COASTAL
FISHERY RESEARCH PRIORITIES
AMERICAN
LOBSTER
(Homarus americanus)
Forward
Executive Summary
Prepared
by the
Gulf of Maine Aquarium
January 10, 2001
Table
of Contents
Acknowledgements
Our thanks to the many
people who have made this project happen. It would not have been undertaken without the commitment and vision
of Linda Mercer, Director of the Bureau of Resource Management at the Maine
Department of Marine Resources (DMR). Her
participation at every step of the way is an integral part of the final
product. Particular thanks go for her careful editing of the document.
Sue Inches, Director of Industry Development at DMR saw the
opportunity to get funding and has provided support throughout. Paul Anderson, Director of the Maine Sea Grant Marine Extension
Program (MSGMEP), provided funding and his planning skills, took excellent
notes, and generously contributed his staff. The staff of DMR and MSGMEP helped in the planning and in making both
the substance and the details of the meetings work. Finally, without the fishermen and scientists who attended the
meetings, this project would not have gone forward nor produced worthwhile
results.
Robin Alden
Don Perkins
Gulf of Maine Aquarium
MAINE DEPARTMENT OF MARINE RESOURCES
COASTAL FISHERY RESEARCH PRIORITIES
AMERICAN
LOBSTER (Homarus americanus)
I.
Background
The American lobster (Homarus americanus) fishery is Maine's signature fishery. It dwarfs all other fisheries in numbers of participants and value to
the state. In 1999 the dockside
value of the catch was a record $185 million, with an estimated economic
impact on the state economy of $500 million. There were 5930 commercial lobster/crab licenses in 1999.
Of those, 3,457 are estimated to be full time and 2,000 are estimated
to be part time.
Lobster abundance,
landings and value have steadily increased since the late 1980s. Prior to that, the long-term average landings had been in the
20 million-pound range. Landings
topped 40 million pounds in 1994 and were 53.5 million pounds in 1999.
In this respect, it is recognized worldwide as one of the few fishery
management success stories. Nonetheless, the federal government includes lobster on its
list of overfished species based on the estimates of fishing mortality rate
from the lobster stock assessment. The
discontinuity between this long-term increase in landings and concerns about
overfishing during the last 10-15 years has resulted in research into some
of the basic dynamics of the lobster population.
The role of lobstering in
the Maine fishery has changed during the last 20 years. Never before has lobstering so dominated the fishing economy
of Maine. This has taken place
through a combination of lobster abundance and various changes in technology
that drew effort into the fishery. It
has been exacerbated by a simultaneous loss of opportunities for Maine
fishermen in other fisheries such as groundfish and scallops as a result of
federal management plans. The
result is a change in Maine's coastal fishery from one that shifted between
various inshore fisheries seasonally and year to year, to a virtually single
species fishery and a dependence on lobstering that is unprecedented in
Maine fishing history.
Lobster management occurs
at a number of levels. Maine
regulates the fishery through both legislative action and Department of
Marine Resource regulatory action. The
state participates in interstate management through the Atlantic States
Marine Fisheries Service (ASMFC). ASMFC
decisions must be implemented in Maine through state action; however ASMFC
has the power to declare a moratorium on lobster fishing in the state if
Maine does not comply. The
National Marine Fisheries Service regulates the lobster fishery in federal
waters, in concert with ASMFC policy, but through federal rulemaking. Finally, instate, Maine has delegated some authority directly
to the lobster industry, which is one of the most significant examples of
co-management in the country.
The state is divided into
seven lobster management zones, each of which is divided into voting
districts of approximately 100 fishermen. Lobstermen elect representatives to a council that can set referendum
questions. Zones can decide by
referendum vote the number of lobster traps below the state cap, the number
of traps on a trawl, and the time of fishing.
Entry to the lobster
fishery is controlled through a two-year, on-board apprenticeship
requirement. In addition,
lobster zones have now been given the power to limit entry in the zone
through an entry/exit ratio. One
member from each zone council sits on the statewide Lobster Advisory
Council.
Maine lobster regulations
protect both juveniles and large lobsters through a dual gauge that includes
a 3 1/4" minimum measure and a 5" maximum measure. Lobstermen may voluntarily cut a v-notch in the tail flipper of an
egged-out female to mark it. That lobster is not legal to catch until the notch disappears
through successive sheds, usually after several years.
Lobster fishing in Maine
State waters and by Maine license holders is restricted to traps.
Maine lobster traps are required to have a vent to release undersize
lobsters. Trap dimensions are also regulated. The state has a statewide trap cap of 800 traps per boat.
One zone has imposed a lower trap limit of 600.
The 1995 imposition of
controlled entry, the trap limit, and the creation of the zone management
system may have been the largest single change in lobster management in
history. Each year since then,
further changes have been made in an effort to fine-tune the new system.
The change to
co-management with the lobster management zones is starting to create a
demand for local scale research, at least at the scale of the seven zones.
The lobstermen are now responsible for certain management decisions
and they are starting to generate research questions for their local area
and to seek monitoring, such as settlement test sites, in their zones.
There is potentially interest and energy in the zones for
collaborative information collection and monitoring.
II. The
DMR Research Priorities Project
These lobster research
priorities were developed as part of a larger research agenda-setting effort
conducted by the Maine Department of Marine Resources (DMR) for five of
Maine's major commercial species: clams,
lobsters, scallops, sea urchins, and shrimp.
Establishment of research
priorities was identified during the late 1990’s as a key strategy to
accomplish several of DMR's agency goals as well as the King
Administration's 1996 Jobs from the
Sea Initiative. The
ultimate purpose of the DMR research priority project is to ensure that
fishery management decisions are based upon the best scientific and
technical information so that Maine's marine resources are sustainable and
productive.
The articulation of
an agenda, however, will accomplish several other goals. First, by establishing and communicating a shared vision of
comprehensive research needs, it will stimulate the market for fishery
research that serves the state's needs. Second, DMR will be able to direct internal funding decisions
appropriately and identify and involve potential research partners from the
broader marine science community, including the fisheries and aquaculture
industries. Third, the agenda
should enable the entire marine science community to develop quick responses
to outside funding opportunities on topics that serve the state's needs.
The project was conducted
under contract by the Gulf of Maine Aquarium (GMA). It was funded by a planning grant from the Economic Development
Administration, the DMR, and the University of Maine Sea Grant Program.
The project was staffed by the GMA consultants, DMR and the
University of Maine Marine Extension Team.
III. Methodology
At least one, all-day
meeting was held for each fishery. The
meetings were designed to be non-regulatory, neutral, and inclusive
following a format developed by the GMA in previous efforts for other
species. The meetings brought together fishermen, academic scientists,
government scientists, non-governmental organizations, and fishery managers
as equals. They created
an open environment for curiosity and questioning. Seven meetings were held on five fisheries to achieve broad input
along the coast.
Four topics were chosen
for each species and scientists were invited to make short presentations on
each of the topics. Each of the
presenters was asked to write a short analysis on some aspect of the topic
or his/her research questions for the final report.
Meetings
ran from 9 a.m. to 5 p.m. with breaks and lunch provided. Each day was divided into four sessions, each on a specific topic
pertinent to the species. The format of the sessions was the same.
First, the group spent ten or fifteen minutes brainstorming the
questions they had about the resource. Then the invited presenter gave a short presentation on a selected
topic and on his or her major research questions about the species. The group then discussed the topic and the presentation, generating a
list of questions that were summarized by one of the facilitators for later
ranking. At the end of the day,
one half hour was spent in an informal ranking process where everyone was
given 10 sticky notes to stick by the topics of their choice. The day wrapped up with an oral evaluation and discussion of
follow-up and ways to improve the process.
Publicity for the meetings
was customized for each fishery. Methods
included direct mail to license holders, personal contact with association
leaders, and posters distributed to sites in each town. All of the meetings were covered in press releases to local and
statewide papers.
IV. Lobster
Research Priority Meetings
Two lobster meetings were held: April 25, 2000 at the Samoset Resort in Rockport, and April 27, 2000
at the White Birches in Ellsworth. Both
meetings were held from 9 a.m. to 5 p.m. Topics and presenters included:
April
25:
1. Oceanography Dr. Lew Incze, Bigelow Laboratory
2. Spawning/ Life
History Dr. Rick Wahle, Bigelow Laboratory
3. Assessment
Carl Wilson, Department of Marine Rescues
4. Socio-economics
Dr. James A. Wilson, School of Marine Sciences, University of Maine
April 27:
1. Oceanography
Dr. Lew Incze, Bigelow Laboratory
2.
Spawning/ Life
History Dr. Rick Wahle, Bigelow Laboratory
3.
Assessment
Dr. Paul Rago, Northeast Fisheries Science Center
4.
Socio-economics
Dr.
James A. Wilson, School of Marine Sciences, University of Maine
Thirty people attended the
April 25 meeting at the Samoset Resort and 36 people attended the April 27
meeting at the White Birches in Ellsworth. Attendees included lobstermen, lobster dealers, representatives of
Maine Lobstermen's Association, Downeast Lobstermen's Association, Maine
Import Export Lobster Dealers Association, and Stonington Fisheries
Alliance, DMR managers and biologists, and researchers from the University
of Maine, Bigelow Laboratory and Northeast Fisheries Science Center.
V. Lobster
Report Format
Results of the meetings
are presented in two different formats:
1)
The priorities voted by the group (Section VI) which are presented
with context; and
2)
A detailed, categorized listing of questions, observations, and
opinions articulated during the discussion (Section VII).
The dual format is
necessary in order to capture the richness of the meetings. The priorities organize thought and focus effort.
The details are essential because it is the local observations and
questions that provide the raw material of good scientific hypothesis.
Although the lobster meetings were divided into four segments: Oceanography, Spawning/Life History, Assessment, and
Socio-economics, the report is not structured around those categories except
where it makes sense. Many
topics, such as oceanography, growth and reproduction were raised in several
of the segments. Therefore we
have given precedence to the priorities articulated at the meeting rather
than those used to organize the meeting. Furthermore, we have not attempted to categorize the research
questions by scientific discipline. Under
a given priority one might find questions for oceanographers, basic
biologists, and economists or anthropologists. The solutions to these problems require collaboration between
disciplines and between science and industry. The first step is to articulate the questions in such a way that
researchers and industry are exposed to the question's rich context.
In every workshop there
were questions and suggestions about management process and communication
between fishermen, scientists, and managers. We have included these observations and suggestions in the report.
We have not included specific suggestions for management measures
because those fall outside the scope of this study.
VI. Priority
Research Questions
Research
Context and Group Research Priorities
Lobster research
priorities are driven by the tension between the federal/ASMFC determination
that the lobster fishery is overfished and the increase in abundance and
landings in the last 20 years. Overfishing
is defined as that stock level where the estimate of egg production per
recruit (EPR) is 10% or less of that in an unharvested population. Currently the Gulf of Maine is at 3.2% EPR and is deemed to be
overfished. Simultaneous
predictions of stock collapse and record abundance result in fundamental
questions: Why do we have this abundance? Where are the bottlenecks for this population?
Does the population really have egg production that is too
low? What is driving
recruitment? What effect do
large and fine scale oceanographic events have on the population?
At both meetings participants stressed the need to
integrate Canadian research efforts and findings into our own.
Lobster Priority
1: Oceanography
The source and sink for lobster larvae remains the
dominant research question for the lobster industry. This is an area that has had considerable research attention in the
last 15 years and that work has yielded new insights that in turn are
producing new areas of research. Management
questions about the relationship of the inshore and offshore lobster stocks
and the value given in the assessment to the V-notched and oversize lobsters
off the Maine continue to make this research directly pertinent to the
future of the Maine lobster industry.
Priority research needs are:
a) Determine the lobster broodstock source for larval settlement and
harvest areas and the relationship and relative contributions of the inshore
and offshore broodstock.
b) Study nearshore oceanography to understand its impact on larval
transport and settlement for lobsters.
c) Study the effect of water quality on lobster reproduction, growth,
and health including chlorine, herbicides and pesticides, and nutrients.
d) Are there large-scale oceanographic or climatic influences causing
the reduced lobster larval settlement in the last five years? If so, through what factors or mechanisms are those influences
operating?
“Oceanography figures strongly in the early life history of lobsters
because the larvae and postlarvae must survive (so growth rates, prey and
predators matter) and because the strong residual flows in the Gulf
transport larvae potentially long distances.”
Lewis
S. Incze, Ph.D.
Attachment
B
|
Lobster Priority 2: Assessment
The lobster stock
assessment is the focal point of all of the disagreement about lobster
population dynamics. As a
result, for the lobster industry, the assessment provides the lens through
which they see lobster science questions. There is interest in both improving the data and assumptions that go
into the model and developing new models. In the process of improving data, there is interest in developing new
ways to monitor the health of the lobster population.
New indices that were
discussed included larval surveys, post settlement surveys, and ventless
trap juvenile surveys. Fishermen
are interested in participating in the ongoing monitoring and concerned that
the modelers involved in the assessment be able to use the information.
Maine dominates the
fishery in New England but until recently, little data from the Maine
fishery was integrated into the federal stock assessment. Two types of data were missing:
biological information about the make-up of the stock and fishery
independent data. In the last
few years, that has started to change. Sea sampling is particularly important in the lobster fishery because
the fishery is regulated to prohibit landing juveniles, breeders, and large
adults. For this reason, port
sampling or landings data will not provide information about those elements
of the population. Maine has
had a limited sea sampling program for years, but data from it was not used
in the federal process. Now
Maine has expanded its sea sampling, including an ongoing experiment with
electronic data gathering and is providing the information to the assessment
process.
Fishery independent data is meant to provide an index
of abundance and normally comes from a trawl survey. Maine and New Hampshire have been the only New England states
without an inshore trawl survey. Furthermore,
the federal survey does not come very far inshore in the eastern Gulf of
Maine because of the bottom topography. As a result, fishery independent information has been missing from
the most productive area for lobster in the Gulf of Maine. In 2000, Maine is initiating an inshore trawl survey.
Priority research needs are:
a) Document lobster abundance in Maine fishing areas through fishery
independent means such as a trawl survey.
b) Research lobster stock structure and migration patterns so that
management areas can be made consistent with stock structure.
c) Explore new models for lobster assessment and incorporate into models
multiple indicators of stock health including results of new collaborative
monitoring.
d) Systematically improve research on inputs to the lobster assessment
model such as natural mortality, growth rates and age, size composition of
population and catch, measurement of fishing effort, lobster behavior and
migration.
“There
is a need for targeted onetime research, such as developing a technique to
age lobster, but we must remember that consistent monitoring programs are
the cornerstone for assessments.”
Carl
Wilson
Attachment
C
“…these
biological attributes have important implications for harvest policies …
A heavily armored species that lives for 50+ years, produces a relatively
small number of eggs, and attains a large size must have evolved under
environmental conditions that favored such characteristics.”
Paul
Rago, Ph.D.
Attachment
D
|
Lobster Priority 3: Life
History and Behavior
As with all crustaceans,
there is no established technique to age lobster. This puts a premium on studies of lobster growth because without
better understanding growth rates, there is no way to link the settlement
survey information to later harvest information.
Research in the last five
years has demonstrated a strong positive relationship between the number of
lobster post larvae in the water, and the number of juvenile lobsters on the
bottom in that area. That work,
and another time series that started in 1989, has shown a downturn in
abundance starting in 1996. Does
this predict a downturn in the fishery in the next few years? If so, why is it occurring?
Priority research needs
are:
a) Improve the understanding of lobster growth rates, particularly of
juveniles, in order to be able to link strength of post settlement year
classes to future catch.
b) Improve/develop better sampling procedures to monitor juvenile
lobster abundance: fishery
independent and fishery dependent.
c) Understand migration and movement of lobster post larvae, juveniles,
and especially broodstock.
“To
what extent does egg production in one area contribute larval settlement
and harvests in another? The
exchange of lobsters among stock assessment areas, in-, off- and along-shore, remains poorly understood.”
“However,
trap-and trawl-based samples have their own problems related to
size-selectivity and differences in sampling efficiency on different
habitats. These biases need
to be evaluated and corrected-for in order to relate data collected by the
different methods.”
Richard
A. Wahle, Ph.D.
Attachment
E
|
Lobster Priority 4: Socio-economic
Issues
If lobster landings fall
even to the long-term average, they will be reduced by more than 50% of
current landings. This
situation will pose serious social and economic problems for the coastal
communities that are now so dependent on lobstering.
Articulation of economics
and policy research questions is not as familiar turf for the industry as
are biological and oceanographic questions. Economic contingency planning for an almost guaranteed eventual
downturn received highest priority from the group. A first step in this planning process is information gathering about
debt load in the industry, since that will determine the capacity of the
industry to respond to lower landings.
In addition, considerable
discussion occurred about the fact that normal economic studies of the
industry miss significant subtleties about the business that, in fact,
determine behavior. The
industry wants policy makers to understand the nature and significance of
the variation that exists within the industry: there are many different business strategies, situations, and
expectations that occur. It
also wants documentation of the profound changes in lobstering since the
1950s. Those changes include
the shift from making a living to seeking the good life, dramatic changes in
technology from haulers to wire traps to electronics. When combined with technological changes, the abundance of lobster
resulted in it being much easier to succeed lobstering, so the business saw
a pulse of new effort. These
changes have undermined a number of the traditional checks on the business,
including the integrity of the informal territories.
The democratic zone
process is a huge experiment in democratic resource management
decision-making. It has had a
rocky start, yet the participants at the lobster meetings did not place a
high priority on improving the functioning of zones. Much of the discussion was about zone issues, but the group did not
identify types of socio-economic work that could assist the process.
Priority research needs
are:
a) Prepare a comprehensive response plan in the event of a sharp
decrease in lobster landings and recommend actions to prepare the industry
and coastal communities prior to a downturn with particular analysis of the
impact of current debt load.
b) Strengthen industry input and participation in science from the
lobster management zones so that it becomes a continuous, ongoing process.
c) Describe the lobster fishery:
economics,
the many different businesses and fishing strategies that exist within the
industry, effect of loss of alternative fisheries, and changes since 1950s.
d) Provide social and economic descriptive material about the lobster
fishery to support state interests in federal and interstate management
arenas.
“It
is quite likely that the current high lobster harvest levels will start to
decline sometime in the near future … What steps can the industry and State take to generate warnings of
this decline and what options do the State, the zone councils and the
industry in general have for responding to this decline?”
James
A. Wilson, Ph.D.
Attachment
F
|
Additional topics:
Two issues that were not part of the planned discussion
were given high priority by the participants:
1. Lobster health and disease issues.
2. Research into the hypothesis that lobsters are being
"farmed," fed by the high number of baited traps on the bottom.
Finally, two ideas were discussed that
could serve as organizing principles for a major research project were
discussed.
1. “Year of the Lobster:”
a
bilateral, one-year, intensive, sampling project that would involve many
researchers and industry members in both United States and Canada.
2. Role of Technology: an
expanded study of the quantitative and qualitative issues, such as the
impact of changed fishing patterns, in documenting lobster fishing effort.
VII.
Lobster Observations and Questions from Discussion
Assessment models
Need a new, better
definition of overfishing. Canadians
use a different one.
Incorporate multiple
measurements into definition of overfishing.
Overfishing designation in
light of increased landings and high abundance creates a credibility
problem.
Look at alternative
assessment models used internationally.
Use multiple indicators to
track and assess trends. Add other measures, indices to stock assessment.
Assessment should provide
information about the strength of incoming year classes. Fishermen would buy in to recommendations and effort could be
adjusted to size of year class (as is done in the shrimp fishery).
Develop spatially explicit population models that
evaluate the consequences of meta-population dynamics to the sustainability
of the resource.
The three ASMFC management
areas are a problem because the movement of larvae and big lobsters between
areas and inshore, offshore, and along shore is poorly understood.
Assessment
Surveys, Indices, and Inputs
Maintain a regional time series of oceanographic data
and abundance indices for juvenile, pre-recruit, and harvestable segments of
lobster life history. From
that data time series, evaluate the power of oceanographic data, and
juvenile and pre-recruit abundance indices to predict harvests.
Develop coast wide larval
monitoring plan using independent monitors (fishermen).
Tagging and monitoring
experiments that involve fishermen should be ongoing all the time. Fishermen who have fished more than 50 years will say they know less
at the end than they did at the start. There is so much to learn.
Use urchin divers to get
information on sublegal lobsters.
Continue development of
ventless trap survey method.
Continue development of
onboard computer data collection system.
Characterize the seasonal and spatial pattern of
fishing effort and landings using electronic reporting.
Monitor indicators of population stress
-
Fraction of newly molted lobsters in total landings|
-
multiple recapture rates
-
incidence of disease
-
Indicators of non-lethal gear encounters— e.g., culls
-
reliance on recently mature lobsters for egg production
-
identify zones or pockets of declining catch rates
Conduct large-scale experiments such as closing an area
and comparing it to an appropriate control area or doing comparative
analyses with Canada, zones within Maine, etc.
Need more fisheries
independent data, such as one get from a trawl survey, because it would give
an independent measure of abundance.
Maine should contribute
more sea sampling data to the stock assessment process: both current and historical information.
Need more test sites in
local areas.
Need assessment more often
than every five years.
Incorporate Canadian
information into assessment.
Need better landings
statistics.
Need better estimates of
abundance at each stage: early
settlement, juveniles, recruits into harvest, oversize. At each stage need to know abundance, movement, distribution,
mortality.
Do inshore surveys in the primary fishing areas for
better abundance estimates
Develop new monitoring methods for fishery independent
surveys such as trap surveys, photographic, mark-recapture etc.
Develop fishery-dependent surveys such as ventless
traps.
Develop a better
description and measure of fishing effort.
Communication
Juvenile traps should be
given to lobstermen. These
concrete observations are necessary in order for fishermen to believe what
science is saying.
Research results should be
easily accessible to everyone, including Canadian information.
Create opportunities for dialogue apart from regulatory
environment.
Need to build trust between fishermen and researchers.
Currently, when landings are high, lobster is said to
be overfished. When lobster
landings decline, lobsters are also overfished. Creates credibility problem.
Goal of achieving at least F10 is seen as unrealistic.
Disease
Overpopulation of lobster
is leading to disease. Increasing
the egg production could be a disaster.
Monitor lobster health in
light of experience in Long Island Sound.
Ecology
What effect does the huge
number of seals, shags have on the lobster population?
What is the effect of boat
traffic on post larvae?
Need more focus on
understanding how the system works and the interactions between species than
fine tuning the assessment.
What are the effects of
other fisheries on the lobster fishery?
Are traps harmful or
helpful in protecting from predators, providing feeding stations?
Ghost gear is a critical
issue. Need a policy to allow
it to be harvested and salvaged.
Effort
How has fishing effort
changed over time? Characterize
and quantify the important changes in the fishery such as the change from
wood to wire in traps.
Need to better
characterize and measure fishing effort.
Gear technology has a huge
effect on effort. (Wood vs.
wire, heads, etc.)
Economics (price) affects
effort. If price goes down,
effort will slack off.
Environmental
issues
What is the effect of
sewage treatment chemicals, nutrients, herbicides, and pesticides on lobster
populations?
What are the effects of
spraying for brown tail moth, golf course chemicals on lobsters?
What is the impact of
global climate change on the lobster population?
What are the effects of
dredging and dumping on lobster populations?
Why is the population high
in Boston Harbor when surrounding areas are down?
What is the effect of
salmon farms on water quality and the lobster population?
Growth
What is the effect of bait
on the lobster population? Will
rawhide bait have negative effects?
Need studies of growth
rate: post larval, immediate
pre-recruits (juveniles) in
order to be able to link strength of post settlement year classes to catch.
Determine the age-size relationship regionally,
especially the variance in size with age. Continue to search for
more reliable indicators of age than body size.
What is the role of
climate and environment on sex of lobsters? They are not differentiated until they are 9 mm.
Life History
Effect of bait on lobster
population. Are lobsters
dependent on it?
Test the effect of bait on
lobster population and growth rates.
What is the effect on the
population of taking offshore egg bearers?
What is the effect of
inshore spawning lobsters on the population?
Document frequency of
egg-out, molting, and multiple egging out.
Increase the number of
lobster settlement test sites at least to one per zone.
Intertidal monitoring,
less expensive, tracks with data from subtidal zone.
What factors affect larval
survival?
Management
Study the effect of
increasing the minimum sizes.
Evaluate effect of Maine
conservation measures by comparing Maine and Rhode Island lobster
populations.
Document contribution of
Maine's conservation measures on population south of here.
Monitor the effectiveness of management measures such
as the incidence of V-notches and within season changes and the abundance of
oversized lobsters.
Develop fishery response plans for emergencies.
Evaluate the effectiveness of v-notch as management
tool.
Management and assessment
seem disconnected from real conservation actions.
Migration and Behavior
Importance of size in
lobster migration.
What are
oversize lobsters' migration patterns?
What is the effect of
barometric pressure on migration?
Need lobster tagging
studies.
Loss of catch by in-trap
mortality. Large egg-bearing
females attack smaller lobsters.
To what extent does egg
production in one area contribute larval settlement and harvests in another?
What role does migration play in this?
Ultrasonic tag technology
is improving, could be used to tag and track individuals.
When, at what age/size
does an individual start to migrate? It is rare to see a big v-notch.
Do a tagging study in
Penobscot Bay to assess the number of berried female lobsters there. Is there a net gain or loss in the Bay?
Do all the lobsters leave in the fall or is there a resident
population?
Tagging in Mt. Desert Rock
area could be important. It is
a hotbed of activity and may help discover relationships between inshore and
offshore populations.
Are there secret nursery
grounds for juvenile lobsters in the Gulf of Maine? Apparently in Long Island Sound there are three-foot tunnels
under the mud.
Are there nursery areas
that should be protected?
Oceanography
What is the distribution
and timing of egg hatching? Use
this to put into model assumptions.
Use field data on larval
and postlarval distributions to test the simulations.
What are the connections
and dependencies between offshore lobsters, the inshore fishery and inshore
recruitment? Do larvae from
offshore subsidize the inshore fishery? If so, how?
Of the adult lobsters, what proportion of the
population remains offshore and what proportion migrates shoreward?
Use oceanography
(temperature, current, wind) to forecast larval movement and settlement.
To what extent does egg
production in one area contribute larval settlement and harvests in another?
What role does larval transport play in this?
Document nearshore
currents all along the coast.
Predation
Could surprisingly high
harvests in an area be due to lack of predators?
Reproduction
As aquaculture grows in
other places, eggs may become our most valuable asset.
What are the
characteristics of the broodstock? Need
to know frequency of spawning by age/size of female. How many eggs per lobster?
What is the importance of
large females to the fishery? Do
they contribute more eggs? Do
their eggs have a higher survival rate?
Quantify and assess
broodstock.
Observe more red
(unfertilized) eggs on lobsters. Why?
What is the contribution
of larval production inshore?
What is the relationship
between inshore and offshore larval production?
Socio-economic issues
What steps can the
industry and State take to generate warnings of if the lobster resource
starts to decline? What options
do the State, the zone councils and the industry in general have for
responding to this decline?
If lobster abundance went
down would effort increase or decrease?
How much is invested in
the lobster fishery and what is the level of indebtedness by age of
lobsterman?
Economic impact studies
miss individual debt load.
Examine the impact of
changes in management on the value of a permit or license.
What is the threshold
income to make it worthwhile to fish?
What are exit strategies
for lobster fishermen?
Document the status of the
fishery by a port-by-port survey similar to the 1880s U.S. Fish Commission
survey.
Describe profile of
various different lobstering strategies within industry.
NMFS has taken away one
fishery at a time (groundfish, tuna, etc.) so we are very dependent on
lobstering.
Do more analysis and
description of the impacts of management forcing fishermen into a single
fishery.
Competition cycle: higher costs, need more traps, more to compete with neighbor.
Wire traps make a huge
difference.
Expectations have changed
in the fishery: people want the
good life, not a living.
Traditionally boundaries
prevented fishermen from moving. Now
fishermen want to move when they hear the fishing is good and want to break
boundaries.
In Zone G, what is the
economic impact of the inshore fishery and the offshore fishery?
How to protect traditional
fishing practices without micromanaging or privatizing the resource?
Concerns that the family
fishery will become a corporate fishery.
People on zone boundaries
are not well served.
Examine zones and catch
data by zone to see if zones match the biology.
Analyze the effects of
zone boundaries on fishermen.
What is needed to make
zones function better. Successful
industries in shoreside business tend to develop networks of people who
converse and inform each other. Is
there any better way to get fishermen in zones talking?
People who fish outside
three miles don't feel it is fair that they have to declare a zone.
Evaluate the effect of
management measures on behavior, effort, and economics. Some rules do the exact opposite of what is intended.
Are there basic ground
rules, principles, that the industry could buy into to help them deal with
fishery management decisions and decisions necessary in the event of a
decrease in lobster abundance?
Attachment
A:
AMERICAN
LOBSTER RESEARCH PRIORITIES
MEETING
ATTENDEES
April 25, 2000 at Samoset
Resort, Rockport
30 Participants
Lew Incze Bigelow Lab, West Boothbay Harbor 04575
633-9600
Barry Hamilton
S-S Seaweed, Camden 236-9602
Jay Smith Nobleboro
563-5208
Larry Peter Rockland
594-7054
Ernie Squires S & S Seafood, Rockland
594-5088
Bob Brown
ME Import Export Lobster Dealers Association
882-7781
John Butler 19 Chamberlain Road, Scarborough 04074
883-5457
Bill Doane
South Portland
775-5448
Lyman Kennedy
Falmouth
781-4662
Arthur Pierce, Sr. P.O. Box 134, Sebasco Estates 04565
389-1177
Marilyn Hotch
92 Bellevue Street, Owls Head 04854
596-7847
Laura Taylor
DMR, Augusta
624-6576
Carl Wilson
DMR, Boothbay Harbor
633-9538
Linda Mercer
DMR, Boothbay
633-9525
Sara Ellis The Lobster Conservancy
P.O. Box 235, Friendship 04557
832-8224
Butch Bowie
P.O. Box 273, Windsor 04363
549-0996
Gaye Robinson
P.O. Box 281, Warren 04864 273-2527
Glenn Nutting
DMR, Boothbay Harbor
633-9514
Corrie Roberts
Island Institute, 410 Main Street
Rockland 04841
594-9209
Ben Neal
Island Institute, 410 Main Street
Rockland 04841
594-9209
Eric Annis UM Darling Marine Center, Walpole 04573
563-3146
Rick Wahle
Bigelow Lab, West Boothbay Harbor 04575
633-9659
Tim Harkins Icebrand Seafoods
92 Waldren
Way, Prtlnd, 04112 797-2850
Patrice Farrey P.O. Box 321, York Beach 03910
363-6783
Pat White 41 Route 103, York 03909 363-6783
Vernon Thompson P.O. Box 176, Port Clyde 04855
372-8831
Sue Inches DMR, Augusta
624- 6558
Dana Morse
Sea Grant/UM Cooperative Extension
563-3146 x205
Don Perkins
Gulf of Maine Aquarium PO Box 7549,
Prtlnd 04112 871-7804
Robin Alden
P.O. Box 274, Stonington 04681
367-2473
April
27, 2000 at White Birches, Ellsworth, ME
38 Participants
Jen Bubar
P.O. Box 317, Stonington 04681 367-2417
Rick Bubar
P.O. Box 317, Stonington 04681 367-2417
Rick Wahle
Bigelow Lab, West Boothbay Harbor 04575 633-9600
Ted Hoskins
P.O. Box 931, Blue Hill 04614
374-2028
Jim Haskell
P.O. Box 40, Union Trust, Milbridge 04658
546-7052
Jason Mibell 117 Great Lory Road, Lamoine 04605
667-0358
Bonnie Crosby P.O. Box 86, Clay Cove, Steuben 04680 546-7052
Dan Hodgkins HC 77, Box 442, Hancock 04640 442-6570
Herb Hodgkins HC 77, Box 445, Hancock 04640 442-6238
Dave Hiltz P.O. Box 117, Isle Au Haut 04645 335-2611
Dan MacDonald P.O. Box 81, Isle Au Haut 04645
335-5577
Ted Ames P.O. Box 274, Stonington 04681 367-2473
Anne Porter P.O. Box 509, Ellsworth 04605 667-2576
Roger Chipman P.O. Box 72, Birch Harbor 963-2391
John Chipman P.O. Box 76, Birch Harbor 963-7051
Bill Anderson RFD 2, Box 3100, Lubec 04652
733-2179
Eric Annis UM Darling Marine Center, Walpole 04573
563-7511
Carin Poeschel 448 Main Street, Orono 04473 866-5983
Carlton F. Joyce 12 Grindle Hill Road, Swans Island 04685
526-4251
Leroy Bridges
RR 2, Box 521A, Deer Isle 04627
348-6992
Linda Mercer
DMR, Boothbay Harbor
633-9565
Stephen Robbins III P.O.
Box 649, Stonington 04681
367-5517
Carl Wilson
DMR, Boothbay Harbor
633-9538
Lew Incze
Bigelow Lab, West Boothbay Harbor 04575
633-9600
Michael Dunnington Bigelow
Lab, West Boothbay Harbor 04575
633-9600
Frank Donnelly
15 Ash Lane, Lamoine 04605
667-0287
Mazy Myers
P.O. Box 345, Hancock 04640
422-4741
Ollie Wenger
RR 1, Box 2325, Bar Harbor 04609
288-5228
Kelli Wenger
RR 1, Box 2325, Bar Harbor 04609
288-5228
Dick Bridges
P.O. Box 27, Sunset 04683 348-2840
Carol Bridges
P.O. Box 27, Sunset 04683 348-2840
Bob Bayer
University of Maine, Hitchner Hall, Orono 04469
581-2785
Bryan Pearce
University of Maine, Boardman Hall, Orono 04469
581-1216
Bill Crowe
P.O. Box 253, Gouldsboro 04607
963-7195
Jennifer Smith
DMR, Boothbay Harbor
633-9599
Sherman Hoyt
Sea Grant/UM Cooperative Extension 800-244-2104
Don Perkins
Gulf of Maine Aquarium PO Box 7549, Prtlnd 04112 871-7804
Robin Alden
P.O. Box 274, Stonington 04681
367-2473
Attachment B:
Oceanography and the Early Life Stages of Lobsters
Lewis S. Incze, Ph.D., Bigelow Laboratory for Ocean
Sciences
Maine DMR Coastal Fishery Research Priority Meetings
April 25 and
April 27, 2000
At hatching, each lobster egg produces a single larva,
the first of four free-living planktonic stages that live in the upper part
of the water column. The depths
of the first three larval stages are not well known and may vary between
locations. The last stage,
called a postlarva, lives close to the surface in most areas where it has
been sampled--usually within the upper 1 meter (m) (39 inches) The postlarva eventually settles to the bottom to become a
Young-of-Year (YOY) lobster. Most
YOY in Maine have been found in cobble habitat less about 10 m (33 feet) below mean low water.
Settlement may occur in offshore waters, but little is known about
it.
The rate of development of larval and postlarval
lobsters is strongly temperature-dependent, being faster at warmer
temperatures. A typical
development time for lobsters hatched in mid-coastal Maine is about 50 days
based on laboratory studies, but seasonal warming, individual differences
and strong spatial gradients in temperature produce a wide range of
development times. In the
Boothbay region where it has been studied, settlement occurs mostly from
mid-July to early September, corresponding with the seasonal appearance of
postlarvae. Postlarvae are not
abundant as larval forms go. In
seven years of sampling in Johns Bay and off Damariscove Island, 75% of the
tows had postlarvae concentrations <10/1000 m2 (less than 10
per 1000 square meters of sea surface area) and more than half the tows had
<5/1000 m2 (1000 square meters is approximately 1200 square
yards). However, our experience
is that they are quite widespread. In
contrast, typical settlement densities in cobble habitat are 1-4 YOY/m2.
Our work shows that currents, 6 or more weeks of postlarvae
availability, and site selection by the postlarvae enable this concentrating
effect from a few per 1000 m2 at
the postlarvae stage to a few per m2 after they settle and become
young of the year.
Because the planktonic stages are long-lived, they can
be moved considerable distances around the Gulf by currents. Most of the currents we observe in coastal waters are tidal, but
underlying these strong flows is a residual flow that is the net movement of
water after the tides have been "subtracted." One can visualize this by considering that a floating particle
usually does not return to exactly the same spot after a tidal cycle. Some of the displacement is due to lateral mixing processes (a random
process), but regular directional displacements also may occur (that is,
over several tidal cycles the displacements are in the same direction and a
similar distance after each tide). These
average “subtidal” flows are typically calculated from data collected by
drifters of various types (today, satellite-tracked drifters are used) and
by special current-measuring devices on moorings and ships. Since the residual circulation in the Gulf is driven primarily by
density (temperature and salinity) differences, it can be closely estimated
in open waters from hydrographic profiles (vertical temperature and salinity
measurements). These are routinely made during research cruises. Finally, since the postlarvae live near the ocean's surface, they are
particularly prone to wind-generated transport. The sea breeze typical of coastal summer air flow in the Gulf of
Maine may play an important role in the shoreward movement of this final
stage toward known settlement habitats. Whether this contributes to interannual differences in
recruitment is currently being studied.
The Gulf of Maine is characterized by a strong
counter-clockwise circulation which is produced by comparatively fresh water
near the coast, salty slope water in the interior of the Gulf, and the
Earth's rotation (Coriolis effects). The
flows are modified by local topography and tidal energy, freshwater inputs
(rivers), and seasonal and interannual weather patterns. The result is a system of coastal currents and gyres, the latter
around major basins (because of saltier water at depth) and banks (because
of steep topography). Some of
these features are well described and predictable in an average sense, e.g., the Eastern and Western Maine Coastal Currents, Jordan Basin
gyre and Georges Bank gyre. However,
we need to know much more about the variability of these flows and the
specific biological and chemical events taking place within them and the
rest of the system if we are to understand processes such as fisheries
recruitment. While studying
mechanisms that affect recruitment from year to year, we cannot forget that
many of the conditions in the Gulf are connected with larger,
"climate-scale" processes that influence precipitation, wind
stress, cloud cover, atmospheric pressure, atmospheric heating and cooling,
and the sources and volumes of Atlantic waters entering the Gulf. Because of this complex setting and the interaction of many
variables, we must think of lobster recruitment patterns and population
trends in the context of a system with variability at a number of spatial
and temporal scales. Understanding
the linkages is both a scientifically interesting challenge and a worthy
goal in terms of how we approach the future of the fishery. It is not, in any case, easy.
Oceanography figures strongly in the early life history
of lobsters because the larvae and postlarvae must survive (so growth rates,
prey and predators matter) and because the strong residual flows in the Gulf
transport larvae potentially long distances. The spatial (geographic) and quantitative linkages ("how many
make it") between egg hatching and eventual settlement have been of
scientific interest for many years. These
are being studied in different ways. I
highlight four activities below which are taking place in Maine (related
just to the planktonic stages), and comment on some of the research needs
identified by them.
1). Modern
circulation models, coupled with biological sub-models, are being used
to simulate some aspects of larval transport, development and recruitment.
The advantage of such models is that they can integrate and do the
book-keeping on many complex processes simultaneously -- think of
"tracking" the fate of a large number of lobster larvae through
space and time when they originated from a variety of hatching locations and
experienced varied oceanographic conditions along their trajectories. It's not practical to think about doing this without a computer
model. Also, "electronic
experiments" can be repeated with a model to examine the results of
different variables and forcing, such as different hatching locations and
times and different wind events. One
of the obvious limitations is that no model incorporates all of nature's
complexity, so one must be careful how the model is used and how the results
are interpreted. Models are
very good at testing ideas and identifying data needs, however, and models
themselves are being refined and tested all the time. If we are to understand the linkages between various parts of the
Gulf of Maine lobster population, then field biology and oceanography will
have to work with modeling efforts to understand larval production and
transport pathways. This is the
process being used in a number of studies in other areas. In recent modeling exercises in Maine, two of the major data needs
that have been identified are: 1)
the distribution and timing of egg hatching (what is the real pattern of
production that we should put into the model?) and 2) field data on larval
and postlarval distributions to test the simulations. The first could be done with assistance from the industry; the latter
would require research vessels and support from the relevant state and
federal agencies in Canada and the U.S. A great deal of coordination would be required to pull this off.
The Gulf of Maine is a multi-jurisdictional system, and any
study should think of the entire geography.
2). The
Inshore/Offshore Question. What
are the connections and dependencies between offshore lobsters, the inshore
fishery and inshore recruitment? Calculations
(paper by M. Fogarty) show that a small subsidy from offshore could help
sustain the heavy exploitation rates of the inshore fishery. Such a subsidy could take place through migrations or through larval
inputs, or both. We don't have
the data needed to test either idea, and meanwhile, there is growing fishing
pressure on the offshore population. We
know that larvae hatched offshore would be transported along the shelf in
the prevailing westward coastal current system--would they also get
transported to near shore? Where?
How? How often? And under what
conditions? Of the adult
lobsters, what proportion of the population remains offshore and what
proportion migrates shoreward? These questions are similar to those raised in topic #1
above, but are specific to the inshore/offshore question and so are
identified in greater detail here. It
is worth pointing out that in 1999, I found VERY FEW postlarvae inshore of
Matinicus Island despite extensive sampling as part of the Penobscot Bay
Collaborative (see next section). Yet,
in a short survey along the coast from Pemaquid to Grand Manan, University
of Maine graduate student Eric Annis found good numbers offshore (typical of
the numbers I used to see in the Boothbay and Seabrook areas prior to 1995).
Is this usual? Do the inshore and offshore waters generally do their own
thing, or are they usually connected in a way that didn't happen in 1999?
Is the apparently low postlarvae supply in Penobscot Bay in 1999 (the
first year of extensive sampling) related to the low recruitment observed at
Boothbay and the low postlarvae supply sampled at Seabrook? If this is part of an over-all pattern, is the same mechanism
responsible?
3). The
Penobscot Bay Collaborative is a multi-institutional, inter-disciplinary
study of circulation and lobster recruitment in Penobscot Bay. Components of the study include satellite remote sensing (sea
surface temperature and chlorophyll patterns), circulation, plankton
distributions (larval and postlarval lobster), and all of the benthic life
stages of lobsters. The
objectives are to understand the connections between Penobscot Bay and the
coastal current system; to understand how lobsters recruit to this very
productive bay (for instance, what proportion of the lobsters harvested in
Penobscot Bay come from egg production inside the bay, and what proportion
from outside?); and to see if satellite data can be used to monitor changes
in circulation and predict consequent changes in lobster recruitment. Numerous lobstermen have been involved in this study, following our
results, sharing ideas and helping with data collection (primarily tagging
and other sea sampling). We
have gained new insights into circulation in the bay and are making progress
with understanding and modeling mechanisms that can affect recruitment.
Funding has been crucial to bringing people together on this
topic (several of them are not usually involved in lobster studies),
providing resources to do the work, and maintaining focus. Funding will be crucial to continued progress.
4). Recruitment
and Postlarval Time-Series. Early
work (1989-1995) on postlarval lobsters and young of the year (YOY)
recruitment (the latter by R. Wahle) in the Boothbay region was instrumental
in establishing that there is a strong positive relationship between the
supply of postlarvae to the nearshore environment and the abundance of early
benthic stages, and that these could show strong interannual variations.
The research funding which made the initial work possible ended in
1995, but the state has funded YOY monitoring since. This monitoring has
turned out to be very valuable (see below). Meanwhile, the electric generating plant in Seabrook, NH has sampled
postlarvae every year since 1989 as part of their environmental monitoring
requirements. They have
generously provided their data to me for scientific purposes, and these data
now constitute the longest time-series of postlarvae in the Gulf of Maine.
Both the YOY data from Boothbay and the postlarvae data
from Seabrook show a reduction of about 50% after 1995 (that is, low numbers
from 1996 through 1999). We do
not have prior experience with "early warnings" of this sort, so
we do not know for sure how this will translate into the fishery. However, data from R. Steneck and co-workers indicate that the
abundance of juvenile and harvestable lobsters along the coast follows the
same spatial pattern as the settlement densities. These findings suggest that a downturn in the fishery in the western
part of the state is likely since the decreased recruitment took place
several years in a row. We are
working on a formal set of calculations for these data, the biggest question
being whether the two sites are representative of settlement along the
substantial intervening section of coastline. The lesson from our findings to date is that time-series are
important, cluing us in to a possible downturn (of concern to fishermen and
managers) and indicating that the cause of this downturn, if it
materializes, will have been the plankton and the very earliest steps in
recruitment. This immediately
raises several questions: was
the reduced postlarvae abundance and YOY settlement somehow related to low
egg production; to low larval survival rates in the plankton; or to
unfavorable transport pathways? Whatever
the explanation, why has it now occurred several years in a row? Is this part of a "regime shift" in the biology or physics
of the Gulf? We have little
data with which to answer these questions, and the absence of such data is
the final lesson here. If,
indeed, the lobster harvest shows a sharp decline in the next few years,
there will be much more interest in understanding the basic mechanisms of
recruitment. I repeat that WE DO NOT KNOW HOW THESE OBSERVATIONS WILL
TRANSLATE INTO THE FISHERY. We
feel it is responsible to share our findings at this time, to be honest
about what we don't know, and to stress that we need to know these things
better. By this I am promoting
both the need for research and the need for open communication of ideas and
results.
Attachment C:
Lobster
Stock Assessments: Current
Approaches and Future Needs
Carl Wilson, Maine Department of Marine Resources
Maine DMR Coastal Fishery Research Priority Meetings
April 25, 2000
The lobster fishery is the most valuable fishery in the
Northeast. Maine landed an
estimated 53.5 million pounds valued at $185 million in 1999. Landings have doubled since the early 1980s.
There is evidence that lobster abundance is a record levels, but
unprecedented levels of fishing effort have maintained a tenuous
relationship between abundance and removal by the fishery. This relationship has spawned heated debates on the status of the
lobster resource. It is the job
of stock assessments to review the status of the resource through fishery
dependant and independent measures.
The assessment reports on trends in abundance,
recruitment, size composition, egg production and fishing mortality. This
information is used as a way to compare where the fishery is in relation to
targets and thresholds established in the Federal Management Plan (FMP). If
the fishery is thought to be approaching threshold levels then management
actions may be taken. By
definition, lobsters are overfished when the egg production per recruit (EPR)
is 10% or less than it would be in an unharvested population. Currently the Gulf of Maine is at 3.2% EPR and is thus thought to be
overfished. There are a number
of areas where further research and long-term monitoring can be inserted
into the assessment process that should help our knowledge of the lobster
resource.
Current fishery dependent information comes from at-sea and port sampling programs.
This is critical information to describe what is being caught and
landed in traps. Sea sampling
also gives us an idea what lobsters are discarded, such as short, egg
bearing and v-notched lobsters. In
Maine the lobster fishery is a passive gear (trap) fishery which implies
that lobsters choose to enter and subsequently get caught. Fishery dependant measures therefore rely on variable conditions such
as lobster behavior, gear selection, and the environment. Improvements in fishery dependant data being collected might include:
-
An
evaluation of the statistical coverage needed for a sea sampling program
-
A
juvenile/oversize lobster survey through modified traps
-
Measures
of the spatial extent of fishing through logbooks, electronic tracking
-
Further
development and definition of what effort is in the lobster fishery
-
Research
on trapability and lobster behavior
Fishery independent methods measure the lobster resource using techniques other than
standard lobster traps such as trawl, submarine, and scuba surveys. Currently the National Marine Fisheries Service trawl survey (largely
based outside state waters) is not surveying areas where the highest fishing
effort is located. There has
been little support of fishery independent surveys other than trawl surveys
in the assessment process. Improvements
in and emphasis on fishery independent surveys for assessments may include:
-
Coast-wide
surveys targeting newly settled and juvenile lobsters
-
An
inshore trawl survey
-
Plankton
sampling
-
ROV
or submarine surveys to index lobsters in areas where trawl surveys
can’t work such as highly irregular habitats
Finally, mathematical
models are used in assessments to fill in the gaps in our knowledge and
make predictions of the stock. Models
are only as good as the information going into them. There is a belief that the current Egg Per Recruit (EPR)
model is not characterizing the lobster resource. The EPR is tied directly into the current management FMP, and carries
a substantial amount of weight in the regulation of the lobster resource.
Investigation of the applicability of the current model needs to be
conducted. Until we can count
every lobster in the Gulf of Maine, we will need models. Models in general could benefit from a better knowledge of:
-
Natural
mortality
-
Fishing
effort and mortality
-
Lobster
behavior
-
Lobster
growth and age
Assessments should be used as a way to report on the
status of the fishery and make forecasts for the future. Management plans should be based on the best available
assessment information. Through
further development of models, and fishery independent/dependent measures we
can improve our estimates of the status of the resource. There is a need for targeted onetime research, such as
developing a technique to age lobster, but we must remember that consistent
monitoring programs are the cornerstone for assessments.
Attachment D:
Critical
Research Needs for Lobster Assessment and Management
Paul Rago, Ph.D., National Marine Fisheries Service
Maine DMR Coastal Fishery Research Priority Meetings
April 27, 2000
Lobsters support the most valuable single species
fishery in the northeast United States. Despite its economic value and the persistence of high landings in
recent years, much remains to be learned about the species and the fisheries
that harvest it. The purpose of
this essay is to suggest a number of areas in which the science underlying
lobster management could be improved. The opinions expressed in this essay
do not represent those of National Marine Fisheries Service (NMFS) but at
least some of these suggestions might find broad support.
The basic process of stock assessment begins with a
review of the fishery — the magnitude and biological characteristics of
the landings, the amount of fishing effort expended, and the seasonal and
spatial distribution landings and effort. These fishery dependent measures are compared to fishery independent
indices of abundance — typically trawl surveys, and various mathematical
models are applied to estimate the rate of exploitation. In and of itself, the rate of exploitation means little; it must be
evaluated with respect to the
life history of the animal. The
biological features and ecological role of lobsters have been shaped by
millions of years of evolution. As
such, scientists, managers, and fishermen recognize that these biological
attributes have important implications for harvest policies. The maximum
possible rate of harvesting is ultimately constrained by these attributes.
A heavily armored species that lives for 50+ years, produces a
relatively small number of eggs, and attains a large size must have evolved
under environmental conditions that favored such characteristics.
These characteristics can be captured in a mathematical model that
predicts the expected lifetime production of eggs for the “average”
female. Exploitation can
then be evaluated with respect to its impact on what might be expected in
the absence of the fishery. Many of the heated debates in recent decades
have centered on this issue. Simply
stated, the overfishing definition recommends that lobsters should be given
the opportunity to produce about one-tenth of what they might produce with
no fishing.
The point of the foregoing is not to debate the merits
of the magnitude of the “one-tenth rule” or its immediate consequences
for lobster management. Instead,
it is important to recognize that harvesting does impose some cost to the
population and utilizes some fraction of the remarkable compensatory reserve
that many species exhibit. Perhaps
the lobster can continue to withstand very high rates of exploitation, but
it is worth noting that most species cannot— as verified by hundreds of
collapsed finfish and shellfish fisheries around the world. From a purely pragmatic viewpoint we can ask if it is worthwhile to
conduct the experiment that will establish the limits of compensation in
lobster populations. If the
economic fallout of a reduced lobster population is deemed inconsequential
then the experiment is worthwhile. Otherwise, it would be prudent to improve
the monitoring of this resource, detect early signs of stress, and plan
responses to such information. It
might even be worth planning how to avoid such a result but such a
discussion would surely divert our attention today.
The preceding arguments suggest a number of useful
lines of research. Some of
these suggestions are enhancements of ongoing work while others would
require new research efforts.
1. Improve
fishery independent surveys
a. Survey the inshore resource in
the primary fishing areas
b. Develop new monitoring methods
(possibilities — trap surveys, photographic, mark-recapture etc.)
2. Develop
fishery-dependent surveys
a. Monitor juvenile recruitment,
especially ventless traps
b. Develop measures of catch per
unit effort
c. Synoptic snapshot surveys —
e.g., Christmas bird count
3. Develop realistic measures of fishing effort and
monitor changes over time
a. Numbers and types of traps
b. Soak time
c. Seasonal deployment
4. Characterize
the seasonal and spatial pattern of fishing effort and landings.
a. Need broad base of support
b. Electronic reporting
5. Monitor
indicators of population stress
a. Fraction of newly molted
lobsters in total landings
b. Multiple recapture rates
c. Incidence of disease
d. Indicators of non-lethal gear
encounters — e.g., culls
e. Reliance on recently mature
lobsters for egg production
f. Identify zones or pockets of
declining catch rates
6. Conduct
field and laboratory experiments to estimate growth rates
7. Conduct
large-scale experiments
a. Closure area and an appropriate control area.
b. Comparative analyses with Canada, zones within Maine, etc.
8. Monitor
the effectiveness of management measures
a. Incidence of V-notches and
within season changes
b. Abundance of oversized
lobsters
9. Develop fishery response plans for emergencies
10. Create opportunities for dialogue apart from
regulatory environment
Attachment E:
Research
Priorities for Lobster Life History
Richard A. Wahle, Ph.D., Bigelow
Laboratory for Ocean Sciences
Maine DMR Coastal Fishery Research Priority Meetings
April 25 and
April 27, 2000
For this segment of the Research Priorities discussion
I focused on major research questions for gaining a better understanding of
lobster life history. This is
clearly a broad topic and there are many interesting research areas I could
discuss. But in this case
my aim is to focus on the research areas that will improve our ability to
assess the health of the lobster population and to forecast its upward or
downward trends. In short the
question is, where can we get the biggest bang for our research buck? Here I
briefly outline some recent scientific advances and identify where gaps
still exist in data collection and modeling.
There are relatively few cases in fisheries sciences
where harvests are being forecast from the earliest life stages, years in
advance of the harvest. There
is at least one however. Harvests
of the western Australian rock lobster have been accurately forecast since
the 1970s. In that case the
yearly abundance of lobster postlarvae settling on artificial collectors
suspended in the water column provide an index of the strength of the
harvest 3-4 years later. More
recently the Australians have come to an understanding of how oceanography
influences the fluctuations in settlement and now can forecast harvests from
prior oceanographic conditions. Fisheries
scientists working with the American lobster have been trying to emulate the
Australian example and some advances are being made in that direction.
First, they have identified a direct correlation
between the abundance of planktonic postlarvae and the strength of the newly
settled year class on the bottom. It
was not until the late 1980s however that anyone knew how to quantify newly
settled lobsters. Artificial
collectors like the Australian’s were ineffective. Instead of this, a diver-operated suction sampling technique used in
natural cobble nurseries has been adopted. Since it is far more cost effective to sample the new settlers than
the planktonic larvae, attention has moved to following year classes after
settlement and ultimately to the harvest some 6-8 years later. Still because settlement strength is determined by larval supply and
larval supply may be determined largely by ocean processes it is important
not to lose sight of the potentially strong influence of oceanographic
conditions on subsequent harvests.
It has been fairly easy to follow year classes over the
first few years of life. From
the time series collected so far in Maine it appears that year-class
strength still reflects settlement strength after at least two years.
After that age though, it becomes more difficult to follow year
classes. One reason is
that there is no good way to estimate the age of a lobster. Size is not a good index of age because some individuals grow faster
than others and year classes eventually mix to the point of being
indistinguishable by the time they reach harvestable size. For predictive purposes then it is not only important to understand
both the increase in average size, but the spread
in size as well. That
will enable us to estimate the proportion of a year-class that has recruited
to the fishery at a given age.
A second reason it has been difficult to follow
year-classes after the age of about two-years is that lobsters begin to
emerge from nursery grounds and become more widely dispersed. Although it has not yet been possible to follow year-classes through
to the harvest, it is encouraging that regional differences in juvenile
lobster abundance estimated by diver sampling correlate well with regional
differences in landings. For
example, eastern Maine nurseries consistently have far lower lobster
densities than western Maine grounds, a regional disparity long reflected in
the landings per length of coastline.
While diver-based methods have been increasing over the
years, traditional lobster traps or bottom trawls may continue to be the
sampling method of choice because of their widespread usage in the
commercial fishery and the large areas they are capable of sampling. However, trap- and trawl-based samples have their own problems
related to size-selectivity and differences in sampling efficiency on
different habitats. These
biases need to be evaluated and corrected-for in order to relate data
collected by the different methods. Mark-recapture
techniques for estimating population size, gains, and losses may represent a
means to reconcile the two sampling methods.
Emergence from nurseries is only the beginning of a
life-long expansion of the lobster’s range of movement. Large reproductive lobsters are known to be capable of traveling
hundreds of kilometers along the bottom. Considering the combined effects of larval transport and benthic
migrations a central question is: To what extent does egg production in one
area contribute larval settlement and harvests in another? The exchange of lobsters among stock assessment areas,
in-, off- and along-shore, remains poorly understood. The implications for management are important though.
There has been growing recognition that many fish populations are in
fact a network of subpopulations, collectively forming a metapopulation.
The strength or weakness of exchange among subpopulations can have
important consequences for their dynamics and sustainability. It makes little sense, then, to manage as separate, isolated stocks a
species with such great potential for movement during its lifetime as the
American lobster.
A list of research priorities might include:
• The need to maintain regional time series of
oceanographic data and abundance indices for juvenile, pre-recruit, and
harvestable segments of lobster life history.
• From data time series, evaluate the power of
oceanographic data, and juvenile and pre-recruit abundance indices to
predict harvests.
• Work out sampling biases inherent to trap- and
trawl-based abundance estimates.
• Determine the age-size relationship regionally,
especially the variance in size with age.
• Continue to search for more reliable indicators of
age than body size.
• Determine the extent to which egg production in one
area contributes to larval settlement and ultimately harvest in another.
• Develop spatially explicit population models that
evaluate the consequences of meta-population dynamics to the sustainability
of the resource.
Attachment F:
Socio-economic Needs for the Lobster Fishery
James A.
Wilson, Ph.D., University of Maine
Maine DMR
Coastal Fishery Research Priority Meetings
April 27, 2000
1)
It is quite likely that the current high lobster harvest levels will
start to decline sometime in the near future. It is not likely that the current high levels of fishing effort will
leave the fishery very easily. Fisheries
managers often argue that this type of situation is very dangerous in a
fishery because there are large amounts of effort chasing a naturally
declining population. The
result can be a collapse. Is
this something the industry needs to worry about? What steps can the industry and state government take to generate
warnings of this decline and what options do the state, the zone councils
and the industry in general have for responding to this decline?
2)
Develop harvest business models similar to those commonly used in
agriculture by family farm operations. Essentially these are very general models designed so that a single
farmer or fisherman can set important parameters (e.g., months fished,
number of traps fished in the month of x, and so on) for the purpose of
tailoring the model to his particular way of doing business. These models are used for developing business plans and/or analyzing
production operations.
3)
Ways to facilitate the operation of the lobster zone councils:
a) Are there ways to streamline meetings, to resolve conflicts and
generally make the councils operate more efficiently (i.e., with less cost
in time and stress to the industry)?
b) Are there ways to make the councils operate more effectively (i.e.,
initiate the interests of fishermen rather than responding always to demands
from state government)?
c)
How do we get a bottom up component in science? Can we learn from the way businesses operate how to spread and
develop new ideas from within the industry through networking and work
groups?
4)
A port by port survey of fishermen and fishing practices, somewhat
along the lines of the U.S. Fish Commission survey of the 1880’s, should
be considered simply to document the status of the industry.
5)
We ought to consider forming a group of ‘zone historians’ who
would summarize once each year – perhaps in a Department of Marine
Resources meeting – significant developments in the lobster, other
fisheries, suppliers, etc. in their zone. Publish the summaries on the web.
Use this approach to give the State some inkling of developments it
should know about but that it might otherwise miss.
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