Lobster Recruitment Index Project

Introduction: A primary research focus for the FSRS is the American lobster, an extremely important species to the Canadian East Coast fishery. Both fishermen and scientist members have expressed concern over the need for more science in support of lobster management. The FSRS has responded by initiating and participating in a number of research projects. A major focus of the FSRS lobster research program is lobster recruitment

In the spring of 1999, the FSRS launched a Lobster Recruitment Index Project. During the regular commercial season, fishermen use a particular number of scientific lobster traps to gather information about undersize lobsters in their area. Volunteer fishermen count, sex and measure the size of lobsters from their science traps and record them in a logbook. They also indicate if lobsters are berried, tagged, and/or v-notched. Participants also monitor bottom temperatures by placing a computerized temperature recorder in one of their project traps for the entire lobster season

The project has participants in all Lobster Fishing Areas (LFAs) along the Atlantic coast of Nova Scotia, from LFA 27 to LFA 34 (ranging from Cape Breton to southwest Nova Scotia), with over 180 fishermen in total. Each participant fishes two to five project traps, depending on the LFA. These project traps, which are fished in the same locations each year to minimize that variable, are in addition to the vessel's legal number of traps. All undersized lobsters are released after they are measured and sexed. Legal size lobsters can be kept by fishermen and help offset the cost incurred by fishermen to purchase the project traps.

Project Objectives: The project is designed to study changes in abundance of juvenile lobsters that will be recruited into the lobster fishery in the upcoming seasons and, as the project continues, allow an index of recruitment to be developed. Lobster fisheries in Atlantic Canada rely heavily on newly-recruited lobsters. Hence, we hope to be able to predict, with some degree of uncertainty, if there will be increases or declines for the commercial lobster fishery.

Trap and Gauge Design: It was decided that all participating fishermen should use a standard trap. The standardized science traps have two 5-inch entrance rings, 1-inch wire mesh, no escape vents, and a biodegradable ghost panel. This design was used to maximize the capture and retention of smaller size lobsters (Figure 1). Fisheries and Oceans Canada (DFO) support this research initiative and supply scientific trap tags for the project traps.

The fishermen use a specially designed gauge to measure the carapace length of captured lobsters within defined size intervals (Figure 2). The size groupings are coded from 1 to 15 and are in 10 mm increments, with the exception of size groupings 8 and 9 which are in 5mm increments to give a clear indication of the number of lobsters just under the legal size limit. In the project logbook fishermen can specify if a captured lobster was above minimum legal size within the size grouping which encompasses the legal limit (which can vary between LFAs in the study region, and over time as new conservation measures are introduced).

A total of 465 project traps were fished in the Spring 2005 season. All LFAs combined for a total of 16,221 total project trap hauls for the season.  A total of 46,875 lobsters were captured, sexed, measured and recorded by fishermen.  Fishermen captured an average of 2.70 lobsters per trap haul in 2005. Overall catch composition remains approximately 50% female and 50% male. There are large differences in catch rates across LFAs.

In the Fall 2004 season, 96 fishermen took part in the project in LFA’s 33 and 34; 244 project traps were fished.  A total of 4,814 project trap hauls were obtained in the Fall 2004.  Both LFAs combined for a total of 20,116 lobsters captured.  LFA 33 averaged 3.0 lobsters per trap haul in 2004 compared to 3.1 in 2003.  LFA 34 averaged: 6.0 lobsters per trap haul in 2004 compared to 7.5 in 2003.   The catch composition was approximately 50% female and 50% male.

The future direction also includes further collaboration with fishermen and scientists in the New England lobster fishery. In 2002, the Gulf of Maine Lobster Foundation (GOMLF) took on a Ventless Trap Survey. Their project had many similarities to that of the FSRS project and it was decided to hold a workshop to look at further standardizing the projects and developing a collaborative action plan

The Joint Fishermen and Scientists Research Society - Maine Lobstermen’s Association Collaborative Lobster Recruitment Research Workshop was held on February 19 and 20, 2003 in Halifax, Nova Scotia. The objectives of the workshop were to

• Review experiences with trap-based, short-term recruitment monitoring projects within the Atlantic Canada/Gulf of Maine region.
• Work towards a consensus on the best approaches for this research (including trap configuration and experimental design).
• Secure a future regionally-coordinated development path for these trap-based approaches in which lobster fishermen play a crucial role.
• Promote partnerships among regions of Atlantic Canada, and between Atlantic Canada and the Gulf of Maine region.

An advantage of the joint workshop was that it solidified the working relationship between the Canadian and USA groups. It also expanded the geographic scope of lobster recruitment research so that it is possible to get a more complete picture of what is happening in the lobster fishery along the east coast from Cape Breton, Nova Scotia to New England. The workshop report, which includes summaries of the FSRS, GOMLF, and other regional recruitment projects, can be found at www.fsrs.ns.ca/events/lobster_workshop2003.html.

Collaboration has enabled the FSRS and GOMLF to standardize the core components of the project such as trap and measuring gauge design, data collection, and data management. It also allows sharing of data and knowledge. Since the fishermen in both areas share the lobster resource, it seems logical to share the science. By working jointly, everyone can have more complete information for making decisions on resource conservation and management.