II. The
DMR Research Priorities Project
These sea urchin
research priorities are 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 a market for 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 GMA consultants, DMR, and University of Maine Marine Extension Team
staffed the project.
III. Methodology
For each fishery,
at least one, all-day meeting was held. 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, and fishery managers as equals.
They created a safe 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. In
addition each of the presenters were 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. Each of the four sessions had the same format.
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 the selected topic and his
or her major research questions about the species.
After that, the group 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. Sea
Urchin Research Priority Meeting
The
urchin meeting was held at the Orland Town Hall in Orland, Maine May 11, 2000
from 9 a.m. to 5 p.m. Topics and
presenters included:
1.
Life History/Behavior
Larry G. Harris, Ph.D., University
of New Hampshire
2. Stock Assessment
Shawn Robinson, Ph.D., Dept. of Fisheries and Oceans, St. Andrews, NB
3. Management Issues
Robert Steneck, Ph.D., University of Maine
4. Urchin Health
Paul Waterstrat, Ph.D., DMR
Forty-nine people
attended the urchin meeting. They
included past and present members of the SUZC -- fishermen, processors and
dealers, and scientists. Draggers,
divers, aquaculturists, and shoreside dealers and processors were represented
among the industry attendees. Scientific
attendees came from as far away as Villanova in Pennsylvania, as well as both
public and private research facilities in Maine. The DMR staff from both the scientific and management sides
of the agency were present.
V. Sea
Urchin Report Format
Results of the
meeting are presented in two different formats:
1. 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 meeting.
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 urchin meeting was divided into four segments:
Life History/Behavior, Stock Assessment, Management Issues, Urchin
Health, the report is not structured around those categories except where it
makes sense. Many topics, such as growth and reproduction, and nearshore
oceanography 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 a 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
Research
priorities in the urchin fishery are both well-grounded in immediate,
practical management questions and at the same time require answers to basic
scientific questions about oceanography, life history, ecology, and disease.
The evolution of urchin co-management with the state also presents a
number of avenues for policy work.
Process questions
around management decisions were expressed less urgently than they were in
some other fisheries such as clams. Nonetheless, there were many specific
suggestions and a focus on the need for better communications between
scientists and the industry, particularly in designing and carrying out
reseeding experiments. Reconciling
the desire for action and experimentation on the part of the industry with the
need to collect information in a scientifically rigorous way will require
considerable investment in communication and mutual education. There was a recognition that communication needs to improve
in both directions between the industry and the SUZC.
Urchin Priority 1:
Reseeding Urchins and Closed Areas
The overwhelming
interest in urchin research expressed at the meetings lies in those basic and
practical questions that surround development and evaluation of both rotating
closures and reseeding urchins for public stock enhancement. Scientific work has shown that the cycle of urchin barren and
macroalgal community (kelp forest) does not necessarily rotate but instead may
be two alternative steady states that do not switch without some external
stimulus. Without intervention,
it is not clear whether urchins are able to reestablish themselves after
macroalgae such as kelp has grown. This
may seem counterintuitive, since urchins prefer kelp as feed. However, at small sizes, it appears urchins have difficulty
becoming established in the mature algal beds, which provide habitat for many
small urchin predators.
Participants
expressed strong interest in evaluating rotational closures as a way to avoid
overfishing and prevent the change in habitat from urchin barren to kelp
forest. The question is still
unanswered whether urchins would reestablish themselves if fishing pressure
were removed without any other intervention.
There is strong interest in reseeding for three distinct purposes (in
order of priority): 1) to change
the environment by shifting a kelp forest to an urchin barren to reestablish
productive urchin bottom, 2) to enhance reproduction in the area, and 3) to
enhance quality or fatten urchins.
Research
priorities are:
a)
Evaluate urchin rotational closures both before and after overfishing
and habitat shift:
-
Can closures prevent overfishing?
-
Can closures prevent habitat shift?
-
Will closures enable urchins to reestablish themselves after a habitat
shift?
b)
Create adequate experimental design for urchin reseeding that fishermen
can participate in, in 2001.
c)
Develop effective urchin reseeding techniques:
timing, disease and urchin source issues, choice of area, handling.
d)
Conduct onsite collaborative experimentation to evaluate the biological
and ecological aspects of urchin reseeding and closed areas relative to the
three purposes:
-
To change ecology by harvesting kelp;
-
To provide reproduction in that area;
-
To enhance quality, "fatten" urchins.
Urchin Priority 2:
Urchin Health Issues
Health concerns
ran a close second to the closure and reseeding issues.
Urchin health and urchin diseases are neither well understood nor well
defined in the scientific literature, particularly in light of the possibility
of significant regional differences. Urchin
populations experience periodic die-offs.
Environmental stress is known to be one significant variable in these
episodes but what the specific stressors are and how they operate within
urchin populations is unknown. In
addition to the oceanographic changes contributing to environmental stress,
participants considered a number of human activities including harvesting
methods and pollution. The
traditional elements of the urchin fishery:
shipping, processing, and dumping waste across habitats all provide
opportunity for the spread of a disease.
Now, as the fishery becomes involved with reseeding urchins from both
hatchery operations and wild stocks, the disease issues become more complex.
The state health infrastructure is unable to do significant monitoring,
diagnostics, or management.
Research
priorities are:
a)
Define and prioritize disease issues raised by urchin aquaculture.
b)
Examine health issues raised by reseeding urchins from one locale to
another.
c)
Examine effects on urchin health of human activities such as harvest
method, disposal of processing wastes, dredging, and pollution.
d)
Document the capacity of the current health management infrastructure
and make recommendations for change.
-
Can the urchin industry collaborate in health monitoring?
-
Best management practices for the urchin industry.
VII. Sea
Urchin Observations and Questions from Discussion
Aquaculture Techniques
Cues
that can be used to trigger metamorphosis in hatchery.
Raising
juveniles from settlement to size where can be planted in the wild.
Penning
and holding urchins: techniques,
issues.
Assessment Techniques
Develop
assessment collaboratively including setting purpose, design, and execution.
What
is the value of counting urchins given the historic variability of stock? Can it be useful in giving us a sustainable yield?
Prior
to assessment design, decide purposes for assessment:
-
To know how to make the most of what we have (catch per unit effort);
-
To assess roe value and market value;
-
To protect brood stock.
What
is a cost-effective assessment strategy given the length of the Maine coast?
Conduct
multiple models of assessment rather than perfecting one.
Link
the life history information to assessment and modify models, protocols as
needed.
Would
a larval survey provide ability to predict recruitment?
Assess
all urchins larger than 3".
Standardize
survey methods and measurements such as density measures with Canada.
Evaluate
the current landings data collection and if necessary, improve the landings
data: quantity, location, time.
Relationship
between landings and effort is skewed due to the fact that the fishery is
managed by limiting the days fished.
Would
mandatory trip reports be advantageous?
Tag
harvest like clam tags to provide better fishery information.
Collect
information on catch per day, landings, and effort per day from fishermen for
the years prior to 1994 when state started collecting effort information.
Behavior
How
do urchins actually move across the bottom?
What
is the behavior of juvenile urchins to avoid predators, seek refuge?
Where
do the urchins found in deep water come from?
At what stage?
Where
in the water column are urchin larvae?
What
is the relationship between population density and reproductive success?
Role
of larger urchins in providing habitat for juveniles?
What
is the right density for urchins? For
what?
Understand
the spawning triggers to a degree that it is possible to predict the time of
spawning.
What
role do urchin clusters play in spawning success?
Why
are there millions of small urchins in some locations?
Ecology, Species Interaction
Are
lobsters or groundfish urchin predators?
Relative
abundance of seaweeds, predators, and urchins at life stages.
Roe
is more marketable on seaward side of islands:
Why? Circulation, current,
feed?
Impact
of codium on kelp populations and implications for urchin populations.
Predators
in macroalgae community.
Effectiveness of Management Measures
Evaluate
effectiveness of closures for spawning and conservation.
Can
small urchins be relocated effectively to non-productive areas where there is
feed available?
Does
penning and holding urchins work?
Would
an oversize measure be useful? Are
large urchins successful reproducers?
Could
you enhance reproduction by moving urchins close together at spawning?
Procedures
for catch per unit effort and landing reports need to be examined for
validity, accuracy, and bias.
Does
taking the legal size urchin impact the ability of the population to produce
large individuals?
Document
effectiveness of reseeding on natural recruitment.
What
is the appropriate scale of a conservation closure?
Logic is important for compliance -- whole island closures, etc.
What
is the survival rate of culled urchins? Is
there a benefit to on-bottom culling?
Growth and Development
Better
understanding of how fast urchins grow; age at size.
How
long do urchins live?
Study
of age distributions -- in New Brunswick some 14-15 year old animals. Lubec Narrows, 4-6 year olds -- need systematic study.
What
is the age/size relationship, and how does this vary depending on location?
How
the rudiment is derived from earliest larva?
Growth
at early post-settlement stage.
Cues
that can be used to trigger metamorphosis in hatchery.
Impact
of juvenile urchins' refuge-seeking behavior on growth and development.
What
happens to juveniles that drift offshore?
Does
settlement occur in deep water?
Health
Conduct
better analysis of dead urchins.
Capture
and record anecdotal information about urchin die-offs to create a database as
a start to disease management.
Develop
a communications system for industry to tell DMR about die-offs.
Better
health infrastructure needed: disease
surveillance, diagnostics, and health management plans.
Both
a "healthy" urchin and an urchin "die-off" need to be
defined.
Do
basic work to describe urchin diseases.
What
is the risk of processing waste dumped at sea or in overboard discharge
spreading disease?
Is
there a correlation between population density and disease?
Are
there oceanographic phenomena that can be correlated to die-offs that can be
used as predictors?
Do
analysis of dead urchins.
Is
there an urchin health benefit to culling on the bottom rather than from the
boat?
Reconsider
disease questions if reseeding efforts become widespread.
What
role does stress play in urchin disease?
Does stress of moving in relocation efforts contribute to disease?
What
role does water quality, especially herbicide run-off, play in susceptibility
to disease?
Relationship
of algae blooms and urchin die-offs?
Do
hatchery-raised urchins carry disease?
Build
a network of information from industry on health observations and related
environmental observations.
Impacts of Fishing/Human Activities
What
is the impact of fishing techniques on urchin movement?
Is
it possible that draggers help clear the bottom (of kelp) and that this is
beneficial?
Document
the benefits of a diver's collector bag size limit.
Assess
impacts of dragging, dredging, and pollution on urchin health.
Documenting
and evaluating culling mortality and its relationship to urchin health.
Urchin
processing waste as a vector for disease.
Stress
factors in moving urchins for reseeding.
Impacts of Aquaculture
Effects
of leases on wild population.
Disease
issues in urchin aquaculture.
Genetics
issues in urchin aquaculture.
What
are the effects on the wild stock of introducing hatchery stock into the wild?
What
are the effects of introducing Nova Scotia urchins (or urchin waste) into
Maine waters?
Management
Find
ways to resolve the contrast in pace between fishermen's action and research
so that fishermen will participate.
Hold
a workshop on assessment for fishermen, scientists, and managers about what an
assessment can tell us.
Develop
a communications system for industry to notify DMR of die-offs, unhealthy
urchins, and related environmental observations.
Interact
with seaweed industry to reduce conflict and address valid concerns of both
industries. Mutually beneficial action may be possible.
Provide
waterproof maps of closures to harvesters.
Make
closures practical and understandable -- e.g. close an entire island instead
of part of one.
Interest
in community management where locals participate in stewardship of their own
area in exchange for exclusive access - as a community not as private owners.
Pace
of research is not fast enough for fishermen who work on intuition, hunch --
how to mesh the two demands.
Oceanography
Where
in the water column are urchin larvae?
What
are the currents at those depths?
Urchins
spawn during spring run-off. Does
the run-off drive juveniles out into the Maine Coastal Current?
Do the larvae from early spawners go different places than those from
late spawners in a given area?
Are
hurricanes and disease outbreaks correlated?
Impact
of temperature, Gulf Stream rings on disease.
Processing/Handling
How
can shelf life be extended?
Reproduction
Are
large urchins competent reproductively? Do
they contribute to reproduction?
Research
the relationship of urchin spacing and gonadal development on fertilization
success.
What
role do urchin clusters play in spawning success?
Reseeding Techniques
Develop
collaborative reseeding experiments.
What
is the optimal time for release of hatchery raised small urchins?
-
Currents, temperature, predators.
Should
hatcheries for reseeding be local to the area where the urchins will be
seeded?
Need
health check before moving urchins.
Does
"nucleation" work -- clearing kelp from a small area and reseeding
urchins to the area. How big does
the area need to be? Will the area spread?
When
is the optimal time for reseeding wild urchins?
How
important is it to relocate urchins to similar habitat (especially
temperature) to avoid disease, enhance survival?
Does
moving urchins cause stress that triggers disease outbreaks?
Socio-economic Issues
How
can we change the market structure to reward quality?
Pros/cons
of aquaculture vs. community management and enhancement.
Development
of governance for community management.
Species Identification
Short-spined
vs. long-spined.
Attachment
A:
NORTHERN
SHRIMP RESEARCH PRIORITIES
MEETING
ATTENDEES
May 11, 2000 at Orland Town Office
51 Participants
Richard Bubar
P.O. Box 207, Stonington 04681
367-2417
Jeannette Bubar
P.O. Box 207, Stonington 04681
367-2417
Gordon J Gianninoto
P.O. Box 73, Sedgwick 04676
359-2345
Seth Harkness
R1 Box 439A Deer Isle 04627
348-0908
Bill Sutter
P.O. Box 109, Wiscasset 04578
882-7230
Austin Humphries
P.O. Box 94, Perry 04667
853-6694
Ivory Preston
438 Roque Bluffs Rd., Machias 04654
255-8095
Bruce McInnis
1 High Street, Eastport 04631
853-4328
Adelbert Vinal Jr.
419 Glenmere Rd., Tenants Harbor
372-8181
Jamie Huntsberger
GSH1, Sunset 04683
266-2167
Cecil Cates
138 Water St., Eastport 04631
853-4423
Hank Stence
RFD2, Box 5120, Lubec 04652
733-4489
Ralph DeWitt
9 High St., Eastport 04631
853-0662
Michael Russell
Villanova University, PA 19085
610-519-4695
Ted Creaser
DMR, Boothbay Harbor
633-9518
Bob Steneck
UM Darling Marine Center, Walpole 04573
563-3146
Larry Harris
UNH, Durham, NH 03824
603-862-3897
Lindsay Seward
University of Maine, Orono
581-2954
Bob Vadas
University of Maine, Orono
581-2974
Joe Dwyer
567-3684
John Vavrinec
UM Darling Marine Center, Walpole 04573
563-3146x304
Amanda Leland
UM Darling Marine Center, Walpole 04573
563-3146x275
Rick Wahle
Bigelow Lab, W. Boothbay Harbor 04575
633-9659
Jeffrey Alley
P.O. Box 581, Winter Harbor 04693
963-7139
Chris Byers
P.O. Box 581, Winter Harbor 04693
963-7139
Maggie Hunter
DMR, Boothbay Harbor
633-9541
Linda Mercer
DMR, Boothbay Harbor
633-9525
Tony Fitch
Rockland
273-5996
Tristan Smith
RR3 Box 952, Belfast 04915
338-4583
Rob Odlin
175 Hancock St., So. Portland
767-0796
Jim Bolen
Friendship
Paul Molyneaux
Trescott
733-5502
Jim Wadsworth
P.O. Box 1005, Camden 04843
763-4709
Shawn Robinson
St. Andrews, NB Canada EB5 229
506-529-8854
Darrin Gendron
3 Pheasant Rd., Saco 04072
282-4467
Paul Waterstrat
DMR, Boothbay Harbor
633-9500
Robert Thomas
HC 33 Box 559A, Spruce Head
04859 594-0560
Dan Placzek
37 Hillside Rd. Orono 04473
866-3700
Jesse Leach
N. Penobscot 04476
326-1723
Eric Gilliam
273 Small Pt Rd, Phippsburg 04562
389-1723
L. Blair Pyne
P.O. Box 208, Bremen
529-5427
Terry Stockwell
DMR, Boothbay Harbor
633-9500
Randy Bacon
Prospect Harbor
963-2686
Richard White
Trenton
667-7506
Atchan Tamaki
P.O. Box 772, Portland 04104
879-1575
Julia Soper
312 Bethel Pt Rd, Harpswell
729-8785
Dean Norris
HC 60 Box 2715, E. Livermore 04228
Paul Anderson
Sea Grant / UM Cooperative Extension
581-1435
Sue Inches
DMR, Augusta
624-6558
Sherman Hoyt
Sea Grant / UM Cooperative Extension
800-244-2104
Robin Alden
PO Box 274, Stonington 04681
367-2473
Attachment
B:
Research
Needs: Sea Urchin Disease and Health
Paul
Waterstrat DVM, Ph.D., Maine Department of Marine Resources
Maine DMR Coastal Fishery Research Priority Meetings
May
11, 2000
Disease
plays a significant role in the population dynamics of all living organisms
from humans to single-celled planktonic algae.
The effects of disease on marine resources and marine resource
dependent industries include: direct mortality, increased rates of predation
due to impaired performance, decreased reproductive effort and recruitment,
decreases in product yield, quality, grade, safety and marketability, and
finally decreased public perception and acceptance of both the seafood product
and the industry.
While “natural mortality”
is a widely recognized factor in fisheries management, the
recognition and assessment of
disease in wild populations is problematic.
There have been only limited efforts at disease surveillance in wild
aquatic species. Diagnostic
assays and procedures are limited, making sampling difficult and expensive. Little research funding exists for the development of
diagnostic procedures, surveillance programs, or epidemiological
investigations of disease outbreaks.
The
failure to implement and maintain disease surveillance and health management
programs for fish and aquatic resources has lead to catastrophic mortality,
significant economic loss and the collapse of such fisheries as herring,
lobster, oysters, salmon and trout. Treatment
of wild, free-ranging aquatic species is rarely a management option.
Health management in these fisheries is dependent on prevention by
either limiting disease exposure or by removing diseased animals to reduce
disease transmission. There has
been limited or no research on developing predictive models for disease
control in aquatic species, or for determining the effectiveness of management
responses to disease outbreaks.
Immediate
needs for the maintaining the sustainability of Maine’s urchin industry
include:
1)
Develop and implement a disease surveillance program.
Disease surveillance is essential so that disease control measures can
be instituted before the disease becomes catastrophic.
Disease surveillance would also allow improved assessment of the urchin
resource with respect to reproduction, recruitment and product quality.
Urchins are generally consumed raw, therefore a surveillance program
may also address the increasing public concern over food safety issues
associated with raw seafood products.
2)
Improve diagnostic procedures for urchins.
Research efforts on urchin health have been limited so few procedures
for urchin health assessment have been established. Improved procedures and capability are essential to disease
surveillance and health monitoring.
3)
Establish either voluntary or mandatory management practices to prevent
the spread of infectious disease within the state. While protocols exist for
the health inspection of hatchery urchin seed, regulatory procedures for
intra-state transfer of wild urchin are ill defined.
This issue is critical to the transfer of urchins among beds or areas
within the state. Implementation and documentation of surveillance and
management programs are also essential in providing data to address the
concerns of other fishing groups, the public and the media that the urchin
industry is responsible and prudent in its utilization of a public resource.
Biosecurity issues associated with sea urchin processing are a growing
concern to both state and federal agencies.
Improper disposal of wastes from imported urchins poses a disease risk.
Health
management of the urchin resource, like most aquatic species, lacks a coherent
infrastructure for dealing with disease or health. These disease risks are
significant and can threaten not only urchins but other fisheries resources as
well. Urchins may act as vectors in disease transmission and many of the
infectious agents associated with urchins can also affect other marine
species. Critical issues
associated with developing a basic infrastructure are outlined below:
Infrastructure
for disease surveillance:
-
Develop sampling protocols and plans
-
Develop, test and evolve where, when, how
-
Mechanism for reporting and epidemiological investigation
Infrastructure
for diagnostics and diagnostic labs:
-
Research to establish improved diagnostic procedures
-
Expertise, capability, quality control
-
Need basics now
Infrastructure
for health management:
-
Responsiveness is the goal
-
Development of action plans
-
Delegation of responsibility
-
Regulatory pathways developed and established
Basic
management practices (BMPs):
-
Surveillance
-
Biosecurity
- Waste
management
Attachment
C:
Sea
Urchin Management Issues
Robert Steneck, Ph.D., Darling Marine Center, University of Maine
Maine DMR Coastal Fishery Research Priority
Meetings
May
11, 2000
Are
we harvesting sea urchins sustainably? If
not what are some of the consequences?
What are some of the possible solutions?
These questions frame my comments on management issues related to the
sea urchin industry in Maine.
Most
harvesters polled by the Sea Urchin Zone Council (SUZC) believe that stocks
are not being harvested sustainably. This
view is supported by Maine Department of Marine Resources' (DMR) fisheries
dependent data. That data shows a
steady decline since 1993 in landings, catch per unit effort, and in number of
licensed harvesters. Similarly,
fisheries independent data shows that the population density of urchins has
declined statewide. Specifically,
both the number of urchins per unit area and the size of urchins have declined
since the early 1990s. Abundance
declines occurred earlier and at a higher rate in the western most regions of
Maine and occurred later and are less evident in eastern zones.
One
troubling correlate with the demographic declines is the observation that
rates of settlement are declining statewide.
It is unknown if these declines are the result of a reduced
reproductive potential (i.e. recruitment overfishing) or due to oceanographic
events that have caused a decline in larval delivery in Maine's coastal zone.
If the latter process is controlling the decrease in decline, then this
is not an issue that can be addressed by management. Whatever the reason, if it continues, the long-term prognosis
for the fishery is not good.
Declines
in urchin abundance have caused changes in the coastal ecosystem.
Sea urchins are the dominant grazer in coastal zones of the Gulf of
Maine. As urchin abundance and
size declined, herbivory (eating of seaweeds) decreased.
With little or no grazing, seaweed (algal) biomass increased statewide.
Kelp forests and macroalgal carpets change the habitat characteristics
of the ocean floor. Living under
the canopy of macroalgae are a variety of small invertebrates such as worms,
baby crabs and sea fleas (amphipods). Significantly,
the survival of settling sea urchins declined dramatically in algal rich zones
in western Maine. Other regions of the coast that have experienced relatively
modest increases of macroalgae have not (yet) had the high post-settlement
mortality that has been recorded in Maine's western-most region.
Other studies have found that the invertebrates living under the algal
canopy are micropredators of settling sea urchins.
Laboratory studies found that small crabs can and do eat newly settled
urchins. Further, micropredators' densities are as great at 200 per
square meter under seaweed canopies but absent in heavily grazed urchin barren
ground. Thus it appears that
fisheries induced declines in urchin abundance and size translates to improved
habitat for micropredatory crabs that consume virtually all newly settled sea
urchins within one year. Since
urchins cannot naturally reseed themselves in an environment rich with
micropredators, then grazing will remain low and the system will remain stable
in the macroalgal-dominated state.
Possible
Management Solutions:
The
Sea Urchin Zone Council (SUZC) has been aware of the urchin declines,
ecosystem changes and micropredator impacts on settlers.
They have adopted a multi-tier strategy to respond to these changes.
To
reduce overfishing, effort has been reduced by first limiting entry into the
fishery. A new person can enter
the fishery for every five that leave. The
number of fishable days has declined to 120 days and is discussing reducing
the fishing days even further. Stricter
limits on enforcing existing regulations has been accomplished by using zone
council funds to hire marine patrol officers to work overtime to catch and
inhibit transgressors.
To
determine how long it takes for unfished populations to recover, 6 regions
were closed to fishing for scientists to monitor demographic changes over
time. The zone council approved research to examine changes to
urchin settlement, survival, population density and biomass over time.
If changes in the ecosystem causes micropredator abundances to remain
high in closed areas, it is unlikely that changes will occur unless the
micropredator abundances are controlled.
To
reverse ecosystem change and micropredator abundance, the SUZC has proposed a
reseeding study to graze down algae and eliminate cover for micropredators.
This sort of bioremediation could greatly increase the productivity of
urchin stocks in seriously depleted areas.
If successful, there should be opportunities for the industry to fish
areas that have recovered and are having successful settlement.
To
prevent a repeat in overfishing, the SUZC is considering rotational closures.
With such closures areas would be left unfished until stocks build up
and then fished every 3 - 5 years depending upon growth rates.
Research on closed areas and the reseeding experiment are designed to
guide management of rotational closures.
Attachment
D:
Life
History Considerations for Sea Urchin Stock Enhancement
Larry G. Harris, Ph.D., University of New Hampshire
Maine DMR Coastal Fishery Research Priority Meetings
May
11, 2000
Populations of the green sea urchin, Strongylocentrotus
droebachiensis, are in decline in the Gulf of Maine due to
overexploitation. Natural
recruitment of sea urchins in depleted sections of the GOM is also declining,
possibly due to reduced reproductive potential of remaining stocks.
Natural recovery of sea urchin populations in fished out areas will
take years to decades since recruitment into recovered seaweed dominated
communities is extremely low. However, we know enough about the life history and ecology of
sea urchins to suggest that recovery of populations can be increased for stock
enhancement of natural populations and/or sea ranching.
What follows is a short description of how populations of sea urchins
might be reestablished based on what is known of the life history and ecology
of sea urchins.
Reproduction in the green sea urchin is highly
seasonal in the GOM. The gonads
produce eggs or sperm through the fall and early winter and natural spawning
begins in late winter and continues into spring.
Spawning urchins communicate by water born cues to synchronize release
of gametes by localized populations to increase fertilization.
There is evidence that the spring phytoplankton bloom may stimulate
spawning to coincide with maximum food availability for larval urchins.
Larval urchins or plutei remain in the water column for a month or more
feeding on micro plankton. Settlement of larvae to become juveniles begins in late May
and continues through July. Recruitment
studies over the last six years suggest that recruitment is low in the
northern portions of the GOM and high, but declining, in the southern portions
of the Gulf.
Settling larval urchins will metamorphose on
any hard substrate, but tend to show a preference for live coralline algal
crusts. Newly transformed urchins are about 0.5 mm in diameter and
take about three weeks to complete the metamorphosis and begin feeding on the
surface film that coats all marine surfaces.
Growth is highly variable among individuals, but it is about two months
before individuals are capable of feeding on fleshy seaweeds.
The green urchin has well developed gonads by the time it is 25 mm in
diameter, thought studies have shown that the larger a sea urchin is, the
greater its reproductive potential. Under
ideal feeding conditions an urchin might reach the legal size of 52 mm in
three years, but there can be wide variation in growth conditions in the field
and most populations of urchins probably take between five and ten years to
reach legal size. If an urchin
takes even five years to reach legal size, it will have reproduced at least a
couple of times before it is harvested, though its reproductive potential will
be less than larger individuals. Green
sea urchins may live from 30 to 50 years and their growth is highly variable
and dependent on how much food is available.
I have seen no indication from laboratory growth experiments or field
studies to indicate that there is a dwarf race of urchins in the Gulf of
Maine.
Studies by K. H. Mann of Dalhousie University
in the 1970's showed that recruitment of urchins was highest in newly formed
urchin barrens in contrast to established barren communities and almost no
recruitment occurred in kelp beds. Larval
urchins settle everywhere, but survival does appear to be best in areas of
intermediate urchin densities. Growth
and roe content appears to be highest when there is abundant food and good
water motion from tides, currents or surge.
Urchins also move very little when there is food available and tend to
aggregate in mixed size groupings when there is an abundance of drift seaweed
to trap and feed upon.
Enhancement of natural populations and
restoration of depleted urchin stocks is possible, but the approaches will
vary depending on where in the GOM the effort is to be undertaken.
Natural recruitment is much lower from Penobscot Bay north and higher
to the south. Recruitment of
settling juveniles will be higher where intermediate densities of urchins
remain to clear algal growth and reduce the densities of small predators. In
depleted areas that have returned to seaweed dominated communities, addition
of larger urchins is likely to be necessary to improve natural recruitment of
juveniles. Studies of the
effectiveness of reseeding on natural recruitment would be most informative.
Hatchery systems to produce small urchins for
out-planting are feasible and this approach has been used in Japan.
The techniques for spawning and raising larval urchins are well
established, though scaling up to commercial scale production will require
investments of effort and resources. A
more difficult problem will be the raising of juvenile urchins from settlement
size of 0.5 mm up to a size where survival when seeded is reasonable.
The Japanese raise juveniles to about 20 - 25 mm before releasing them.
In the highly seasonal GOM, timing of release may be more important
than size. Warm water
temperatures and predator abundance are likely to make summer seeding a poor
risk. Winter seeding when
predators are mostly inactive has been shown to be much more effective. Juveniles may be grown to 10 or more mm in less than a year
and out planting of this sized urchin in the winter should result in high
survival.
In
summary, I would suggest that regional hatcheries using urchins adapted to
local conditions could be used for stock enhancement and sea ranching of
urchins. A hatchery system would
produce juveniles through the late winter and spring spawning period. Juvenile grow out to about 10 mm is feasible over the next
nine months and small urchins could be out-planted in the winter before the
next spawning period. Seeding
will be most effective in areas with some populations of larger urchins
already present to boost the potential survival of both winter seeded urchins
and natural recruits the following summer.
Attachment
E:
Surveying
for Sea Urchins in Southwestern New Brunswick
Shawn
Robinson, Ph.D., Dept. Fisheries and Oceans (DFO)
St. Andrews, New Brunswick, Canada
Maine DMR Coastal Fishery Research Priority Meetings
May
12, 2000
The
sea urchin fishery, in southwestern New Brunswick in the Bay of Fundy,
initially developed as an additional source of product for the industry based
in the United States. Small landings (1-2 tons) occurred in the 1950’s and
1960’s just before the Christmas season on Campobello, but the industry did
not really develop until 1987. The
majority of the harvesting effort in the area has been with the use of drags,
although the number of diving-based operations has increased to almost 50%.
In 1994 the drag fishery switched from using scallop drags to a lighter
gear known as the “Green” drag. Landings
have steadily risen from 47 tons in 1987 to a peak of 1,900 tons in 1996 and
have subsequently dropped to 1,709 tons in 1999.
The value has increased from less than $16,000 during this period to
over $4 million. The fishery is
regulated through limited entry, size limits, seasons, time of harvesting,
gear restrictions, sorting catch at sea, statistical reporting through a
logbook program, protected areas for scientific research, sanctions and
dockside monitoring with individual non-transferable quotas.
One area uses a total TAC with an individual cap on landings.
Urchin
population surveys are a key part of urchin management in New Brunswick.
Prior to starting large-scale surveys of the Quoddy region and Grand
Manan, preliminary information on the sea urchin populations was gathered from
several sources in order to design the sampling protocol.
Information was collated on sea urchin densities from the surveys of
Neish (1973) and MacKay (1976, 1979). Information
from logbooks was used to determine the location of the existing important
commercial beds. In addition,
individual fishermen were interviewed confidentially and their information was
used to better define areas that should be surveyed. All this information was
used in conjunction with the local knowledge of the Invertebrate Fisheries
Section at the DFO Biological Station at St. Andrews, NB, to classify sections
of the coastline into high, medium, or low priority.
The entire coastline of the study areas was divided into 250-meter (m)
intervals as potential transects. Transects
were randomly assigned in each section of coastline and the number of
transects per section was based on the length of the section and the weighted
importance factor of high:medium:low (4:2:1).
For example, a high importance section would receive four times as many
transects as a low importance section of the same size.
The
transect apparatus consisted of a collapsible two-meter bar with 150 meters of
3/16" nylon transect rope wound on a centred rotating spool. The line was divided into one-meter increments with markers
and had increment tags every ten meters.
The bar would collapse and the rotating spool had an attached handle to
facilitate rewinding the survey line at the conclusion of each transect.
Each
transect began at mean low water (MLW) and continued perpendicular to shore to
obtain a cross section of the sea urchin population as it varied with depth
and distance from MLW. Two divers
would swim side-by-side, jointly holding the transect bar and counting the
urchins as they passed under the bar. The transect continued for a distance of
150 meters or to a maximum depth of 25 m (75 ft). On a few occasions the dives
continued to 33 m (100 ft) when visibility was adequate and the urchin
populations remained interesting. Completing
a transect took approximately one hour and occasionally exceeded one and a
half hours when counting became difficult with high urchin numbers, or when
heavy seaweed cover was encountered. Landmarks
were noted for each transect location so that each one could be repeated at
later dates for continued stock information.
Each
diver counted the number of sea urchins one meter out from the transect line
and recorded the total number after each ten meter section.
At the conclusion of each 10m section, observations on relative sea
urchin size, water depth, bottom type, macrophyte composition, and other
commercially important benthic species were recorded. Upon completion of each transect, four collections of 100
urchins each were made at intervals along the transect to best indicate the
changing population characteristics with depth.
An effort was made to collect all the animals from a particular area in
order to avoid biasing the estimate of the population size structure.
The four collections of sea urchins were then returned to the vessel
where they were measured for test diameter to the nearest millimeter with a
specially designed measuring board.
This
survey technique was used both in 1992-93 and in 1994 to survey the coastline.
Certain reference transects in key areas were chosen to re-survey in
subsequent years using the same technique.
The results of this type of surveying technique enable us to get a much
better picture of the size ranges of animals from populations and also a very
good estimate of numbers of animals less than 1 inch.
The surveys also showed how there were changes in numbers of animals
along the shore as well as a dramatic decrease of urchins with depth.
The survey allowed us to calculate the numbers and weight of animals
within a zone and from this we were able to calculate a standing stock of sea
urchins within a management area. Once
we had this, we could then set an exploitation rate (3-6% annually of the
harvestable biomass).
The
benefits to this type of work are:
1)
It is a much more accurate way of looking at the population
characteristics.
2)
It gets the fishermen involved in managing local sea urchin
populations.
3)
It supplements the information received from fishing logs.
4)
It allows for comparisons to be made between years.
5)
It allows for initial calculation of total allowable catches.
6)
It allows for further work to be done at the same time.
The
perceived drawbacks of this type of work are:
1)
There is a significant cost to getting this information.
2)
It requires the support
of the industry (both moral and logistic)
3)
It needs to be done on a semi regular basis.
4)
There needs to be a center for organization, collating and storage of
the data.
In
our experience, the drawbacks can be relatively easily overcome.
