|
|
Sea Lice/Pink Salmon - Report
(May 2004)
Click here for a printable PDF copy of
this report.
Proceedings of the
PSARC Habitat and Salmon Subcommittee Meeting
April 6-7, 2004
Nanaimo, BC
B. Antcliffe
Subcommittee Chair
Fisheries and Oceans Canada
Pacific Scientific Advice Review Committee
Pacific Biological Station
Nanaimo, British Columbia V9T 6N7
May 2004
PACIFIC SCIENTIFIC ADVICE REVIEW COMMITTEE (PSARC)
HABITAT AND SALMON SUBCOMMITTEE MEETING
INTRODUCTION
DETAILED COMMENTS FROM THE REVIEW
-
H2004-01: Sea lice on juvenile salmon and on some non-salmonid
species caught in the Broughton Archipelago in 2003
-
H2004-02: Abundance and distribution of juvenile salmon and
other fish caught in the Broughton Archipelago, Knight Inlet
and Muchalat Inlet, B.C. in 2003
-
H2004-03:
Evaluation of site selection methodologies for use in marine
protected area network design
-
H2004-04: A
Science-based Boundary for the Central Coast Integrated
Management Area
APPENDIX 1:
Working Paper Summaries
APPENDIX 2: PSARC
Habitat Subcommittee Meeting Agenda April 6-7, 2004
APPENDIX 3. List of Attendees
SUMMARY
Four working papers were reviewed by the Pacific Scientific
Advice Review Committee’s (PSARC) Habitat and Salmon
Subcommittees on April 6-7, 2004 at The Grand Hotel in Nanaimo,
BC. Topics covered by these papers included results of the
Pink Salmon Action Plan Marine Monitoring Program (MMP) in the
Broughton Archipelago in 2003, an evaluation of candidate
marine protected area site selection methodologies, and a
proposed Central Coast Integrated Management (CCIM) boundary.
The two MMP papers assessed 1) distribution and relative
abundance of juvenile pink and chum salmon (and other marine
fish species) and 2) prevalence and infection rates of sea
lice on juvenile salmon in the Broughton area. The analysis
indicated that juvenile pink and chum salmon were spatially
distributed throughout the Broughton area in the 2003 sampling
period. No significant adverse effects of sea lice on juvenile
salmon growth and condition factor were observed for the
period studied. Sampling was terminated, however, about the
time the intensity of the sea lice motile stages were
increasing. The subcommittee agreed that the base-line
juvenile salmon distribution data collected in 2003 will be
useful in providing the foundation for more deductive-type
studies in the future. Future studies should be designed to
identify potential sea lice sources/reservoirs and factors
affecting sea lice prevalence and infection rates including
fish density and physical and chemical oceanographic
steady-state variables.
The paper entitled “Evaluation of site selection methodologies
for use in marine protected area network design” identified
and compared different methodologies used for the selection of
candidate marine protected areas (Areas of Interest). The
report also referred to two case-specific applications of
these algorithms currently being used in Canada. These
projects, by Living Oceans Society and World Wildlife Fund
Canada, were highlighted with regard to their potential
applicability to future DFO studies.
The final paper presented “A science-based Boundary for the
Central Coast Integrated Management Area” as a proposed
modification to the current Central Coast ‘working boundary’.
The boundary modifications proposed in this document represent
a relatively new approach to boundary definition based on a
more comprehensive consideration of scientific and ecosystem
information. The boundary is intended to define the Large
Ocean Management Area (LOMA) for BC’s Central Coast as a pilot
area for integrated management. The main criteria used to
define the proposed modifications of the boundary were
physical environment (e.g. habitat, bathymetry, substrate,
oceanography) and biological information.
INTRODUCTION
The PSARC Habitat and Salmon Subcommittee met April 6-7, 2004
at The Grand Hotel in Nanaimo, British Columbia. The Habitat
Subcommittee Chair, B. Antcliffe, opened the meeting by
welcoming the participants. During the introductory remarks
the objectives of the meeting were reviewed, along with the
protocol to be observed by external participants and
observers. The Subcommittee accepted the meeting agenda.
The Subcommittees reviewed four Working Papers. Summaries of
each are in Appendix 1. The meeting agenda appears as
Appendix 2. A list of meeting participants, observers and
reviewers is included as Appendix 3.
DETAILED COMMENTS FROM THE REVIEW
H2004-01: Sea lice on juvenile salmon and on some non-salmonid
species caught in the Broughton Archipelago in 2003.
Simon Jones and Amanda Nemec.
H2004-02: Abundance and distribution of juvenile salmon and
other fish caught in the Broughton Archipelago, Knight Inlet
and Muchalat Inlet, B.C. in 2003.
Brent Hargreaves, Doug Herriott and Vic Palermo
Subcommittee Discussion (H2004-01 and H2004-02)
The Subcommittee (SC) agreed that the objectives of the two
working papers as described in the PSARC working paper
requests were largely met. Although some reviewers commented
on the lack of a specific study design for hypothesis testing
that linked captive fish in farms, wild fish and sea lice, the
authors noted that the study objectives were not designed to
examine cause and effect relationships among sea lice
infection rates and fish farm site location or farm management
practices. The SC agreed with the reviewers, however, that
the design was not appropriate to address this relationship,
or allow interpretation beyond the descriptive analysis of the
data as presented in the working papers. The authors
commented that additional analyses are ongoing to further
explore the data collected in 2003.
The SC also acknowledged that the 2003 Marine Monitoring
Program (MMP) was an important first step in gathering
important base-line information and data on distribution of
juvenile pink and chum salmon and current state of sea lice
infection rates in the Broughton Archipelago. This
information would form the basis of the experimental design of
future sampling where hypothesis can be established and
tested.
The SC discussed the potential sources of sea lice infection,
including captive farmed salmon, wild adult and juvenile
salmon as well as non-salmon species, and agreed that there
are potentially multiple sources of sea lice. It has been
hypothesized that the captive farmed salmon could act as
reservoirs in addition to natural sources. A senior author
(H2004-01) commented that non-salmon species such as smelt and
herring could be a source of infection for Caligus species,
but not for L. salmonis.
The principal focus of the study was on juvenile pink and chum
salmon, thus some of the reviewers queried why so much of the
analytical effort was devoted to sticklebacks. They also
noted that herring and smelt were more abundant than pink and
chum salmon or sticklebacks, based on survey catch data, and
they represent species that could be important sources for
some species of sea lice, compared to sticklebacks. Most SC
members agreed that the data for non-salmonid species were a
valuable contribution to the report. The SC agreed with a
reviewer that the sampling information from Muchalet and
Esperanza inlets contributed little to the assessment of
juvenile sea lice and juvenile salmon in the Broughton Area.
Part of the rationale for the study, as identified in the
Request-for-Working Papers, was to determine if there was a
significant main migration corridor for juvenile salmon
migrating through the Broughton area during the sampling
period, as hypothesized in 2002. The MMP study was not
definitive with respect to the null hypothesis that the bulk
of juvenile salmon from the Broughton Archipelago and Knight
Inlet do not migrate seaward via the hypothesized “migratory
channel”. Reviewers suggested further analysis of fish size
variation, spatial and temporal fish distribution and
oceanographic variables be carried out to enhance the
interpretation of the migration corridor hypothesis. The
authors noted that they had carried out such analyses, but the
findings were inconclusive. The senior author (H2004-02)
suggested that a mark-recapture experiment was the only direct
way to confirm the existence of a migration corridor.
Although the methods used to collect the samples are well
established sampling techniques, one reviewer recommended that
the authors provide information on whether the techniques that
they used for copepod collection may have led to
underestimates of some species of sea lice such as Caligus
clemensi.
Statistical and sampling design was debated. Some
participants cautioned that the authors may be unable to
separate the effects of salinity, weight and fish size from
the effects of fish farms in any future data analysis as these
are co-variables and thus not independent (i.e., salinity
increases as fish move to and beyond fish farm sites).
Although it was noted that other software (e.g. SatScan) may
be useful for analyzing spatial and temporal dynamics of louse
infections, participants cautioned that all sources of
infection, including captive farm salmon and natural sources
and factors, would need to be assessed. There was a
suggestion that researchers may need to find a reference area
elsewhere on the Central Coast to study these natural factors
in non-farmed waters. Additional analyses of the new data
obtained by the authors in 2003 from Muchalat Inlet, prior to
the installation of the first fish farm in August, may prove
to be valuable in this regard. It was also suggested that the
authors should conduct a more detailed statistical analysis
using non-averaged data to assess within-zone effects of
factors influencing sea lice prevalence.
It was the view of one external expert that louse nauplii are
planktonic for up to seven days prior to molting to the
infectious copepodid stage. This expert further concluded
that any study trying to identify the source of lice in the
Broughton or elsewhere must be cognizant of the fact that
nauplii distribution is dependant on tidal and other current
patterns for their dispersal. Any future studies attempting to
link cause and effect should take this complex relationship
into consideration.
Although it was stated in the paper that “the study was not
designed to answer questions relating to the origins of
parasitic copepods on wild juveniles”, one reviewer and some
SC members acknowledged that the authors should make greater
efforts to compare their data to that collected in other sea
lice studies in the Broughton area. This reviewer stated
that the sea lice numbers reported in the 2003 MMP were
generally lower and the proportions of sea lice species
present were reportedly different than the results of an
independent research sampling in 2002 in this area. It was
suggested that the differences among years may indicate that
there is large annual variability in the species of sea lice
present and their numbers. As mentioned by the authors and
reviewers, further research on the oceanography of the area,
the abundance of wild hosts and the variability in sea lice
populations among years may be valuable.
An invited expert stated that the most striking difference
between the findings of this study and other studies on sea
lice infestations on Salmo species was that fish growth and
condition seemed little (if any) affected by sea lice. This
expert indicated that other studies show significant
differences in Salmo growth and condition factor responses to
lice infestation. The results further emphasize the need for
caution in comparing studies on sea lice on different salmonid
species and from different geographic areas.
The SC deliberated over making a conclusion with respect to
impact of sea lice on juvenile salmon based on these two
papers. Although the analysis suggested that in 2003 there
was no observed impact (i.e., differences between infected and
uninfected juvenile salmon) based on the variables examined
(condition factor or fish size) in the available samples, the
authors emphasized the work is on-going. The authors
cautioned against making a definitive conclusion regarding
sources of sea lice because the study did not examine all
factors that affect sea lice infection, including information
from the fish farms in the Broughton area with respect to
numbers of farmed fish, stocking densities, farmed salmon sea
lice loads (species, number and developmental stages),
chemical treatments on the farms to reduce lice levels, and
other natural factors and sources affecting sea lice
prevalence and infection rates.
There was considerable discussion on the need for continued
studies. All were in agreement that the 2003 MMP provided a
single-year of sampling and that multi-year sampling over a
variety of conditions, including salmon abundance which was
low in 2003, was required to understand the causal factors
that produce inter-annual variability. The reviewers also
suggested that it should be possible to reduce future
monitoring efforts to fewer sites and the capture of smaller
numbers of fish, and to move the research into the deductive
phase, i.e. hypothesis testing. No specific direction on
future sampling could be provided without a better description
of the short and longer term objectives of the research.
It was agreed that the two papers should be published as
stand-alone papers, however, they should be part of a series
and cross-referenced in the title with the H2004-02 as Part I
and H2004-01 as Part 2.
The SC discussed further analysis and additional information
for expansion of the discussion during each paper’s revision.
One author stated that H2004-02 was purposely written for the
public given the general interest in the issue. There was
consensus among participants that the papers should have a
technical focus. It was suggested that the revisions should
consider the following points:
-
Locations of salmon bearing streams on maps and, where
possible, links to salmon escapement data, linked to salmon
abundance;
-
Oceanographic data (e.g., currents, salinity and
temperature, river discharge, timing of runoff, winter
precipitation);
-
Additional discussion on the life cycle of sea lice
and aging of parasites allow for the tracing of infection
source;
-
More detailed temporal and spatial analysis of the
data including differences among zones and variation among
catches in sets within zones;
-
Focus on CPUE rather than total catch as a measure of
relative abundance;
-
More detailed analysis of spatial and temporal
patterns in the fish size data;
-
Comparison of results with other published studies,
the inclusion of the analysis/figures that were provided in
the presentation; and
-
The inclusion of the analysis/figures that were
provided in the presentation of H2004-01.
Subcommittee Conclusions (H2004-01 and H2004-02)
Both papers were accepted subject to revisions.
No significant adverse effects of sea lice on juvenile salmon
growth and condition factor were observed for the period
studied, though collections terminated about the time the
intensity of the sea lice motile stages were increasing.
The base-line data collected in the 2003 MMP will be most
useful in providing the foundation for more deductive-type
studies in the future.
Subcommittee Recommendations (H2004-01 and H2004-02)
Further research is required to confirm or reject the
observations in 2003 that showed little impact of sea lice on
juvenile salmon.
If the impact of sea lice on juvenile salmon is found in
future studies to be significant to adult recruitment, then
source(s) of sea lice and factors affecting sea lice
prevalence and infection rates, including fish density and
physical and chemical oceanographic steady-state variables,
should be determined.
The study design for future studies requires both careful
consideration of key questions and hypotheses formulation, and
where necessary, the use of controlled experiments.
H2004-03: Evaluation of site selection methodologies for use
in marine protected area network design
S.M.J. Evans, G.S. Jamieson, J. Ardron, M. Patterson and S.
Jessen
Subcommittee Discussion
SC members expressed concerned that first reviewer’s comments
should not be considered because of a personal involvement
with the development of the MARXAN model. This reviewer also
raised comments that were not directly related to the purpose
or were outside the scope of the paper. The second review was
deemed a very satisfactory review on its own by all SC
members, and thus the SC used only the second reviewer’s
comments.
Most SC members were supportive of the working paper and
concluded that it was a good comparison of methodologies.
They noted that any of the models reviewed could be used by
DFO to bring stakeholders together to discuss and assess
candidate MPA site selection. It was noted that the selected
model could also be used to address not only ENGO concerns,
but those of industrial stakeholders such as aquaculture,
fisheries, etc. DFO is currently working with other federal
partners, which provides a forum where the utility of these
models can be further discussed. One SC member noted that
Parks Canada is in the process of evaluating MARXAN for
site-selection in the proposed NMCA in the Strait of Georgia.
To address management needs, authors were urged to include a
few words in the WP on the existing DFO MPA establishment
process, and where and how the chosen model would be used.
The authors were encouraged to give due consideration to the
following two key points made by the reviewer: that a
retrospective analysis be carried out to compare the outputs
of the techniques; and connectivity, a most important criteria
in planning a network of MPAs, be considered and addressed to
the extent possible. Connectivity is indirectly determined by
proximity and other factors; functional connectivity
algorithms do not presently exist. These tools are step
towards attaining what we ultimately want, which is a network
with connectivity relationships also optimised.
It was agreed that “network” should be removed from the title
as the paper does not deal fully with the connectivity issue.
Key terms, including connectivity, network, and other terms,
will be defined in the glossary along with a flow diagram. An
appendix with a flowchart describing the methodologies is also
recommended, and the paper needs to be simplified.
Reviewers and SC members indicated that the shortcomings of
MARXAN, their preferred model, should be better enunciated in
the paper. These include: lack of transparency as to why or
when (during the selection process) a given site or place is
selected because this technique is attempting to evaluate the
‘set of sites’ rather than individual sites; 2) uncertainty
and variability in results associated with the removal or
locking in of any given site; 3) area (or currency) goals that
must be pre-established; and 4) MARXAN and its predecessors
are very flexible, with the potential for numerous user inputs
that can create markedly different selection results. This
flexibility and the lack of fixed methods of using this tool
may create variation in outputs.
The “user-friendliness” of the authors recommended method –
MARXAN – was discussed. The authors stated that MARXAN is
indeed “user friendly” and that specialists would not have to
be hired to run it. The challenge is in the formatting of the
input data. For example, World Map had a good front piece
which included a map. The author stated that a couple of the
models tested were not easy to use.
The reviewer stated that this paper only generically reviewed
the techniques and did not review the programs with respect to
DFO’s needs. However, the authors clarified that this was not
the intent of the paper, and that there were a series of
different DFO considerations identified, including spatial
constraints, development of a systematic and transparent
system, and the incorporation of socio-economic and
environmental data consistent with IM. The need for a role by
the public in MPA determinations was noted, including the
desirability of public consultation and stakeholder buy-in.
One SC member inquired whether MARXAN, with all the variables
and assumptions involved, leaves too much to chance. The
authors suggested that if one defines the goals and objectives
of the exercise well, then the “chance” element is much
reduced. There was discussion as to whether MARXAN was a
“probabilistic” model or a “stochastic” model, and the authors
pointed out that because it uses randomly chosen information
in each run, it is stochastic, but because it is run hundreds
of times in any analysis, it also produced a probabilistic
distribution. It was also pointed out that the weighting
function does to some degree dictate results, which on one
hand is desirable as there is a need to weight options with
project values in mind but on the other hand makes the final
result somewhat subjective.
The SC discussed how a sensitivity analysis might be
conducted. The Living Oceans Society has used the model in BC
waters, and had also verified some outputs and has done some
sensitivity analysis. In operation, the model produces a
“report card” that allows one to determine how well its output
is meeting defined objectives. Model tuning is carried out
via weighting factors. The authors agreed to add more
information on verification and sensitivity analysis
considerations.
Concerns regarding data values and weightings were also
discussed, and it was agreed it is appropriate to set values
and explore the implications of different value and weighting
options. Weightings can be assessed and adjusted after the
model is run based on the output score sheet produced by
MARXAN.
The value in using optimisation models to explore different
goals and objectives of different agencies was discussed.
Defining DFO management needs and objectives will be critical
to the evaluation and selection of a methodology, and the
evaluation framework in the report allows for this process to
occur.
The context of conservation planning processes within DFO need
to be addressed and where the methodologies discussed here fit
in should be elaborated on. The Department is moving forward
in the direction of multi-agency collaboration for marine
planning and establishing MPA in conjunction with Parks
Canada, Environment Canada and others. The Canada BC MPA
strategy is also an important context for this paper. Parks
Canada is looking at using MARXAN as part of its Southern
Strait of Georgia study. MARXAN was selected base on a review
of the literature. It was noted by the SC that a
multi-agency approach has a better chance of success overall
in functional MPA network establishment, and planning at
multiple scales (e.g., LOMA, Coastal Management) is desirable.
Subcommittee Conclusions
The paper was accepted subject to revisions.
A better understanding of ecological processes would help
determine baseline data requirements, which are key to the
success of any site-selection methodology.
Data needs and weightings need to be established in a
multi-agency forum.
MARXAN can accommodate multiple data sets from various
agencies and stakeholders.
Subcommittee Recommendations
MARXAN is an appropriate and available decision support tool
for MPA site-selection.
DFO and partners should conduct a case study to evaluate the
utility of this method for BC situations that incorporate
multiple values from different stakeholders.
The output of MARXAN must be analyzed to determine whether the
goals of DFO and other stakeholders are being achieved.
H2004-04: A Science-based Boundary for the Central Coast
Integrated Management Area
Duncan Johannessen, D. Haggarty and J. Pringle
Subcommittee Discussion
Oceans Managers and the SC were satisfied that the revised
paper meets the objectives of the working paper request and
management needs. The revised document incorporates and
defines scientific criteria used to consider changes to the
existing CCIM working boundaries. There were no external
reviews of this paper as it was reviewed externally at a
previous PSARC meeting, where it was declared a
work-in-progress.
The relation with the CCIM and Pacific North Coast Integrated
Management Area (PNCIMA) area was discussed, with PNCIMA being
a larger management area for management of issues such as
offshore oil and gas, aquaculture, and turning point First
Nations consultation. However, this paper provides valuable
information relative to the existing CCIM boundaries and it
proposes a new management boundary that is aligned with
scientific criteria.
There was discussion about the ecological rationale for
setting of the Brooks Peninsula boundary. Water currents were
considerations, along with oceanographic conditions, as the
northern waters are more oceanographically similar to and they
are influenced by the Alaska currents. Fisheries information
was specific to the northern boundary, as groundfish data
relative to substrate type were available. Other data
indicate that the Brooks peninsula area is a dividing line
between southern and northern fish species. Biological
communities (e.g., plankton communities) also indicated a
difference between the southern and northern boundary, and
ecologically important features such as Scott Islands were are
not separated by using Brooks Peninsula.
The continental slope was put with the shelf rather than
abyssal plain because the gullies which are characteristics of
Queen Charlotte sound make it difficult to define the top of
the slope. Also ground fish come off the shelf onto the
slope but not onto the abyssal plain. The biological slope is
also quite a biologically active area, and the biology is more
closely related to that on the shelf, rather than the abyss.
However, it was also noted that the abysal plain is very
diverse from a meiofauna perspective
It was noted by one SC member that killer whales are divided
between northern and southern resident killer whales and the
borders they use is the proposed inland waters line but on the
west coast, it would be further south of Brooks Peninsula.
Different species thus have different spatial distributions,
making oceanographic data better criteria for boundary
definition then species spatial distributions.
The SC agreed that there were northern boundary options around
the mainland islands, including taking into account the
freshwater influence of the Skeena River (i.e., the
freshwater-saltwater interface). The science is uncertain in
this area and hence the revised paper will suggest possible
variations on this northern boundary around the coastal
mainland islands.
Discussion could be expanded to include some recent literature
on large ocean management areas to put initiatives in BC in a
broader perspective. It was also suggested that the criteria
used for setting of the proposed new boundaries will be
outlined in table format.
It was pointed out that the CCIM/offshore boundary, the
Johnstone Strain boundary and the Brooks Peninsula boundary
were also ecoregion boundaries identified at the recent DFO
Ecoregion Working Group national meeting.
The author concluded that the proposed boundary changes be
considered in the final development of a Central Coast Large
Ocean Management Area (LOMA) boundary along with management,
economic and social factors.
Subcommittee Conclusions
The paper was accepted subject to revisions
Subcommittee Recommendations
The boundaries identified provide an ecological rationale that
might be used for establishing boundaries relevant to a LOMA
for central and northern BC waters.
APPENDIX 1: Working Paper Summaries
H2004-01: Sea lice on juvenile salmon and on some non-salmonid
species caught in the Broughton Archipelago in 2003
Simon Jones and Amanda Nemec
Copepods of the family Caligidae (Siphonostomatoidea: Copepoda)
are parasitic on the skin, fins, gills and buccal cavity of
marine fishes. In British Columbia (BC) coastal waters these
niches have been exploited by 11 species belonging to the
genus Lepeophtheirus and one species of Caligus. There is
little historic data on sea lice infection rates of juvenile
salmonids in the Broughton Archipelago. In addition, prior to
2001, juvenile pink and chum salmon in the Broughton
Archipelago had received virtually no scientific attention.
Annual variations in the number and condition of out-migrating
smolts from specific streams had been relatively poorly
documented and their migratory routes through this region were
speculative. The present study was an effort to
systematically survey juvenile Oncorhynchus spp. for caligid
copepods throughout their nearshore marine migratory phase
following seawater entry. The overall objective of the study
was to describe patterns of spatial and temporal variations in
the prevalence and intensity (or abundance) of sea lice
infections on juvenile pink and chum salmon in a limited area
of coastal BC: the Broughton Archipelago and Knight Inlet.
For the purpose of this study, it was hypothesized that the
prevalence and intensity (or abundance) of infections on
salmonid and non-salmonid fishes would be uniformly
distributed temporally and spatially throughout the study.
Approximately 25% of juvenile pink and chum salmon were
infected with two species of sea lice: Lepeophtheirus salmonis
and Caligus clemensi. On both salmon species most infections
consisted of a single chalimus stage and most of these were C.
clemensi. The prevalence of motile L. salmonis increased
towards the end of the study and was coincident with a decline
in the proportion of L. salmonis chalimus stages. Prevalence
of sea lice infections on juvenile salmon varied significantly
in time and space was this variation was significantly
associated with sea water salinity and temperature and with
size of salmon. There was no evidence that infection with sea
lice adversely affected size or condition factor of juvenile
pink and chum salmon during the time that was monitored.
Caligus clemensi and an unidentified Lepeophtheirus sp. were
found on approximately 60% of sticklebacks. Lepeophtheirus
hospitalis and C. clemensi were also found on herring.
The paper made three major recommendations: 1, to initiate and
coordinate field and laboratory studies to better understand
the impact of sea lice and other infectious diseases on wild
juvenile salmon; 2, to establish mechanisms for sharing
relevant disease information between industry and DFO for
example by initiating collaborative research programs to
better understand local factors influencing prevalence,
distribution and sources of sea lice infections on juvenile
salmon and 3, to initiate studies to improve knowledge of the
morphological characteristics of the chalimus stages of
Lepeophtheirus species.
H2004-02: Abundance and distribution of juvenile salmon and
other fish caught in the Broughton Archipelago, Knight Inlet
and Muchalat Inlet, B.C. in 2003.
Brent Hargreaves, Doug Herriott and Vic Palermo
During 2001 and 2002 intense public concern was raised about
the infection of wild juvenile pink salmon by parasitic sea
lice in the Broughton Archipelago area of the B.C. coast, and
the possibility that commercial salmon aquaculture farms might
be the source of these sea lice. In February 2003 the
Minister of Fisheries and Oceans Canada announced DFO’s Pink
Salmon Action Plan (the “Action Plan”) that focused on the
Broughton Archipelago. This Action Plan had several
components, including a marine monitoring program (MMP). The
main objective of this MMP was to obtain samples of wild
juvenile pink salmon (Oncorhynchus gorbuscha) from marine
areas throughout the Broughton, to assess the incidence and
severity of infection by sea lice by location and time. A
secondary objective was to regularly monitor the abundance of
wild juvenile pink salmon at many locations during the early
sea life period, to obtain additional information about the
migration routes of juvenile pink salmon in the Broughton. A
third objective, subsequently added in March 2003, was to
conduct a separate marine sampling program to assess the
prevalence and intensity of infection by sea lice on wild
juvenile salmon in Muchalat Inlet. It was anticipated that
these two marine sampling programs would allow baseline
assessment of sea lice infection of wild juvenile salmon in
areas both with (Broughton) and without (Muchalat Inlet)
commercial salmon farms, and before and after the first salmon
farms were installed in a new area (Muchalat Inlet).
This PSARC Working Paper describes the results for the field
sampling portion of the 2003 MMP in the Broughton area and
Muchalat Inlet, including the fish catch, abundance and size
information. The results from the analyses of sea lice
infections of these fish are documented in a separate PSARC
Working Paper (Jones and Nemec 2004).
The 2003 MMP was very ambitious. The PSAP was announced by DFO
on February 20, 2003 and by March 2 fish sampling began in the
Broughton. The program utilized two main DFO vessels (Walker
Rock and Clupea), four smaller DFO skiffs, and contracted
three commercial salmon seine vessels and their crews. More
than 43 people directly participated in the field sampling,
including 15 volunteer DFO staff, 19 First Nations people and
4 additional commercial fishermen hired under contract. Four
additional biologists were provided by the B.C. Province and
one person was also provided by the salmon aquaculture
industry (Stolt and Heritage Aquaculture Ltd. and Stolt Sea
Farms).
In the Broughton Archipelago and Knight Inlet fish samples
were collected 5 days each week, for 15 weeks. A total of 1472
sets were made with purse seines and beach seines, and more
than 1.1 million fish (all species) were captured. A total of
105,00 juvenile pink salmon, 89,000 juvenile chum salmon, and
82,522 three-spined stickleback were captured. This PSARC
report focuses on the results for juvenile pink and chum
salmon, but also includes results for stickleback because this
species was observed in the field to be heavily infected with
sea lice.
In Muchalat Inlet a total of 206 beach seine sets were
completed from March 26 to June 11, 2003. A total of 38,465
fish (all species) were captured, including 19,587 juvenile
chum salmon and 1 juvenile pink salmon. An additional 4 beach
seine sets were also done on one day (June 4) in Esperanza
Inlet, to obtain some fish samples from an area with active
fish farms that was closest to Muchalat Inlet. A total of 39
fish were caught, including 11 juvenile chinook and 12
juvenile chum salmon. To minimize costs, no purse seining was
done in either Muchalat Inlet or Esperanza Inlet.
This PSARC paper provides extensive analyses of the catches,
abundances (CPUE), and size of juvenile pink and chum salmon,
and stickleback, for the Broughton and Knight Inlet. In
general, juvenile pink and chum were caught throughout the
Broughton and Knight Inlet in all time periods, and frequently
these two species were found together. The abundances of pink
and chum remained low throughout the study area during March,
then gradually increased during April. The peak abundances of
both pink and chum salmon occurred in Knight Inlet in
mid-to-late April, about two to three weeks earlier than in
the Broughton. The average size of both pink and chum remained
low (30 – 40mm fork length range) during March, then increased
steadily to 70-80 mm by mid-June. Stickleback were caught
throughout the study area but there were no clear patterns in
either stickleback abundances or sizes.
This PSARC paper also provides some new information on
migration routes and timing of juvenile pink and chum salmon
in the Broughton and Knight Inlet. The primary question was
the “main migration corridor” for juvenile pink salmon that
was proposed in 2002 by an independent biologist (Alexandra
Morton). In 2003 the B.C. Province required that all
commercial salmon farms along this route be fallowed (cease
production) to protect juvenile pink and chum salmon. The
results from the 2003 MMP show that juvenile pink and chum
salmon were widely distributed throughout the Broughton and
Knight Inlet, and do not provide confirmation or even strong
support for the existence of a “main migration corridor” in
the Broughton. However, these results represent only one year
and the conclusion may be different in other years when the
abundances of pink or chum are substantially higher or lower.
Determining the migration routes and timing for juvenile pink
and chum was not the primary objective for the 2003 MMP, and
the sampling program was not optimal for resolving these
questions. The authors suggested that if more definitive
answers to these questions are required then a different
approach will likely be required (e.g. mark and recapture
experiments conducted over several years).
The prevalence and intensity of infection by sea lice of
juvenile pink salmon, juvenile chum salmon and three-spined by
sea lice that were captured in the Broughton and Knight Inlet
in the 2003 MMP is assessed in a separate PSARC Working Paper
(Jones and Nemec 2004. However, the sea lice data for the fish
sampled in Muchalat Inlet and Esperanza Inlet have not yet
been fully analyzed and are not included in the Jones and
Nemec 2004 PSARC Working Paper. Preliminary analyses
indicates that the infection rates of juvenile salmon in
Muchalat Inlet generally remained at zero percent or very low
(maximum 3.0% at one location) during March – May, then
suddenly increased in early June. In the final sampling
period (June 09-11) the percentage of juvenile chum infected
with at least one sea louse ranged from zero to a maximum of
19% for chum captured at various locations in Muchalat Inlet.
A total of 10 of the 11 juvenile chum that were caught in
Esperanza Inlet on June 04, 2003 were infected with sea lice.
The authors provided several recommendations and conclusions.
Regarding any additional DFO research on juvenile salmon and
sea lice in the Broughton, they recommended that: 1) if the
MMP is repeated in 2004, that only beach seines be used prior
to mid-April to minimize costs. After mid-April, both beach
seines and purse seines should be used, 2) the total number
of pink and chum kept for sea lice analyses likely can (and
should) be reduced without reducing the reliability of
results, and 3) extending sampling to include the head of
Knight Inlet should be reconsidered. Regarding juvenile
salmon migration routes, the authors concluded that “main
migration corridor” hypothesis was not clearly supported by
the 2003 MMP results, but cautioned that this conclusion may
be different in other years. The authors recommended that
tagging and recapturing juvenile pink and chum would likely be
the most conclusive method of confirming this.
Regarding sea lice and wild juvenile salmon marine research
more generally, the authors concluded that continued progress
towards resolving the concerns and debate surrounding the sea
lice - wild salmon - fish farm interaction issue likely will
require a multi-year research program. This research will be
most effective if it is planned and conducted with the full
cooperation and participation of DFO, the B.C. government and
the B.C. finfish aquaculture industry.
H2004-03: Evaluation of site selection methodologies for use
in marine protected area network design
S.M.J. Evans, G.S. Jamieson, J. Ardron, M. Patterson and S.
Jessen
This report identifies and compares different methodologies
used for the selection of (candidate) marine protected areas.
It is hoped that this will provide DFO with the necessary
information to evaluate which selection methodology would be
most effective in furthering it’s MPA objectives within the IM
framework.
Choosing the most appropriate methodology depends on the
underlying goal for establishing the set of marine protected
areas. Clearly defining the purpose and the overall
conservation goal is an important first step that must not be
overlooked.
There are two main approaches to selecting AOIs;
scoring/weighting (non-systematic) and systematic.
Scoring methods assign a rank of relative importance to all
sites based on some user-defined criteria and then add those
sites with the highest rank to an existing reserve. The
product from this type of reserve site selection is not able
to identify how each site relates to the others in the system
beyond it’s ‘score’ which is not indicative of what is being
captured by the sites. While the objective nature of a
scoring selection process is preferred to subjective or
opportunistic decision-making, it is not very rigorous, it is
not able to efficiently select a set of complementary sites
and does not have the spatial capacity to create a network.
Systematic methods of reserve selection make use of
algorithm-based decision support tools. Systematic selection
of MPAs is based on the concept of ‘complementarity’ in which
new sites contain features that are not currently captured in
the reserve system and thus augment the overall diversity and
representivity of the system. Of the systematic methods there
are 4 main types of algorithms used; linear integer
programming (ILP), simple iterative algorithms (heuristics),
iterative simulated annealing and explicitly spatial
population based models.
The advantage of the ILP methodology over other
complementarity methods is its ability to find an optimal
solution. However, if there are too many constraints or the
problem is too complex (non-linear) this method will often
fail to produce a solution. Thus it is best applied when
there are only a few constraints to be optimised.
Heuristics are much faster than the ILP methods, but may
arrive at a solution which is considerably less efficient than
the theoretical minimum. These programs can manage
conservation problems comprised of large datasets and several
constraints. In some cases spatial constraints can be
incorporated into the method via additional programming.
The simulated annealing method is considered superior to the
other methodologies for selecting priority areas for
conservation reviewed here. This algorithm can produce
multiple solutions for a given scenario unlike heuristics
which only provide one solution. It can produce more
efficient solutions compared to heuristics in terms of
minimising total area needed to meet the desired conservation
objectives. There is a random component of this algorithm
that allows for the search of the ‘global minima’.
The last systematic method reviewed in this paper, explicitly
spatial programs, specifically address the issue of species
persistence through the application of environmental variable
models (those which influence the distribution of
biodiversity) or metapopulation models that will direct the
selection of a ‘connected’ set of sites. These programs can
only select sites for a limited number of species and require
detailed data sets regarding either environmental parameters
or species population dynamics. Thus, they are often most
appropriately applied at smaller scales for which this type of
data exists, or as a post-selection tool (see section 3.3) to
choose among candidate sites in the development of a network
that ensures a particular species persistence.
This report also reviewed two case specific applications of
the systematic algorithms to identify priority areas for
conservation currently being used in Canada. These projects,
by Living Oceans Society and World Wildlife Fund Canada are
highlighted with regard to their potential applicability to
DFO.
Upon review of the methodologies we recommend that DFO
consider the use of a site selection methodology in its IM
program. From our analysis we concluded that MARXAN (a
software package which employs simulated annealing) would be
most appropriate tool to assist DFO in furthering its mandate
and MPA objectives under the Oceans Act.
Other recommendations include;
do multi-scale planning in MPA network design;
perform analyses with multiple MPA objectives and datasets
determine if MPA networks created using multiple agency
mandates requires less area than performing the analyses
separately specific for each agency
improve our understanding of the usefulness of the various
frameworks and approaches to applying Marxan, especially those
ongoing in Canada;
investigate current selection analyses used to date in Canada
to provide DFO with compiled data and information on lessons
learned in applying MARXAN and developing ecological planning
frameworks for both coasts
determine the ecological attributes for cells in terms of
parameters reflective of criteria used by different agencies
to rationalise their mandates to establish MPAs;
undertake a pilot MPA selection analysis in some relevant
geographical area, as DFO has the mandate among federal
departments to show leadership in marine protected area
studies;
Although spatial optimisation offers a powerful solution to
MPA network design and while these programs make a
contribution to improving rigour, transparency and efficiency
of what is a complex process, they only contribute to part of
the process. Other decision support tools (such as GIS and
Delphic approaches – see Lewis et al. 2003) may need to be
employed when fine-tuning boundaries, developing zoning plans,
or when choosing among candidate sights that are of interest
to several stakeholder groups.
H2004-04: A Science-based Boundary for the Central Coast
Integrated Management Area
D. Johannessen, D. Haggarty and J. Pringle
The Science Branch of Fisheries and Oceans Canada’s Pacific
Region was asked by the Central Coast Integrated Management (CCIM)
Working Group to propose modifications to the Central Coast
‘working boundary’ based on scientific and ecosystem
information. Traditionally, marine boundaries have been based
on one type of criteria such as political information,
management requirements, or ecosystem-based information.
Thus, Canada’s Pacific waters can be politically bounded by
the Canada-US border to the north and south and by the 200
nautical mile limit of national jurisdiction. Canada’s
Pacific waters have also been bounded by a number of different
administrative systems, such as Fisheries and Oceans Canada
(DFO) management areas, as well as smaller polygons used to
manage specific fisheries. Boundaries have also been
developed that attempt to define marine ecosystems at various
scales, as described in section two of this paper. Section
three reviews the latest work by the British Columbia (BC)
provincial government using GIS analysis to define marine
ecosystems at two scales. Section four lists some of the
existing boundaries in the Central Coast Area. Section five
describes the criteria used to define the proposed changes and
discusses in detail the reasoning behind each portion of the
boundary.
The boundary modifications proposed in this document represent
a relatively new approach to boundary definition. The
boundary is intended to define the Large Ocean Management Area
(LOMA) for BC’s Central Coast as a pilot area for integrated
management. According to the Oceans Act, these areas are to
be drawn using a mix of ecological consideration and
administrative boundaries (Fisheries and Oceans Canada 2002).
Boundaries developed in Australia for the purpose of marine
management have ostensibly been created using only ecological
criteria (IMCRA 1998). What is unclear from this work is how
various State and Commonwealth jurisdictions and interests
will be integrated into this system of boundaries,
particularly as much of the boundary development work was done
by individual states using different data and criteria.
Furthermore, political jurisdictions, such as state versus
commonwealth waters, were clearly used in the boundary
definition. This illustrates the fact that if resource
management is the end purpose of the area, then the definition
of the area cannot ignore political boundaries. The
definition of the area must also consider whether the area is
suitable for management. For example, the intertidal zone
could be defined as a single ecosystem for the entire BC
coast, but that would create a very long, thin, convoluted
area which would be unsuitable for management as a single
area.
The definition of an ecosystem is also problematic. Watson
(1998) reviews a variety of these definitions and it is clear
that they can range from purely scientific, to mixtures of
scientific and management criteria. Canada’s Oceans Strategy
(based on the Oceans Act) defines an ecosystem as: “The system
of interactive relationships among organisms (e.g. energy
transfer), and between organisms and their physical
environment (e.g. habitat) in a given geographical unit.”
(Fisheries and Oceans Canada 2002).
Given the difficulty and subjectivity in defining an
ecosystem, and given that the question put to Science Branch
is to propose modifications to an existing boundary, this
paper does not attempt to define a single Central Coast
ecosystem. Instead the general Central Coast area is taken as
defined by the working boundary (Figure 1) and modifications
to that boundary are proposed wherever there exists scientific
information to support an alternative to the working
boundary. Since the general area is based on management
considerations and the proposed modifications are based on
science, the resulting area fits the Oceans Act recommendation
for defining LOMA boundaries based on a mixture of management
and scientific considerations (mentioned above).
The main criterion used to define the proposed modifications
of the boundary is evidence for a clear and defined change in
the physical environment (e.g. habitat). A sharp change (as
opposed to a diffuse or gradational change) is the most
desirable because it can more reasonably be represented by a
boundary line. During the course of the project two specific
factors, bathymetry and substrate material, were most often
found to have readily available data, and to provide a sharply
defined marine boundary. Whenever possible, biological
information was also used to inform the proposed boundary
modification. Although all of the proposed modifications in
this paper are based on scientific information, where these
modifications also make sense politically, culturally, or
managerially, those factors are mentioned.
APPENDIX 2: PSARC Habitat and Salmon Subcommittee Meeting
Agenda April 6-7, 2004
AGENDA
PSARC HABITAT SUBCOMMITTEE
April 6 & 7, 2004
Grand Hotel Nanaimo
4898 Rutherford Road
Nanaimo, B.C.
April 6, 2004 Start time: 09:00
-
Introductions and PSARC meeting procedures
-
Review agenda
-
Review of WP# H2004-02: Abundance and distribution of
juvenile salmon and other fish caught in the Broughton
Archipelago, Knight Inlet and Muchalat Inlet, B.C. in 2003.
(Brent Hargreaves, Doug Herriott and Vic Palermo)
-
Sub-Committee Review – Conclusions and Recommendations
- WP#2
-
Preliminary results of the study examining the impacts
of sea lice on juvenile salmon: “The health of juvenile
salmon in August 2003 in the Broughton and associated areas”.
-
Review of WP# H2004-01: Sea Lice on juvenile salmon
and on some non-salmonid species caught in the Broughton
Archipelago in 2003. (Simon Jones and Amanda Nemec)
-
Sub-Committee Review – Conclusions and Recommendations
- WP#1
April 7, 2004 Start time: 08:30
-
Review of WP# H2004-03: Oceans Strategy – Evaluation
of site selection methodologies for use in marine protected
area network design. (Glen Jamieson, Susan Evans, J. Ardron,
M. Patterson and S. Jessen)
-
Review of WP# H2004-04: A Science-based Boundary for
the Central Coast Integrated Management Area. (Johannessen et
al.)
-
Sub-Committee Review – Conclusions and Recommendations -
WP#3 and 4
-
Next meeting – Fall 2004
|