Thursday April 15 Afternoon - Abstracts

Session: Ecology and Management of Freshwater Fishes (Part II)

[5101] Fish community structure and environmental correlates in the highly altered southern Sacramento-San Joaquin Delta

Author: Frederick Feyrer, Aquatic Ecology Section, California Department of Water Resources, 3251 S Street, Sacramento, California 95816, ffeyrer@water.ca.gov, 916-27-2552; Michael P. Healey , Central Valley Bay-Delta Branch, California Department of Fish and Game, 4001 North Wilson Way, Stockton, California 95205

Abstract: We sampled 11 sites in the southern Sacramento-San Joaquin Delta from 1992-1999, to characterize fish communities and their associations with environmental variables. Riparian habitats were dominated by rock-reinforced levees, and large water diversion facilities greatly influenced local hydrodynamics and water quality. We captured 33 different taxa, only eight of which were native. None of the native species represented more than 0.5% of the total number of individuals collected. The abundance of native species was consistently low but typically peaked during high outflow periods. Fish communities were predominantly structured along environmental gradients of water temperature and river flow. Native species (tule perch Hysterocarpus traski & Sacramento sucker Catostomus occidentalis) were associated with conditions of high river flow and turbidity, while the majority of the non-native species were associated with either warm water temperature or low river flow conditions. The exceptions were the non-native striped bass Morone saxatilis and white catfish Ameiurus catus which were positively associated with relatively high river flow. Variation in fish community structure was greater among river locations within years than within river locations among years, thus fish communities at each river location were consistently different each year. Differences in fish communities among river locations were correlated with river flow and turbidity. We predict that the fish communities of this region will remain numerically dominated by non-native species if the environmental conditions we observed persist in the future.

[5102] Seasonal variation in diet of coastal cutthroat trout in relation to riparian vegetation

Authors: Nicolas Romero and Judith L. Li, Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR 97331, (541) 754-4831 Nicolas_Romero@usgs.gov; Robert E. Gresswell United States Geological Service-Forest and Rangeland Ecosystem Science Center, Corvallis, OR.

Abstract: Recent research suggests that riparian plant communities can influence food availability to stream salmonids. For example, the structure and function of aquatic food webs in some forested streams appear to be related to the phenology of allocthonous material derived from deciduous trees and shrubs. To increase understanding of the interaction between riparian vegetation, season, and diet of coastal cutthroat trout, we removed stomach contents from captured fish in stream sections with conifer, deciduous, and mixed vegetation in three streams in the Oregon Coast Range. Mean invertebrate prey mass and number consumed per fish were greatest in the spring and declined from fall through winter. Mean terrestrial invertebrate prey mass ingested per fish was greater than aquatic invertebrate prey in the summer and fall and highest in deciduous sections in the summer. In addition, mean terrestrial invertebrate prey mass ingested remained constant among seasons except winter. It appeared coastal cutthroat trout condition indices were related to invertebrate prey mass consumed. These results suggest that riparian plant communities seasonally influence prey consumption by coastal cutthroat trout. Furthermore, results suggest that anthropogenic manipulation of riparian plant communities could have previously unanticipated effects on aquatic food webs and coastal cutthroat trout fitness.

[5103] Effect of Organic Chromium on Growth and Carbohydrate Utilization in Hybrid Tilapia Oreochromis Niloticus x O. aureus

Authors: Jiaxi Wang, Xing Zhao and Wei Li; Hubei Province Fisheries Institute, 18 Donghu Road, Wuhan, China

Abstract: An 8-week growth trial was conducted to investigate the effects of different forms of organic chromium (Cr) on glucose and starch utilization in hybrid tilapia Oreochromis niloticus x O. aureus. The forms of Cr were chromium nicotinate acid (Cr-Nic), chromium picolinate acid (Cr-Pic), chromium methionin (Cr-Met) and chromium acetic acid (Cr-Ac). The inclusion level of Cr was 2mg/kg per diet. Fish of weighing1.4g were reared in a still water system and fed 6%-8% of their body weight for 4 meals/day. Significantly (p<0.05) higher specific growth rate were observed in fish fed the glucose diet with Cr-Nic and Cr-Pic, while no significant difference was observed in those fed the starch diet (p>0.05). Feed efficiencies in fish fed diets with Cr-Nic and Cr-Pic were significantly higher than those fed diets without Cr. The body moisture levels in fish fed the glucose diet were significantly lower than those fed the starch diet, while the body lipid levels were significantly higher. Dorsal muscle phosphfructokinase activity in fish fed the glucose diet with Cr-Pic was significantly higher than in those fish fed the starch diet with Cr-Pic, whereas hepatic fructose-1, 6-phophatase activity was significantly lower. The results suggest that organic Cr could improve glucose utilization significantly in hybrid tilapia under the present experimental condition. There was no significant difference between glucose and starch utilization in hybrid tilapia, while dietary carbohydrate sources could affect the whole body composition.

[5104] Habitat Use and Overlap Between Hatchery-Reared Adult Razorback Suckers and Flathead Catfish in the Lower Colorado River

Authors: Joe E. Slaughter, IV, Presenter, Research Branch, Arizona Game and Fish Department, 2221 West Greenway Road, Phoenix, Arizona 85023, 602/789-3663(W), 602/789-3918(F), JSlaughter@gf.state.az.us; Kari Ogren, Research Branch, Arizona Game and Fish Department, 2221 West Greenway Road, Phoenix, Arizona 85023, 602/789-3670(W), 602/789-3918(F), KOgren@gf.state.az.us.

Abstract: Razorback sucker Xyrauchen texanus is an endangered southwestern fish that has suffered severe population declines due to habitat alteration and destruction, decline in water quality, and direct competition and predation by non-native fishes. Razorback recovery efforts have been in effect for over 20 years, but information regarding life history and biological requirements or preferences is limited. The flathead catfish Pylodictis olivaris is a large bodied non-native predator, targeted as a potential threat to razorback recovery. In an effort to determine habitat use and overlap between flatheads and razorbacks, we concurrently tracked ultrasonically tagged individuals over a two year period in the Imperial Division, lower Colorado River. Habitat use was compared to available habitat within the study area to determine habitat selection. Flathead catfish were shown to select main- and side-channel habitats while razorback suckers selected side-channels, backwaters, and impoundment habitats. There was moderate overlap between these two species, occurring in side-channel habitats, although flathead catfish and razorback suckers rarely coexisted in the same location unless moving among preferred areas. As a result of this work, we suggest that flathead catfish pose a moderate predation risk to hatchery-reared adult razorback suckers released into the lower Colorado River, due to moderate overlap in habitat selection.

[5105] Response of Brown Trout to Improved Metal Concentrations in the Arkansas River Near Leadville, Colorado.

Authors: L.C. Bergstedt (Presenter), J.W. Chadwick, D.J. Conklin, Jr., and S.P.Canton. Chadwick Ecological Consultants, 5575 S. Sycamore Street Suite 101, Littleton, CO, 80120, 303-794-5530 (W), 303-794-5041(F), Chadeco@aol.com.

Abstract: Fish population data collected since 1994 were examined to identify the historic and current status of fish populations on the Arkansas River to assess improvements in water quality resulting from reclamation efforts at the California Gulch Superfund site. Poor water quality has resulted from over 150 years of mining in the basin. Brown trout density and biomass directly downstream of California Gulch have historically been substantially lower than at sites upstream of California Gulch and in the tributaries. Correlation analysis indicates that density and biomass are strongly associated with the magnitude of spring flow throughout the basin. Brown trout density and biomass directly downstream of California Gulch have demonstrated consistent, but minor, improvements from 1994 through 2001 . Density and biomass increased dramatically at this site in 2002, further suggesting improvements in this reach. Relative weight for brown trout has been as high or higher at this site compared to other sites. Effects at the population level but not the individual level suggests that fish may be exhibiting a behavioral response opposed to reductions due to acute or chronic effects. The reduction of metal inputs from California Gulch appears to be improving the fishery in this reach of the Arkansas River.

[5106] Do native fishes reared in non-moving water become couch potatoes?

Authors: K.D. HILWIG, Graduate Student-Presenter, Northern Arizona University, Department of Biological Sciences, PO Box 5640, Flagstaff, AZ 86011, (928)523-7505, hilwigk@hotmail.com; and D.L. Ward, Arizona Game and Fish Department, Research Branch, 1535 ½ S. Milton Ave., Flagstaff, AZ 86001, (928)226-7677, dwardagf@qwest.net.

Abstract: Rare native fishes are often propagated at hatcheries and reared in ponds for later stocking into streams with depleted fish populations. Fish unaccustomed to moving water may experience increased stress, downstream displacement, or high predation mortality when released into swift stream systems. We compared the swimming performance of fish held in non-moving water, fish exercised in flowing water, and fish captured from the wild to evaluate the effects of holding environment on swimming performance. The swimming performance of flannelmouth suckers, bonytail chub, and spikedace held in non-flowing water increased by 10%, 18% and 57% respectively after exposure to flowing water (0.1 – 1 m/s) for as little as 10 days. Swim performance of wild-caught spikedace was similar to exercised individuals. Exercising fish raised in non-moving water prior to stocking may improve swimming performance and increase success of stocking programs for stream-dwelling native fishes.

[5107] Phylogenetic relationships, diversity, and zoogeography of western Cottus.

Authors: David A. Neely, Presenter. Department of Biology, Saint Louis University, 3507 Laclede Ave, St. Louis, MO 63103. Office phone: 314-977-3935, email: neelyda@slu.edu. Richard L. Mayden, Department of Biology, Saint Louis University, 3507 Laclede Ave, St. Louis, MO 63103. Phone: 314-977-3494, email: maydenrl@slu.edu.

Abstract: Sequence data from the mitochondrial control region were used to reconstruct phylogenetic relationships of North American Cottus, with particular emphasis on populations formerly allocated to Cottus bairdii. Several novel hypotheses of relationships were identified, while some other traditionally recognized groups (i.e., a Cottus asper clade) were strongly supported. Populations of “Cottus bairdii” from eastern and western North America were resolved as sister taxa, although both clades were rendered paraphyletic by currently accepted species (Cottus carolinae, Cottus extensus, Cottus rhotheus). Morphological data support recognition of at least five species in the western C. bairdii clade. These taxa have largely allopatric distributions corresponding to major hydrological basins of western North America, and which are consistent with zoogeographic patterns in other groups of freshwater fishes. Preliminary data for other western sculpin taxa also suggest similar patterns of differentiation, suggesting that we have seriously underestimated the diversity of this enigmatic group of fishes.

[5108] Assessing self-sustainability of trout populations in Sierra Nevada lakes using an experimental halt to stocking

Authors: T. Armstrong – Presenter, Sierra Nevada Aquatic Research Laboratory, HCR 79, Box 198, Mammoth Lakes, CA 93546, (760) 935-4709 (W), (760) 935-4867(F), (mail to) twarmstrong@ucdavis.edu; R. Knapp, Sierra Nevada Aquatic Research Laboratory, HCR 79, Box 198, Mammoth Lakes, CA 93546, (760) 647-0034 (W), (760) 935-4867(F), knapp@lifesci.ucsb.edu.

Abstract: Trout are often stocked into alpine lakes based on the assumption that resident populations are not self-sustaining and would go extinct without regular stocking. However, this assumption has not been rigorously tested. Our objectives were to (1) estimate the proportion of currently stocked alpine lakes in the Sierra Nevada study area containing self-sustaining trout populations, (2) identify the physical lake factors associated with self-sustainability, and (3) quantify the effects of stocking termination on the density and growth rate of self-sustaining populations. To achieve these objectives, we surveyed trout populations in 95 lakes before and after a 4-9 year stocking halt. Seventy percent of study lakes contained self-sustaining trout populations based on evidence of successful recruitment during the no-stocking period. Regression analysis and recursive partitioning models identified spawning habitat availability and lake elevation as significant factors influencing trout population persistence. Self-sustaining trout populations were nearly always found in lakes with >2.1 m2 of spawning habitat and located at elevations <3520 m. For self-sustaining populations, the termination of stocking did not result in significant changes in population density or growth rate. We conclude that most trout stocking in Sierra Nevada alpine lakes could be permanently halted without negative impact on these fisheries.

[5109] The “Net” Benefits of the Web to Fisheries Science

Author: Mary E. Whalen -presenter, U.S. Geological Survey, Alaska Science Center, Biological Science Office, 1011 E. Tudor Rd., Anchorage, AK 99503, 907-786-3496 (W), 907-786-3636 (F), mary_whalen@usgs.gov.

Abstract: The World Wide Web is all about communication. Whether we are trying to get information out to other scientists or the general public, the web is an important tool in accomplishing these tasks. Fisheries web sites can offer knowledge about fisheries methods, species, stocks, data serving, and contact information. Creating web pages to effectively convey fisheries objectives involves many criteria. Some of these include useful structure and navigation, fast load times, appropriate content, visual appeal, consistency, accessibility to the disabled, and being found by search engines. You can have important data served from your web site, but if the site is not designed correctly, your audience may not being able to find your site or have the patience or time to visit it. I will discuss some of the basic aspects of web design and how they relate to effective fisheries science web sites.

Session: Western Native Trout

[5201] Native Trout Recovery in Arizona: Past, Present, and Future

Authors: S. Gurtin, Presenter, Arizona Game and Fish Department, 2221 West Greenway Road, Phoenix, AZ 85023, 602-789-3518(W), 602-789-3926(F), sgurtin@gf.state.az.us.

Abstract: Arizona’s two native trouts (Apache trout Oncorhynchus gilae apache, and Gila trout Oncorynchus gilae gilae) evolved in habitats subject to enviornmental extremes, and were nearly rendered extinct in the early-mid 1900s. Species’ decline was due mostly to human-induced factors, and both species were considered endangered with passage of the Endangered Species Act in 1973. Since the mid 1900’s, conservation efforts have restored the species’ to several streams/watersheds they historically occupied. Recovery efforts will continue with the goal of delisting. At present, Apache trout are considered threatened with potential for delisting as early as 2004. Gila trout is being proposed for downlisting, which could occur as early as 2003 or 2004. An overview of conservation efforts, potential obstacles to recovery, and future management of the species’ will be provided.

[5202] Reconnecting fragmented Lahontan cutthroat trout habitats

Authors: A.L. Harig, presenter, Trout Unlimited, 1430 Nelson Road, Suite 201A, Longmont, CO, 80501, 303-772-4007, aharig@tu.org; W.T. Colyer, Trout Unlimited, 230 West 100 North, Logan, UT, 84321, 435-753-3132, wcolyer@tu.org; J. McGurrin, Trout Unlimited, 1500 Wilson Boulevard, Suite 310, Arlington, VA, 22209, 703-284-9407, jmcgurrin@tu.org.

Abstract: Recent recovery efforts for Lahontan cutthroat trout have focused on removing barriers to fish movement in drainages that support multiple isolated populations. Though widely viewed as one of the few methods for restoring large interconnected habitats, barrier removal efforts have not been sufficiently monitored to evaluate success. Therefore, we are scientifically monitoring such efforts using a BACI (before-after-control-impact) research design to provide essential data for evaluating, planning, and implementing future large-scale reconnection projects. In the Maggie Creek drainage in northeastern Nevada, a road culvert that fragments tributary habitat and isolates a critical population of Lahontan cutthroat trout will be removed in fall 2003. In 2001, we began annual electrofishing surveys on this tributary stream and others in the drainage to document characteristics of local cutthroat trout populations including genetics, population size, and age structure. These initial basin wide surveys suggest the presence of large migratory adults that may use tributary habitats for spawning, so we plan to trap and mark large cutthroat trout in spring 2003 to monitor their movement within the drainage. We will continue our movement studies and population monitoring after culvert removal to evaluate response to this tributary-main stem reconnection.

[5203] Assessing the Extent of Introgression in Native Greenback Cutthroat Trout (Oncorhynchus clarki stomias) from Introduced Trout Species Using Microsatellite Loci and Mitochondrial DNA Sequences.

Authors: Jessica Metcalf - Presenter, Ramaley Biology N122, University of Colorado, Boulder, Colorado 80309, (303) - 492 - 2573, jessica.metcalf@colorado.edu, Dr. Andrew P. Martin, University of Colorado, andrew.martin-1@colorado.edu, Dr. Jeffrey B. Mitton, University of Colorado. Mitton@colorado.edu.

Abstract: The greenback cutthroat trout (Oncorhynchus clarki stomias) is a federally listed threatened species living in the Rocky Mountains of Colorado. Past and current hybridization between native greenback cutthroat trout and introduced trout species compromises the integrity of greenback cutthroats and is a threat to the native species survival. The extent of past hybridization and the frequency of contemporary hybridization is unclear and must be elucidated for conservation management purposes. I will assess the extent of hybridization that has occurred between greenback cutthroat trout and non-native trout species and subspecies using molecular techniques. DNA will be extracted from adipose fin-clips. Hybridization will be assessed using microsatellite loci and mitochondrial DNA sequences. The results of this research will be presented.

[5204] Habitat-specific survival, biomass and biomass accrual of trout in a small coastal stream

Authors: Jason White, Presenter, USFS Redwood Sciences Lab, 1700 Bayview Drive, Arcata, CA 95521, 707-825-2934 (W) 707-825-2901 (F), jwhite01@fs.fed.us; Bret Harvey, USFS Redwood Sciences Lab, 1700 Bayview Drive, Arcata, CA 95521, 707-825-2926 (W) 707-825-2901 (F), bch3@humboldt.edu.

Abstract: We examined mesohabitat-specific survival, biomass and biomass accrual of trout over a summer in Jacoby Creek, a small coastal stream in northwestern California. The study included 59 experimental units (pools and riffles) enclosed by plastic mesh fences, 809 PIT-tagged fish, and measurement of physical factors including water velocity, depth, canopy and several measures of cover complexity and density. Habitat-specific survival was unrelated to the physical factors we measured. Predation by otters during the experiment occurred even in pools with large quantities of woody debris. Physical factors, particularly those related to cover, strongly predicted the distribution of trout biomass among mesohabitats (r-squared values greater than 0.75). However, biomass accrual was negatively related to the amount and complexity of cover. Similar to results obtained for trout in classic artificial-stream experiments, the relationship between biomass accrual and biomass appeared dome-shaped in Jacoby Creek. Where oversummer growth and the overall abundance of individuals are both important to stream salmonid populations, a high level of physical heterogeneity among habitats appears beneficial. However, greater opportunities for growth in other seasons probably reduce the significance of summer growth for many salmonid populations.

[5205] Evaluating population-level effects of elevated turbidity on stream trout using an individual-based model

Authors: B.C. Harvey, Presenter, USFS Redwood Sciences Lab, 1700 Bayview Drive, Arcata, CA, 95521, 707-825-2926 (W) 707-825-2901 (F), bch3@humboldt.edu; S. F. Railsback, Lang, Railsback & Associates, 250 California Ave., Arcata, CA, 95521, 707-822-0453 (W), 707-822-1868 (F), LRA@northcoast.com.

Abstract: We examined the effects of elevated turbidity on stream-resident trout populations using a spatially explicit, individual-based model. We completed 12-y simulations of cutthroat trout abundance and biomass in a 184-m reach of Little Jones Creek, a relatively clear third-order stream in northwestern California. Turbidity - discharge relationships established with > 3 y of data from Little Jones Creek and a second stream in northwestern California, Freshwater Creek, provided the two extremes for simulated turbidity regimes. Turbidity affected fish in the model by reducing their: 1) reactive distances to drifting prey and 2) risk of predation. The more turbid regime yielded substantially lower abundance and biomass than the less turbid regime; the virtual population went extinct in about half the runs under the more turbid regime while the less turbid regime produced relatively stable abundance and biomass across years. Doubling food availability eliminated differences among turbidity regimes in patterns of abundance, but biomass remained higher in lower turbidity. Results were not highly sensitive to changes in the relationship between turbidity and predation risk or to the particular sequence of hydrologic years. The results indicate that turbidity regimes should be considered when assessing the effects of changes in watershed processes on fish.

[5206] Seasonal Movement Patterns of Stream-Resident Cutthroat Trout in the Snake River Headwaters of Wyoming

Authors: M.A. Novak, Presenter, USFS, Bridger-Teton National Forest; Aquatic, Watershed, and Earth Resources, 5210 Old Main Hill, Utah State University, UT 84322-5210; 435.797.4078(W) 435.797.1871(F); markn@cc.usu.edu; M.L. Sadak, USFS, Bridger-Teton National Forest, P.O. Box 1888, Jackson, WY 83001, 307.739.5803; msadak@fs.fed.us; J.L. Kershner, USFS, Fish and Aquatic Ecology Unit, Aquatic, Watershed, and Earth Resources, Utah State University, Logan, UT.84322-5210; 435.797.2500(W), 435.797.1871(F); kershner@cc.usu.edu.

Abstract: Radio telemetry was used to assess mobility of cutthroat trout in the Snake River headwaters of Wyoming from July 2001 to August 2002. Four adult Yellowstone cutthroat trout Oncorhynchus clarki bouvieri and sixty-three adult finespotted Snake River cutthroat trout O. c. subsp. were surgically implanted with one of three sizes of radio transmitter (100 d, 256-341 mm TL; 35 d, 317-392 mm TL; 283 d, 319-440 mm TL). A pattern of summer-fall (median 0-50 m; range 0-6,000 m) and winter-spring (median 0-250 m; range 0-800 m) movements was observed. In late-fall, twelve fish exhibited a single movement (range 250-2000 m) from a summer-fall range to a winter-spring range. In late-spring, five fish exhibited two distinct movements (range 1,000-4,800 m) after the winter-spring season and prior to establishing summer-fall ranges. We found cutthroat trout displayed two distinct patterns of mobility: 1) Median summer-fall movements were smaller than winter-spring movements, however, summer-fall ranges were larger than winter-spring ranges; and 2) Some fish exhibit fall migrations possibly in search of over-winter habitat, and spring migrations either seeking refuge from high spring flows or to spawn.

[5207] Factors influencing the spawning migrations and natural reproduction of the adfluvial Bear Lake Bonneville cutthroat trout in St. Charles Creek, Idaho.

Authors: Paul Burnett – Presenter, Utah State University, Aquatic Watershed and Earth Resources Department, 5210 Old Main Hill, Logan, UT 84322-5210, 435-797-4078, palado@lycos.com; Jeffrey L. Kershner, Utah State University, Aquatic Watershed and Earth Resources Department, 5210 Old Main Hill, Logan, UT 84322-5210, 435-797-2500, kershner@cc.usu.edu.

Abstract: The Bear Lake Bonneville cutthroat trout (BLBCT) is one of two remaining adfluvial populations of Bonneville cutthroat trout. This population exhibits an obligate migratory life history, highlighting the need to maintain all critical habitats required to complete their life cycle. St. Charles Creek represents the primary spawning tributary for BLBCT, but has been severely impacted by improper land use and water development. This study investigated the factors that limit the spawning migrations and natural reproduction of BLBCT. We investigated the spawning movements of the population using radio telemetry. The redd sites were characterized by measuring physical characteristics and assessing gravel quality. Our results illustrate that spawning cutthroat trout in St. Charles Creek consistently spawn in suboptimal habitat and that critical habitat in St. Charles Creek is periodically fragmented. Unscreened irrigation diversions influenced spawning migrations by blocking upstream and downstream movement and by entrainment. High numbers of hatchery fish may also influence spawning migrations because they spawn opportunistically in suboptimal habitat and lack homing mechanisms. This study provided a framework for the creation of a resource management group involving local land owners and agencies, which should be influential in improving habitat conditions in the stream.

[5208] An evaluation of the effectiveness of barriers at protecting Apache trout.

Author: A.T. Robinson, 2221 W. Greenway Road, Phoenix, AZ 85023, (602)-789-3376(W), (602)-789-3918, trobinson@gf.state.az.us.

Abstract: Barriers have been constructed on many White Mountain streams to protect Apache trout Oncorhynchus apache from nonnative salmonids. These barriers can fail to serve their purpose if fish are able to move through, around, or over the barrier due to poor design, decay of materials, washout, or if anglers move fish upstream of the barrier. In addition, barriers may hinder Apache trout movements and metapopulation dynamics. On each of six streams, we marked trout downstream of the barrier and then sampled both below and above the barrier to detect movement nonnative salmonids. We also marked Apache trout upstream of the barrier to detect downstream passage below the barrier. In two years of study we only detected movement of one marked nonnative trout upstream past a barrier, but several unmarked nonnative trout have been found upstream from barriers on four streams. The distribution of length classes of Apache trout in four streams tended to be skewed towards smaller fish below barriers, whereas above the distribution tended towards bigger fish. This may indicate that young fish are dispersing downstream to below the barriers, and if so, could indicate a net loss of a dispersing genotype from the protected areas.

Session: Overcoming Impediments to Fish Passage (Part II)

[5301] Participation in Hydro Relicensing as a Tool for Furthering NOAA Fisheries Mission.

Author: S.A. Edmondson-Presenter, NOAA Fisheries, Habitat Conservation Division, 777 Sonoma Ave. RM 325. Santa Rosa, CA 95404, 707-575-6080(W), 707-578-3435(F), steve.edmondson@noaa.gov.

Abstract: In many California watersheds, such as the Sacramento and San Joaquin, (Central Valley) dams block as much as 95% of historic salmonid spawning habitat. As a result, chinook salmon and steelhead are extirpated from approximately 5,700 miles of their historic habitat in the Central Valley. In most cases the habitat remaining is of much lower quality than the habitat lost and is subject to further degradation by direct and indirect impacts of hydroelectric operations. Non-federal, FERC licensed dams account for approximately 40% of all surface water storage in Central Valley. There are 122 FERC licensed hydroelectric projects in California. Of this total, there are 42 project licenses that are either currently undergoing relicensing or will expire between 2000 and 2010. In general, relicensing is initiated 5 to 8 years prior to license expiration. Accordingly, workload is expected to increase rapidly in the next few years. With the term for FERC hydropower licenses generally running from 30 to 50 years, Hydropower dams in California present unique challenges to anadromous fish. According to a 1994 study by the Department of Energy, upstream passage/protection facilities are present at 6.7% (out of a total of 450 plants) of FERC licensed hydroelectric projects and downstream passage/protection/mitigation facilities are present at 9.3% (42 plants). Many of the existing passage facilities perform poorly. Additionally, many hydropower facilities significantly decrease stream flow, impair water quality and destroy important fish habitat, causing serious harm to anadromous fish. Sections 18 and 10(j) of the Federal Power Act (FPA) assign to NOAA Fisheries broad, and in the case of section 18, mandatory authorities for protecting fish. Consequently, the FPA provides a powerful vehicle for achieving fishery management and species recovery goals by reintroducing viable fish runs to historic habitat; enhancing existing runs through habitat improvements within a river basin; and the timely and safe passage of fish around hydropower projects. Because of the unprecedented number of relicensings in California, FERC?s shift to the collaborative process, and growing interest in decommissioning, NOAA Fisheries faces a unique opportunity to apply our FPA conditioning authorities more comprehensively. By affording fish access to viable habitats denied for decades a realizable potential exists to restore fish to their historic range where dams have reduced or extirpated salmonid stocks. Further, by improving flows and other key habitat components NOAA Fisheries can increase utilization of the remaining important key cold water habitat necessary for the stabilization and recovery of many stocks of wild salmonids.

[5302] Assessing the passage potential of anadromous salmonids at five natural falls in Ward Creek, Alaska under varying flow conditions

Authors: D.W. Reiser (presenter), R2 Resource Consultants, Inc., 15250 N.E. 95th St. Redmond, Washington 98052, 425-556-1288 (W); 425-556-1290 (F); dreiser@r2usa.com, C. Huang, M. Gagner, E. Jeanes, and M. Ramey (same addresses and phone/fax)

Abstract: We evaluated the ability of anadromous salmonids (coho, pink, chum, and sockeye salmon, and steelhead) to pass 5 sets of falls within Ward Creek, Alaska under varying flows. Ward Creek was historically regulated by Connell Dam and therefore the study focused on determining suitable instream flow releases to afford passage. Each falls was surveyed under three flow conditions (20, 40, 100 cfs) and access portals identified. Using computed stage – discharge relationships and other data, and published swimming and jumping criteria, we evaluated the falls barrier potential over a range (8-400 cfs) of flow conditions. Analysis indicated pink and chum salmon would be relegated below the lower two falls. Flows affording passage over all 5 falls for the other species were identified as “flow-windows”. Flow windows varied by species and ranked from narrowest to widest range of acceptable passage flows as: sockeye < coho < steelhead. Escapement surveys confirmed our analysis; pink and chum salmon were only found below the lowermost falls, coho were observed above the uppermost falls; steelhead and sockeye have been reported above the upper falls. Our approach could be applied to other regulated systems where passage issues need to be considered in developing suitable instream flow regimes.

[5303] Fish passage barriers in Colorado: the good, the bad, and the ugly.

Authors: Christine L. Hirsch – presenter, White River National Forest, PO Box 948, Glenwood Springs, CO 81602, 970-945-3243(W), 970-945-3211(F), chirsch@fs.fed.us; Mark R. Weinhold, White River National Forest, PO Box 948, Glenwood Springs, CO, 81602, 970-945-3306(W), 970-945-3211(F), mweinhold@fs.fed.us.

Abstract: The primary focus on fish passage barriers has been on anadromous species with their dramatic migrations. We have been slow to consider the problems barriers cause for resident fish. Streams in Colorado naturally contain many barriers; humans have greatly increased that number with roads and diversions, yet systematic barrier inventories are in their infancy. For the Forest Service, BLM, and State, identification and treatment of fish passage barriers is largely driven by the individual interests and concerns of the local biologists and hydrologists. Formal state and federal direction requiring fish passage is inconsistent and often lacking. Native trout in the Southern Rockies currently occupy less than 5% of their historic range. Ironically, it is migration barriers that have provided for their persistence. Barriers protect native cutthroat trout from invasion by introduced trout species, which can either extirpate them through direct competition or hybridize with them. Consequently, construction of barriers is becoming more commonplace in cutthroat restoration. Native cutthroat are now primarily restricted to the headwaters of their historic range where natural barriers are more likely to occur.

[5304] Fish Passage: Beyond dams and migratory fishes

Authors: Mark Hudy – Presenter, USDA Forest Service, National Aquatic Ecologist-East, MSC 7801, 225 Burruss Hall, James Madison University, Harrisonburg, VA 22807, 540-568-2704 (w), 540-568-6064(f), hudymx@jum.edu or mhudy@fs.fed.us; J.Keith Whalen, USDA Forest Service, James Madison University, Harrisonburg, VA 22807, 540-568-8152 (w), 540-568-6064(f), whalenjk@jmu.edu.

Abstract: Historically in the U.S. considerable efforts have focused on the ecological and economic impacts of the over 75,000 large (over 6 feet in height) dams and 2.5 million smaller dams on migratory fishes. By comparison little effort has been placed on the impacts of road/stream crossings (1.4 million) on non-migratory freshwater fish species, crayfishes, freshwater mussels, fresh water snails, aquatic insects and riparian dependant mammals. In our study on a 5th level watershed with no migratory fish, road/crossing impacts (mainly culverts) were at the species level (63% of culverts had less fish species above), population level (44% of these same culverts had lower relative abundance above the culvert.), and habitat level (94% had small or large scale impacts). Genetic impacts (fragmentation and isolation of gene flow) were suspected but were not a study objective. These results were alarming and highlighted the potential fragmentation of aquatic organisms from road/stream crossings. We propose states and federal agencies closely re-examine the impacts of road/crossings on fish and other aquatic organisms and develop standards, guidelines, and best management practices that have a goal of 1) passage for all aquatic organisms and 2) stream simulation of channels at road/crossings.

[5305] Caltrans Fish Passage Improvement Projects in Northern California

Author: Jonathan Oldham – Presenter, California Department of Transportation, District 2 Office of Environmental Management, 1657 Riverside Drive, Redding, CA 96001, 530-225-3308 (w), (530) 225-3019 (f), jonathan.oldham@dot.ca.gov.

Abstract: The California Department of Transportation (Caltrans) is responsible for constructing, maintaining, and operating the State’s highway system. The Department’s strategic plan includes important environmental goals and objectives that help protect and enhance natural resource systems. Fish passage is one issue pertinent to Caltrans due to it’s many road culverts, bridges, cross drains, and other conveyance systems that potentially affect fish and other aquatic species. In Northern California, fish passage improvement projects are being pursued from various angles. Several projects have been completed while others are being planned. Surveys are being conducted to help identify, assess, and prioritize potential fish passage locations needing enhancement, replacement, or maintenance projects. The Caltrans District 2 office has established an interagency working group called FishPAC (Fish Passage Advisory Committee) to develop and coordinate projects, and is working with other private and agency partners in project cost sharing, design, and implementation. Projects that have been constructed or are in design include fish ladders, bridges, culvert replacements, culvert baffle systems, road removal, and weir construction. A summary of the projects and approaches Caltrans is using to improve fish passage will be presented.

[5306] Monitoring culvert passage of juvenile salmonids with PIT tags and stationary and portable PIT-tag readers.

Authors: Hansen, B.P., 541-750-7311(W), bhansen@fs.fed.us; Hendricks, S.R., Presenter, 541-750-7394 stevehendicks@fs.fed.us; and S.N. Lampson, 541-750-7320, slampson@fs.fed.us, U.S. Forest Service PNW Research Station, 3200 SW Jefferson, Corvallis, OR 97333; J.L. Ebersole, U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, 200 SW 35th St., Corvallis, OR 97333; B. Miller, Oregon Department of Fish and Wildlife, 4475 Boat Basin Dr., Charleston, OR.

Abstract: Federal land management agencies in the PNW face increasing pressure to replace culverts that do not pass all life-history stages of anadromous salmon and trout. Prioritization of culverts for replacement is often based on the physical parameters of culverts, and not on how fish may use habitat upstream of culverts. This is especially true for juvenile fish. A key component to developing criteria and guidelines for prioritization is knowing the features of streams that fish move into and when juvenile fish move. In an effort to increase understanding of juvenile fish movement and seasonal habitat use, we will monitor the movement of juvenile coho salmon and steelhead and cutthroat trout into and out of selected tributaries of the West Fork Smith River (central Oregon coast) for a year. Juvenile fish implanted with PIT tags will be used to determine movement, habitat use, survival and growth. PIT-tagged fish will be monitored with stationary PIT tag readers located in three tributaries with “fish friendly” culverts (i.e. meet current design standards) and with portable PIT-tag readers throughout the watershed. Fish will also be captured by seining. Preliminary results from the first six months of the project will be presented.

[5307] Design Considerations for an Experimental Test Bed for Assessment of Culverts for Passage of Juvenile Salmonids

Authors: W. H. Pearson, Staff Scientist, Pacific Northwest National Laboratory, Marine Sciences Laboratory, 1529 West Sequim Bay Road, Sequim, WA 98382, 360-681-3661 (W), 360-681-3699 (F), Walter.Pearson@pnl.gov; M. C. Richmond, Chief Engineer, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 98352, 509-372-6241 (W), 509-372-6089 (F), marshall.richmond@pnl.gov; H. E. Dunham, Principal Engineer, MWH, 2375 130th Ave. NE, Suite 200, Bellevue, WA 98005, 425-881-1100 (W), 425-881- 8937 (F), Harry.E.Dunham@us.mw.com.

Abstract: Culverts block upstream juvenile salmonid movement. With Washington State Department of Transportation, the Pacific Northwest National Laboratory has undertaken an assessment of juvenile fish passage through various culvert designs. This program addresses the testing and assessment of retrofit and new culvert designs with full-scale physical models of culvert systems deployed in an experimental test bed. Experiments in the test bed will measure the hydraulic conditions (mean velocity, turbulence, and water depth) associated with various culvert designs under various slopes and flow regimes and relate these measures to repeatable, quantitative measures of fish passage through the culvert system. To facilitate design of the test bed research program, the team developed a behavioral model of juvenile fish passage. The design features of the test bed include the ability to exchange different culvert systems and to conduct testing under slopes from near level to 10% slope and flows up to 20 cfs. Installation of an acoustic doppler velocimeter enables fine-scale measurements of water velocity and turbulence. The test bed was fabricated and installed at a Washington State Department of Fish and Wildlife Hatchery in January 2003.

[5308] Fish Passage for Native Species of the Western United States

Authors: B.W. Mefford, Hydraulic Research Engineer, US Bureau of Reclamation, Denver Technical Center, PO Box 25007 Denver, Co. 80225, 303-445-2149, bmefford@do.usbr.gov.

Abstract: During the last 100 years, the Bureau of Reclamation has constructed a large number of small irrigation diversion dams throughout the western United States. Most of these diversion dams reside on rivers that are home to mainly non-game fish. Starting in the late 1980’s, Reclamation recognized the need for new research on design of fishways for native species of the west. This research has resulted fishways designed to provide flow conditions suited to the behavior and swimming abilities of native species. This paper covers Reclamation’s fish passage research and evaluation of many recently constructed fishways. Hydraulic design of natural-like fishways and structural fishways are discussed.

[5309] Stream Simulation – Culvert Design for Passage of Aquatic Organisms

Author: K. Bates, Fish Passage Consultant, 5211 Blvd Ext SE, Olympia, WA 98501, 360-701-8909 (W), 253-541-6949 (F), bateskmb@attbi.com.

Abstract: A guide for passage of aquatic organisms at road-stream crossings is presented. Tools are being developed with the goal of maintaining or restoring stream form and biologic, hydrologic and geomorphic function at road crossings of streams. Traditional culvert design methods only address passage of target species of adult fish, yet the need for passage of juvenile fish and other organisms has long been recognized. Stream simulation is a culvert design method to economically emulate the diversity and complexity of a natural channel inside a culvert. The premise of stream simulation is that the simulated channel inside a culvert presents no more of an obstacle to movement of organisms than the adjacent natural channel. The method does not resolve issues of darkness, openness ratio, and floodplain hydrology. Preliminary design process and criteria for stream simulation culverts are presented. Criteria include culvert size and slope, and bed material. The design process includes a bed stability analysis that depends on channel classification and slope. Special issues such as steep channels, bed forms, and floodplain contraction are discussed. Monitoring conducted at 19 stream simulation culverts is described. Parameters were tested to evaluate the similarity with natural channel.

Session: Biology, Ecology, and Management of Pacific Coast Sharks (Part II)

[5401] Pop-up archival tagging of shortfin mako sharks, Isurus oxyrinchus, in the Southern California Bight.

Authors: D. Holts (david.holts@noaa.gov) and S. Kohin – Presenter (skohin@ucsd.edu) Southwest Fisheries Science Center, National Marine Fisheries Service, 8604 La Jolla Shores Dr., La Jolla, CA, 92037, 858-546-7000(W), 858-546-7003(F).

Abstract: In summer months, the Southern California Bight is home to a large population of shortfin mako sharks. Abundance surveys and fishing reports indicate that juvenile mako sharks appear in the Bight in spring when water temperatures rise above 16º C and may depart from the area in fall when water temperatures decline. Little is known about residence times of individual makos in the Bight, their habitat use patterns, and whether water temperatures constrain the behaviors of these warm-blooded sharks. We deployed pop-up archival tags on 8 makos (118-275 cm TL) in June and July, 2002 and studied behaviors of individual sharks for 2 to 4 months. Pop-up locations ranged from 20 to 911 km from deployment locations. The sharks utilized near-shore and open-water areas off California and Baja California roughly between 23-43º N and out to 125º W. While the records indicate that greater than 90% of the time was spent above 50m, several sharks showed a diurnal pattern of vertical excursions to beyond 300m during daylight hours. Sharks frequently dove into water less than 10º C. These data demonstrate the extreme range of habitats utilized by mako sharks and begin to shed light on their daily and seasonal behaviors.

[5402] Commercial Pelagic Sharks Fishery from the Western Coast of Baja California Sur.

Author: Jorge Ramírez González¹*, Jonathan Sandoval Castillo¹, Carlos Villavicencio Garayzar¹ and Oscar Sosa Nishizaki²; *Presenter; Laboratorio de Elasmobranquios, Departamento de Biología Marina, Universidad Autónoma de Baja California Sur. Carr. Al Sur Km 5.5, La Paz, BCS, Mexico Phone: +52(612) 1280775, Fax: +52 (612) 121 80 80. cvilla@uabcs.mx; CICESE, Km 107 Carretera Tijuana Ensenada, Ensenada, B. C., Mexico. Phone: +52 (646) 175 05 00, Fax: +52 (646) 175 05 45. ososa@cicese.mx.

Abstract: Since 1994 a small fleet (n=3) of medium size fishing boats based at Puerto San Carlos, Baja California Sur, started to target sharks, fishing with gillnets and longlines. In order to describe the catch species composition of this fishery, we analyzed the fishing logbooks of the three vessels for the fishing seasons between 1994 and 2001. Also, in order to have better biological information, we observed onboard six fishing trips of one of the boats. Fishing area covers from Cedros Island to Cabo San Lucas, but most of the fishing operations were carried out off Magdalena Bay. The most important species in order of importance were Prionace glauca, Isurus oxyrinchus, Carcharhinus falciformis, Alopias spp., Sphyrna spp. Gillnets were used more frequently than longline, but the later had a higher blue shark (P. glauca) catch rate. P. glauca, and I. oxyrinchus were principally present during the first semester of the year, while C. falciformis y Alopias spp. were more mostly present during the second semester of the year. We will present size composition, sex rates and maturity state for P. glauca, C. falciformis, I. oxyrhincus, Alopias pelagicus y Sphyrna zygaena based on onboard observations.

[5403] Elasmobranches fishery at Isabel Island in the Central Mexican Pacific

Author: Juan C. Perez-Jimenez* and Oscar Sosa-Nishizaki; *Presenter; CICESE, Km 107 Carretera Tijuana Ensenada, Ensenada, B. C., Mexico. Phone: +52 (646) 175 05 00, Fax: +52 (646) 175 05 45. jcperez@cicese.mx.

Abstract: In order to describe the shark fishery in the region, biological and fishery information was obtained for sharks and rays caught around Isabel Island during the fishing season 2000-2001. We registered 7,464 sharks of 16 species and 141 rays of 8 species. Rays were bycatch and some species were commercialized only when sharks landings were not very abundant. The principal fishing gear was bottom longline. Most important shark species were juvenile scalloped hammerheads Sphyrna lewini (49 %) and subadult and adult sharpnose sharks Rhizoprionodon longurio (45 %). In this zone it was possible to observe a periodicity of fifteen days in the fishing effort and therefore in the captures of these two species, which suggests a relation with the lunar cycle. A list of all species of sharks and rays, the abundance of the principal species through the fishing season, their size distribution, sex ratio and some reproductive aspects will be described.

[5404] Estimating a Local MSY for the Common Thresher Shark

Authors: David Au, NMFS Southwest Fisheries Science Center, 8604 La Jolla Shores Dr., La Jolla, CA 92037; (858) 546-7071(W), (858) 546-5653(F); David.Au@noaa.gov. .
Christina Show, NMFS Southwest Fisheries Science Center, 8604 La Jolla Shores Dr., La Jolla, CA 92037; (858) 546-7078(W), (858) 546-5653(F); Christina.Show@noaa.gov. .

Abstract: We estimate local MSY for the common thresher shark (Alopias vulpinus) off southern California by a non-traditional approach that circumvents the difficulties of estimating mortality on a long-lived slow-growing species and estimating sustainable production from catches reflecting unsustainable, non-equilibrium fishing and changing regulations. These are common problems in assessing low productivity species. The simple logistic production curve, utilizing estimates of the parameters Bo (initial biomass) and r (intrinsic rate of population increase) was fitted to the 1981-99 gillnet fishery=s catch-CPUE relationship to estimate this shark=s MSY. Intrinsic rate r was estimated from demographic parameters using a procedure we call Aintrinsic rebound potential.@ Parameter Bo was prorated from Bt (biomass during 1992-3 when the population was temporarily at equilibrium with natural production), which was estimated by dividing the catch of those years by the annual population growth rate then, based on the r at the population size then. Population size was based on CPUE, which was estimated as the annual weighted average catch (numbers of fish) per unit of net effort (length - hours soaked). Data from approximately 4000 sets per year were utilized. The resulting production curve applies to the portion of the stock accessed by U.S. fishers. It does not include the unknown production from off Mexico. Thus the MSY given by the curve is actually an estimate of local MSY (LMSY). The central estimate of LMSY is 450 mt for all gears. This is to be compared with the Pacific States Marine Fisheries Commission=s guideline of 578 mt, and also with the 306 mt average catch since 1992. The maximum catch was 1521 mt in 1981.

Session: Oncorhynchus at Their Southern Extremes

[5501] Steelhead Recovery Planning in Southern California: Taking the First Steps

Author: Mark H. Capelli, National Marine Fisheries Service, Southwest Region, 735 State Street, Santa Barbara, CA 93101 (805) 963-6478, Mark.Capelli @noaa.gov.

Abstract: Listing of steelhead (Oncorhynchus mykiss) in southern California as endangered in August 1997 requires the development of a recovery plan leading to the de-listing this designated Evolutionarily Significant Unit (ESU) of steelhead. The recovery process will be divided into two distinct phases: (1) the development of specific recovery goals, based upon the biological requirements of the species and the best scientific data available; and (2) the development of specific conservation actions to achieve those recovery goals. The first phase will be conducted by a Technical Review Team (TRT) under the auspices of the NOAA Southwest Science Center. Some of the first responsibilities of the TRT will be to identify independent populations within the ESU; characterize the relationship between habitat characteristics and the size and productivity of populations; identify factors of decline and current limiting factors; identify research need to address critical issues; and establish criteria for evaluation and monitoring of recovery efforts. The second phase will be undertaken by a larger array of co-managers and stakeholders under the direction of a NOAA Fisheries Area Recovery Coordinator.

[5502] Status, habitat, and restoration of southern steelhead in Topanga Creek and State Park, just south of Malibu Creek.

Authors: Rosi Dagit, Resource Conservation District of the Santa Monica Mountains, 122 North Topanga Canyon Boulevard, Topanga, CA 90290, 310 455-1030, OAKSRUS@mac.com; Camm C. Swift, Emeritus, Section of Fishes, Natural History Museum of Los Angeles County, Mailing address: 346 West Leroy Avenue, Arcadia, CA 91007-6909, 626 447-5846, camswift@pacbell.net.

Abstract: Topanga Creek lies about 10 kilometers east of Malibu Creek and harbors a small population consisting of both resident and migratory Oncorhynchus mykiss. To assess the status of this population, habitat assessment transects and snorkel surveys have been conducted for two years. Planned upstream and downstream trapping has been prevented by lack of rain during the study period. The maximum number of fish counted in any one snorkel survey is 159, and at least one large migratory individual was observed trapped in lower pools for 8 months in 2002. All steelhead are confined to the lower 4.4 km of stream today. Relatively good habitat conditions are reflected in low temperatures, lack of predatory exotic fishes, and successful reproduction by resident fish even during a very low rainfall year. Since much of the surrounding land has recently been acquired by the State Park system, there is a good prognosis for increasing numbers of fish with restoration of the lagoon and opening access upstream to more of the drainage where historical records indicate steelhead used to occur.

[5503] Visual display of stream habitat survey profiles using GIS: An example from Topanga Creek, coastal southern California

Authors: Kevin Reagan, Presenter, 4832 Minden Pl, Los Angeles, CA 90041, voice: 323-255-6402, fax: 323-255-4646, kreagan@inreach.com; Rosi Dagit, Resource Conservation District of the Santa Monica Mountains, 122 N Topanga Canyon Blvd, Topanga, CA 90290, voice: 310-455-1030, fax: 310-455-1172, oaksrus@mac.com; Camm Swift, 346 W Leroy Ave, Arcadia, CA 91007, voice: 626-447-5846, fax: none, camswift@pacbell.net.

Abstract: In California, many stream habitat surveys are conducted using methodologies based on the Department of Fish and Game's CALIFORNIA SALMONID STREAM HABITAT RESTORATION MANUAL. Habitat characteristics are recorded at each reach and cross-section. The elevation of the survey locations along the stream may also be recorded. In the context of GIS mapping of habitat surveys, reaches have traditionally been displayed as lines and the cross-sections treated as points, and the map is usually in plan view. The supplementary approach suggested here is to use GIS to display a profile in elevation view. The profile has the appearance of a bar chart where each bar corresponds to a survey reach, with three features: 1) the width of each bar is proportional to the length of the reach, 2) the height of each bar is proportional to the elevation of the reach, and 3) the color-coding of each bar represents a habitat characteristic of the reach. The resulting display provides a visual summary of information such as: where reaches with certain characteristics are, the elevations at which they occur, and the distribution (separation or contiguity) of a certain characteristic along the stream. Such information cannot be discerned from summary tables of numbers.

[5504] Survival of the Southernmost Population of Steelhead in San Mateo Creek coastal couthern California

Author: Tim E. Hovey, Presenter, Associate Fisheries Biologist for The California Department of Fish and Game. 4949 Viewridge Avenue San Diego, CA 92123 thovey@dfg.ca.gov.

Abstract: Southern steelhead/rainbow trout occupying the San Mateo Creek drainage in San Diego County, California have been continually monitored with routine California Department of Fish and Game fisheries surveys from December 1999 to August 2002. Trout presence on San Mateo Creek (SMC) began to decline shortly after the surveys began and trout have not been detected on SMC proper since August 2000. Juvenile trout were discovered on Devil Canyon Creek (DCC), a tributary of SMC in May and June 2000 and adults continue to be present within the confluence. Data on water temperature indicates that temperature is more stable in DCC than in SMC. We assume that this enhances survival of steelhead in DCC. Genetic analysis established that at least two pairs of anadromous steelhead entered the drainage in 1997 to spawn and that successful F2 reproduction has occurred in DCC. Age analysis of a single adult individual indicates that maturing F2’s currently occupy DCC. Observed spawning behavior and monitoring evidence gathered during this study suggests that the original steelhead trout may have spawned in DCC and not SMC. Water availability and the presence of exotic fish species continue to be the two main principles influencing trout survival on the San Mateo Creek drainage.

[5505] Historical Notes on Trout/Steelhead in San Diego County & Northern Baja California”

Author: A. R. Greenwood, Presenter, San Diego Trout, 4344 Newport Ave., San Diego, Ca. 92107, tel. & fax: 619-222-4051, boogieboard@juno.com.

Abstract: This paper presents a condensed history from the mid 1850’s with emphasis on the 20th century to the present of selected San Diego County, California and northern Baja California, Mexico steelhead and trout streams. Documentation and interviews are presented to prove that steelhead/ rainbow trout were native to this region. Evidence is presented to show the slow but steady degradation of the regions watersheds resulting in a decline of steelhead/rainbow trout to the point that only a few individuals remain in two streams south of Malibu Creek. Today, we are primarily left with very small populations of resident rainbow trout that live in very small-secluded sections of the back country. Last a plan is presented to help restore on single watershed with native freshwater fish including the southern steelhead.

[5506] Removing Matilija Dam: Opportunities and Challenges for Ventura River Steelhead

Author: Mark H. Capelli, National Marine Fisheries Service, Southwest Region, 735 State Street, Santa Barbara, CA 93101 (805) 963-6478 Mark.Capelli @noaa.gov.

Abstract: The removal of Matilija Dam on a major tributary of the Ventura River presents an opportunity to restore a significant portion of the steelhead spawning and rearing steelhead within the Ventura River watershed. Pre-dam estimates indicate that approximately 50% of the steelhead spawning and rearing habitat is located above the impassible dam. A major challenge to dam removal with be the management of the 6 million cubic yards of sediment impounded upstream of the facility. Natural flushing of this material through the system could adversely impact spawning and rearing habitat in the lower reaches, including the estuary. A variety of methods have been identified for the removal of this sediment, including controlled flushing through incremental notching of the dam structure, slurrying finer fractions of sediments through a conduit to the ocean; conveying course fragments to an off-site location; stabilizing and permanently storing a portion of the sediments at the dam site. Because none of the sediment management alternatives is free of environmental constraints, some combination of these options may provide the best strategy to minimize adverse impacts to steelhead and other aquatic species.

[5507] Salmon and Steelhead Recovery Planning: The Essential Need For Accelerated Recovery Planning Efforts With Measurable Population Objectives

Authors: Jim Edmondson, Presenter, California Trout, Inc.; 5436 Westview Court, Westlake Village, CA 91362, 818-865-2888 troutmd@earthlink.net.

Abstract: While seven years have passed since the first listing of California's salmon and steelhead, Recovery Plans are finally beginning to be developed. It is essential that standards of accountability and measurement be established so that success will be insured. History has too often indicated that government plans and projects fail to follow up adequately on performances, thereby dooming projects to failure and continuing the cycle of waste and ineffectively utilized taxpayer dollars. Requiring standards of accountability from government efforts is consistent with federal and state guidelines, and is necessary to provide assurances to the American public that recovery is progressing, cost effective, and ultimately successful. The recovery of California's beleaguered salmon and steelhead populations is dependent on standards of accountability that properly measure this progress and effectiveness. This policy position paper reviews the status of California's federally listed salmon and steelhead recovery planning; discusses government laws and resource management programs requiring measurable recovery practices; and, updates the condition of recovery planning efforts. It concludes with a series of policy recommendations to accelerate the planning process, including recommendations for accountable recovery standards and prudent reforms to the Federal Endangered Species Act of 1973.

Reservoir Management in the Arid West

[5601] Assessing Species Interactions in Elephant Butte Reservoir, New Mexico

Authors: David E. Cowley and Gary W. Roemer, Department of Fishery & Wildlife Sciences, New Mexico State University

Abstract: Elephant Butte Reservoir, impounded in 1916, is characterized by unpredictable annual surface elevations and water storage that varies with periods of drought and winter snow accumulation. During drier periods, low water levels allow shrub growth along formerly high water shorelines. Wetter periods inundate terrestrial vegetation within the reservoir, which, over the short term, boosts production of sport fish populations. Improved fishing increases angler use and the expectations of anglers for a quality fishery. Declines in sport fish populations occur when water levels remain high long enough for inundated vegetation to decompose or when reservoir storage declines. The purpose of this study is to understand the trophic linkages between fish species in the lake, so that fishery managers can better understand management options available under conditions leading to declining sport fish populations. Trophic linkages are being studied from two perspectives, analysis of gut contents and analysis of stable isotopes contained within fish body tissues. These perspectives will be coupled with another approach, the “envirogram”. An envirogram is a conceptual framework that is used to identify and prioritize the abiotic and biotic factors influencing a population. Using the literature and data collected from the study, we will develop envirograms for approximately 10 species of fish that are either important sport fish or potential drivers of the aquatic community. Through this design, we hope to gain a deeper understanding of the factors regulating fish populations in the reservoir.

[5602] Assessing interactions between two species of bass within the same reservoirs.

Authors: Shawn R. Denny, NM Game and Fish, 1912 W. Second, Roswell, NM 88201, sdenny@state.nm.us; Casey L Harthorn, NM Game and Fish, 566 N. Telshor, Las Cruces, NM 88011, charthorn@state.nm.us; Dr. Kevin Pope, Wildlife and Fisheries Management Institute, Texas Tech. University, mail stop 2125, Lubbock, TX 79409-2125, kevin.pope@ttu.edu.

Abstract: Historical stocking has resulted in the presence of largemouth (Micropterous salmoides), smallmouth (Micropterus dolomieu), and spotted bass (Micropterous dolumi) inhabiting the same reservoirs throughout the Pecos River drainage. Angler concerns and extreme drought conditions have led biologists to investigate the interactions and consequences this species composition may have on the quality of these fisheries. We documented largemouth bass and spotted bass food habits, condition, age, and growth from Brantley and Sumner reservoirs, New Mexico. Fish were collected monthly by night electrofishing from May 2001 through May 2002. Stomach contents were removed using acrylic tubes and were preserved. Stomach samples were enumerated and identified to Order for insects and to Family for other categories. Age was determined by viewing whole otoliths with a dissecting microscope. In Sumner Reservoir (located north of Brantley Reservoir), bass ate mainly crayfish, whereas bass in the southern reservoir ate mainly insects and fish. However, seasonal variation in diet composition did occur in both species. This presentation will concentrate on diet analyses, age, growth, and population trends of both species of bass within each reservoir and the possible role water management is having with these fisheries.

[5603] Effects of dam operations on largemouth bass in a southwestern reservoir

Authors: Brouder, M.J., US Fish & Wildlife Service, Arizona Fishery Resources Office - San Carlos, PO BOX 710, Peridot, AZ 85542; Stewart Jacks, US Fish & Wildlife Service, Arizona Fishery Resources Office – Pinetop, PO BOX 39, Pinetop, AZ 85935; Cliff Schluesner, US Fish & Wildlife Service, 1011 E. Tudor Rd, Anchorage, AK 99503

Abstract: We examined temporal changes in size structure, relative abundance, and condition of largemouth bass in San Carlos Reservoir and evaluated associations between dam operations and population indices from 1999 – 2002. Substantial among-year differences in mean reservoir elevation and variance, maximum reservoir elevation, and maximum daily change in reservoir elevation during the spawning/hatching period were observed. Likewise, minimum reservoir elevation during the summer drawdown period was also highly variable across years. In only 1 of 4 years (2001) was a strong age 1 cohort present. Largemouth bass PSD values increased steadily from 47% in 1999 to 72% in 2001, but decreased to only 5% in 2002; a 93% decrease in the number of bass > 300 mm total length. Catch rates of all largemouth bass combined and age-specific catch rates significantly differed among years (F = 34.01, df = 3, P < 0.0001). We also found a strong negative correlation between CPUE of age 1 and age 2 largemouth bass in year x and variance associated with mean lake elevation (r = -0.909; P = 0.001) and maximum daily change in lake elevation (r = -0.845; P = 0.001) during the spawning/hatching period in year x-1 and x-2, respectively. However, catch rates of largemouth bass were independent of mean and maximum reservoir elevation during the spawning/hatching period and minimum lake elevation during summer drawdown. Similar to catch rates, relative condition of largemouth bass significantly differed among years (F = 27.8, df = 3; P < 0.0001). We also found a strong positive relationship between relative condition of > age 3 largemouth bass in year x and minimum summer pool in year x-1 (r = 0.949; P = 0.026), whereas the condition of age 1 and age 2 largemouth bass was independent of minimum summer pool in year x-1 (P > 0.05). Results from this study suggest that the magnitude of fluctuations in water level during the spawning/hatching period is an important factor determining largemouth bass year class strength more so than the reservoir level itself, either during the spawning/hatching period or summer drawdown.

[5604] Vegetative Islands: A possible alternative to killing them fast or killing them slow.

Author: Harthorn, C. L., New Mexico Dept. of Game and Fish, Fisheries Division, 566 N. Telshor Las Cruces, NM, 88011, charthorn@state.nm.us

Abstract: New Mexico reservoirs were constructed for the primary purpose of irrigation and often lack any form of aquatic vegetation. The establishment of aquatic vegetation within these reservoirs is often hindered by fluctuation water elevations, high turbidly, unfavorable substrate, lack of a propagules, and more recently the lack of water. We created a vegetation island in Elephant Butte Reservoir, New Mexico, to act as a “founder population” for establishing a vegetation community, as well as a nursery habitat for fry and fingerlings. From April – June 2002, we located nesting and nursery sites for largemouth bass (Micropterus salmoides) in Elephant Butte Reservoir through the aid of SCUBA. One school of newly hatched largemouth bass fry was located within the confines of the island. Antidotal evidence suggests these islands have some utility as nursery habitat, we have not seen any evidence of the islands acting as a “founder population” for aquatic vegetation. While plants were growing on the island, water management practices prevented establishment of vegetation in surrounding coves. We will continue to monitor and evaluate the effectiveness of these islands. If they prove to be effective, construction plans will be distributed to the local community and interested angling organizations.

[5605] Lake Pleasant Then and Now: A Look at Changes in the Fishery and Limnology Over the Past 12 Years

Author: S.D. Bryan, Arizona Game and Fish Department, 2221 W. Greenway Rd., Phoenix, AZ 85023, 602-789-3250 (W), 602-789-3918 (F), sbryan@gf.state.az.us.

Abstract: In 2000, the Research Branch of the Arizona Game and Fish Department, in cooperation with the U.S. Bureau of Reclamation, began Phase II of a study to determine the effects of the operation of New Waddell Dam on the fishery and limnology of Lake Pleasant. Phase I, which documented baseline pre-dam conditions in Lake Pleasant, was completed in 1990. In Phase II, gill netting, electrofishing, and creel surveys were used to make preliminary comparisons between pre- and post-dam fisheries population dynamics. Water quality data was also collected to determine any limnological changes that may be affecting the fishery. Analyses of biological data (including stock density and condition indices) indicate that the fishery has declined statistically, but the biological significance of that change is not clear. In addition, overall mean angler catch rates differ between pre-dam (0.46 fish/hr) and post-dam (0.36 fish/hr) conditions and anglers are not satisfied with the current largemouth bass fishery in Lake Pleasant. Several changes in the limnology and fisheries of Lake Pleasant have occurred over the last ten years that may help explain the apparent declines. We will discuss the potential impacts of these changes on the fishery and hypothesize on what the future holds for the fishery at Lake Pleasant.

[5606] Age Determination of Walleye in Central Arizona Reservoirs.

Authors: M.E. Meding, Arizona Game and Fish Department, 2221 W. Greenway Rd. Phoenix, AZ, 85023, 602.789.3672 (W), 602.789.3918 (F), MMeding@gf.state.az.us; M.J. Brouder, USFWS, AZ Fishery Resources Office, PO Box 710, Peridot, AZ, 85542, 928.475.2552 (W), 928.475.2701 (F), Mark_Brouder@fws.gov; J.E. Slaughter, IV, Arizona Game and Fish Department, 2221 W. Greenway Rd. Phoenix, AZ, 85023, 602.789.3663 (W), 602.789.3918 (F), JSlaughter@gf.state.az.us.

Abstract: Arizona Game and Fish has actively stocked fry and fingerling walleye Stizostedion vitreum into Central Arizona reservoirs for ~25 years in an attempt to establish productive walleye fisheries. A three-year study was implemented in 2000 to assess walleye stocking, growth and reproduction in these reservoirs. Walleye were collected via gill-nets from Saguaro, Canyon and Apache Lakes, and otolith and scale samples were collected (n = 260; 290 to 575 mm TL) and examined to determine suitability for age estimation. Use of scales to age walleye proved to be infeasible for aging walleye in these systems due to poor annuli formation. However, walleye consistently and clearly laid down annuli on otoliths, and in contrast to temperate fishes, did so during summer months (July-August). Examination of otoliths provided consistent age estimates via multiple readers indicating it is possible to estimate walleye age in these reservoirs. A Von Bertalanffy length-at-age relationship was developed for the 2000-2002 data using FAST (v1.0) and was subsequently used to assign ages to walleye sampled from the same lakes during annual surveys from 1990 – 1999. Walleye aged from otoliths appear to have an average lifespan of approximately 7 years, and experience rapid growth during the first 3 years after stocking (mean TL = 550 mm), after which growth slows. Walleye sampled during 1990 – 1999 reached total lengths of 730 mm and were estimated to reach 13 years of age. Year class strength indices were assigned to all data years to assess stocking methods (fry vs. fingerling). Preliminary findings indicate that fry stockings produced strongest year classes and were the most time efficient and cost-effective method for sustaining the walleye fishery in these three reservoirs.

[5607] The biology and foraging demands of northern pike in Arizona lakes and reservoirs.

Author: J.M. Flinders , Presenter, Arizona Cooperative Fish and Wildlife Research Unit, 104 Biological Sciences East, University of Arizona, Tucson AZ 85721, 928-342-0091 (W), jflinders@gf.state.az.us; S.A. Bonar, Arizona Cooperative Fish and Wildlife Research Unit, 104 Biological Sciences East, University of Arizona, Tucson AZ 85721, 520-621-1193 (W), sbonar@ag.arizona.edu.

Abstract: Northern Pike were first introduced into Arizona in the 1960's to provide sport-fishing opportunities. Recently, the range of the northern pike's range in Arizona has expanded due to illegal introductions. An illegal introduction in 1997 was even successful in expanding the southern range of the species near the US-Mexico border. The small number of sport fishing lakes in Arizona coupled with the range expansion by northern pike through illegal introductions raised questions about the potential impacts. We sampled three Arizona reservoirs containing northern pike to determine their potential predation impacts upon the prey base. Growth rates, diets, and population estimates of northern pike were obtained along with temperature profiles from each of the reservoirs. Data was then used in a bioenergetics model to estimate the prey consumption of each population of northern pike. Life history information and the ranges of northern pike prey consumption obtained from the bioenergetics modeling can be used to estimate potential impacts from future illegal introductions and serve to educate the public about consequences resulting from illegal northern pike stockings.

Session: Guidelines for Decision Making and Technical Applications for Captive Breeding Programs (Part II)

[5701] Application of Captive Broodstocks for Preservation of ESA-listed Endangered Redfish Lake Sockeye Salmon.

Authors: Thomas Flagg, National Marine Fisheries Service, Northwest Fisheries Science Center, Resource Enhancement and Utilization Technologies Division, P.O. Box 130, Manchester, WA 98353, 360-871-8301 (W), 206-842-8364 (F), tom.flagg@noaa.gov; Paul Kline, Idaho Department of Fish and Game, 600 South Walnut Street, P.O. Box 25, Boise, ID 83707, 208-939-4114 (W), 208-939-2415 (F), pkline@idfg.state.id.us; Madison Powell, University of Idaho, Center for Salmonid and Freshwater Species at Risk, 3059F Fish Hatchery Road, Hagerman, ID 83332, 208-837-9096 (W); 208-837-647 (F); mpowell@uidaho.edu; Doug Taki, Shoshone-Bannock Tribes, Fisheries Department, PO Box 306, Fort Hall, ID 83203, 208-478-3914 (W), 208-238-3742 (F), dtaki@shoshonebannocktribes.com; Jeffrey Gislason, Bonneville Power Administration, Fish and Wildlife Division - KEWU4, P.O. Box 3621, Portland, OR 97208, 503-230-3594 (W), 503-230-4564 (F), jcgislason@bpa.gov.

Abstract: In 1991, the National Marine Fisheries Service listed Snake River sockeye salmon (Oncorhynchus nerka) as endangered under the U.S. Endangered Species Act (ESA). Snake River sockeye salmon are a prime example of a species on the threshold of extinction, with the last known remnants of this stock returning to Redfish Lake, Idaho. During the decade of the 1990s, a total of 16 wild fish returned to Redfish Lake (0-8 per year). All returning fish were captured and reared for captive broodstock, resulting in production of hundreds of thousands of progeny (prespawning adults, eyed eggs, presmolts, and smolts) replanted to habitats. Between 1999-2002, over 300 adults returned from the ocean from captive broodstock releases -- an amplification of almost 20 times the number of wild fish that returned in the 1990s. The captive broodstock program has, at least for the short-term, prevented extinction of Redfish Lake sockeye salmon. Operational issues including development of successful captive husbandry procedures, maintenance of genetic diversity, assessment/enhancement of habitat carrying capacity, and intensive evaluation of restocking efforts are discussed.

[5702] A history of broodstock management and egg production for white seabass (Atractoscion nobilis) in southern California.

Authors: M.A. Drawbridge, Hubbs-SeaWorld Research Institute, 2595 Ingraham Street, San Diego, CA 92109, 760-434-9501 (W), 760-434-9502 (F), mdrawbr@hswri.org; D.B. Kent, Hubbs-SeaWorld Research Institute, 2595 Ingraham Street, San Diego, CA 92109, 619-226-3870 (W), 619-226-3944 (F), dkent@hswri.org.

Abstract: Abstract: Reliable production of high quality eggs is a critical component to the success of any aquaculture program. Techniques for managing and spawning white seabass (Atractoscion nobilis) have been developed since 1983 as part of a regional stock enhancement program. Spawning activity has been documented primarily by volumetric enumeration of floating (viable) and sinking eggs, and more recently by visual observation, individual isolation, and parent identification using DNA fingerprinting. Nearly 1,800 spawning events have been recorded. Egg production from single spawning events, which varied widely depending on the number of females that participated, ranged from 10,000 eggs to more than 13 million. The maximum annual egg production observed was 15 million eggs per female (average 5 million) when all females were assumed to contribute. An isolated female of 10kg released 1.2 and 1.4 million eggs during spawning events spaced 10 days apart. Female seabass starting at 5kg released an average of 700,000 eggs per batch, increasing at a rate of 100,000 eggs/kg until the fish reached 13kg. Egg viability typically averaged 60-70%. Low or reduced egg viability was associated with newly established and old populations, the beginning and ending of spawning seasons, and when spawning seasons were extended beyond 3-4 months.

[5703] The Use of Fish Culture in the Recovery of the Endangered Sacramento River Winter-run Chinook Salmon.

Author: John Rueth, United States Fish and Wildlife Service, Livingston Stone National Fish Hatchery, Shasta Lake, CA 96019, 530-275-0549 (W), john_rueth@r1.fws.gov.

Abstract: The numbers of winter-run chinook salmon (WCS) Oncorhynchus tshawytscha returning to California's Sacramento River have declined precipitously, from 117,800 in 1967 to less than 200 by the early 1990s. Consequently, the WCS was listed as a threatened species in 1990 and formally listed as endangered in 1994. In 1988, the USFWS, CDFG, and NMFS entered into a cooperative agreement to improve habitat conditions for and increase numbers of WCS. This agreement included the development of a WCS propagation program at Coleman National Fish Hatchery (NFH), which was initiated in 1989. In 1991, a captive broodstock program was developed at the U.C. Davis Bodega Marine Laboratory (BML) to serve as an emergency insurance policy against extinction. Propagation efforts resulted in increased release numbers, from 10,000 in 1991 to 51,000 in 1995. By 1995, culture techniques for the WCS program were largely successful, however two concerns threatened the success of the recovery efforts. First, adult fish were returning to Battle Creek (site of Coleman NFH). Second, it appeared that there was a potential for hybridization with other chinook runs. The USFWS placed a moratorium on the propagation program until a rearing site on the main stem of the Sacramento River could be found and until WCS could be genetically distinguished from the other salmon runs in California?s Central Valley. In 1996 and 1997, captive broodstock adults were spawned to provide the only juveniles produced by the program. Within 2 years the Livingston Stone NFH was constructed at the base of Shasta Dam to assure imprinting on and return of adults to the main stem. The genetic issues were also resolved as researchers at BML developed a suite of microsatellite markers for run discrimination. The propagation program was restarted in 1998 and a total of 153,908 juvenile fish representing 21 family groups were released that year. The program continues to be successful, and adult contribution from the juveniles produced in the propagation and captive broodstock programs has been documented in the ocean fishery and in escapement monitoring in the upper Sacramento River.

[5704] Status of the Captive Breeding of Totoaba, endemic species of the Sea of Cortez.

Author: Conal D. True, Eduardo Talamás Rohana, Gerardo Sandoval Garibaldi, Ivan Monay Díaz, Luz M. Lopez Acuña. Facultad de Ciencias Marinas, Universidad Autonoma de Baja California, Carretera Tij-Ens Km 103, Ensenada, B.C., 617-74-45-70 ext. 121 (W).

Abstract: The totoaba is the largest member of the croaker family, and is endemic to the Sea of Cortez. Like many other fisheries it was over utilized, and now is considered an endangered species, protected both by Mexican and international law. Research in the past 10 years has led to the establishment of a captive breeding program, providing a base line for an enhancement program. This project is a "first of its kind" in Mexico. A brood stock population has been established since mid-1994 and appropriate protocols for maturing and spawning have been employed. Embryo and larval development of Totoaba macdonaldi under laboratory conditions are described and larval culture procedures have been applied to further develop the early life stages of this species. Procedures for larval culture and morphology are described, with the corresponding weaning process form live larval food (rotifers and Artemia) to a pelletized diet. To date, 5 releases of captive bred organisms into the Sea of Cortez have been completed. The implications of the findings are discussed with emphasis on developing culture protocols for enhancement of this endangered species. A perspective on future required research and a delineation of the social implications of this project will be presented.

[5705] The U.S. Gulf of Mexico Marine Stock Enhancement Program (GMSEP): Developing Techniques for the Culture of Red Snapper, Lutjanus campechanus.

Authors: J.T. Ogle, Gulf Coast Research Laboratory, College of Marine Sciences, The University of Southern Mississippi, P.O. Box 7000, Ocean Springs, MS 39566; R.B. Blaylock, Gulf Coast Research Laboratory, College of Marine Sciences, The University of Southern Mississippi, P.O. Box 7000, Ocean Springs, MS 39566, 228-872-4293 (W), 228-872-4204(F), reg.blaylock@usm.edu; J.M. Lotz, Gulf Coast Research Laboratory, College of Marine Sciences, The University of Southern Mississippi, P.O. Box 7000, Ocean Springs, MS 39566.

Abstract: GMSEP is investigating the use of aquaculture technology as a tool for the restoration of depleted marine stocks, particularly the red snapper, Lutjanus campechanus. Our culture system combines an extensive outdoor zooplankton production system with an intensive indoor fish culture system. Wild zooplankton is bloomed and harvested through a series of sieves to collect size-graded copepod nauplii, which we use as our only food for snapper larvae. Snapper larvae produced from wild-caught, hormonally-induced and strip-spawned broodstock are reared in clear water in a three phase culture system which begins with static water and is followed by a doubling of the water volume and then the addition of recirculation and biofiltration. A progressively increasing size fraction of copepods is fed through day 24. Commercial pellets are introduced at day 12. Larvae are harvested, counted and moved to nursery tanks on day 24. At day 40 juveniles are transferred to growout raceways. In 2002, we produced 8,001 taggable fish from 160,000 larvae. Major constraints include the supply of copepod nauplii, aggressive behavior in the nursery, and chronic Amyloodinium infections.

[5706] Status of the Grande Ronde Basin Spring Chinook Salmon Captive Broodstock Program

Authors: Timothy L. Hoffnagle - Presenter, Richard W. Carmichael, William T. Noll and Patrick J. Keniry, Northeast Oregon Fish Research, Oregon Department of Fish and Wildlife, 211 Inlow Hall, Eastern Oregon University, La Grande, OR 97850, Ph: (541) 962-3777, Fax: (541) 962-3067, email: thoffnag@eou.edu, rcarmich@eou.edu, nollw@eou.edu, pkeniry@eou.edu.

Abstract: The Grande Ronde Basin Chinook Salmon Oncorhynchus tshawytscha Captive Broodstock Program began in 1995 to restore populations in three streams to 150 returning adults while maintaining genetic diversity and integrity of each stock and nearby wild stocks. Up to 500 wild parr are collected from each stream and cohort, reared to smoltification under an accelerated or simulated natural growth regime and from smoltification to adulthood in freshwater or saltwater. Growth, survival, fecundity and fertility rates, age of maturation and causes of mortality are evaluated for the captive broodstock fish and the F₁ generation is monitored for survival, growth, migration and return indices. Indices are compared among stocks, cohorts and treatments and with expected rates from the literature that were used to develop this program. The Captive Broodstock Program has met or exceeded most, but not all, expected rates. Unresolved problems remain, including: inability to collect parr each year in Grande Ronde River; BKD-caused mortality and culling of eggs; low growth rate; synchronizing maturation timing with wild fish; low fecundity; and F₁ egg-to-smolt survival, smolt production, migration survival and disposition of excess F₁ fish in years of overproduction. This program will provide information that will be useful to other, similar efforts.

[5707] Documenting Biodiversity of Coastal Coho Oncorhynchus kisutch in Northern California.

Authors: K.A. Bucklin, Trout Unlimited, 621 Spencer Ave. Santa Rosa, CA 95404, 707-579-4952 (W), kbucklin@tu.org; P.A. Siri, Marine Life Management Project, 123 Howard Street, Petaluma, CA 94952, 707-78-6104 (W), 707-778-0211 (F), psiri@earthlink.net; D. Hedgecock, Bodega Marine Lab, University of California Davis, 2099 Westside Road, Bodega Bay, CA 94923, 707-875-2075 (W), 707-875-2089 (F), dehedgecock@ucdavis.edu.

Abstract: Northern California Coho are presently absent from approximately 62-71% of streams historically occupied by coho. Existing relict populations are at risk due to the low abundance of adult spawners. To establish genetic relationships within and among 57 collections of coho salmon from 14 California watersheds, we use a suite of seven highly polymorphic microsatellite DNA markers. We find significant deviations between observed genotypic ratios to those expected under random mating in samples of juveniles and adults. In juvenile samples we discriminate and attempt to correct for two potential causes of deviations from random mating equilibrium-inadvertent admixture of genetically distinct subpopulations in a single collection, and/or relatedness among individuals. Genetic distances among populations support the present State ESU structure, forming statistically significant clusters, which correspond to the SO/NC, CCC, and SSF NMFS designations. Sampling of different year-classes at seven sites reveals that temporal variation is typically significant though smaller than geographic distance. The congruence of genetic and geographic distance in light of the history of coho out-of-basin and State stock transfers, suggests that either stock transfers have left no genetic mark on extant populations or alternatively, that the rate of genetic drift balances the homogenizing effects of hatchery practices.

[5708] Initial Protocols for The Captive Breeding and Rearing of the Spotted Sand Bass (Paralabrax maculatofasciatus) in Southern California.

Authors: E.F. Miller, Nearshore Marine Fish Research Program, California State University, Northridge, Northridge, CA 91330-8303, 818-677-4037 (W), 818-677-2034 (F), tunaguy@hotmail.com; L.G. Allen, Nearsh