceans and fishes; and lobster trap and diver-based surveys that collect data on adult and juvenile lobster.

The RIDEM Marine Fisheries Section conducts monitoring activities in cooperation with commercial lobstermen using modified lobster traps without escape vents or ventless traps as part of a regional program to characterize northeast lobster stocks. Typically, escape vents are required in commercial lobster traps to allow small lobsters beneath the legal size minimum to escape. Ventless traps prevent the small lobsters from escaping so they can be measured and then released. This survey was implemented to improve the characterization of lobster populations, particularly in shallow and rocky bottom habitats that are not currently sampled by RIDEM trawl surveys or other federal surveys.

RIDEM also conducts a diver-based young-of-the-year (YOY) settlement survey, which counts the number of lobsters hatched in the last year to help predict how the adult lobster population will change in the future. This survey is part of the larger Atlantic Lobster Settlement Index (ALSI), which incorporates similar YOY surveys from Rhode Island to Canada.  The ventless trap and YOY settlement surveys have been incorporated into the Atlantic States Marine Fisheries Commission (ASMFC) American Lobster Stock Assessment.

Implemented By

  • Rhode Island Department of Environmental Management, Marine Fisheries Section (in collaboration with commercial lobstermen)
The ventless traps used to collect data on lobster populations. Photo courtesy of RIDEM
Divers conducting YOY settlement surveys. Photo courtesy of RIDEM.

Restoring Lost Lobsters

In January 1996, the North Cape oil barge struck ground off the coast of Moonstone Beach in South Kingstown, releasing 828,000 gallons of No. 2 heating oil. The state and federal governments estimated that this spill impacted approximately nine million lobsters, and the natural recovery time for the lobster population was estimated to be four to five years. As part of the legal settlement with K-Sea Transportation, owner of the North Cape, for natural resource damages, the K-Sea Transportation agreed to conduct a lobster restoration project to compensate for the decreased lobster population over that 4-5 year time period.

V-notches on lobster tails is a no-harvest strategy used to protect the number of lobster eggs laid and increase future populations. Photo courtesy of National Oceanic and Atmospheric Administration.

The restoration project included release of nearly 1.25 million legal-sized female lobsters. Each of these lobsters had a v-shaped notch cut into its tail, and regulations were passed to protect v-notched lobsters from harvest so the female lobsters could produce eggs that would increase the lobster population in the coming years. After molting, the v-notch disappeared and the lobsters would become legal to harvest. In 2000, 300,000 lobsters were released near Point Judith, but monitoring showed that many of these lobsters were harvested from areas outside of Rhode Island waters. After v-notching occurred in accordance with the restoration plan, it was determined that many of these lobsters left the area and the agreed upon protection of the restoration project thereby voiding the hoped-for benefit of egg production. In 2001-2006, local lobster fishermen were paid to catch, notch, and release female lobsters with trained observers on board. This strategy distributed the lobsters over a larger area and improved compliance by actively engaging the lobster fishing industry. Analysis of the restoration impact indicated that the lobster population increased six percent each month during the restoration period; however, other population trends such as settlement of juveniles and the number of new adult lobsters that settled in the area continued a downward trend, indicating that improving the number of spawning females may not improve future population trends.