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Wednesday April 15 Morning - Abstracts Session: Mexican Fisheries [2101] Index of Biological Integrity of the Río Nazas, Durango, México Authors: Salvador Contreras-Balderas1, Ma. de Lourdes Lozano-Vilano2 and Ma. Elena Garcia-Ramirez2. 1Bioconservacion, A.C. and 2Laboratorio de Ictiologia, Facultad de Ciencias Biologicas, Universidad Autonoma de Nuevo Leon, Monterrey, N.L., Mexico Abstract: The biological integrity index were used in recent years to show clearly the problem of water and their biodiversity of fishes that used as indicators, the method of IBI from Karr (1981 and 1997) was modificated. In this case consider minimum of 10 biological parameters of the group of flora/fauna and gave a value that require calibration and interpretation, Contreras et al (2000) adapted the method to elaborate an analysis of tendencies in time and transformer in percent for each locality versus its self or a line base antique that not require more validation; the results show in numbers enters with an scale of 100; we present a list of introduced and an invasive fishes in the basin of Rio Nazas, the integrity for the low río Nazas is clearly low with an average of 33% for the localities this ecological impact show a marked tendency of stoppage by turbidity, as product of erosion, terrestrial as on both sides of river, also is very important the decreased of water flow. [2102] Jewel cichlid, Hemichromis guttatus, an exocit fish eradicated from Poza San Jose del Anteojo, Cuatro Cienegas, Coahuila, Mexico and reestablishment of the original population of native fishes Authors: MA. DE LOURDES LOZANO-VILANO, MA. ELENA GARCIA-RAMIREZ AND ARMANDO J. CONTRERAS-BALDERAS. LABORATORIO DE ICTIOLOGIA, FACULTAD DE CIENCIAS BIOLOGICAS, UNIVERSIDAD AUTONOMA DE NUEVO LEON, MONTERREY, NUEVO LEON, MEXICO. marlozan@ccr.dsi.uanl.mx. Abstract: The present study was conducted in Poza San Jose del Anteojo, Cuatro Cienegas Basin, Coah., Mexico, from May 2000 to April 2002 with objective of eradicating the jewel cichlid Hemichromis guttatus, an African fish introduced in many places in the basin by unknown persons. From the first visit to Poza San Jose del Anteojo we found jewel cichlid and a few individuals of Mexican tetra Astyanax mexicanus, but all other species that had previously occupied this poza had been eliminated by the introduced species. We visit the area 19 times during 3 years. The population of jewel cichlid varied throughout the study, with first sample in May 2000 containing 3,041 specimens. Only 4 specimens were captured in the last sample in April 2002. In total collected 19,115 specimens 18,041 by us and 1,074 by the owner of the land who helped us in the extraction of the exotic fish. Along with the removal of exotics, the first reintroduction of native fishes was made in May 2000 by stocking Astyanax mexicanus, Ictalurus sp., Gambusia marshi and Cichlasoma minckleyi. No natives were found at the next sampling, so in April 2002 we again reintroduced the same species. On August 2002 Astyanax mexicanus and Gambusia marshi were abundant, Ictalurus sp. released were juveniles and success of the reintroduction cannot yet assessed. Cichlasoma minckleyi in nuptial coloration were seen, but no broods or eggs were detected. The jewel cichlid was not found at the last sampling, so we think it was totally eradicated and that this therefore represents the first documented active extirpation of this exotic species. [2103] An overview of AFS with emphasis on the steps for forming a Mexican AFS chapter Author: E. Eric Knudsen, USGS, Alaska Science Center, 1011 East Tudor Rd., Anchorage, Alaska. 907—786-3842, FAX 907-786-3636, eric_knudsen@usgs.gov. Abstract: Interest has been expressed among Mexican AFS members regarding the formation of a Mexican AFS chapter or chapters. The purpose of this talk is to provide information on the background, requirements, and process of organizing a Mexican chapter. The talk will focus first on an overview of the AFS mission, structure, and benefits and costs of individual membership. Second, the merits of AFS chapter-level activities will be discussed. Third, the steps required for organizing and implementing a chapter will be presented. This background information is intended to help set the stage for a subsequent discussion among Mexican AFS members, and other AFS interested parties, that will focus on a decision about chapter implementation. [2104] Development Of An Aquatic Resource Management Strategy For The Sierra Gorda Biosphere Reserve Of Central Mexico Authors: Dave Heller, Co-Presenter, USDA Forest Service, Pacific Northwest Region, Regional Office, PO Bos 3627, Portland, OR 97214, 503 808-2994 (W), dheller@fs.fed.us; Jeff Uebel, Co- Presenter, USDA Forest Service, Pacific Northwest Region, Regional Office, PO Box 3627, Portland OR, 97214, 503 808-2847 (W), juebel@fs.fed.us; Steve Lanigan, USDA Forest Service, Regional Ecosystem Office, Portland, OR, 97214, 503 808-2261, slanigan@fs.fed.us. Abstract: How to provide for sustainable use by 90,000 inhabitants, yet maintain and improve the health of the watersheds and aquatic resources on more than one million acres of incredibly diverse Biosphere Reserve? Developing answers to this question is now the focus of a cooperative effort between the US Forest Service, Wolftree (a non profit science learning organization) and the Grupo Ecologico Sierra Gorda (a highly committed group of local residents in the State of Queretaro, Mexico). Starting in 2001, a team of scientists began the process of helping to develop an aquatic management strategy for the Reserve. This effort complements existing management plans for the area. Work has included: assessment and characterization of perennial stream habitat; sampling/identification of fish and other aquatic biota; on-the-job training for Grupo staff and school liasons; field work with local school children and community members and development of a joint, multi- year plan for improved watershed and aquatic resource management. Work to date has documented a diverse set of aquatic resources and watershed conditions in this mountainous Reserve. More than 37 sites on 10 streams have been examined. Initial reconnaissance has shown that although in generally good health, a wide variety of human related impacts are evident in the systems. These include: bacterial contamination in streams; accelerated surface erosion and sediment loading in many watersheds; deformities of fish in some streams and reductions in fish diversity and abundance due to over harvest. Most of these findings are news to local managers and and residents. Community interest is high regarding watershed and aquatic resource health. There appears to be a major opportunity to improve resource conditions through a program to inform and involve locals. Future work will focus on implementing a program of community-based resource education, watershed analysis, restoration and trend monitoring. Session: Use of Science in Public Policy
Session: Ocean Ecology of Pacific Salmon (Part I) [2301] Survival rates for 120 pink, chum, and sockeye Pacific salmon stocks show positive covariation on regional scales (less than 1000 km) Authors: Randall M. Peterman, School of Resource and Environmental Management, Simon Fraser University, Burnaby, B.C., Canada, V5A 1S6, 604-291-4683 (W), 604-291-4968, peterman@sfu.ca; Brian J. Pyper, School of Fisheries and Ocean Sciences, University of Alaska-Fairbanks, 11120 Glacier Way, Juneau, Alaska 99801, USA; Franz J. Mueter, Sigma Plus Consulting, 697 Fordham Drive, Fairbanks, Alaska 99709, USA, 907-479-8815, fmueter@alaska.net; David J. Blackbourn, 562 Bradley Street, Nanaimo, B.C., Canada, V9S 1C1, 250-753-0836; Chris C. Wood, Department of Fisheries and Oceans, Pacific Biological Station, Nanaimo, B.C., Canada, V9R 5K6, 250-756-7140, WoodC@pac.dfo-mpo.gc.ca. Abstract: We examined spatial patterns of covariation in indices of survival rate (residuals from stock-specific, best-fit stock-recruitment curves) across four decades among 43 wild pink salmon (Oncorhynchus gorbuscha) stocks from 14 geographical regions in Washington, British Columbia, and Alaska. We performed similar analyses for 37 sockeye salmon (O. nerka) stocks and 40 chum salmon (O. keta) stocks spanning those same geographical areas. In each of the three species, we found strong evidence of positive covariation in survival rates among stocks within each region and between certain adjacent regions, but no evidence of covariation between stocks of distant regions (e.g., separated by 1000 km or more). These results suggest that important environmental processes affecting temporal variation in survival rates of these three species of Pacific salmon operate at regional spatial scales (on the order of several hundred kms), rather than at the larger, ocean-basin scale that is often cited from studies based on catch data, not survival data. These spatial results helped identify summer sea-surface temperature as an environmental variable that may improve forecasting and understanding of climatic changes on salmon productivity. These results also led to new models of stock and recruitment (multi-stock mixed effect and hierarchical Bayes models). [2302] A spatial hierarchical Bayesian model for multi-stock stock-recruitment analysis of Pacific salmon Authors: Z. Su-Presenter, R. Peterman, and S. Haeseker, Fisheries Science and Management Research Group, School of Resource and Environmental Management, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada, V5A 1S6, 604-268-6738, zsu@sfu.ca. Abstract: We developed a spatial Bayesian hierarchical model (SBHM) for a multi-stock analysis of salmon stock-recruitment relationships and the effects of environmental factors on salmon survival rates. The SBHM explicitly models spatial correlation in productivity among salmon stocks by applying a spatially correlated prior distribution to the stock-specific parameters. We applied the SBHM to analyze the environment and recruitment data of pink salmon stocks. We found that the SBHM produces more consistent and reliable estimates of early summer coastal sea-surface temperature (SST) effects than a single-stock approach that estimates each stock separately. In addition, the multi-stock approach substantially reduces uncertainty in the estimates of SST effects compared to the single-stock approach. Similar to earlier results using mixed-effects models on the same data, we found significant positive effects of SST on survival rates of pink salmon of northern stocks, but weaker negative effects of SST on survival rates of pink salmon of southern stocks. [2303] Genetic mixed stock analysis of juvenile chinook salmon in coastal areas of the Pacific Northwest Author: David Teel-Presenter, National Marine Fisheries Service, Post Office Box 130, Manchester, Washington 98353, 206-842-5832(W), 206-842-8364(F), David.Teel@noaa.gov. Abstract: Ocean migration patterns of juvenile chinook salmon were studied using genetic mixed stock analysis. Fish were captured during the summers of 1998 – 2001 in surface trawls in nearshore coastal areas ranging from northern California to southern British Columbia. Approximately 2,500 juveniles were genotyped at 32 allozyme loci. Allele frequencies from 150 chinook salmon spawning populations in California and the Pacific Northwest were used as baseline data. Stock compositions of marine samples varied greatly by month and location reflecting the juvenile movements of genetically distinct populations of chinook salmon. Migration patterns are described for populations from two distinct evolutionary lineages of chinook salmon originating in the Columbia and Snake rivers. Spring-run (season of adult migration to freshwater) fish from the interior Columbia River basin are the most abundant population group off Washington throughout the early summer (58% of our marine catches) and are prevalent in nearshore areas off Vancouver Island in late June and early July. Columbia River basin fall-run chinook salmon predominate in late summer sampling off Oregon and Washington (45% to 89%). Two ecotypes of fall-run populations identified by genetic and life history differences (“brights” and “tules”) have distinct juvenile migration patterns after sea entry. [2304] Over-Winter Marine Distribution & Movements of Juvenile Coho and Chinook salmon Authors: D.W. Welch-Presenter, Fisheries and Oceans Canada, Pacific Biological Station, Nanaimo, British Columbia, Canada, V9T 6N7, 250-756-7218(W), 250-756-7053(F), welchd@pac.dfo-mpo.gc.ca; M. Trudel, M. Thiess, and J. Morris, Fisheries and Oceans Canada, Pacific Biological Station, Nanaimo, British Columbia, Canada, V9T 6N7 Abstract: The W.E. Ricker conducted extensive (1 month) trawl surveys for juvenile salmon in October 2000, and repeated the survey in March 2001. The same survey pattern was then repeated in October 2001 and February-March 2002, providing two separate years where the distribution and movements of juvenile salmon over the first marine winter of life can be assessed. By autumn, catches are predominately chinook and coho, indicating that the vast majority of sockeye, pink, and chum salmon have migrated out of the coastal region. There are clear differences in the autumn distribution of coho and chinook, with coho primarily distributed over the open shelf, and chinook found primarily nearshore in sheltered waters (fjords along the West Coast of Vancouver Island and inside waterways of SE Alaska). The distribution of the two species is nearly disjunct, suggesting competitive displacement. By winter’s end, chinook appear to be expanding their distribution out onto the open shelf. In contrast, although juvenile coho are caught in good numbers off the west coast of Vancouver Island in spring, in both years not a single coho was caught north of Vancouver Island, in sharp contrast to the chinook catches. DNA composition of the coho catches demonstrates that these northern coho are genetically distinct and do not move south overwinter to mix with the stocks off the west coast of Vancouver Island. In summary, there are clear differences in the migratory behaviour of different coho stocks, and extensive migration during the winter period occurs for at least some stocks. [2305] Otolith based studies on the ecology of juvenile chinook salmon from the Central Valley of California. Authors: C.B. Grimes-Presenter, R.C. Johnson, and C. J. Donohoe. U.S. National Marine Fisheries Service, Southwest Fisheries Science Center, Santa Cruz, CA 95060, 831-420-3931(W), 831-420-3977(F) churchill.grimes@noaa.gov. Abstract: Four distinct runs of chinook salmon spawn in the Sacramento-San Joaquin River system of the Central Valley of California. Spawning occurs at many locations in tributaries and in the main stem rivers and at five hatcheries. Outmigrants swim downstream and enter the sea via the confluence of the Sacramento and San Joaquin Rivers, through San Francisco Bay and into the Gulf of the Farallones. Otolith microstructure and microchemistry are being exploited to determine natal origin (hatchery vs.or natural production and natal stream) measure growth and determine period of estuarine residency of juveniles. Results will be applied to determine the contribution of different production sources to ocean fisheries, and determine critical factors related to survival of juvenile salmon (e.g., hatch date, production source, growth, and estuarine residency). Discriminant analysis using the mean and standard error of microincrement width, circularity and the distance from the primordium to hatch and exogenous feeding checks as variables correctly classifies 100% of natural fish and 95% of hatchery fish using a jackknife procedure. Strontium isotope ratios Trace metalsare significantly different among natal streams and differences are reflected in otoliths of juvenile fish can be distinguished (Weber and Ingram in press), and thus may be exploited to determine hatchery and stream of origin. Sr:Ca ratios at the otolith margin of outmigrants is strongly related to salinity, and will be exploited (along with otolith microstructure) to determine the period of estuarine residency. Growth trajectories of juveniles sampled sequentially during outmigration suggest that fish surviving to enter the sea are randomly drawn from the outmigrant population with respect to growth. [2306] Simulating juvenile salmon growth and swimming in a near shore flow field. Authors: L.W. Botsford-Presenter, Department of Wildlife, Fish and Conservation Biology, University of California, Davis, CA 95616, 530-752-6169(W), 530-752-4154(F), lwbotsford@ucdavis.edu; J.L. Largier, Scripps Institution of Oceanography, La Jolla, CA 92093; D.M. Kaplan, Department of Wildlife, Fish and Conservation Biology, University of California, Davis, CA 95616; C.A. Lawrence, Department of Wildlife, Fish and Conservation Biology, University of California, Davis, CA 95616 Abstract: Inter-annual variability in cohort strength of Pacific salmon species is believed to be largely determined in the early ocean phase. Here we describe our simulation of growth and mortality of juvenile salmon with size-dependent swimming speed in a flow field derived from HF radar observations near Pt. Reyes. The dominant mode of variability in the flow field follows an alternating pattern of several days of strong upwelling followed by several days of upwelling relaxation. The fate of each smolt depends on the timing of their entry relative to this pattern. [2307] The Role of the Columbia River Plume in Growth and Survival of Juvenile Salmon. Authors: E. Casillas-Presenter, Fish Ecology Division, NWFSC, Seattle, Washington, edmundo.casillas@noaa.gov; W. Peterson, R. Brodeur, R. Emmett, Fish Ecology Division, NWFSC, Newport, Oregon; J. Fisher, Oregon State University, Corvalis, Oregon; A. Baptista, and D. Jay, OHSU, Portland, Oregon. Abstract: The nearshore ocean environment, particularly that associated with the Columbia River plume, is a critical habitat to outmigrating juvenile salmon. Recent evidence suggests that improvement in survival of the estuarine and early ocean life history phase of Columbia River salmon may be critical to recovery of endangered stocks. In the case of salmonids originating in the Columbia River Basin, survival success hinges on the complex interaction of smolt quality and the abiotic and biotic ocean conditions at the time of entry and during their first year of ocean existence. We have been able to begin to characterize the physical and biological features of the nearshore ocean environment using mesoscale and fine scale oceanographic surveys, develop coupled physical-biological models and perform retrospective assessment of the Columbia River plume as it interacts with coastal circulation. We hypothesize that variation in the physical and biological conditions of the nearshore environment, particularly that associated with the plume, affects overall survival of Columbia River stocks. We provide evidence that suggest (a) that primary factors driving the variation in the nearshore and plume environment include oceanographic and land-based (river flow) processes modulated by climatic and anthropogenic factors, (b) that trophic relationships modulated by these physical variations affect growth and survival of juvenile salmon and (c) that management of the hydropower system can be used to regulate the Columbia River plume habitat to benefit salmon growth and survival. With our new understanding of salmon-plume-coastal circulation interactions, we can begin to explore the possibility of developing a set of hydropower management scenarios that could benefit survival, growth, and health of juvenile salmon by changing the dynamics of the Columbia River plume. Session: An Unique Ecosystem: The Salton Sea, A Saline Lake in a Desert Environment (Part I) [2401] The Salton Sea: Avian and aquatic resources at the crossroads Authors: C. A. Pelizza, U.S. Fish and Wildlife Service, 906 W. Sinclair Road, Calipatria, CA 99933, 760-348-5278, charlie_pelizza@fws.gov and D. A. Barmum, Salton Sea Science Office; 78-401 Highway 111, Suite R, La Quinta, CA 92253, 760-777-1564, doug_barnum@usgs.gov. Abstract: Often misunderstood, ignored, and underappreciated for its ecological value, the Salton Sea is one of the continent’s premier ecosystems. Concentrations and diversity of avian species attract visitors worldwide to this unique aquatic ecosystem located in one of driest and hottest areas of the continental United States. One of the key factors to the productivity of this ecosystem and its attractiveness to wildlife is the abundant fishery found in the waters of the Salton Sea. However, both ecological and political issues threaten the health of the Sea and its associated aquatic and wildlife resources. Restoration proposals, scientific research, and increasing human interest in the Sea all offer opportunities for the Salton Sea amidst predictions of ecosystem collapse. This presentation will explore the geologic origin of the Salton Sea; aquatic and avian resource values; threats to the ecosystem; and the opportunities for a healthy and secure future for the Salton Sea. [2402] Limnology of the Salton Sea, a saline desert lake Authors: M. A. Tiffany y los Saltones fieros, Center for Inland Waters, San Diego State University, San Diego, CA, Phone 619-594-5409, Fax 619-594-5676; Abstract: The limnology of the Salton Sea is driven by its basin topology, solar insolation and evaporation, wind events, and history of water, salt and nutrient inputs. The organisms are primarily of marine origin due to fish and invertebrate introductions. Dinoflagellates, diatoms and a raphidophyte constitute most of the phytoplankton biomass with coccolithophores, green algae, cryptomonads and euglenoids as minor components. The zooplankton is made up of several rotifers, a copepod and larvae of benthic barnacles and polychaete worms. Waterboatmen, amphipods, and several other worms are found nearshore. The lake is a place of extremes: high salinity, immense algal blooms, high riverine nutrient input, wide temperature extremes, and oxygen concentrations ranging from supersaturation to complete anoxia. The lake warms up in spring due to increasing solar insolation causing thermal stratification during periods of slack winds. When periodic windstorms occur stratification breaks down and warmer water is injected into lower strata raising the temperature at all depths throughout spring and summer. Anoxia develops during warmer months and large portions of the lake become uninhabitable for fish and benthic invertebrates. In autumn, overturn events cause the entire water column to be stripped of oxygen. This raises sulfide concentrations to levels toxic to fish and plankton. [2403] Some observations on desert pupfish at the Salton Sea Author: R. Sutton, Presenter, Bureau of Reclamation, Denver Federal Center, Bldg. 56, P.O. Box 25007 (D-8210), Denver, Colorado 80225, 303-445-2495, fax – 303-445-6328, rsutton@do.usbr.gov. Abstract: The endangered desert pupfish (Cyprinodon macularius) is the only fish species endemic to the Salton Sea (Sea). Current populations occur in agricultural drains discharging into the Sea, shoreline pools of the Sea, several artificial refugia, and desert washes at San Felipe Creek and Salt Creek. This species is remarkably tolerant of dynamic changes to their habitat from extreme natural events, such as flash flooding, wind, and drought. During the summer of 1999, the Bureau of Reclamation found pupfish moving between various habitat types around the Sea. Use of the Sea was not demonstrated. However, recent surveys by the California Department of Fish and Game show that desert pupfish occur in the main body of the Sea. This further suggests the importance of the Sea as a migration corridor and the need to maintain connectivity among habitats to allow mixing of the gene pool. [2404] Gut contents of nonnative fishes in agricultural drains Authors: B.A. Martin, U.S. Geological Survey, Western Fisheries Research Center-Dixon Duty Station, 6924 Tremont Road, Dixon, CA 95620, 707-678-0682x612 (T) 707-678-5039 (F), barbara_ann_martin@usgs.gov; M.K. Saiki, U.S. Geological Survey, Western Fisheries Research Center-Dixon Duty Station, 6924 Tremont Road, Dixon, CA 95620, 707-678-0682x617 (T) 707-678-5039 (F), michael_saiki@usgs.gov. Abstract: We assessed the gut contents of several nonnative fishes inhabiting agricultural drains within the Salton Sea drainage to determine if they preyed on the endangered desert pupfish (Cyprinodon macularius). Altogether, we examined the gut contents of 182 western mosquitofish (Gambusia affinis), 32 longjaw mudsuckers (Gillichthys mirabilis), 235 porthole livebearers (Poeciliopsis gracilis), 285 sailfin mollies (Poecilia latipinnia), and 510 tilapia (a mix of Sarotherodon mossambica and Tilapia zillii) collected during September 1999-December 2001. Mosquitofish consumed mostly aquatic and terrestrial insects, other aquatic invertebrates, and eggs, whereas mudsuckers ate fish in addition to aquatic and terrestrial insects, and other aquatic invertebrates. By comparison, porthole livebearers, mollies, and tilapia consumed mostly unidentifiable organic matter (detritus). Desert pupfish remains were found in the guts of two longjaw mudsuckers. In addition, one longjaw mudsucker consumed tilapia, two longjaw mudsuckers consumed porthole livebearers, and six longjaw mudsuckers consumed unidentifiable fish remains. Unidentifiable fish remains also occurred in guts of six mosquitofish, eight porthole livebearers, two sailfin mollies, and 17 tilapia. Two adult mosquitofish contained mosquitofish fry in their guts. From these data, mudsuckers are probably major predators of pupfish whereas other nonnative fishes have the potential for preying on pupfish or their eggs. [2405] Unusual Dynamics of the Salton Sea Fish Populations Authors: L. Caskey, US Fish and Wildlife Service, 6010 Hidden Valley Road, Carlsbad, CA 92009, (760) 431-9440, x249, Lucy_Caskey@r1.fws.gov, R. Riedel, B. Costa-Pierce and S. H. Hurlbert, Dept. Biology and Center for Inland Waters, San Diego State Univ., San Diego CA, (619)594-5409, Fax (619)594-5676, shurlbert@sunstroke.sdsu.edu. Abstract: The Salton Sea is a highly saline lake that supports a successful sportfishery. A study was initiated in 1999 to assess the status of these sportfish that include orangemouth corvina (Cynoscion xanthulus), gulf croaker (Bairdiella icistia) and tilapia (Oreochromis mossambicus X Oreochromis urolepis). Multimesh (50 X 2 m) gillnets were set at nine stations in 1999, ten stations in 2000 and six stations in 2002. These stations were sampled every two months in 1999, every three months in 2000 and once in 2002. O. mossambicus was the most abundant of the four species. The abundance of all species declined over time. The summertime CPUE for tilapia, gulf croaker and orangemouth corvina dropped from 55 to 0.1 fish/net /hour, 8.0 to 6.2 fish/net/hour and from 2.0 to 0.1 fish/net/hour, respectively, between 1999 and 2002. In addition, the tilapia population consisted essentially of only the1995 and 2000 year classes during the study period. Harsh conditions at the Sea have led to unstable population sizes and age structures for its resident fishes. Significant causes likely include massive parasite infestations of fry and physiological stressors such as anoxia, high sulfide levels, high salinity and extreme high and low temperatures. [2406] Salinity tolerance of juvenile Mozambique tilapia hybrids (Oreochromis mossambicus x O. urolepis hornorum) during direct and gradual transfer to elevated salinity. Authors: B. Sardella, Department of Zoology, University of British Columbia, Vancouver BC, Canada V6T 1Z2, quobee@yahoo.com. J. Cooper; Department of Biology, University of San Diego, 5998 Alcala Park, San Diego CA, 92110, jillc@sandiego.edu. R. Gonzalez; Department of Biology, University of San Diego, 5998 Alcala Park, San Diego CA, 92110, gonzalez@hannah.sandiego.edu. C. J. Brauner; Department of Zoology, University of British Columbia, Vancouver BC, Canada V6T 1Z2 brauner@zoology.ubc.ca. Abstract: The salinity of the Salton Sea is presently 43 g/L and increasing annually. Although Mozambique tilapia (Oreochromis mossambicus) are very salinity tolerant (surviving in up to 120g/L), salinity tolerance of the Salton Sea tilapia hybrid (O. mossambicus x O. urolepis hornorum) has not previously been measured. Mozambique hybrids (similar to those in the Salton Sea) were kindly donated by Pacific Aquafarms (Niland, CA) and gradually acclimated to full strength seawater (SW; 35 g/L) over 4 weeks. Fish were then directly transferred (DT) to higher salinities (60 or 85 g/L) or gradually transferred (GT) to increasing salinities of 45, 55, 65, 75, 85 and 95 g/L every 5 days to assess salinity tolerance as indicated by mortality and sublethal indicators such as plasma osmolality, Na+ and Cl- concentrations and muscle water content. Fish survived DT to 60g/L, with large ionoregulatory disturbances at 24 h, but almost complete recovery by 120 h. Hybrids could not tolerate DT to 85g/L. During GT, hybrids survived up to 95g/L with relatively minor ionoregulatory disturbances, however, there were progressive increases in plasma osmolarity and ion levels with salinity that may be used to model salinity tolerance of this hybrid species in the Salton Sea.
[2407] The effect of temperature on salinity tolerance in juvenile Mozambique tilapia hybrids (Oreochromis mossambicus x O. urolepis hornorum). Authors: C. J. Brauner, Department of Zoology, University of British Columbia, Vancouver BC, Canada V6T 1Z2, brauner@zoology.ubc.ca; Brian Sardella; Department of Zoology, University of British Columbia, Vancouver BC, Canada V6T 1Z2 quobee@yahoo.com. J. Cooper; Department of Biology, University of San Diego, 5998 Alcala Park, San Diego CA, 92110, jillc@sandiego.edu. R. Gonzalez; Department of Biology, University of San Diego, 5998 Alcala Park, San Diego CA, 92110, gonzalez@hannah.sandiego.edu. Abstract: The salinity of the Salton Sea is currently 43g/L and increasing annually, posing a large osmoregulatory challenge to resident fishes. Furthermore, the temperature of the Sea can fluctuate between 13 and 35°C further exacerbating effects on osmoregulation. Little is known about the effect of temperature on salinity tolerance of the Salton Sea tilapia hybrid (Oreochromis mossambicus x O. urolepis hornorum). Mozambique hybrids (similar to those in the Salton Sea) were kindly donated from Pacific Aquafarms (Niland, CA) and were gradually acclimated to seawater (SW; 35g/L) over 4 weeks. Groups of seven fish were then transferred to 35, 43, 51, or 60g/L at 15, 25 or 35°C, yielding a total of twelve treatments. Twenty-four hours following the salinity/temperature transfer, osmoregulatory status was assessed as indicated by sublethal indicators, such as plasma osmolarity, Na+ and Cl- concentrations and muscle water content, and mortality. At 25 and 35 °C, all fish survived all salinities, although osmoregulatory stress (high plasma osmolarity and low muscle water content) was observed at 51 and 60 g/L at 35 °C. At 15 °C, mortality was substantial at 51 and 60 g/L (86 and 100%, respectively) indicating that low temperature leads to a substantial reduction in salinity tolerance under the conditions of this experimental design. Session: Determining the Number of Salmon Historically Present and Implications of Those Estimates on Management and Recovery of Populations and Ecosystems (Part I) [2501] Estimating the Historic and Optimum Salmon Productivity of Sockeye Nursery Lakes in the Fraser River, British Columbia Authors: E. MacIsaac, Presenter, Fisheries and Oceans Canada, Co-operative Resource Management Institute, Simon Fraser University, Burnaby, BC, V5A1S6, 604-666-7917 (W), 604-666-1995 (F), macisaace@pac.dfo-mpo.gc.ca ; K. Shortreed, Cultus Lake Salmon Research Laboratory, 4222 Columbia Valley Highway, Cultus Lake, BC, V2R 5B6, (604) 824-4707 (W), (604) 858-3757 (F), shortreedk@pac.dfo-mpo.gc.ca; J. Hume, Cultus Lake Salmon Research Laboratory, 4222 Columbia Valley Highway, Cultus Lake, BC, V2R 5B6, (604) 824-4705 (W), (604) 858-3757 (F), humej@pac.dfo-mpo.gc.ca . Abstract: The Fraser River is one of the largest sockeye salmon rivers and three large nursery lakes (Chilko, Shuswap and Quesnel lakes) dominate production. Estimating optimum escapement targets and smolt carrying capacity for the lakes is key to managing the sockeye fisheries. Productivity-based models of smolt production suggest historic changes in lake productivity due to shifts in escapements and loads of salmon-derived nutrients (SDN) may affect the carrying capacity and production of smolt from the lakes. Multiyear, whole-lake nutrient additions to Chilko Lake also confirmed that higher SDN loads could substantially increase smolt productivity. To improve our understanding of optimum sockeye escapements and smolt production, sediment cores from Shuswap and Quesnel Lakes were used to determine escapements and lake productivity over the last 200-1000 years. Cores were analyzed for 15-N nitrogen, phaeopigments, and cladoceran microfossils to determine escapements, SDN loads, lake productivity changes, and juvenile sockeye grazing densities. Core data suggests both lakes are currently well below pre-European escapement levels and Shuswap Lake showed the strongest evidence of a reduced SDN effect on lake productivity and smolt carrying capacity. However, anthropogenic effects make comparisons with the short, recent escapement records problematic and can confound estimates of historic escapement levels from the sediment cores. [2502] A Comparison of Four Different Approaches to Estimating Pre-Euroamerican Salmon Run Size, in the Clearwater River, Washington. Authors: C. J. Cederholm, Presenter, Washington Department of Natural Resources, Land Management Division, 1111 Washington St. SE, Olympia, WA 98504-7016, 360-902-1609(W), jeff.cederholm@wadnr.gov; L. G. Dominguez, Washington Department of Natural Resources, Forest Practices Division, 1111 Washington St. SE, Olympia, WA 98504-7012, 360-902-1695(W), larry.dominguez@wadnr.gov. Abstract: For the purpose of returning salmon stocks to some level of sustainability, there is an increased interest in knowing the relative magnitude of pre-Euroamerican run sizes, particularly for rivers of the Pacific Northwest. Present run sizes range widely, depending on the condition of the stock and the general locality. Many runs in the lower 48 states are either already extinct, or are presently listed as threatened or endangered, under the Federal Endangered Species Act. Salmon run declines have been attributed to many causes, including: overfishing and some hatchery practices, habitat degradation caused by poor logging and agricultural practices, urbanization, hydropower development, and changing ocean conditions. Historic run size estimation techniques take many forms, and each has its own inherent positive and negative attributes. This paper compares the results of using four different historical run size reconstruction approaches, on an intermediate sized river basin with five species of Pacific salmon. The four approaches were based on: 1.) back calculations from juvenile rearing densities, 2.) commercial catch data, 3.) spawning territory size, and 4.) carcass nutrient subsidy. [2503] Restoration goals for Puget Sound chinook Authors: N.J. Sands-Presenter, NWFSC, NOAA, 2725 Montlake Blvd E, Seattle, WA, 98112, 206-860-5607(W), 206-860-3467(F), norma.sands@noaa.gov. Abstract: The Puget Sound chinook Evolutionarily Significant Unit (ESU) was listed as threatened in 1999. The Puget Sound Technical Recovery Team (TRT) was established in 2000 to work on the technical aspects of developing a recovery plan for this ESU. The TRT identified 22 separate existing populations of chinook in the ESU and these are the building blocks of the recovery recommendations. A target range for the escapement level needed to ensure viability (restoration goals) has been or is being developed for each population. The amount and type of data available for each population differ. What data are available directs how the TRT can estimate the restoration goals. The TRT has looked at variability around recent trends in escapements, capacity estimates developed from habitat analysis for both current and historical conditions, indications of past abundance based on early surveys and historical verbal accounts, and are looking at spawner-recruit analysis coupled with risk assessment in our effort to develop population specific restoration goals. Restoration goals for the ESU as a whole, needed for delisting, will involve an integration of population goals; this integration is still under development. [2504] Considerations for Establishing Recovery Plans and Goals for Endangered Salmonids Author: Gordon H. Reeves, Aquatic and Land Interaction Program, 3200 SW Jefferson Way, Pacific Northwest Research Station, Corvallis, OR 97331, 541-750-7314, greeves@fs.fed.us and Kelly M. Burnett, Aquatic and Land Interaction Program, 3200 SW Jefferson Way, Pacific Northwest Research Station, Corvallis, OR 97331, 541-750-7309, kburnett@fs.fed.us. Abstract: Two potential components of recovery programs for endangered salmonids and their goals for endangered salmonids are: (1) determination of the historical distribution and abundance of habitat over large spatial scales (i.e., 102-103 km2; and (2) identifying habitats with the greatest potential to provide high quality habitat for a given species. The former can be can be determined with models of: (1) historic natural disturbances that influenced aquatic habitat and relations between features of watersheds; and (2) relations between conditions of watersheds (eg., amount of mid-successional vegetation) and in-channel features such as pools and amount of large wood. Natural features of a watershed, such as gradient, valley width, and stream size, determine habitat potential. These features can be determined from Digital Elevation Models (DEMs). The exact value of given feature is species specific. The components provide insight into the distribution of habitat and how much habitat was potentially used historically by a given species. We will illustrate each component using examples from the Oregon Coast Range. [2505] Restoring nutrients and productivity in salmonid food webs Authors: M.S. Wipfli (presenter), Pacific Northwest Research Station, U.S. Forest Service, Wenatchee, WA, 98801, 509-662-4315 x224 (P), 509-664-2742 (F), mwipfli@fs.fed.us; J.P. Hudson, Pacific Northwest Research Station, U.S. Forest Service, Juneau, AK, 99801, 907-586-8811 x254 (P), 907-586-7848 (F), jhudson@fs.fed.us; J.P. Caouette, U.S. Forest Service, Alaska Region, Juneau, AK, 99801, 907-586-7809 (P), 907-586-7860 (F), jcaouette@fs.fed.us; D.T. Chaloner, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, 574-631-0580 (P), 574-631-7413 (F), dchalone@nd.edu; G.A. Lamberti, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, 574-631-8075 (P), 574-631-7413 (F), glambert@nd.edu; R.W. Merritt, Departments of Entomology and Fish and Wildlife, Michigan State University, E. Lansing, MI, 48824, 517-355-8309 (P), 517-355-xxxx (F), merrittr@msu.edu; P.H. Ostrom, Department of Geological Sciences, Michigan State University, E. Lansing, MI, 48824, 517-353-9768 (P), 517-353-xxxx (F), ostromp@msu.edu; R.T. Edwards, Pacific Northwest Research Station, U.S. Forest Service, Juneau, AK, 99801, Pacific Northwest Research Station, U.S. Forest Service, Juneau, AK, 99801, 907-586-8811 x269 (P), 907-586-7848 (F), rtedwards@fs.fed.us; J.L. Tank, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, 574-244-0286 (P), 574-631-7413 (F), jtank@nd.edu; and R.A. Heintz, U.S. National Marine Fisheries Service, Auke Bay Laboratory, Juneau, AK, 99801, 907-789-6058 (P), 907-789-6608 (F), Ron.Heintz@noaa.gov. Abstract: The nutrients and carbon that Pacific salmon (Oncorhynchus spp.) runs provide to Pacific Rim freshwater ecosystems are widely viewed to increase aquatic productivity. However, many watersheds no longer receive the massive salmon runs they once did. Subsequently, various artificial nutrient enrichment products are being developed for replenishing lost nutrients to restore productivity. We carried out a series of experiments that investigated the comparative effects of salmon carcasses, salmon carcass analogs (fish cakes), and slow-release fertilizer (nutrient pellets) on stream nutrients and food webs (nutrient concentrations, biofilm mass, invertebrate densities, and fish growth and lipids). Food web responses varied considerably to treatments. Salmon carcasses generally produced the most consistent and largest overall responses across trophic levels, followed by analogs, and lastly by artificial nutrient pellets. Results further indicated that carbon plays a major role in supporting stream food webs, shading reduces enrichment effects, and benefits to upper trophic levels comes directly through consumption of carcass and analog material, as well as indirectly via bottom-up effects transferred through the food web. Artificial fertilizer and salmon analogs hold promise for helping restore nutrients and aquatic productivity in nutrient-deficient systems, and may be valuable temporary management tools for aiding the restoration of salmon stocks. [2506] Effects of the abundance of spawning sockeye salmon (Oncorhynchus nerka) on nutrients and epilithic algal biomass in forested streams in north-central British Columbia Authors: Tom Johnston (presenter); BC Ministry of Water, Land, and Air Protection; 2204 Main Mall; Vancouver, BC, V6T 1Z4; Phone: (604) 222-6754; Fax: (604) 666-1849; e-mail: tom.johnston@gems3.gov.bc.ca; Erland MacIsaac; Fisheries and Oceans Canada; School of Resource and Environmental Management; Simon Fraser University; Burnaby, BC, V5A 1S6; Phone: (604) 666-7917; Fax: (604) 666-1995; e-mail: macisaace@pac.dfo-mpo.gc.ca; Peter Tschaplinski; Research Branch; BC Ministry of Forests; 712 Yates Street; Victoria, BC, V8W 1L4; Phone: (250) 387-3025; Fax: (250) 387-0046; e-mail: peter.tschaplinski@gems4.gov.bc.ca; Ken J. Hall; Institute for Resources and Environment; 2206 East Mall; University of British Columbia; Vancouver, BC, V6T 1Z3; Phone: (604) 822-6474; Fax: (604) 822-9250; e-mail: kjhall@civil.ubc.ca. Abstract: The abundance of sockeye salmon carcasses influenced the productivity of three oligotrophic spawning streams in north-central BC. There were large differences among years in spawner abundance and distribution within the streams. Salmon carcasses were the dominant source of allochthonous CPOM in low gradient stream reaches. Sockeye carcasses were retained at the spawning sites, primarily (75-80%) by LWD or pools formed by LWD. Carcass biomass accounted for much of the variation in post-spawning peak nutrient concentrations and algal biomass among reaches. Simple process models based on empirical measurements of nutrient release from carcasses successfully described the observed temporal variation in nutrient concentrations within years. Most of the salmon-derived N and P were exported from the spawning streams. The biomass of epilithic algae increased with increasing carcass biomass between 20 and 500 g DW·m-2 to reach maxima 10-fold higher than ambient levels. Epilithic algae were dominated by a small number of common, large diatom taxa. Epilithon and insect d13C and d15N increased with increasing salmon abundance, suggesting the utilization of salmon-derived nutrients by the biota, but interpretation of the stable isotope data is potentially confounded by fractionation processes between salmon tissue and algae. [2507] Reconstructing Salmon Abundance in Rivers: An Initial Dendrochronological Evaluation Authors: Deanne C. Drake (presenter) and Robert J. Naiman; School of Aquatic and Fishery Sciences Box 3550020 University of Washington Seattle, WA 98195 (206) 221-5406 (W) (206) 685-7471(F) ddrake@u.washington.edu, naiman@u.washington.edu. Abstract. Decision-makers concerned with salmon or their stream habitats are faced with many persistent, difficult questions including: how large and variable were these populations before European settlement? Here, we examine the feasibility of reconstructing salmon abundance using links between marine nutrients carried upstream by Pacific salmon (Oncorhynchus spp.) and growth of dominant riparian trees in two Alaskan systems. We employ standard dendrochronology methods and regression models to quantify relationships between annual tree-ring growth, salmon escapement, and the climate pattern that affects oceanic production of Northeast Pacific salmon stocks, the Pacific Decadal Oscillation (PDO). We find that known, annual salmon escapement is significantly related to tree-ring growth at two sites in the Pacific coastal rainforest (PCRF) (r2 = 0.23, P< 0.05 at each site), but not at two sites in the boreal forest. We then use relationships established at PCRF sites to reconstruct preliminary salmon spawning abundances to 1820 A.D. PDO was not correlated with local, 19-year salmon escapement records and could not be used in reconstructions. Reconstructions compare favorably to SE Alaska fisheries catch data from 1924 – 1994 (Pearson correlation = 0.301 (P = 0.02), and 0.401 (P < 0.01)). This study demonstrates the promise and utility of dendrochronology for reconstructing salmon returns to streams. Session: Emerging Theory, Experiences, and Issues Related to Fire, Fire Management, and Aquatic Resources (Part I) [2601] An introduction to fire, fisheries and aquatic research, technology transfer and the need for improved interagency coordination and collaboration in support of the National Fire Plan and Healthy Forest Initiative. Author: Glen P. Contreras (Presenter), U.S. Forest Service, WFWAR Staff, Mail Stop 1113, Washington D.C, 1400 Independence Ave SW, Washington D.C., 20250-1113. (W) 703 605 5286 (F) 703 605 0279, gcontreras@fs.fed.us . Abstract: Wildfire, forest health, and the declining status of many aquatic species frame an important debate about land management in the western United States. Based on wildfire’s occurring in the Western United States since 2000 researchers, biologists and managers are faced with new challenges. Changes in vegetation patterns and associated conditions in fuels and fire behavior now appear to threaten larger, more severe fires in some forest types than were characteristic of the past. Wildfire and management intended to mitigate, mimic, or replace the effects of fire have become central issues for land managers, as has the need to protect aquatic resources. Major initiatives such as the National Fire Plan and Healthy Forest Initiative are in place to support massive fuels and fire management programs. Such efforts may involve mechanical thinning and harvest as well as prescribed and natural fire in efforts to restructure whole forest ecosystems. Aquatic resources are an important component of this program, but there is important debate about the risks and benefits such management represents. Better information and integration of these two elements of forest management are badly needed. Interim solutions, must focus on evaluating the relative risks of action or lack of it based on current information. In the longer term agencies will need better understanding based on the results of the work they do. Meeting these needs on an ongoing basis will ultimately require rethinking the way we conduct the important business of synthesizing, packaging, and distributing information to the management community. It will require a stronger partnership between the science and management communities, and an interagency commitment to provide resources specifically for the task. The success of the national level interagency wildfire and our aquatic resources program depend on it. [2602] Fire and aquatic ecosystems of the western USA: current knowledge and key questions Authors: Peter A. Bisson, Presenter, USDA Forest Service, Pacific Northwest Research Station, 3625 93rd Avenue SW, Olympia, WA 98512, 360-753-7671 (W), 360-956-2346 (F), pbisson@fs.fed.us; Bruce E. Rieman, USDA Forest Service, Rocky Mountain Research Station, Boise, ID 83702, 208-373-4386 (W), 208-373-4391 (F), brieman@fs.fed.us; Charlie Luce, USDA Forest Service, Rocky Mountain Research Station, Boise, ID 83702, 208-373-4382 (W), 208-373-4391 (F), cluce@fs.fed.us; Paul F. Hessburg, USDA Forest Service, Pacific Northwest Research Station, Wenatchee, WA 98801, 509-664-2709 (W), 509-664-2742 (F), phessburg@fs.fed.us; Danny C. Lee, USDA Forest Service, Pacific Southwest Research Station, Arcata, CA 95521, 707-825-2965 (W), 707-825-2901 (F), dclee@fs.fed.us; Jeffrey L. Kershner, USDA Forest Service, Washington Office, Logan, UT 84322, 801-750-2500 (W), 801-750-3798 (F), jkershner@fs.fed.us; Gordon H. Reeves, USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR 97331, 541-750-7314 (W), 541-750-7329 (F), greeves@fs.fed.us; Robert E. Gresswell, USGS Biological Resources Division, Forest and Rangeland Ecosystem Science Center, Corvallis, OR 97331, 541-750-7410 (W), 541-750-7761 (F), Robert_Gresswell@usgs.gov. Abstract: Understanding of the effects of wildland fire and fire management on aquatic and riparian ecosystems is an evolving field, with many questions still to be resolved. Limitations of current knowledge, and the certainty that fire management will continue, underscore the need to summarize available information. Integrating fire and fuels management with aquatic ecosystem conservation begins with recognizing that terrestrial and aquatic ecosystems are linked and dynamic, and that fire can play a critical role in maintaining aquatic ecological diversity. To protect aquatic ecosystems we argue that it will be important to: (1) accommodate fire-related and other ecological processes that maintain aquatic habitats and biodiversity, and not simply control fires or fuels; (2) prioritize projects according to risks and opportunities for fire control and the protection of aquatic ecosystems; and (3) develop new consistency in the management and regulatory process. Ultimately all natural resource management is uncertain; the role of science is to apply experimental design and hypothesis testing to management applications that affect fire and aquatic ecosystems. Policy-makers and the public will benefit from an expanded appreciation of fire ecology that enables them to implement watershed management projects as experiments with hypothesized outcomes, adequate controls, and replication. [2603] Status of Native Fishes in the Western United States and Issues for Fire and Fuels Management Authors: Bruce Rieman (Presenter), U.S. Forest Service, Rocky Mountain Research Station, 316 E. Myrtle St., Boise, ID 83702;voice: (208) 373-4386; fax: (208) 373-4391; brieman@fs.fed.us; Danny Lee, U.S. Forest Service, Pacific Southwest Research Station, 1700 Bayview Dr., Arcata, CA 95521; Dave Burns3, U.S. Forest Service, Payette National Forest, 800 W. Lakeside Ave., McCall, ID 83638; Robert Gresswell, US.G.S. Biological Resources Division, 3200 SW Jefferson Way, Corvallis, OR 97331; Michael Young, U.S. Forest Service, Rocky Mountain Research Station, P.O. Box 8089, Missoula, MT 59807; Rick Stowell, U.S. Forest Service Region 1, P.O. Box 7669, Missoula, MT 59807; John Rinne, U.S. Forest Service, Rocky Mountain Research Station, 2500 South Pine Knoll, Flagstaff, AZ 86001; 7 and Philip Howell, U.S. Forest Service, Pacific Northwest Research Station, 1401 Gekeler Lane, La Grande, OR 97850 Abstract: Conservation of native fishes and changing patterns in wildfire and fuels are defining challenges for managers of forested landscapes in the western United States. Many species and populations of native fishes have declined in recorded history and some now occur as isolated remnants of what once were larger more complex systems. Land management activities have been viewed as one cause of this problem. Fires also can have substantial effects on streams and riparian systems and may threaten the persistence of some populations of fish, particularly those that are small and isolated. Despite that, major new efforts to actively manage fires and fuels in forests throughout the region may be perceived as a threat rather than a benefit to conservation of native fishes and their habitats. We argue that management of forests and fishes can be viewed as part of the same problem, that of conservation and restoration of the natural processes that create diverse and productive ecosystems. We suggest that progress toward more integrated management of forests and native fishes will require at least three steps: 1) better integration and development of a common conceptual foundation and ecological goals; 2) attention to landscape and ecological context; and 3) recognition of uncertainty. [2604] Effects of fire on fish populations: landscape perspectives on persistence of native fishes and nonnative fish invasions Authors:
J.B. Dunham and Bruce Rieman U.S. Forest Service Rocky Mountain Research
Station, Boise Forestry Sciences Laboratory, 316 East Myrtle, Boise, ID
83702, 208-373-4380 (voice), 209-373-4391 (fax), jbdunham@fs.fed.us
(email), brieman@fs.fed.us (email);
M.K. Young, U.S. Forest Service Rocky Mountain Research Station, Forestry
Sciences Lab, 800 Block East Beckwith, P.O. Box 8089, Missoula, Montana
59807, 406.542.3254 (voice), 406-543-2663 (fax), mkyoung@fs.fed.us
(email); R.E. Gresswell U.S. Geological Survey – FRESC, 3200 SW
Jefferson Way, Corvallis, OR 97331, Phone: 541-750-7410 (voice), 541-758-7761
(fax), Robert_Gresswell@usgs.gov
(email) [2605] Altered vegetation and disturbance patterns: Inland Northwest Forests, 1800-2000 Authors: Paul F. Hessburg, USDA Forest Service, Pacific Northwest Research Station, 1133 North Western Avenue, Wenatchee, WA 98801-1229, (W) 509-664-2709, (F) 509-664-2742, phessburg@fs.fed.us; James K. Agee, College of Forest Resources, Box 352100, University of Washington, Seattle, WA 98195, (W) 206-543-2688, (F) 206-543-3254, jagee@u.washington.edu. Abstract: Fire was arguably the most important forest and rangeland disturbance process in the Inland Northwest United States for millennia. Prior to the Lewis and Clark expedition, fire regimes ranged from high-severity with return intervals of 1 to 5 centuries, to low-severity with fire-free periods lasting 3 decades or less. Two centuries of settlement, exploitation, management, and climate variation have transformed the fire regimes, vegetation and fuel patterns, and overall functionality of these forests. In 200 years the region has undergone fur trapping and trading, sheep, cattle, and horse grazing, timber harvesting, mining, road construction, native grassland conversion to agricultural production, urban and rural area development, and fire suppression. We highlight the key changes to forest landscape patterns and disturbance processes that occurred under these combined influences, discuss implications of the changes, frame the current “fire problem” in western forests, and discuss priorities for altering current fire behavior. [2606] Effects of Wildfire and Subsequent Flood, Landslide, and Debris Torrent on Fish Distribution and Abundance in Tributaries of North Fork John Day River Author: Philip Howell--presenter, USDA Forest Service, PNW Forestry and Range Sciences Laboratory, 1401 Gekeler, La Grande, OR 97850, 541-962-6559 (w), 541-962-6559 (f), phowell@fs.fed.us. Abstract: Recent large wildfires in western states have fueled increasing concern of resource managers and the public about fire effects, including risk to fish, particularly listed species. However, there are few empirical studies of the response of fish to fire, and none that includes anadromous species. The Tower Fire was one of four large fires in 1996 in the upper John Day basin in Oregon. Much of the fire in the study area was a large, high severity fire that differed from smaller, more frequent, low severity fires that were characteristic historically in dry forest types. We investigated the effects of the fire on fish distribution and abundance in three streams immediately following the fire and through 2000. An intense storm in May 1998 triggered a large flood, landslide, and debris torrent. Mortality was extensive in moderate-high intensity burn areas. Fish began to repopulate defaunated reaches the year following the fire, and by 2000 fish distribution was equal to or more extensive than prior to the fire. Densities of rainbow trout/steelhead in both burned and unburned reaches downstream of the fire have rebounded to levels similar to or greater than densities in comparable control streams outside of the fire. Juvenile spring chinook also began to use one of the streams following the flood. [2607] Scale Considerations for the Evaluation of Physical Effectiveness and Ecological Utility of Post-Fire Stabilization and Rehabilitation Treatments Authors: Charlie Luce (Presenter), USDA Forest Service, Rocky Mountain Research Station, 316 E. Myrtle St. Boise, ID 83702; voice: (208)373-4382; fax (208)373-4391; cluce@fs.fed.us; Tom Black, USDA Forest Service, Rocky Mountain Research Station, 316 E. Myrtle St. Boise, ID 83702; voice: (208)373-4382; fax (208)373-4391; tblack@fs.fed.us; Bruce Rieman, USDA Forest Service, Rocky Mountain Research Station, 316 E. Myrtle St. Boise, ID 83702; voice: (208)373-4382; fax (208)373-4391; brieman@fs.fed.us; Jason Dunham, USDA Forest Service, Rocky Mountain Research Station, 316 E. Myrtle St. Boise, ID 83702; voice: (208)373-4382; fax (208)373-4391; jbdunham@fs.fed.us; Jack King, USDA Forest Service, Rocky Mountain Research Station, 316 E. Myrtle St. Boise, ID 83702; voice: (208)373-4382; fax (208)373-4391; jgking@fs.fed.us. Abstract: Post-fire treatments to prevent watershed effects are expensive, and there is a lack of information on effectiveness and design standards. An important issue is the probable effectiveness of treatments given the magnitude-frequency relationship for post-fire storms. Because fire related disturbance can be ecologically important, it is also unclear when treatments are either a benefit or detriment from an ecological perspective. Public accountability calls for a clearer set of rules for decision making on emergency treatments. Not surprisingly, context is important, both at small and large scales. At small scales, treatments like logs retain little water on their own, and spatial continuity of water repellency, hydraulic conductivity of underlying soils, and the local characteristics of precipitation are critical determinants of treatment effectiveness. At larger scales, the ecological utility depends on the size of storm disturbances relative to the spatial scale and distribution of fish populations and metapopulations in a stream network. Fragmentation of those populations by fish passage barriers is also a critical issue. This presentation will discuss how to use local and stream network scale information to make decisions about emergency post-fire treatments. Similar reasoning can be applied to both concepts about fire suppression and fuel treatments to reduce wildfire ignitions and spread. [2608] Replacing Wildfire with Management Activities: Will We “Protect” Aquatic Ecosystems to Death? Author: Gordon H. Reeves, Aquatic and Land Interaction Program, 3200 SW Jefferson Way, Pacific Northwest Research Station, Corvallis, OR 97331, 541-750-7314, greeves@fs.fed.us. Abstract: Management agencies are proposing policies and programs to the replace wildfire with active management activities on public lands throughout the western United States. A primary reason for this is to “protect” aquatic ecosystems from the perceived negative effects of wildfire. However, wildfire may be an integral factor that maintains the long-term productivity of aquatic ecosystems. Active management generally differs from natural disturbance in several important aspects. Primarily, it has differs magnitude and frequency and leaves behind a different legacy than natural disturbance. The consequence is that features and processes of natural ecosystems are lost or altered. Therefore it is important to consider several factors when identifying the need for and components of programs that replace wildfire with active management. First is an understanding of the potential role of fire in influencing the structure of aquatic ecosystems. Important processes such as the delivery of sediment and wood delivery, important building blocks for physical habitat are strongly influenced by fire. This requires that considerations of how aquatic ecosystems historically responded to wildfire at large spatial (103 km2) and long temporal (101-102 years) scales. Life-history attributes of fish need to be considered because they determine, to a large extent, how they respond to disturbances. Attempts to protect aquatic ecosystems from disturbance by wildfire could actually be detrimental to the aquatic ecosystems in the long term. Session: Biology and Management of Native and Exotic Freshwater Fish, Amphibians, Aquatic Reptiles in Coastal Southern California and northern western Mexico (Part II) [2701] Captive maintenance and reproduction of native cyprinid fishes; a case study of the Santa Ana Speckled Dace, Arroyo Chub and Santa Ana Sucker. Author: K.S. Russell, Presenter, Resource Management Specialist, Riverside-Corona Resource Conservation District, 4500 Glenwood Dr., Riverside, CA, 92501, 909-683-7691, russell@rcrcd.com. Abstract: Captive reproduction, rearing and study of coastal southern California native fishes has not been attempted on a large scale or under semi-controlled conditions with data and procedures that have provided adequate documentation on captive success rates, life history, fecundity or mortality. The Riverside-Corona Resource Conservation Districts Native Fish Stream and associated riparian habitat has been designed to track and study natural trends of three native fishes, Catostomus santaanae, Rhynicthys osculus ssp., and Gila orcutti, which have been trans-located from local tributaries in the Santa Ana River watershed to the 300 foot-long outdoor facility. The life history and habitat preferences of these fish in the stream have validated some of the studies conducted in the field, with the native fish stream surveys indicating that certain species have large variations in populations and class sizes from year to year, despite consistent environmental conditions. [2702] Relationship of biological communities to water source and channel type in the highly urbanized Santa Ana River Basin Authors: Carmen A. Burton, Presenter, U.S. Geological Survey, 5735 Kearny Villa Rd., Ste. O, San Diego, CA, 92123, 858-637-6878, caburton@usgs.gov; Larry R. Brown, U.S. Geological Survey, Placer Hall, 6000 J St., Sacramento, CA, 95819, 916-278-3098, lrbrown@usgs.gov. Abstract: Urbanization of the Santa Ana River Basin, located in southern California has led to alteration and loss of habitat and changes in water quality. Nineteen sites along the river and its tributaries, representing a range of water sources (mountain runoff, ground-water discharge, urban runoff, treated wastewater) and channel types (natural, channelized, and concrete-lined) were sampled during summer 2000 to assess the composition of fish, macroinvertebrate, and periphyton communities and habitat and water quality measures. Macroinvertebrates and periphyton were sampled using artificial substrates to minimize the effects of substrate differences among channel types. One fish, 24 macroinvertebrate, and 6 periphyton metrics were significantly different among water sources. Streams supplied with treated wastewater generally had less diversity but higher abundance of macroinvertebrates than other water sources. These metrics correlated with several chemical (e.g., Kjeldahl nitrogen and inorganic salts) and physical parameters. Three fish, 13 macroinvertebrate, and 3 periphyton metrics were significantly different among channel types. Concrete channels had lower abundances of trichoptera and tanytarsini genera but higher abundances of noninsects than channelized or natural streams. These metrics correlated with several physical parameters (e.g., stream depth and substrate). Results indicate that changes in water sources and channel types have altered the water quality and aquatic community in the Santa Ana River Basin. [2703] East Meets West: Mosquitofishes in Southern California Author: J. A. Seigel, Section of Fishes, Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, CA 90007, (213) 763-3374, jseigel@nhm.org. Abstract: Mosquitofishes (Gambusia spp.) have been in California since 1922 and there is anecdotal evidence that eastern mosquitofish (G. holbrooki) have been introduced along with the well-documented western mosquitofish (G. affinis). Key characters used to distinguish these species are dorsal and anal-fin ray counts and differences in gonopodial structure. Eleven southern California counties were recently sampled for mosquitofishes, augmented with historical Museum collections. Fin-ray counts and gonopodial characters indicate that G. holbrooki is present in southern California. DNA studies may confirm these morphology-based identifications and help elucidate relationships among southern California Gambusia populations. The implications of dealing with a second mosquitofish species in southern California waters are discussed. [2704] Dynamics of sport fish and non-sport fish species and drawdown effects at Silverwood Reservoir Authors: J. S. Sunada, and M. Chmiel, Presenter, California Department of Fish and Game, 4775 Bird Farm Rd, Chino Hills, CA. 91709 jsunada@dfg.ca.gov. Abstract: Silverwood reservoir is a 995 surface acre lake located in the San Bernardino Mountains and is supplied by water from the California aqueduct. Since it was created in 1972, a number of non-native sport fish and non-sport fish species have been introduced via the aqueduct and by the department of fish and game. The reservoir has undergone a drawdown in 1995 for dam repairs. As a result, various fish species have declined in numbers. Data from electrofishing surveys from 1988 to 2002 and creel surveys from 1999 to 2002 were analyzed to determine abundance of largemouth bass and other centrarchids in relation to non-sport fish such as carp, goldfish and tule perch. Results indicate that there was a negative correlation between numbers(percent composition) of large cyprinids and certain centrarchids although the relationship was not significant (P<0.05). The negative relationship maybe the result of the non-sport fish removal program that was initiated in 1999. Largemouth bass and black crappie numbers were also negatively correlated and was significant (P<0.05). [2705] Introduced prasites of freshwater fish in southern California Authors: M.L. Warburton, Presenter, U.S. Geological Survey, Biological Resources Discipline, 5745 Kearny Villa Road, San Diego CA, 92123, (858) 974-3563, mwarburton@usgs.gov; B.I. Kuperman, V.E. Matey, San Diego State University, Center For Inland Waters, 5500 Campanile Drive, San Diego CA, 92182, (619) 594-0356, and R.N. Fisher, USGS/BRD. Abstract: During the 20th century, over 140 fish species were introduced to California in an effort to enrich the depauperate native fauna. Some aggressive parasite species associated with these introductions have naturalized and persisted in California waterways. Until now, little has been known about the spread of these parasites in the state. We present new data on the status and distribution of three species of harmful parasites incidentally introduced to California: a cestode Bothriocephalus acheliognathi, a ciliate Ichthyopthyrius multifiliis, and a copepode Lernaea cyprinacea. In 1999-2001, a parasitological survey was conducted on fish from 11 different coastal watersheds of Southern California. A total of 1, 314 fish specimens from six native species and eleven non-native species were examined for ecto- and endoparasites. Bothriocephalus acheilognathi was found in fish from eight watersheds. I. multifiliis was found in fish from seven watersheds. L. cyprinacea occurred in four watersheds. We conclude that B. acheilognathi, I. multifiliis and L. cyprinacea are widespread in the major coastal water systems of Southern California. Parasites infect both native and non-native species and may represent a high potential risk for conservation efforts, aquaculture and sport fisheries in the region. [2706] Fisher************************* [2707] The plight of the arroyo toad (Bufo californicus Camp) and other amphibians in the rivers of northern Baja California: Tales of sapos and tacos, and random impacts Authors: Robert Lovich, Loma Linda University; Sal Zimmitti, P and D Environmental; Clark Mahrdt, San Diego Natural History Museum and Gustavo Danemann, Pronatura Noroeste Abstract: The southwestern arroyo toad (Bufo californicus) is a federally endangered species whose range straddles coastal California, USA and northern Baja California, México. During the last several decades this species has seen its habitat reduced by more than 75% in the United States. The status of this species in the rapidly developing region of northern Baja California, México is poorly known, and basic natural history information on the arroyo toad from this region is lacking. Herein we present data on the known historical distribution of this species along with recently acquired survey data on its present status and distribution in Baja California, México. Surveys found arroyo toads in seven (7) of sixteen (16) rivers surveyed, one of which represents a range extension. Anthropogenic impacts to the rivers of northern Baja were typical, and are shown to be adversely affecting resident herpetofauna. This study provides new information on the status and distribution of the arroyo toad and other riparian herpetofauna, exotic species, and anthropogenic impacts affecting the rivers of northern Baja. This study also provides new information on the status and distribution of the arroyo toad in México, which will assist biologists and land managers throughout the region in protecting not only this species, but also the watersheds it inhabits in a diverse region under increasing pressures from urbanization. [2708] The California red-legged frog population at the Santa Rosa Ecological Reserve (1989-2002): What happened to all the frogs there? Author: Mark R. Jennings, Rana Resources, 39913 Sharon Avenue, Davis, CA 95616-9456, and Research Associate, Department of Herpetology, California Academy of Sciences, 530-753-2727 (voice and FAX), RanaResources@aol.com. Abstract: The last known population of the California red-legged frog (Rana aurora draytonii) between Ventura County and the Mexican border was located at the Santa Rosa Ecological Reserve in western Riverside County, California. Over the past 14 years, this population has gone from 25 adults, to over 200 adults, to only 2 adult males. Despite the best efforts of the Nature Conservancy, resource agencies, and amphibian researchers, the population quickly declined to the point where it was no longer viable. Currently there are plans to reintroduce red-legged frogs into the Reserve from stock obtained in northern Baja California. However, before this happens there should be a thorough analysis of why the frog population became functionally extinct in the first place. In my presentation, I will discuss some of the negative effects on the frog population at the Reserve and why it is so hard to protect isolated frog populations from extinction—even when you have the habitat “protected” in perpetuity. |
