A. Brief Project Overview:
The Science Consortium For Ocean Replenishment And Enhancement (SCORE) is a new science-based approach to hatchery-based rebuilding (enhancement) of marine fish stocks. SCORE scientists are conducting research to resolve critical uncertainties about the effectiveness of culture-based marine stock enhancement as a fishery management tool. It is anticipated that significant progress will be made in the next five years, leading to greater and greater success from marine enhancement programs in the U.S.

As scientific gains are made in understanding the potential, SCORE scientists will partner with NMFS and regional fishery-management agencies to develop policy and apply fishery-enhancement science to rebuilding depleted coastal stocks. Linkages with local fishing communities will provide the cadre of citizens needed to support and expand enhancement as a fishery management strategy. SCORE scientists envision that much of enhancement technology developed here will be supported by funds generated by contributions and license fees paid by stakeholders and user groups. To fully embrace and use the marine enhancement concept, demonstrated success stories are needed in a few key states. SCORE research is planned and coordinated to achieve such successes. Built around the principles of a responsible approach to marine stock enhancement, SCORE scientists will conduct key experiments to resolve critical uncertainties about how to conduct and control the biological, ecological, and economic effectiveness of stock enhancement.

SCORE is an R&D initiative conducted by a consortium of national partners. It is a powerful alliance of scientists and fishery managers currently working in the field of marine stock enhancement in the U.S.A., which encourages improved utilization of their expertise and resources. Bringing these scientists and managers together through SCORE allows synergisms to develop that would not occur otherwise.

SCORE research commenced in the summer of 2001. Although the funded contract did not arrive until Early October, the provision was made to cover research costs starting July 1, 2001. This interim report covers progress made during the period July 1, 2001 through December 31, 2001.

B. Project Accomplishments:

a. Tasks scheduled for this period
i. Develop snook broodstock diets
ii. Develop snook spawning induction
iii. Develop snook larval feeding
iv. Conduct snook trophic analysis
v. Conduct habitat and predation study with snook
vi. Develop habitat/release model for winter flounder
vii. Develop marine fish culture policy (Washington)
viii. Complete genetic population analysis on lingcod ix. Collect economic data (all species)
x. Develop risk/benefit models (all species)

b. Tasks accomplished this period:
i. Develop snook broodstock diets (Primary responsibility: Mote Marine Laboratory)
Advances in common snook aquaculture technology are needed to provide snook for the proposed stock enhancement studies. In order to provide a reliable supply of snook larvae, we need to gain greater control over controlled maturation and spawning of snook. Our current methods for snook production include collecting wild broodstock and strip spawning fish in the field. The timing for strip spawning is limited and is highly dependent on locating large numbers of brood fish that are ready to spawn.

In order to provide a more reliable source of snook larvae in future years, we are developing a captive broodstock population of snook and developing controlled maturation and spawning protocols. Our original work plan indicated that we would begin this work in the fall 2001. However, the results of our 2001 production season along with space limitations caused us to postpone the work on snook Broodstock diets until fall/winter 2002/2003.

ii. Develop snook spawning induction (Primary responsibility: Mote Marine Laboratory)
This work is closely related to the above and is postponed until fall/winter 2002/2003. A no-cost extension of the project has been requested to provide the additional time needed to complete both Tasks i and ii.

iii. Develop snook larval feeding (Primary responsibility: Mote Marine Laboratory)
Several snook larval-rearing and juvenile production trials were conducted in July and August 2001. During this reporting period, larval culture and nursery work resulted in the production of over 20,000 90-day old snook juveniles. ~20% of these are being nursed ~100 ­ 200 mm in length for SCORE release-recapture experiments that will be conducted in 2002.

All eggs and sperm were collected from spawning snook captured on the west coast of Florida, between Longboat Key and Venice. Eggs and sperm were collected from 117 females and 109 males captured at Longboat Pass, Big Pass, New Pass, and Venice Inlet. Eight spawning trips were conducted and 264 adult snook captured. Eggs and sperm were collected on six of the eight spawning trips. The last spawning trip was conducted in October, and the fish captured had regressed with respect to gonad development.

Progress was made in understanding the factors that will contribute to improvement of snook survival in culture. Growth of the snook fingerlings showed good progress, and during the fall, size estimates for juveniles were between 60 - 150 mm TL. Size sorting was performed irregularly to reduce cannibalism, and several ‘control’ tanks that were left ungraded showed high levels of cannibalism.

The larval-culture and juvenile-rearing trials revealed that new snook-culture studies are needed in 2002 to address two critical areas:

• Increasing survival in larval, nursery I, and nursery II stages by improving larval nutrition and reducing cannibalism in larval and nursery I stages.
• Determining the factors responsible for, and reducing the incidence of, lordosis in juvenile snook.

We planned the experimental trials that will be conducted in 2002 to address these areas. We also redesigned the larval and nursery culture systems to (1) improve filtration systems, (2) add new current patterns to the larval tanks to reduce cannibalism, (3) add continuous feeding systems for live feeds, and (4) add skimmers to remove the surface films in larval tanks. Construction of new filtration systems was initiated and will continue throughout the spring and early summer months of 2002. A second round of snook larval rearing trials is scheduled to begin in late May 2002.

iv. Conduct snook trophic analysis (Primary responsibility: Mote Marine Laboratory)
Our first study on this topic was conducted in July and August. Feeding patterns of juvenile snook collected at several sampling sites were evaluated using the Carr and Adams gravimetric sieve fractionation procedure. This procedure provides quantitative data (actual dry weights) of the various food items found in the stomachs of the snook we collected. This work revealed a strong reliance of juvenile snook on small crustacean prey, particularly mysid shrimps. This study showed no differences in feeding habits by location (different microhabitats sampled within snook nursery areas ­ tidal creeks in Sarasota Bay) or among various sizes of juvenile snook. Subsequent studies will evaluate a broader size range of juveniles and begin to look at sub-adult and adult snook feeding patterns.

v. Conduct habitat and predation study with snook (Primary responsibility: Mote Marine Laboratory)
At our current stage of snook enhancement research and development, we are conducting research to define optimal release strategies needed to document snook enhancement potential. A major focus of those studies now is determining effects of microhabitat on dispersal and survival of hatchery snook released into nursery habitats in Sarasota Bay, Florida. Predation studies will follow, as we are now designing new experiments to study density-dependent effects on dispersal and predation rate.

Optimal release habitat studies -- During this reporting period, SCORE biologists concentrated field studies on assessing treatment effects of release-recapture experiments established in Sarasota Bay prior to 2001. Quantitative collections were made in various common-snook habitats in Sarasota Bay to determine effects of release microhabitat on recapture rate and growth and survival of hatchery snook in the wild. These hatchery snook had been released by the Center for Fisheries Enhancement at Mote Marine Lab in preliminary studies to assess snook release strategies and are now part of our ongoing SCORE studies. Ongoing collections are recovering snook from several year classes that were established following these previous releases of age-0 hatchery snook. Additionally, snook were sampled to determine if there were differential feeding habits between snook released with T-bar and Visible implant elastomer (VIE) tags, and among snook released in different habitats. All recaptured snook were processed for stomach content analysis, and coded-wire tags (CWT) were extracted to identify experimental-release treatment conditions. Computer algorithms were written to identify a recaptured fish’s original release length, weight, and release site, tag type and release date. The data from these field collections are currently being analyzed.

Tagging refinement studies ­ Planning was conducted for developing a CWT head mold system for speeding up the tagging of juvenile hatchery-reared snook. Excess snook afflicted with skeletal deformities (lordosis), but with normally shaped heads, will be tested with the new head molds. These fish will be held in recirculating systems for up to 6 months to determine the tag-retention performance provided by the head molds. This study will be conducted in winter 2002. Both nose cartilage and cheek muscle will be targeted.

Release contribution to juvenile recruitment at release sites -- Overall, during the summer of 2001, 934 juvenile snook were captured and of these, 123 were tagged hatchery fish (a 13% contribution of tagged juvenile hatchery snook to young-of-the-year recruitment in the nursery habitats).

Release contribution to spawning stock: fishery-independent data -- For examining the contribution of released snook to the adult population, a fishery independent sampling program was designed and implemented to (1) determine growth and maturation of hatchery snook in the wild, (2) determine the contribution of hatchery-reared snook to the wild snook population in Sarasota Bay, (3) determine the distribution and migration of hatchery and wild snook in relation to each other and in relation to their release sites, (4) determine the adult spawning locations used by hatchery-released snook in relation to their release site, (5) determine the relative success of various release strategies (release microhabitat, size-at-release, seasonal and diel timing of releases, and (6) determine estimates of the population of wild and hatchery-reared snook within the sampling ranges.

In Summer 2001, sampling of adult snook was conducted along beaches and in the inlets (barrier-island passes) where spawning occurred. The summer of 2001 yielded three year classes of adult hatchery snook, which had been released prior to 2001 as part of our studies initially funded by NMFS, the state of Florida and by private funds provided by Mote Marine Laboratory (see SCORE proposal for background about this earlier work). In 2001, intensive sampling for adult snook occurred through October 3, 2001. Sampling gear included a 450’ seine, a 150’ seine, heavy cast nets, and hook-and-line equipment. Often sampling occurred in barrier island passes in Sarasota Bay, in conjunction with spawning trips where the primary goal was to collect fertilized eggs for rearing in the hatchery. Other sampling sites included habitat located in the inter-coastal waterway near passes and outlets to the Gulf of Mexico. All snook captured were counted and checked for the presence of coded-wire tags (CWT’s) and visible-implant elastomer (VIE) tags. Lengths were measured on all snook captured unless numbers of snook collected were very large, in which case lengths from subsamples of at least 25 snook were taken. Sex was also recorded for all snook captured. Gonads from all tagged snook were removed and preserved in Bouins solution for histological examination. Otoliths were also removed from hatchery snook.

During this report period, 783 adult and sub-adult snook were captured in adult habitat along beaches, passes and in the intercoastal waterways. Of these, 10 were tagged (1.28%). Although histological examination has not yet confirmed this, preliminary examination of these snook revealed 6 mature males and 4 mature females. Four of these fish were actually captured during spawning activities and a female hatchery snook was actually captured in a spawning aggregation. The largest hatchery snook captured was a male at 21.4 inches fork length. Preliminary observation of gonad development, as well as GSI values, of the hatchery snook, plotted across seasons, reflects normal snook developmental progress.

Release contribution to spawning stock: fishery-dependent data -- On September 21-22, we organized what we termed a “Snook Shindig” fishing derby. This fishing derby was held to obtain information on hatchery snook previously released into Sarasota Bay and surrounding waters. The invited participants of the derby included previous tournament anglers and friends of the laboratory who are snook fishing enthusiasts, as well as some local fishing guides. A $25.00 entry fee was used to offset derby costs.

The specific goals of the “Snook Shindig” were:
I. To promote angler awareness and enthusiasm about participating in fishery-dependent studies in our snook stock-enhancement research,
II. To allow our researchers to further develop a working relationship with local fishermen,
III. To collect important dispersal information on hatchery-reared snook and wild snook, which we’d tagged and released in Sarasota Bay and its surrounding waters,
IV. To collect important angling CPUE data on the hatchery snook,
V. To evaluate fishery contribution rates of tagged hatchery-reared snook from different areas of Sarasota Bay, and its surrounding waters, in the snook fishery in Sarasota Bay, and
VI. To collect growth and condition data from both wild and hatchery snook.

During the 20-hour derby, which involved 30 fishers who fished at various locations throughout Sarasota Bay, 128 snook were caught and recorded by our biologists at weigh-in stations that we had established throughout the bay. Seven of the snook caught were tagged hatchery snook (5.5%), a remarkable contribution to the bay-wide fishery, given that only 40,000 hatchery snook (total) have ever been released into the bay in our previous studies. The seven tagged snook were identified by the presence of the Coded Wire Tag (CWT); some had retained theVisible Implant Elastomer tag (VIE), which we are in the process of adapting to snook. The decoded CWTs revealed that hatchery snook from each release year (1997, 1999, 2000, 2001), except for 1998, were represented in the catch from this 20-hour tournament. The largest hatchery snook caught was 24.8 inches fork length (FL). All wild snook were released unharmed back into the water from which they were caught.

vi. Develop habitat/release model for winter flounder (Primary responsibility: University of New Hampshire)
Improving Marine Finfish Stock Enhancement Programs Through the Use of Habitat Suitability Index Modeling -- The objective of this research is to use Habitat Suitability Index (HSI) modeling to predict appropriate release locations for winter flounder in the Great Bay Estuary of New Hampshire. Habitat variables used in the modeling have included temperature, salinity, depth, substrate type, prey availability, and predator abundance. Individual variables, as well as the HSI values, will be layered in a geographic information system (GIS) to produce habitat maps that should be useful in choosing release locations. We have made excellent progress, and are on schedule to complete the study over the next 6 months.

To start the study, eight sites were chosen in the Great Bay Estuary system. They are a subset of 80 others being studied as part of EPA’s Coastal 2000 project. Sites were selected because the varied in temperature, salinity, and substrate type. All sites are a minimum of 2 kilometers from each other. Sampling of sites occurred monthly to November 2001. On each sampling date, 2 ten-minute tows were conducted with both a 1-meter beam trawl and a 6-meter otter trawl to determine the spatial and temporal distribution of fishes and potential predators. All species collected have been identified and enumerated, and the lengths and weights of all winter flounder have been measured. Fish were frozen and returned to the lab where stomach content analyses have been performed. All contents have been weighed, and prey taxa have been identified to the lowest possible taxonomic level. To obtain information on prey abundance, benthic cores have also been taken at each site. All cores were washed through a 1-mm sieve, and all organisms have been identified to the lowest possible taxonomic level. Temperature at each site has been measured once per hour using an Onset HOBO data logger anchored one foot off the substrate at the center of each site. Salinity was measured (refractometer) at the time of sampling, and depth was recorded at the time of each trawl. Substrate information has been obtained from two sources; grain size composition from the EPA’s Coastal 2000 project, and sediment organic content from archived data already available.

To gain an understanding of the importance of different prey species, an Index of Relative Importance (IRI) has been calculated for each prey item. Eleven prey taxa made up >97% of the diet. For these, we have also examined if, and how, their importance changed with different sized fish (50-100, 101-150, 151-200, 201-250, and 251mm and larger). Three size categories of fish have also been used to compare the diets at different sites and different seasons.

The eleven most important prey items were used to characterize the similarity between sites during each season, and the similarity between months at each site. Data were square-root transformed and entered into the Bray-Curtis Similarity equation. Resultant similarity distances were graphed using Cluster Analysis and Multidimensional Scaling to determine how the different sites grouped relative to prey composition and abundance. The composition of each site was graphed over time to see general trends in benthic productivity, and the abundance of each prey item, for all sites combined, was graphed to depict their productivity over time

To examine the temporal and spatial overlap between winter flounder and their potential predators and competitors, we have compared the catch-per-unit-effort of winter flounder to those of smooth flounder, green crab, and two species of sand shrimp using ANOVA.

An overall habitat suitability index has been determined for each site and month. This will next be compared to catch per unit effort of winter flounder (# fish per 100 m2) to see if the distribution of fish fits the habitat model. We also intend to compare the catch-per-unit-effort of winter flounder with each variable within the model (ANOVA and ANCOVA) to determine which component(s) may be driving habitat selection.

A remaining goal of the research is to test the HSI model predictions. We intend to do this by conducting in-situ growth and survival trials. Winter flounder juveniles that will be used for this are currently being produced.

vii. Develop marine fish culture policy (Primary responsibility: Washington Department of Fish and Wildlife)
The Washington Department of Fish and Wildlife (WDFW) has prioritized culture system development of Pacific Cod over releases of lingcod to evaluate ecology, population status and species interactions. Work with genetic structure and habitat preference, however, will proceed as planned for lingcod, although this work will be conducted during 2002 instead of 2001.

To accomplish the work identified with lingcod and capture Broodstock to start the Pacific Cod culture work, WDFW requested less funds than were approved for their subcontract funded by the SCORE project. It is WDFW’s desire and intent that the NMFS Manchester Laboratory will continue culture system development work with lingcod and start culture development of Pacific Cod so that WDFW will have the capability to test ecological interactions, population status, and fishery impacts with releases of juvenile hatchery fish in the future (see attached letter from Geraldine Vander Haegen of WDFW dated March 15, 2002).

viii. Complete genetic population analysis on lingcod (Primary responsibility: WDFW)
During this reporting period, WDFW collected all of the samples, processed the samples, and began analyzing the data. The genetic structure analysis will be accomplished within a few months. Preliminary analysis shows no unique stock structure except for the possibility of minor delineation between inland waters and coastal fish in more pelagic areas.

Currently WDFW is attempting to collect additional samples from Canada to include in the West Coast stock structure analysis.

A subcontract for work to be done by the University of Washington (UW) is nearing completion. UW scientists will be looking at early life history and ecology of lingcod juveniles, as well as settlement cues, for eventual releases of Lingcod.

ix. Collect economic data (all species)
No work was conducted during this report period.

x. Develop risk/benefit models (all species)
No work was conducted during this report period.