Environmental biology of fishes, tập 94, số 1, 2012

Environ Biol Fish (2012) 94:1–6 DOI 10.1007/s10641-012-9987-3 Ecological interactions between wild and hatchery salmonids: an introduction to the special issue Peter S Rand & Barry A Berejikian & Todd N Pearsons & David L G Noakes Received: 18 January 2012 / Accepted: 12 February 2012 / Published online: 22 March 2012 # Springer Science+Business Media B.V 2012 The optimism of early salmon hatchery practitioners to increase abundance (Lichatowich 1999) has been tempered in recent decades by theoretical and empirical studies indicating unintended negative effects hatcheries can have on wild Pacific salmon and steelhead (Naish et al 2008; Pearsons and Temple 2010) Unintended effects of hatcheries are much more difficult and costly to assess than evaluating the benefits of hatchery production to provide harvest opportunities Holistically evaluating the relative costs and benefits of past and current hatchery practices requires an understanding and estimation of the unintended effects (Pearsons 2010) In recent years, national and local governments, indigenous P S Rand (*) State of the Salmon, Wild Salmon Center, Portland, OR, USA e-mail: prand@wildsalmoncenter.org B A Berejikian NOAA Northwest Fisheries Science Center, Manchester, WA, USA T N Pearsons Grant County Public Utility District, Ephrata, WA, USA D L G Noakes Department of Fisheries and Wildlife and Oregon Hatchery Research Center, Oregon State University, Corvallis, OR 97331-3803, USA (e.g First Nations or tribal) resource agencies, private industry and NGO conservation groups have begun efforts to reform public salmon and steelhead hatchery systems in North America, which include critically evaluating societal and biological risks and benefits A significant number of national and international policy concerns and actions are directly relevant to this issue In the US Pacific Northwest, for example, the National Oceanic and Atmospheric Administration (NOAA) is currently evaluating the environmental impact of salmon and steelhead hatcheries through federal mandates such as the Endangered Species Act and the Mitchell Act The US State of Alaska is faced with ongoing challenges of adhering to the State’s fisheries policies regarding sustainability, genetics and escapement goals in the face of a growing private salmon hatchery industry in the State In Canada, the Department of Fisheries and Oceans (DFO) is in the process of implementing an ambitious new Wild Salmon Policy that must address impacts hatcheries have on wild salmon There is fresh thinking and emerging new initiatives in both Japan and Russia to identify and separately manage wild salmon in these nations The growing demand for sustainable seafood has put the global spotlight on salmon, which is near the top of the list of most desired seafood, buoyed by reports of health benefits of eating salmon Third party sustainability certifications of wild capture fisheries is required in many global markets, and Pacific salmon fisheries are coming under increased international scrutiny with respect to how salmon hatcheries are managed and the degree to which hatchery salmon interact with and affect wild salmon, both genetically and ecologically (Peterman 2002; Chaffee and Bosworth 2007) Salmon populations (comprised of both wild or hatchery populations, or a mixture of the two) also continue to play a critical role in supporting subsistence, ceremonial and recreational fisheries across the North Pacific region The effects of hatchery-produced salmon on aquatic ecosystems have been vigorously debated in academic and natural resource forums and in the scientific literature The attention to hatchery effects has resulted in coordinated efforts to reform the public hatchery system in the United States and led to very specific guidelines to mitigate genetic impacts (Mobrand et al 2005; Paquet et al 2011) Although genetic interactions have received most of the attention in the scientific literature (Waples 1991; Araki et al 2008; Fraser 2008; Christie et al 2011), negative associations between the numbers of hatchery fish released and wild salmon survival rates have been hypothesized to be the result of ecological interactions (e.g., Nickelson 2003) Indeed, a number of recent reviews highlight the potential importance and gaps in our understanding of the ecological effects of hatchery salmon on wild salmon populations and their freshwater and marine habitats (Naish et al 2008; Pearsons 2008) In 2009, a small group of scientists and policy makers recognized the need and value of convening a diverse group of experts and stakeholders to describe what is known about the scale and magnitude of ecological interactions between wild and hatchery salmonids, and to describe a logical path forward to address unintended effects hatchery salmonids can have on wild salmonids throughout their native range in the North Pacific The papers contained in this volume are a product of convening experts and stakeholders at a conference entitled “Ecological Interactions Between Wild and Hatchery Salmon” The meeting was organized by State of the Salmon and held on 4–7 May 2010 in Portland, Oregon, USA Our conference aimed to present the most current information about ecological interactions, identify critical scientific uncertainties, identify available tools for managing ecological risks, and to develop a path forward for improving the understanding and management of ecological interactions between wild and hatchery salmonids in the North Pacific region The Environ Biol Fish (2012) 94:1–6 conference was the first pan-Pacific event designed to explore the scale and magnitude of the ecological effects of salmon and steelhead hatcheries Over 300 people attended the meeting and participants in the conference hailed from the United States, Canada, Russia, and Japan The conference agenda included 47 talks and was organized into seven separate sessions This special journal issue represents 23 original scientific investigations and reviews on ecological interactions We also encourage the reader to visit the conference website (http://www.stateofthesalmon.org/conference2010/) for additional information The agenda and expected outcomes from the conference were shaped by a steering committee composed of agency and academic experts from the United States, Canada, Russia and Japan The steering committee members were as follows (listed in alphabetical order): Brian Allee, NOAA Barry Berejikian, NOAA Stephen Brandt, Oregon Sea Grant Dan Bottom, NOAA Craig Busack, Washington Department of Fish and Wildlife Ken Currens, Northwest Indian Fisheries Commission Robert Devlin, Department of Fisheries and Oceans, Canada Ian Fleming, Memorial University Susan Hanna, Oregon State University Masahide Kaeriyama, Hokkaido University David Noakes, Oregon State University Ken Ostrand, U.S Fish and Wildlife Service Todd Pearsons, Grant County Public Utility District Pete Rand, State of the Salmon Bill Smoker, University of Alaska Fairbanks (retired) Alex Wertheimer, NOAA (retired) Lev Zhivotovsky, Institute of General Genetics, Russian Academy of Sciences While we sought to encourage wide ranging participation and perspectives at the conference, the guest editors wish to emphasize that any views or suggestions expressed in this special issue are not intended to represent the views of any particular salmon management entity whose jurisdiction includes the North Pacific We hope, however, that views and perspectives expressed are thought provoking and help spur meaningful dialogue toward an important goal of conserving wild salmon Environ Biol Fish (2012) 94:1–6 The structure of this special issue addresses the ecological interactions between wild and hatchery salmon and steelhead as a life history progression across ontogenetic stages and habitats In addition, a number of review and perspective papers were presented at the conference Below we provide an overview on the unique contribution made by each of the authors in this special issue We began by examining interactions occurring in the early life history of Pacific salmon and steelhead in freshwater A review of juvenile salmon competition described how factors including duration of freshwater cohabitation, relative body size, prior residence, and species differences all influence competitive interactions, with fish density in relation to habitat carrying capacity likely exerting the greatest influence (Tatara and Berejikian 2012, this issue) Another review described evidence of predation by stocked hatchery steelhead on juvenile wild salmon (Naman and Cameron 2012, this issue) exemplifying the variability in predation rates that can be associated with timing of emergence and hatchery release practices This paper provided practical suggestions on how to minimize predation risk through hatchery management changes Manipulation of growth regimes in steelhead hatchery facilities to induce more natural life history expression and minimize negative effects on wild fish further exemplified efforts to reform hatchery practices to minimize predation and competition risks of released steelhead trout during their freshwater residence (Berejikian et al 2012, this issue) A unique modeling tool (PCD Risk 1) has been developed for conducting risk assessment and facilitating risk reduction associated with predation, competition and disease among salmonids in freshwater environments (Pearsons and Busack 2012, this issue) Methods to manage ecological risks of a hatchery program in the US State of Washington were used to reduce adverse impacts to a variety of non-target taxa, which are frequently overlooked (Temple and Pearsons 2012, this issue) And, a broad scale risk assessment approach using the PCD Risk model and expert based opinion is described for the Upper Columbia River, USA/Canada (Pearsons et al 2012, this issue) Following the freshwater juvenile stage, smolts originating from natural spawning habitat and hatcheries may differ in their early marine life histories but may still compete during their seaward migration Wild and hatchery chum salmon in inlet and near shore habitats in Southeast Alaska, USA partitioned diets and habitat resources, which suggests transitory effects of density-dependent competition between wild and hatchery chum salmon during the early marine phase of the life cycle (Sturdevant et al 2012, this issue) A similar study on Chinook salmon in waters off the coast of the US States of Oregon and Washington showed less differentiation in diet and habitat use among wild and hatchery individuals, with evidence that both populations responded synchronously to ocean conditions (Daly et al 2012, this issue) A study in coastal British Columbia suggests wild Chinook salmon may be more resilient to future climate change than their hatchery counterparts given observations of higher near shore survival of wild postsmolts (Beamish et al 2012, this issue) There remains substantial uncertainty regarding the interpretation of spatial, temporal, and dietary overlap between hatchery and wild fish during their early life history in the marine environment, but these studies have provided a starting point for understanding some of the conditions under which overlap can occur, the degree of overlap in different regions, and some initial interpretations of its significance Less is known about the offshore marine life history of Pacific salmon However, two papers in the special issue have “lifted the curtain” on the potential interactions occurring between wild and hatchery salmon in the open ocean An increase in Asian hatchery chum salmon abundance from 10 million to 80 million fish may have influenced body size, age-at-maturation, productivity and abundance of a distant wild chum salmon population in Norton Sound, Alaska (Ruggerone et al 2012, this issue) Growth and survival of North Pacific salmon are declining as a result of competitive interactions among salmon at sea, a process that may be exacerbated by hatchery programs for pink and chum salmon and future climate change (Kaeriyama et al 2012, this issue) A number of studies addressed interactions occurring at the time of adult return migration and spawning Recent research was presented on straying of hatchery produced pink, chum and sockeye salmon in Prince William Sound, Alaska This helps frame some of the challenges in minimizing adverse effects of hatchery populations on wild salmon in this region (Brenner et al 2012, this issue) The first comprehensive salmon escapement survey of chum salmon in Hokkaido, Japan, provided evidence of natural reproduction in a region that has focused for many decades on hatchery development (Miyakoshi et al 2012, this issue) The unique history of hatchery development in Sakhalin, Russian Federation and the emerging understanding of interactions between wild and hatchery pink and chum salmon provides insight into potential competition between wild and hatchery salmon in this region (Kaev 2012, this issue) New evidence was presented on trait divergence between wild and hatchery populations of chum, Chinook and sockeye populations in southern Kamchatka, Russian Federation and the first documentation in the literature on the contribution of hatchery chum salmon to the natural spawning population of chum salmon in this region (Zaporozhets and Zaporozhets 2012, this issue) Three additional papers address reproductive interactions and demonstrate the power of genetic tools in understanding the nature of ecological interactions between wild and hatchery salmon Shifting demographics of hatchery Chinook salmon populations to earlier male maturity may influence overall DNA pedigree-based estimates of reproductive success in natural populations supplemented with hatchery-reared Chinook salmon (Schroder et al 2012, this issue) A study of genetic markers reveals how a rare lake-type chum population is being swamped by a rapidly expanding hatchery chum salmon population in a small island in the Kurile archipeligo, Russian Federation (Zhivotovsky et al 2012, this issue) Genetic differences among cultured and wild populations of masu salmon in Hokkaido, Japan were highlighted in another study, and the authors urged fisheries managers to consider the risk of fitness loss in wild masu populations that might interbreed with hatchery fish (Yu et al 2012, this issue) A number of broad reviews were presented on different dimensions of the conference theme A succinct summary of enhancement of Alaska salmon fisheries noted many of the positive benefits to the fishery and the state (Heard 2012, this issue) A summary of five case studies provides a rich description of the history, ecological dimensions, and the interplay between emerging scientific information and the creation of public policy in the US Pacific Northwest context, concluding with some practical suggestions on how to effectively contain risks in the future (Kostow 2012, this issue) A cogent argument for developing and implementing a new wild salmon policy in Japan was introduced (Nagata et al 2012, this issue), emphasizing reforms needed to conserve remaining natural reproductive components of Japanese salmon and to restore degraded salmon habitat Theory and empirical studies highlight the risks of hatchery fish eroding the potential for adaptation in wild salmon, and underscores the importance of protecting wild Environ Biol Fish (2012) 94:1–6 populations to achieve sustained harvests of Alaskan salmon (Grant 2012, this issue) Finally, a regional synthesis paper summarizing the state of understanding of ecological interactions across the diverse North Pacific region highlighted efforts underway or planned to increase our understanding and identify needed actions to minimize negative effects in the context of fisheries management (Rand et al 2012, this issue) We were encouraged by the positive testimonials that we received during and following the conference We hope that this special issue will further inspire collaboration among scientists, managers, conservationists, indigenous peoples, fishers, business people, and politicians and serve as a long-term record of the conference Furthermore, our hope is that through collaboration we can increase our understanding and advance the management of ecological interactions so that beneficial interactions can be facilitated and detrimental interactions can be minimized Acknowledgements We would like to thank the many sponsors of our 2010 conference, particularly our main sponsor, the Gordon and Betty Moore Foundation We received additional support from the following entities: US Fish & Wildlife Service, National Oceanic and Atmospheric Administration, Sea Grant College Programs of Oregon, Washington and California, Oregon and British Columbia-Washington Chapters of the American Fisheries Society, National Marine Technologies, Skeena Wild Conservation Trust, Pacific Salmon Foundation, Long Live the Kings, Northwest Power and Conservation Council, Marine Stewardship Council, Deschutes Brewery, Bodhichitta Winery, Pacific Rim Winery, Bridgeport Brewery, Keen, Indian Country Conservancy, Washington State Recreation and Conservation Office, Smith Root Inc., and Icebreaker We would like to particularly thank Wild Salmon Center staff for organizing the event, including Sarah O’Neal, Cathy Kellon, Josh McLaughlin and Rich Lincoln We also wish to thank the many student volunteers that provided much needed assistance during the event We thank the VIP conference speakers, including Spencer Beebe, Ray Hilborn, Jim Martin, Guido Rahr, Don Sampson, Jack Stanford, and Rob Walton We would especially like to thank Tom Brokaw for delivering an inspirational and memorable dinner address at the Portland Art Museum to kick off our conference Finally, we express our gratitude to Roy Stein, for providing a fresh perspective on this issue at the conference, and for ably 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Mechanisms influencing competition between hatchery and wild juvenile anadromous Pacific salmonids in fresh water and their relative competitive abilities Environ Biol Fish doi:10.1007/s10641-011-9906-z Temple GM, Pearsons TN (2012) Risk management of nontarget fish taxa in the Yakima River Watershed associated with hatchery salmon supplementation Environ Biol Fish doi:10.1007/s10641-011-9811-5 Waples RS (1991) Genetic interactions between hatchery and wild salmonids: lessons from the Pacific Northwest Can J Fish Aquat Sci 48:124–133 Yu JN, Azuma N, Abe S (2012) Genetic differentiation between collections of hatchery and wild masu salmon Environ Biol Fish (2012) 94:1–6 (Oncorhynchus masou) inferred from mitochondrial and microsatellite DNA analyses Environ Biol Fish doi:10.1007/s10641-011-9869-0 Zaporozhets OM, Zaporozhets GV (2012) Some consequences of Pacific salmon hatchery production in Kamchatka: changes in age structure and contributions to natural spawning populations Environ Biol Fish doi:10.1007/ s10641-011-9932-x Zhivotovsky LA, Fedorova LK, Rubtsova GA, Shitova MV, Rakitskaya TA, Prokhorovskaya VD, Smirnov BP, Kaev AM, Chupakhin VM, Samarsky VG, Pogodin VP, Borzov SI, Afanasiev KI (2012) Rapid expansion of an enhanced stock of chum salmon and its impacts on wild population components Env Biol Fish doi:10.1007/s10641-0119873-4 Environ Biol Fish (2012) 94:7–19 DOI 10.1007/s10641-011-9906-z Mechanisms influencing competition between hatchery and wild juvenile anadromous Pacific salmonids in fresh water and their relative competitive abilities Christopher P Tatara & Barry A Berejikian Received: 30 July 2010 / Accepted: 10 July 2011 / Published online: 30 July 2011 # Springer Science+Business Media B.V (outside the USA) 2011 Abstract Avoiding negative effects of competition from released hatchery salmonids on wild fish is a primary concern for recovery efforts and fisheries management Several factors affect competition among juvenile salmonids including: (1) whether competition is intra- or interspecific, (2) duration of freshwater cohabitation of hatchery and wild fish, (3) relative body size, (4) prior residence, (5) environmentally induced developmental differences, and (6) fish density Intraspecific competition is expected to be greater than interspecific because of greater niche overlap between conspecific hatchery and wild fish Competition is expected to increase with prolonged freshwater cohabitation Hatchery smolts are often larger than wild, and larger fish are usually superior competitors However, wild fish have the advantage of prior residence when defending territories and resources in natural streams Hatchery-induced developmental differences are variable and can favor both hatchery and wild fish Although all these factors influence competitive interactions, fish density of the composite population (wild + hatchery fish) in relation to habitat carrying capacity likely exerts the greatest influence The extent of competition and C P Tatara (*) : B A Berejikian NOAA Fisheries, Northwest Fisheries Science Center, Manchester Research Station, P.O Box 130, Manchester, WA 98353, USA e-mail: chris.p.tatara@noaa.gov relative competitive ability of wild and hatchery fish can be determined by additive and substitutive experimental designs, respectively, and the limited body of substitutive experiments suggests that the relative competitive ability of hatchery and wild fish is approximately equal when measured as growth Conducting substitutive experiments becomes difficult as the spatial and temporal scales increase Largescale experiments comparing supplemented and control reaches or streams hold some promise for quantifying the effects of released hatchery fish on wild fish behavior, growth and survival Keywords Competition Hatchery and wild Pacific salmonids Freshwater life stage Relative competitive ability Introduction The production of anadromous Pacific salmonids in hatcheries for both harvest augmentation and, more recently, conservation and rebuilding of depressed populations has created conditions where hatchery and wild populations interact at life stages ranging from parr to spawning adults, and habitats ranging from freshwater tributaries to open oceans Of all the potential interactions between hatchery and wild salmonids, competition uniquely and regularly occurs at all life stages and associated habitats, thus raising concerns about the impact of hatchery fish on the management and recovery of wild salmon populations Competition among juvenile salmonids primarily occurs during the time period spanning emergence until smoltification and seaward migration, and takes place in freshwater habitats ranging from tributaries to higher order rivers Competition occurs when multiple organisms exploit a common limited resource and the fitness of at least one is reduced (Birch 1957) Low productivity and loss of freshwater rearing habitat have been identified as factors limiting the recovery of wild salmon populations (McClure et al 2008; Morita et al 2009) and as reasons for initiating hatchery salmon populations (Hilborn 1992) The greater relative productivity of ocean habitat compared to freshwater systems is a major evolutionary pressure driving anadromy in salmonids (Gross et al 1988) Competition in juvenile salmonids occurs through agonistic contests (interference competition) and through depletion of resources (exploitative competition) In freshwater streams, resource limitations coupled with high hatchery fish densities following release suggest competition may strongly affect wild fish during juvenile life stages and constitute an important determinant of lifetime fitness Numerous studies have documented effects of competition between hatchery and wild juvenile salmonids Recent reviews have synthesized much of the existing knowledge of competition between hatchery and wild fish across the entire family Salmonidae (Einum and Fleming 2001; Weber and Fausch 2003; Kostow 2009) Our paper considers only competition that occurs between hatchery and wild anadromous Pacific salmonids from the time the hatchery fish are released until their seaward migration as smolts The intent is to review evidence for key mechanisms that may influence relative competitive ability of hatchery and wild fish and highlight approaches that show promise to separate the hatchery rearing effects from density-dependent processes Indicators of competition for juvenile Pacific salmonids include agonistic behavior (Peery and Bjornn 1996; Riley et al 2005, 2009a), feeding behavior (Riley et al 2005, 2009a), growth (Peery and Bjornn 1996; Weber and Fausch 2005; Yamamoto et al 2008), and survival (Weber and Fausch 2005) Because competition ultimately results in a reduction of fitness for at least one of the competing populations of organisms, it makes sense to select experimental or Environ Biol Fish (2012) 94:7–19 assessment endpoints most closely associated with fitness (Fig 1) The strength of correlation between indicators of competition and fitness impacts varies, and reflects tradeoffs between establishing evidence of competition and its consequences for fitness Measurements of agonistic behavior or habitat use provide evidence that competition is occurring but may reflect transient effects, making it difficult to extrapolate their fitness consequences Experiments that demonstrate displacement from energetically profitable stream micro-habitats or differential rates of food consumption should more strongly reflect impacts on fitness Measured differences in growth rates between competing populations are likely to have a strong correlation with fitness Finally, demonstrating differential survival between competing populations directly measures fitness consequences of competition, but it may be more difficult to design experiments powerful enough to detect such consequences Mechanisms affecting competition between hatchery and wild salmonids can be loosely categorized as (1) ‘population factors’ that affect groups of competing individuals, and (2) ‘individual factors’ that are properties of competing individuals (Fig 2) Population factors include whether competition occurs between members of the same species (intraspecific competition) or different species (interspecific competition), the duration of cohabitation in a common environment, and the population density Individual factors include relative body size of competitors, effects of rearing environment (hatcheries) on behavioral development, and the advantage of prior Survival Growth Food consumption Displacement Habitat use Behavior none moderate strong Relationship between endpoint and fitness Fig Relative relationship to fitness of several common experimental endpoints of competition experiments reported for juvenile salmonids Endpoints with a strong relationship to fitness are preferred over those with weaker relationships Environ Biol Fish (2012) 94:7–19 Fig Six primary factors affecting competition between hatchery and wild juvenile salmonids Factors labeled as “Population Factors” (left side of figure) affect groups of competing individuals, while those labeled “Individual Factors” (right side of figure) are properties of competing individuals The arrows indicate that multiple factors within and between groups can interact to influence competition residence Although we have categorized the factors, and discuss them singly, it is important to recognize that multiple factors can act simultaneously to affect the outcome of competition In this paper, we first discuss six primary factors influencing competition between hatchery and wild juvenile salmon and whether each factor either favors wild or hatchery fish during competition Next, we discuss different experimental designs for studying competition Finally, we estimate the relative competitive ability of juvenile hatchery salmon by summarizing results of published substitutive competition experiments Where competition data is limited for Pacific salmonids our review includes data reported for anadromous salmonids from other regions (e.g., charrs (Salvelinus spp.) and Atlantic salmon (Salmo salar) and brown trout (S trutta) Population factors influencing competition Interspecific versus intraspecific competition Competition between species (interspecific) in native assemblages of anadromous salmonids is minimized because the species occupy somewhat different ecological niches (habitats within a common river system) either spatially or temporally (Hearn 1987; Quinn 2005) Several studies have documented spatial habitat segregation in Pacific salmonids For example, Bisson et al (1988) demonstrated that when juvenile coho salmon (Oncorhynchus kisutch), steelhead (O mykiss), and cutthroat trout (O clarkii) co-occur they use habitat differently and that channel hydraulics (flow and depth) and body morphology determine the habitat preferences of each species Similarly, Yamamoto et al (2010) found that white spotted charr (S leucomaenis) were found exclusively in upstream reaches while masu salmon (O masou) were found in the middle and downstream sections of the same Japanese stream The previous studies document niche segregation among species in salmonid populations where the influence of hatchery fish was minimal In cases where the instream location and distribution of wild Chinook salmon (O tshawytscha), coho salmon, steelhead, and cutthroat trout were monitored before and after smallscale releases of hatchery Chinook and coho salmon, few if any changes in wild fish density, group size, microhabitat use, and size were observed (Riley et al 2004), suggesting the ecological niche of wild fish did not change when hatchery fish were released and low potential for interspecific competition Among-species diversity in traits such as spawn timing and outmigration timing can act to temporally segregate salmonid species within the same river A classic example of temporal separation within a river is the spawning and juvenile residence patterns of Pacific salmon (Chinook) species in the fall, and steelhead spawning in the winter and spring (Brannon et al 2004) When the ecological niches of different salmonid species overlap, intrinsic differences in competitive ability among species may influence the outcome of competition as demonstrated with experimental pairwise contests among four species of wild salmonids (Hasegawa et al 2004) Most experiments using pairwise comparisons of salmonid species are conducted using introduced and native species, but the same type of experiments could be conducted using the species comprising native anadromous salmonid assemblages Because both species and effects of hatchery rearing can influence interspecific competition among hatchery and wild salmonids, it is difficult to generalize whether hatchery or wild fish would be favored Hatchery salmonids released into streams commonly share habitat preferences with wild conspecifics, and consequently have greater potential for niche overlap than would be seen for heterospecifics Hatchery steelhead parr released into replicated fenced stream Environ Biol Fish (2012) 94:343–358 347 more advanced stage compared to other regions, so it was decided that this particular session should focus on presentations on ongoing case studies that emphasize approaches of describing and modeling risks from hatcheries on wild salmon Some of these presentations appear in the form of papers in this special issue (Kostow 2012, this issue; Pearsons and Busack 2012, this issue; Pearsons et al 2012, this issue; Temple and Pearsons 2012, this issue) A panel discussion involving speakers was carried out during the final day of the conference, and we report a summary of key points from that discussion here While salmon enhancement has been described in a very broad context (e.g including habitat restoration) in a number of publications (reviewed recently by Naish et al 2007), for the purposes of the work group discussions, focus was placed specifically on hatcheries and spawning channels (Fig 3) Below, we present summaries from each of the work sessions Salish Sea session Participants in this session identified and discussed key interactions and associated research needs, focusing on issues in the estuarine, nearshore, and marine environments more so than interactions in the freshwater environment (Table 1) The participants chose not to focus on management actions (both current and recommended) Of special concern was the impact that changing environmental conditions may have on marine survival of both wild and hatchery salmon while those fish reside in the Salish Sea and how that affects interactions between the two groups (e.g populations such as coho salmon Oncorhynchus kisutch and resident Chinook salmon O tshawytscha, that use the Salish Sea for a longer period than other species such as pink salmon O gorbuscha and chum salmon O keta, have declined dramatically with indications that marine survival may be an issue) Changes in primary productivity, reduced forage fish populations, and changes to predator/prey species compositions and the sizes of predator/prey populations were referenced as examples The group indicated a long-term need to improve regular monitoring, measuring, and analyzing of the effects of a changing marine environment; for example, participants recommended understanding the population Fig Pacific salmon that occupy open waters of the North Pacific now originate from three distinctly different environments: 1) natural river ecosystems (example is Opala River in Kamchatka Krai, Russian Federation), 2) artificial spawning channels (example is Weaver Creek spawning channel in British Columbia, Canada), and 3) hatchery facilities (example is Osotsubetsu Hatchery on the Kushiro River, Hokkaido, Japan) dynamics of key prey species and bioenergetics, and to use this information to help guide management decisions, such as changes to hatchery release timing, numbers, size at release, and release locations The group also discussed the need for large-scale experiments by manipulating hatchery releases to 348 Environ Biol Fish (2012) 94:343–358 Table A list of key interactions between wild and hatchery salmon in the Salish Sea region identified and discussed by breakout session participations Interactions that were the focus of most of the discussion in the breakout session are identified with an asterisk Some interactions types (left blank in the table) were not elaborated on either pre-conference or during the session discussion These blank cells (identified with a dagger) not necessarily imply that these types of interactions not exist or are of trivial importance Key interactions identified and discussed Freshwater Juvenile / Smolt (Predation) Predation of zero-age listed Chinook salmon by 1, 2, 3-year-old by hatchery steelhead (very little data available) (Competition) Competition between hatchery (i.e Chambers/Skamania steelhead stocks) and wild steelhead smolts Competition between offspring of early emerging Chambers Creek steelhead and later emerging wild steelhead Early emerging fry will have prior residence and body size advantages over later emerging wild fry (Disease) Transmission of Infectious Haematopoietic Necrosis (IHN) virus (Columbia River MD strain) between hatchery and wild stocks (Other) † Estuary/ nearshore/ fiord (Predation)* Predator–prey interactions may be contributing to the poor marine survival of Puget Sound/Georgia Basin steelhead Smolt-to-adult survivals for these populations have declined and remained low since the 1980's and not correlate with smolt-to-adult survivals or abundance of coastal populations.(Predation/Competition)* Limited food resources result in salmonid vs salmonid predation due to a lack of other forage fish (Competition)* Lack of preferred habitat areas (e.g blind tidal channels) and lack of food resources result in poorer conditions for smolts, lowering overall survival (e.g plankton and zooplankton productivity is very patchy both spatially and temporally, limiting production up trophic levels) Increased density of coho smolts in Salish sea result may be related to observed erosion of second year residency and deceases in marine survival This may have a role in dictating winter and second summer behavior/survival of sub-adults Effects may be exacerbated during periods of lower marine productivity (Disease)* Transmission of IHN virus (Columbia River MD strain) between hatchery and wild stocks Warming lower river, estuary and nearshore water temperatures may increase exposure to Vibrio and toxic algae/zooplankton (Other) † Marine (Predation)* Non-native predators consume salmon smolts at higher than normal level (e.g and influx of non-local species such as Humboldt squid) (Competition)* Density dependent survival associated with variable and declining ocean conditions Pearcy, Peterson, Beamish and others have shown a strong correlation between physical and biological ocean conditions and hatchery releases and their subsequent survival Unprecedented recent ocean conditions including years of dead zone/low DO conditions off the coast of Oregon and Washington.Limited food resources in the ocean result in hatchery and wild salmon competing with lower survival of both (Disease) Transmission of IHN virus (Columbia River MD strain) between hatchery and wild stocks (Other) † Adults on spawning grounds (Predation) † (Competition) What is the impact of remote site incubator and other direct release hatchery programs for fall chum salmon on naturally spawning Chinook salmon in Puget Sound and Hood Canal? Fall chum salmon spawn after Chinook salmon and may superimpose a large number of Chinook salmon redds in some streams (Disease) Transmission of IHN virus (Columbia River MD strain) between hatchery and wild stocks (Other) How have reduced spawning escapements affected stream productivity and the ability of streams to support coho and steelhead populations that reside for or more years in freshwater? Well segregated hatchery programs may reduce genetic interactions, but by definition not contribute marine derived nutrients Natural populations expressing limited life-history and genetic diversity are at greater risk, especially in the face of climate change Current harvest management practices utilizing nonselective techniques to target hatchery stocks returning earlier/later than their wild counterpart may impede natural population run-time expansion and thus life history and genetic diversity Environ Biol Fish (2012) 94:343–358 349 Table (continued) Key interactions identified and discussed Overarching Should large numbers of hatchery salmon continue to be released when habitat is a limiting factor for wild populations and food supplies (freshwater and marine) are highly variable, potentially limiting survival of wild fish due to competition? How we match hatchery and wild salmon population sizes to available habitat to maximize survival of both (to allow for recovery of natural stocks and sustainable harvest levels)? How is climate change affecting habitat/food availability (amount, type, timing of availability, location of availability, etc.)? Can salmon adapt? determine whether releasing large numbers of hatchery fish (and at a certain size and time) is: a) leading to competition and predation issues, and/or b) leading to overall reductions in hatchery and wild fish survival if the environment’s carrying capacity is limited To improve the potential for seeing if impacts are occurring, the group suggested looking to regions that have multiple hatcheries releasing large numbers of a particular species, and where those hatchery stocks have similarly depressed smolt-to-adult survival rates They also suggested establishing controls and treatments by comparing effects in different representative areas, or by isolating the work to nearshore comparisons Some members of the group questioned whether attempting such an experiment would lead to any positive results for wild fish, from an environmental carrying capacity perspective, given the significantly lower number of wild and hatchery fish that utilize the Salish Sea compared to historic numbers Basically, if there’s something that bad going on in the estuary/ nearshore/marine environment, it’s likely not going to get much better by manipulating hatchery release numbers Also, the political issues surrounding such an experiment were cited as a concern One specific near-term study that members of the group did feel was worthwhile repeating was a salmon diet assessment performed in the 1970’s (Fresh et al 1981) In the short-term, however, the group focused on the need to answer a basic question: “How have the conditions changed for salmon in the Salish Sea?” They believed this could be achieved via a body of scientists that includes oceanographers and experts on predator and prey species as well as salmon biologists and ecologists Scientists from both the United States and Canada should be included to represent the entire Salish Sea region Such an effort could be partnered with ongoing or past activities, such as the Fisheries and Oceans Canada Strait of Georgia Ecosystem Research Initiative and the work performed by NOAA, including that of the Northwest Fisheries Science Center and NOAA’s Fisheries and the Environment (FATE) program The group suggested that this effort include a robust literature review and retrospective analysis of existing data and trends in marine survival for salmon and prey and predator species (including comparisons to hatchery release numbers and wild juvenile population sizes) They also suggested that the convened scientists consider how hatcheries can be used to inform this discussion Results of this effort could be discussed at local conferences such as the Puget Sound Georgia Basin Ecosystem Conference, American Fisheries Society Conference, the Salmon Ocean Ecology meeting, or the annual event put on by the Institute of Ocean Sciences The group also briefly discussed concerns about the spread of the Columbia River strain of Infectious Haematopoietic Necrosis (IHN) virus that is currently affecting coastal Washington wild and hatchery steelhead O mykiss stocks Genotyping of subclades has demonstrated a direct relationship between viral strains emerging in Columbia River basin hatcheries and subsequent spread to the basin and onward to the Washington coast Members of the group commented that a cumulative effort is needed by Columbia River basin managers to reduce the potential for amplifying the virus The group recommended that a dialog be initiated as soon as possible between hatchery managers in the Columbia River basin (Idaho, Oregon and Washington) and hatchery managers outside of the basin to develop mutually-needed solutions Members also commented that we need to improve our understanding of how climate change may 350 Environ Biol Fish (2012) 94:343–358 influence disease risks, predation, competition and environmental carrying capacity (e.g vibriosis, a bacterial disease affecting salmonids in saltwater, has been shown to intensify at temperatures exceeding 15.6°C) Western Pacific session This session was composed mostly of delegates from Russia and Japan The session opened with a series of focused presentations We refer the reader to the papers that appear in this volume to become Table A list of key interactions between wild and hatchery salmon in the Western Pacific region identified and discussed by breakout session participations Some interactions types (left blank in the table) were not elaborated on either pre-conference familiarized with the topics presented (Kaev 2012, this issue; Miyakoshi et al 2012, this issue; Yu et al 2012, this issue; Zhivotovsky et al 2012, this issue; Zaporozhets and Zaporozhets 2012, this issue) It was clear from the presentations and initial discussions that very little directed research has been conducted on ecological interactions between wild and hatchery salmon in this region A number of key interactions thought to be important in the region were discussed and are identified in Table Much of the discussion in this session was focused on listing recommendations for future research Below are key recommendations that came out of this session: or during the session discussion These blank cells (identified with a dagger) not necessarily imply that these types of interactions not exist or are of trivial importance Key interactions identified and discussed Freshwater Juvenile / Smolt (Predation) Involving chum, pink and coho, and perhaps other species Potential ecological impacts Large hatchery releases may attract predators Intra-specific predation between wild and hatchery individuals does not occur given similar sizes (Competition) There is concern, but no compelling evidence, that hatchery salmon are replacing wild salmon populations (by lowering survival of wild salmon) It is thought that spatial/temporal overlap between wild and hatchery salmon is low Competition for food may be occurring (Disease) Potential risk of disease transmission from hatchery fish to wild fish Hatchery fish appear to suffer higher incidence of disease compared to wild fish (Other) Pollution from hatcheries may be affecting rivers, but there is little direct evidence of this Estuary/ nearshore/ fiord & Marine (Predation) † (Competition) Intra- and inter-specific, density-dependent effects may be occurring (Disease) † (Other) † Adults on spawning grounds (Predation) None (Competition) It is thought to occur, particularly breeding interactions, resulting in hybridization Straying of hatchery fish into wild salmon rivers is likely occurring Pink salmon in the Russian Far East are thought to be subjected to higher straying than the North American populations of this species In particular, the pink salmon that have been released from hatcheries may interbreed with wild pink salmon far away from the home hatchery, and vice versa (Disease) † (Other) There may be a positive interaction between large, hatchery-supported salmon runs and the level and intensity of poaching (resulting in potentially unsustainable high harvest rates) in the Russian Far East Some argued this was not relevant to the topic of ecological interactions Transfer of fertilized eggs to distant hatcheries may lead to extensive gene flow from genetically distinct donor populations into wild populations that are in close proximity to the recipient hatchery Environ Biol Fish (2012) 94:343–358 i ii iii iv v vi vii viii ix x Establishment of a new international research committee that can address Pacific salmon sustainability in the region Development of a collaborative, international database for ecological, biological and genetic research focused on ecological interactions Hatchery salmon need to be marked and tracked, specifically for pink salmon that are thought to exhibit high, and long-distance straying Research on carrying capacity of freshwater and marine ecosystems Establish long term monitoring of escapement and natural reproduction Organize and collect biological and genetic data from hatcheries and spawning grounds to understand population structure and gene flow Introduce new genetic markers (SNPs) to help distinguish wild and hatchery salmon from field samples and archive collections Develop monitoring and modeling methods for the adaptive management of Pacific salmon Develop models that include selective reproduction in hatcheries, selective catch, and straying Initiate studies of fitness in wild populations of pink and chum salmon In addition, there was some discussion on the importance of management reform to better address interactions between wild and hatchery salmon Attendees agreed it would be beneficial for hatchery programs to be explicit about their goals Explicit goals of hatchery programs is generally lacking in this region There was some discussion on the concept of zone management where populations of wild and hatchery salmon can be managed separately (see Nagata et al 2012, this issue) There was also an emphasis on the importance of developing new policies that will allow protection of wild salmon while maintaining sustainable fisheries supported by hatchery programs North America West Coast estuary and shelf ecosystems This session was unique in that it did not specifically address a particular region, but rather focused on a 351 particular ecosystem type (estuaries and continental shelf habitat) The discussion in this session focused on the unique properties of these ecosystems and the challenges in conducting research on ecological interactions in the estuary and marine environment Here we provide a broad summary of the unique attributes of these ecosystems, followed by specific recommendation for future research West Coast shelf and estuary habitats are unique from other regions considered in several important ways, which potentially influence both opportunities and outcomes for ecological interactions between wild and hatchery fish First, because all salmon within a particular river system must pass through the estuary to reach the ocean, fish from geographically distant parts of a basin have opportunities to directly interact in the estuary Because of this, fish released from hatcheries that are genetically or physically isolated from wild populations may share common habitats in the estuary with potentially negative consequences for wild and/or hatchery salmon Similarly, shelf habitats are occupied by juvenile salmon originating from a large number of basins, again providing opportunities for interactions between geographically distant groups of wild and hatchery fish Furthermore, because of inconsistent marking of hatchery fish between drainages, basins, regions, or species, the origin (wild or hatchery) of juvenile salmon caught in estuarine and especially shelf habitats is often difficult to discern; in most cases, unclipped fish represent a mixture of both wild and unmarked hatchery populations Second, unlike most freshwater systems, juvenile salmon, either wild or hatchery, are a minor component of shelf ecosystems and may be a minor component of estuarine ecosystems Salmon occupying estuarine and shelf habitats are also typically undergoing high mortality during the critical transition from freshwater to marine environments This mortality is largely dependent on environmental variation influencing factors such as prey availability and predator abundances, and has little to with hatchery origin or practices In this respect, wild and hatchery salmon in estuarine and shelf habitats are more likely to be influenced by natural variation in the ecosystems upon which they depend than by the factors associated with hatchery strategies (e.g., number, size, or timing of releases) 352 The session participants generated the following list of recommendations for estuarine and shelf environments: i Mark all hatchery fish so that origin of salmon (wild or hatchery) can be determined ii Determine the degree of spatial, temporal, and ecological overlap between wild and hatchery salmon throughout the estuarine/marine phase Is there evidence for density-dependent mortality or limits to growth and production at specific times or locations, including energetic constraints to fish performance? iii More attention needs to be placed on predator effects related to hatchery programs Are hatchery releases concentrating predators in estuarine or shelf ecosystems? Are all species/life history types affected equally? iv Vary hatchery production in order to conduct large controlled experiments to test hypotheses concerning interactions between wild and hatchery salmon, including responses to variable estuarine/ocean conditions v More work is needed to establish reference conditions and determine the applicability of behavioral or ecological interactions between freshwater, estuarine, and marine habitats What can or cannot be inferred from present conditions? What context we use for setting management goals? vi We need to consider sampling scale explicitly What are we missing with traditional sampling methods, and how does it affect our perception? vii Future research needs to be holistic and consider life stage connections and employ integrative methods to assess the performance of individual fish We cannot fully understand hatchery-wild interactions when viewing either particular habitat types (e.g freshwater, estuarine, shelf, and ocean) or performance metrics (e.g., growth, food habits, and physiological indicators) in isolation Alaska/North Coast British Columbia While participants in this session spent some time identifying key ecological interactions and the need for research, much of the discussion centered on Environ Biol Fish (2012) 94:343–358 appropriate management scenarios given our current ecological understanding Most session participants felt that prolonged discussion of research needs was not an efficient use of the time allotted, and that most of these topics are, if not well-understood, then at least well-known Some of the key interactions raised in discussion are listed in Table Most participants were eager to get to the much harder discussion of risk management and possible management recommendations, given what we already know (or think we know) A somewhat contentious debate ensued regarding environmental carrying capacity and whether hatcheries are negatively impacting wild stocks in Alaska and Northern British Columbia In fact, there were differences in attitudes between Canadian and Alaskan participants, with the Canadians generally more cautious about hatcheries, and the Alaskans more positively inclined towards them Many participants from Alaska shared the view that hatcheries are not having any measurable adverse effects, and that hatcheries pose a small threat compared with habitat loss (e.g logging, agriculture, dams, urban development) prevalent in the United States (exclusive of Alaska) and the southern mainland of British Columbia It was also stressed that hatcheries are vital to sustaining and growing the Alaskan fishing sector Differing opinions regarding hatcheries among participants led to a discussion of other pressing research needs, including the accurate quantification of ecologic, economic and social impacts of hatchery production Some attendees focused on the economic benefits of hatchery production, and one participant asked whether contemporary fishing communities could even survive in the absence of large-scale hatcheries Others were curious about whether there would be ancillary benefits to restricting production, and wondered if we need to move beyond simple input/output analysis using traditional economic models to take into account ecological and social factors For example, beyond economic costs and benefits, what is the impact of hatchery production on the long-term resilience of both wild stocks and local fisheries and fishing communities? Are hatcheries part of a fishery system that is resilient to climate and market shifts? The conversation was rounded out by a brief discussion of the lack of information about the potential impacts of Alaskan hatchery production on other seafood markets Environ Biol Fish (2012) 94:343–358 Table A list of key interactions between wild and hatchery salmon in the Alaska and North Coast British Columbia region identified and discussed by breakout session participations Some interactions types (left blank in the table) were not 353 elaborated on either pre-conference or during the session discussion These blank cells (identified with a dagger) not necessarily imply that these types of interactions not exist or are of trivial importance Key interactions identified and discussed Freshwater Juvenile / Smolt (Predation) † (Competition) Wild juveniles may be at a competitive disadvantage if hatchery fry/smolts are larger when released into these systems What is the carrying capacity of freshwater systems? How wild/hatchery hybrids or pure hatchery stray offspring compete with wild juveniles? (Disease) Infectious Haematopoietic Necrosis (IHN) virus is a concern (Other) † Estuary/ nearshore/ fiord (Predation) Are returning pink salmon adults in Prince William Sound (PWS) preying on pink salmon juveniles (wild and hatchery)? Are hatchery pink salmon in PWS keeping herring populations depressed (through predation or competition)? (Competition) What are the competitive interactions between wild and hatchery fish in the nearshore environment? (Disease) † (Other) † Marine (Predation) † (Competition) Factors controlling marine productivity are a huge unknown in southeast Alaska, PWS, and Georgia Strait We just don’t know what impact releasing huge numbers of hatchery juveniles is having on the marine system What are the offshore interactions between wild and hatchery fish and between species (eg., hatchery pinks and wild sockeye)? (Disease) † (Other) † Adults on spawning grounds (Predation) † (Competition) Density-dependent interactions: spawning ground competition can lead to high stress levels, which can in turn lead to egg retention and early mortality There is spatial competition for redd sites, and disruption of redds by later-arriving fish We know almost nothing about mate selection, or differences in competitive ability/aggression between wild and hatchery fish (Disease) † (Other) Straying is a big issue: it impacts wild stock escapement estimates and adds to mixed stock fishery impacts (which we understand fairly well) It also leads to spawning ground competition, and potential introgression and long-term fitness and productivity effects, which we don’t have a good handle on What are the effects on fitness, genetic diversity and productivity of wild stocks? Overarching Climate change: how will increasing temperatures, changing weather patterns, changing freshwater systems, and ocean acidification impact all these relationships? How can we hope to grasp this when we don’t understand the system as it is today? A number of attendees believed there is currently enough scientific data to be able to run risk analyses that incorporate uncertainty The group agreed that formal risk assessments could and should be performed for various fisheries, modeling different scenarios of climate change, carrying capacity, production levels, gear types and run timing While these could be performed in a computer environment, there was also discussion of the need for large-scale natural experiments involving reductions of releases in alternate years or variations of species released There was general agreement around the room that we are currently running an uncontrolled experiment across the North Pacific, and that a controlled experiment in one or several regions might give some real insight into impacts of hatchery fish on wild stock production This was greeted much more positively from the British Columbia participants than the Alaskans, primarily because many British Columbia stocks are depleted at this point, and the economic forces in favor of hatcheries are weaker than in Alaska One theme that emerged several times during this session was the overall impact of the number of salmon 354 Environ Biol Fish (2012) 94:343–358 being released into the North Pacific, which includes production by Russia and Japan Participants agreed that the numbers of chum salmon and pink salmon being released by these two countries is very large, and in the future will likely far outweigh production in the Eastern Pacific It was emphasized that although hatchery releases in Alaska may not by themselves be deleterious to wild stocks, Alaska is not operating in a vacuum Releases in Southeast Alaska and the Gulf of Alaska may impact wild salmon in other regions, and large releases of chum salmon in the Western Pacific may in turn impact catches in the Gulf of Alaska One participant stressed that Russia is looking to Alaska as an example of successful enhancement, with little consideration of the ocean-wide impacts of large-scale production Understanding the total carrying capacity of the North Pacific (and how this varies across time) arose as a vital information need, and management responses to this issue should include continuing multilateral negotiations regarding an overall cap on production (e.g a cap and trade system) Several participants stressed that we shouldn’t avoid difficult conversations or management decisions by using the excuse that we don’t yet know enough Some argued that we already have enough general knowledge about salmonid systems, and some idea about threshold effects; therefore, we should be acting proactively with the precautionary principle in mind rather than waiting for more data or an unequivocal collapse This perspective led to a discussion of management recommendations, reproduced here: i ii iii iv v vi vii Reducing hatchery production and/or placing caps on production Releasing species that have better homing abilities to reduce straying Releasing hatchery fish at older ages to reduce early life-stage competition with wild stocks Restructuring or repositioning terminal harvest areas to alleviate mixed stock fisheries and straying Siting release locations to minimize freshwater and nearshore competition with wild stocks, and to improve homing success Making decisions concerning species releases based on potential competition for food resources with wild fish Releasing species that are of higher value (i.e releasing sockeye or Chinook instead of pinks or chums – this alleviates straying and marine competition issues, and you can release fewer fish and make the same amount of money) viii Tying hatchery practices/production levels to climate conditions ix Establishing refuges for wild salmon x Promotion of adaptive management, emphasizing the importance of experimental manipulations xi Establishing management objectives and best practices for all hatcheries to ensure that goals not shift over time xii Establish system of cap and trade across the North Pacific as a means to regulate hatcheries releases xiii Establish clear goals for hatchery programs, and emphasize the importance of monitoring and evaluation Columbia River session This session differed from the other regional breakouts in that it consisted entirely of presentations and related discussion surrounding the general theme of “Moving from theory to practice”, with a primary focus on freshwater aspects of risk assessment, risk reduction and adaptive management approaches related to wildhatchery ecological interactions These presentations drew heavily from Columbia River basin case studies and many of these talks are presented as manuscripts in this volume (Kostow 2012, this issue; Pearsons and Busack 2012, this issue; Pearsons et al 2012, this issue; Temple and Pearsons 2012, this issue) Rather than session participants discussing a set of predefined questions and reporting back in plenary session, the presenters in this session assembled in a panel discussion the following day to present their perspectives on two questions related to the general risk management theme: i What are the most critical scientific or management uncertainties regarding ecological interactions between wild and hatchery fish; and ii What are the best approaches to address these uncertainties? The presenters answered these questions in the context of topical areas from their presentations but a number of common themes emerged and are summarized here Environ Biol Fish (2012) 94:343–358 A number of disease related uncertainties were highlighted, nested within a broad observation that managers simply not have sufficient data and knowledge about disease transmissions between wild and hatchery fish For example, a better understanding of disease ecology in the wild would help determine how practices like extended rearing and changed time at release could affect pathogen propagation and transmission More comprehensive marking, larger scale studies and use of better modeling approaches to predict disease effects were offered as example approaches to address disease uncertainties The unstudied interaction mechanisms and locations related to predation were identified as important uncertainties in the specific context of ‘indirect predation’ Specifically what is the effect of hatchery releases on predator population dynamics, e.g., what are the functional, numerical and long-term responses of predators to the abundance of hatchery-origin prey and how can this indirectly affect wild populations? Salmon can have strong ecological interactions and impacts on other species, yet multi-species evaluations are rarely conducted at a full hatchery production scale The approach needed is to perform formal ecological risk assessments and establish robust risk containment monitoring programs within a multi-species framework Costs and benefits of hatchery programs must be evaluated in ways that include ecological perspectives and metrics The uncertainty of density dependent effects of hatchery juveniles and adults in the freshwater environment and shared river/marine migration corridors was highlighted, especially the potential effects on wild fish population dynamics when large numbers of hatchery fish intermingle with small numbers of wild counterparts What kind of density dependent depression in wild fish survival might occur, for instance, when hatchery fish might outnumber wild fish by five- to tenfold or where hatchery fish could exceed the natural carrying capacity by a similar magnitude? The panel identified a need for enumeration and evaluation programs, with institutional funding commitments, that could establish long-term data sets to examine these questions Another approach offered for finding such answers more quickly was the experimental manipulation of hatchery releases at large 355 production and spatial scales Audience discussion explored the political and institutional challenges of finding support for significant manipulations in the numbers of hatchery fish released inherent in such system experiments Complementary ways to frame and potentially evaluate these uncertainties include examining the community and population level impacts of single hatcheries throughout their life cycles, and also assessing the cumulative impacts of multiple hatchery programs, considering that most assessments focus on particular components of single hatcheries No one particular organization can address questions successfully at broader scales, simply due to the cost, the need for collaborative thinking and implementation of programs, policy and funding If part of the approach for addressing multi-scale uncertainties will require rethinking current paradigms of static release locations and numbers of fish annually, then the organizations involved in funding and managing these programs will need to invest in robust evaluation and adaptive management strategies together Uncertainty will always exist with hatchery programs and their impacts on wild populations, but in some cases existing populations are sufficiently depleted that managers simply not have enough time to perfectly understand how to resolve uncertainty Rethinking the current management paradigms of static programs while taking some risks in implementing adaptive strategies (whose success cannot be guaranteed) will be necessary to address ecological interaction issues Discussion The regional work sessions summarized here represent the first broad, international effort to convene experts and stakeholders to discuss an important, emerging issue related to identifying, describing and reducing risks from salmon hatchery programs across the North Pacific While hatcheries have been touted as a measure to restore wild salmon populations and establish more productive and stable fisheries, the potential negative ecological effects on wild populations has received scant attention The overall aim of the conference was to stimulate discussion on what we currently know about ecological risks from hatchery programs on wild salmon, 356 identify key knowledge gaps, and chart a course for the future to increase our knowledge and begin to discuss new approaches to hatchery and fishery management to reduce these risks While each work session was presented with the same set of questions, the discussions and the products out of each session were unique Much of this can be explained by understanding the historical context of research and management efforts at play in each region For example, there have been a number of case studies and research efforts conceptualized, planned and implemented in the Salish Sea and the Columbia River on wild and hatchery salmon interactions, and hence the focus of these sessions were on filling research gaps specific to these regions and emphasizing the importance of collaboration among biologists and management entities Conversely, participants in the Western Pacific session recognized early that very little effort has been devoted to identifying ecological interactions as a critical issue in contemporary salmon management, and the scale and magnitude of wild and hatchery salmon interactions is poorly understood and not fully appreciated Thus, much of that session was focused on the need to establish a working group to help spearhead a new initiative throughout this region, emphasizing active international collaboration and the need to develop information on basic genetics and salmon biology to serve as a foundation for future work Those working in the North America Shelf and Estuarine work session cast a wide net to encompass a broad spectrum of research questions and existing gaps in our understanding of interactions occurring during the coastal marine life history stage of salmon, emphasizing all along the need to work toward a broad synthesis The pressing need to explore the socio-economic dimensions of wild and hatchery salmon interactions served as the focal point of discussion in the Alaska/North Coast British Columbia work session, capitalizing on the presence of a diverse set of attendees in that session, including aquaculture corporation representatives, conservationists and resource agency staff A number of attendees in this session pressed the idea that we can move forward with an eye toward reform based on existing scientific knowledge and understanding While the explicit connections between science and management can be intractable, we feel substantive progress was made in each Environ Biol Fish (2012) 94:343–358 group given the state of understanding of this topic in each region As we point out above, one of the important broad outcomes from the work sessions was a deeper appreciation of differences between regions, and the level of stakeholder awareness and research focused on the issue As identified early by the conference steering committee, there is heightened awareness and some directed progress in answering key research questions related to ecological interactions in the Columbia River A number of case studies now exist, and there has been marked progress in developing tools to quantify and manage risks associated with specific hatchery programs, including ones described in this special issue (Pearsons and Busack 2012, this issue) It is interesting to note that NOAA Fisheries has recently finalized a draft of an Environmental Impact Statement (EIS) on federallysupported hatchery programs in the Columbia River basin that includes explicit accounting of ecological effects of hatchery programs on wild salmon (http:// www.nwr.noaa.gov/Salmon-Harvest-Hatcheries/ Hatcheries/MA-EIS.cfm) This is contrasted with the Western Pacific region, where, despite significant investment in hatchery programs, there is less awareness and focused research on the potentially harmful effects of hatcheries on wild salmon populations It is important to note, however, that important steps are currently being taken to develop more focused field research programs in both Japan and Russia to begin to address this knowledge gap (Kaeriyama et al 2012, this issue; Kaev 2012, this issue; Miyakoshi et al 2012, this issue; Nagata et al 2012, this issue; Yu et al 2012, this issue; Zaporozhets and Zaporozhets 2012, this issue; Zhivotovsky et al 2012, this issue) One of the key issues discussed within the work sessions was the differences among the cultured species across regions and the overall aim or objective of regional hatchery programs As one can clearly glean from Fig 1, focus in the US Pacific Northwest and British Columbia is on Chinook salmon and coho salmon hatchery programs, while the emphasis in Alaska, Russia and Japan has been on pink salmon and chum salmon hatchery production While the aim of US Pacific Northwest hatchery programs includes a mix of conservation and fisheries enhancement goals, programs in Russia, Japan and Environ Biol Fish (2012) 94:343–358 Alaska are nearly all focused on expanding and stabilizing fisheries There were a number of cautionary words expressed in the work sessions aimed at avoiding generalizations regarding hatchery risks, as each species and hatchery program presents a unique situation that demands a more nuanced approach for addressing risks While we see evidence of marked progress on research addressing the issue of wild and hatchery interactions and some nascent efforts at reforming hatchery programs to reduce risks in particular rivers and regions, it is clear that little attention has been placed at the macro-, North Pacific Basin scale While some work sessions addressed our level of understanding of competitive interactions in shared, international waters of the North Pacific (particularly the Alaska/North Coast BC and Western Pacific sessions), it is clear that little progress has been made on bi- or multi-lateral agreements to manage or regulate hatchery production with an eye toward avoiding density-dependent effects on growth and survival in estuarine, shelf, and marine waters (Holt et al 2008; Ruggerone et al 2010; Kaeriyama et al 2012, this issue; Ruggerone et al 2012, this issue) Two important issues were discussed that have direct relevance to this topic In the Western Pacific session, an idea was introduced to establish an international research council (potentially involving Russian, Japanese and Korean representatives) that would be in a position to oversee research efforts addressing salmon sustainability in this region, including a charge to examine the role of hatcheries Specific recommendations were discussed to help facilitate research collaboration among the countries, including assisting in sample and data sharing The other important issue raised was the value of instituting a cap and trade system to regulate hatchery releases at the scale of the North Pacific The Alaska/North Coast British Columbia working group discussed the potential benefits, and the significant challenges, of reaching agreement at the international level that could potentially limit hatchery production to avoid negative effects to salmon and the ecosystems that support them We feel these are two very interesting, provocative ideas that are worth pursuing While the majority of the public likely perceives a salmon raised and released into the wild at a young 357 age as an obvious, proactive measure to benefit the salmon resource, discussion in all the work sessions emphasized our emerging understanding of potential risks to wild salmon from these practices As a way to explore this issue of substitutability of hatchery salmon for wild salmon, I (PSR) commissioned an image of wild masu salmon (O masou) that required digital alteration to remove the adipose fin from one (the larger) of two wild masu (Fig 4) While clipping adipose fins is a common practice in North America to externally mark hatchery fish prior to release, this is not practiced commonly in the Western Pacific region where masu are endemic Indeed, culturing this species for fisheries enhancement has been largely unsuccessful in Japan While the image conspicuously adorned the conference program, web banners and other conference materials, I am not aware of anyone that noticed anything peculiar This speaks to the complexity and challenges of this particular issue In many cases, differences between wild and hatchery salmon may be very subtle and are often overlooked, but ecological effects can be profound and significant We hope this summary serves as an important step forward in addressing risks from hatchery programs to help conserve wild salmon Fig Image of masu salmon O masou that served as a brand for the State of the Salmon Conference held in Portland during 4–7 May 2010 The image was digitally manipulated to remove the adipose fin on the largest individual (indicated by a white arrow) The alteration of the image went unnoticed This exercise was undertaken to demonstrate how differences between wild and hatchery salmon are often subtle, but interactions and effects can be significant Photo credit: Anatoly Semenchenko 358 Acknowledgements We would like to thank all those individuals that contributed directly to discussions in the work sessions that were an integral part of the 2010 State of the Salmon Conference on Ecological Interactions between Wild and Hatchery Salmon held in Portland during 4–7 May 2010 We would also like to thank a number of individuals that helped organize these breakout sessions, particularly Sarah O’Neal, Pat Corcoran, Judy Gordon, Brian Allee and Erica Valentine We would also like to acknowledge the work of Josh McLaughlin and Amber Gladieux for producing Fig and the regional maps displayed in each of the work sessions rooms PSR would also like to thank Lori Alexander Howk for producing the digitally altered image of the wild masu salmon that appears as Fig in the manuscript References Araki H, Cooper B, Blouin MS (2009) Carry-over effect of captive breeding reduces reproductive fitness of wild-born descendants in the wild Biol Lett 5(5):621–624 Fresh KL, Cardwell RD, Koons RR (1981) Food habits of Pacific salmon, baitfish, and their potential competitors and predators in the marine waters of Washington, August 1978 to September 1979 Wash Dep of Fish Prog Rep 145:58 Holt C, Rutherford MB, Peterman RM (2008) International cooperation among nation-states of the North Pacific Ocean on the problem of competition among salmon for a common pool of prey resources Mar Policy 32(4):607–617 Kaeriyama M, Seo H, Kudo H, Nagata M (2012) 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DNA analysis Environ Biol Fish doi:10.1007/s10641011-9869-0 Zaporozhets OM, Zaporozhets GV (2012) Some consequences of Pacific salmon hatchery production in Kamchatka: changes in age structure and contributions to natural spawning populations Environ Biol Fish doi:10.1007/ s10641-011-9932-x Zhivotovsky LA, Fedorova LK, Rubtsova GA, Shitova MV, Rakitskaya TA, Prokhorovskaya VD, Smirnov BP, Kaev AM, Chupakhin VM, Samarsky VG, Pogodin VP, Borzov SI, Afanasiev KI (2012) Rapid expansion of an enhanced stock of chum salmon and its impacts on wild population components Environ Biol Fish doi:10.1007/s10641-0119873-4 Environ Biol Fish (2012) 94:359–361 DOI 10.1007/s10641-011-9945-5 ERRATUM Erratum to: An overview of salmon enhancement and the need to manage and monitor natural spawning in Hokkaido, Japan Mitsuhiro Nagata & Yasuyuki Miyakoshi & Hirokazu Urabe & Makoto Fujiwara & Yoshitaka Sasaki & Kiyoshi Kasugai & Mitsuru Torao & Daisei Ando & Masahide Kaeriyama Published online: 16 November 2011 # Springer Science+Business Media B.V 2011 Erratum to: Environ Biol Fish DOI 10.1007/s10641-011-9882-3 Unfortunately, wrong images were published for Fig 1A and Fig 2A, and should appear as shown in this paper The online version of the original article can be found at http:// dx.doi.org/10.1007/s10641-011-9882-3 M Nagata (*) : Y Miyakoshi : H Urabe : M Fujiwara : Y Sasaki : K Kasugai : M Torao : D Ando Salmon and Freshwater Fisheries Research Institute, Hokkaido Research Organization, Eniwa, Hokkaido 061-1433, Japan e-mail: nagata-mitsuhiro@hro.or.jp M Kaeriyama Faculty of Fisheries Science, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan 360 Environ Biol Fish (2012) 94:359–361 Fig Long term changes in annual commercial catch, hatchery catch and stocked juveniles of chum salmon in Hokkaido Island (a), location (solid line) of streams stocked juveniles (b) and commercial catch for each region in Hokkaido, Japan (c, d) Environ Biol Fish (2012) 94:359–361 361 Fig Long term changes in annual commercial catch, hatchery catch and stocked juveniles of pink salmon in Hokkaido Island, Japan (a), and location (solid line) of streams stocked juveniles (b) [...]... when combined with the release of large numbers of hatchery yearlings (> 0.25 M) may result in the loss of a high proportion of the number of wild subyearling salmonids produced Reducing the number of hatchery fish released can decrease the estimated number of subyearlings consumed for a given predation rate (Fig 3) This is a very effective means to reduce the number of subyearlings consumed by hatchery... associated with the counts of residuals in each stream However, they do provide estimates of the relative abundance of hatchery residuals and similarly sized wild fish We used 2×2 contingency table analyses (Zar 1984) to test the null hypothesis that the frequency of fish in each of two body size categories (100–200 mm or >200 mm) was independent of the frequency of the two categories of fish observed (hatchery... subyearlings/hatchery fish and a release of 0.5 M hatchery fish would result in 13 846 subyearlings being consumed in a single day The term b h= bt in this model is largely out of the control of natural resource managers The biology and ecological setting of piscivorous hatchery fish dictates the number of feeding hours in a day The gastric evacuation rate is mainly a function of water Fig 3 Subyearling salmonids... competitive ability of hatchery fish; WW = average response of wild fish alone (control); WH = average response of wild fish with hatchery fish (treatment); W = average response of wild fish; and, H = average response of hatchery fish There are three possible interpretations of the calculated RCA value When the RCA