Sustaining a thriving lobster fishery through science and community.
Volunteer-based Juvenile Lobster Monitoring Program
The Juvenile Lobster Monitoring Program (JLMP) is TLC’s cornerstone community-based research program. The purpose of the JLMP is to measure the health and productivity of lobster nursery habitats over space and time. We do this by measuring the abundance and distribution of juvenile lobsters and using mark/recapture techniques to investigate growth rates and survival.
TLC scientists have developed a set of rigorous training tools to teach volunteers how to become “citizen scientists” by censusing lobsters at nursery grounds in the lower intertidal zone. Harboring “baby” lobsters under rocks, these nursery sites are accessible once a month during the lowest low tides.The census data collected by volunteers are extremely valuable as indicators of lobster fishery health because the juvenile lobsters of today represent the catches of tomorrow.
The Origin of TLC's Juvenile Lobster Monitoring Project (JLMP)
The Juvenile Lobster Monitoring Program was created by TLC’s founder and senior scientist Diane F. Cowan. It is an outgrowth of a project she initiated in 1995 when a group of community volunteers surveyed Harpswell's shoreline to identify the locations of lobster nursery grounds. That project was organized by the Harpswell Conservation Commission with support from the Collaboration of Community Foundations for the Gulf of Maine and the Coppedge Foundation. To this day, many of the original Harpswell volunteers are still active in the program.
In early 1997, The Lobster Conservancy received a grant from the Davis Conservation Foundation to develop the Town of Harpswell's Juvenile Lobster Monitoring Program (JLMP). This program involved training community volunteers to census intertidal areas on a monthly basis along the coastline of Harpswell, Maine for the presence of juvenile lobsters. This kind of censusing program is important because the location of nursery grounds of the American lobster was largely unknown until recently. The primary objectives of TLC’s community-based research are to identify and seek protection for coastal nursery habitats for juvenile lobsters by: (1) identifying the location and time of settlement of postlarval lobsters; (2) quantifying the abundance of juvenile lobsters inhabiting the intertidal zone; and (3) describing the basic ecology and behavior of early juvenile lobsters. Over time, intertidal lobster monitoring data can show which locations, months, and years are the most or least productive and may provide clues necessary for forecasting future lobster landings for particular regions.
Since 1998, TLC has been spreading the program throughout the Gulf of Maine including coastal Maine, New Hampshire, and Massachusetts. This project has now expanded to include more than 100 volunteers from all walks of life and several TLC staff censusing lobsters at more than 25 sites. Our volunteers include schoolchildren and teachers, retired scientists, lobster fishermen, restaurant wait staff, directors of the Maine Lobstermen's Association and Massachusetts’ Southshore Lobstermen’s Association, staff from various non-profits, etc. In Maine, TLC monitors lobsters in all 7 state-designated lobster management zones.
Counting lobsters in the intertidal zone: JLMP Methodology
During the lowest low tides of the month, juvenile and recently-settled lobsters can be found hiding under rocks in the lower intertidal zone. TLC scientists train volunteers to monitor lobsters using quadrat sampling. Volunteers are certified by means of written and practical tests. To strengthen hands-on training sessions, volunteers are provided with a field handbook and a volunteer training video.
Monthly sampling takes place between April and November. Volunteers record environmental data including weather, temperature of air, water and substrate, and water salinity. To sample for lobsters, they lay out a 20-meter transect tape and lay a meter-squared PVC quadrat beside the tape (below).
In each quadrat they record percentage rock cover and note presence of species of seaweed and marine organisms within the quadrat. They also record the density of green crabs, rock crabs and Asian shore crab. When volunteers find a lobster they carefully measure it, then record its sex, shell condition, and number of missing appendages. After data is collected, all lobsters are returned to their shelters.
In addition to work by volunteers, TLC scientists conduct long-term, year-round tagging studies at three of our monitoring sites to see how long juvenile lobsters stay in the intertidal zone, how much they move, and how much they grow over time.
Intertidal Lobster Monitoring: new paradigm, novel results
The lobster's habitat in the lower intertidal zone is especially vulnerable to disruption and destruction due to anthropogenic (human) activities. Why? Because houses and their septic systems abut such areas, human activities of land-filling result in sediment buildup that can cover over lobster habitat, people wash fertilizers and other pollutants into this zone, and garbage easily collects here. At the same time, because of its ease of access, this habitat represents an ideal site for scientific research focusing on questions we have been unable to answer concerning the projected future of an area's lobster stock abundance. For the first time, juvenile lobster populations can be censused throughout the year by monthly sampling at the same location, and year-round fluctuations in population size can be attributed to seasonal variations in behavioral patterns of the lobsters. By monitoring young lobsters, the JLMP can act as a barometer measuring the health and productivity of an area's juvenile lobster habitat. Observed changes in population size can therefore be attributed to actual variation in numbers of individuals present at one location. In contrast, the suction (vacuuming) sampling techniques that have been used subtidally disrupt the habitat to the extent that, with repeated sampling, the location begins to resemble a desert patch. Finally, sampling in the lower intertidal zone allows for the study of the same individuals over time. By recovering individually tagged juvenile lobsters, TLC is collecting the first data on natural growth rates and determining the degree of fidelity to "home coves."
The special benefits of the Juvenile Lobster Monitoring Program are many and varied. The JLMP uses standard, well-accepted ecological procedures to quantify general population dynamics of the American lobster. Previously, all quantitative sampling of any segment of the lobster population has taken place underwater. By taking advantage of the lobster's use of the intertidal zone as a nursery ground, we can now create a more complete database using inexpensive, accessible, readily available tools and techniques.
Perhaps, best of all, just about anyone with the time and inclination (and a good pair of boots!) can participate in this program. It's easy and it's fun. Involving volunteers of different age groups and backgrounds aids in community building and provides public access to scientific research and knowledge. This project can thereby help to bridge science and the public through hands-on training and accessible learning.