Getting it Right: Contemporary Approaches to Captive Rearing and Release for Recreation, Restoration, and Recovery: Part I

Captive rearing is a common tool in fisheries and wildlife management, and applications include supporting recreational and harvest-based fishing, hunting, and trapping sectors; restoration and recovery of declining populations; rehabilitation of displaced or injured animals; and outreach and education. Implementation occurs via a variety of vectors: zoos, aquariums, hatcheries, rehabilitation centers. Outcomes range from wild supplementation or release programs to refugia maintaining individuals or populations entirely in captivity. Despite the multi-faceted role that rearing programs play in management, wild populations exposed to captively-raised cohorts may experience altered performance and even transgenerational shifts in variation. Successful application relies on continued efforts to improve processes, protocols, and decision-making. With varied objectives and emerging challenges, the captive-rearing community must apply rapidly advancing technologies and techniques to meet goals and targets that are often moving while also supporting interests of stakeholders across the conservation spectrum and ensuring the health and persistence of fish and wildlife communities. This symposium aims to build bridges between aquatic and terrestrial agencies and missions to ensure that efforts are maximized and outcomes enhanced. We ask that authors submit papers revolving around one or more of the following topics: • Descriptions of advancements in genetic management and techniques fostering improved outcomes. • Descriptions of means to enhance or enrich captive environments which lead to shifts in performance. • Strategies or tactics to acclimatize individuals or populations either for release into the wild or for introduction to captivity. • Strategies or tactics to reduce domestication of captive animals. • Efforts to target fitness or improve performance in wild release or supplementation programs. • Means to manage, diagnose, treat, or prevent disease outbreaks and pathogen exchange. Abstracts for presentations are solicited from policy and management agencies, fish and wildlife industries, non-governmental organizations, technology-partners, research institutions, citizen-scientists, academia (including students), and other stakeholders.

8:00AM Getting It Right: Captive Rearing in the 21st Century
  Nathan Wilke
Captive rearing has long been a tool for species conservation and its utility has never been more important. In fact, some researchers suggest that 2,000-3,000 terrestrial species alone will need to be reared in captivity in the next 200 years. While numerous success stories have resulted from captive rearing efforts, the tool is often subject to criticism. In order to continue success in captive rearing programs, it is critical that managers and researchers work together to identify clear thresholds for success, apply research-based methods to evaluate contemporary protocols, employ the latest available technology to meet objectives, and communicate successes and advances to the conservation community as a whole. This is true for programs aimed strictly at supplementation to those aimed at maintaining valuable genes, and the myriad outcomes in between. The author provides a broad look at some of the challenges facing captive rearing, and some of the historical and contemporary efforts to overcome those challenges. This introductory talk serves as a kickoff to a valuable and important Symposium to build connections in the captive rearing community across multiple sectors, academic interests, and conservation goals.
8:20AM Canceled Talk
8:40AM Genetics As a Tool for Conservation Hatcheries
  Jennifer Von Bargen
Anthropogenic activities and natural environmental events have impacted many species. The winter run Chinook salmon (Oncorhynchus tshawytscha) found in the Sacramento River, California is one of these impacted species. Two of the dams built on the Sacramento River effectively eliminated a large portion of the spawning habitat for the winter run Chinook salmon, Shasta Dam (1945) and Keswick Dam (1950). The winter run Chinook salmon were listed as threatened under the U.S. Endangered Species Act in 1989 and upgraded to endangered in 1994. The United States Fish and Wildlife Service in 1997 built Livingston Stone National Fish Hatchery at the base of Shasta Dam to help propagate winter run Chinook salmon with conservation as its main goal. Conservation of genetic resources and the use of genetic tools to monitor this species played important roles in shaping the program. Genetic analysis using pairwise estimates of relatedness has helped hatchery staff reduce the chance of spawning related individuals. Over time the hatchery managers have continued to make adjustments in their culture practices to compensate for changes in the environment outside the hatchery. Genetic data continues to inform hatchery managers and play a key role in recovery actions for this endangered species.
9:00AM Applied Conservation Genetics at the Lahontan National Fish Hatchery Complex
  Corene Jones, Lisa Heki, Mary M. Peacock
The Lahontan National Fish Hatchery Complex maintains a broodstock of a unique genetic strain of federally threatened Lahontan cutthroat trout. Extirpated from their native range in the 1940s but rediscovered in the 1970s as an out-transplanted population, these fish represent the large, lacustrine strain native to ancient Lake Lahontan. Over a fifteen year period and in partnership with the University of Nevada, Reno, the Complex developed a genetically sound captive broodstock from this rediscovered population while at the same time advancing hatchery techniques in preserving genetic integrity. Using neutral nuclear microsatellite loci and pairwise mating matrices, our current genetic management program has resulted in increases in heterozygosity and maintenance of rare alleles in both broodstock and production fish. To refine genetic management of this important broodstock we are in the process of integrating single nucleotide polymorphism technology into development of future mating matrices. Concurrent development of a cryopreservation program to collect and store milt from potential wild broodstock donors will further preserve genetic diversity in this iconic native trout.
9:20AM Feralization: Restoration, Rehabilitation, Invasion, and the Establishment Process for Domesticated Organisms
  Quenton Tuckett, Jeffrey Hill, Michael Kinnison, Zachary Wood
The scale and pace of fish domestication has reached unprecedented levels, the degree of which varies from the formation of new species to more modest changes occurring over one or more generations or even within a single generation. These domesticated organisms are also accidentally or deliberately introduced into the environment. The outcome of these introductions can ultimately influence the success of restorations, rehabilitation projects, and invasions. Despite the ubiquity of domesticated organisms and their often deliberate release and potential to escape from captivity, there is no unified perspective which examines how domesticated organisms become feral, despite the potential similarity among disparate pathways. Our overall goal is to unite the field of introduced domesticated organisms behind a broader definition of feralization, the establishment process for domesticated organisms. Secondary goals include identifying the key steps or stages of feralization, examining the similarity of the establishment process across introduction pathways, organismal consequences of feralization, and identification of key areas of feralization research. In order to gain wider traction and increase synthesis, a broader view of feralization is needed, one that incorporates individual and population level responses to rearing environments and examines evolutionary processes and organismal states during and after feralization.
09:40AM Break
1:10PM An Approach to Improving Survivorship in a Marine Finfish Replenishment Program in Southern California
  Michael A. Shane, Mark Drawbridge, Ruairi MacNamara
The white seabass, Atractoscion nobilis, is a highly prized recreational and food fish saltwater species that inhabits the west coast of the U.S. and Baja California, Mexico. A stock replenishment program began in 1983 to help restore the depressed fishery. From 1988 through 2017 researchers tagged and released more than 2.5 million hatchery-reared juvenile white seabass with a total biomass exceeding 260 tonnes. An important release strategy of this program has been the use of growout cages that are located at the point of release which facilitates larger sizes at release and pre-release acclimation to local conditions. The mean size of fish released from growout cages was larger than 20 cm in length. Since 1992 there have been as many as 14 cages dispersed in southern California and most are operated by volunteers. Survivorship models, constructed from tag recaptures, have shown that fish released from the growout cages have better survivorship, until their recruitment into the fishery at 71 cm, for all seasons compared to direct releases from the hatchery. The growout cage technique has most likely helped to reduce domestication and improve their performance in the wild. We have recently initiated tank based foraging studies to further improve survival.
1:30PM Advancing Kootenai River Burbot Restoration: Integrating Parental Based Tagging into Conservation Aquaculture to Support Research, Monitoring, and Evaluation
  Shawn Young, Nathan R. Jensen, Tyler J. Ross, Ryan S. Hardy, Sarah Stephenson, Valerie Evans
The Kootenai Tribe of Idaho assisted by the University of Idaho has maintained a conservation aquaculture program for Burbot since the 2000’s to counter near extirpation due to recruitment failure. Parental Based Tagging (PBT) genetic techniques were developed by Idaho Department of Fish and Game, and have been integrated into the Kootenai Tribe’s Conservation Aquaculture Program. By archiving broodstock fin clips, and then tracking parentage of resulting progeny in the hatchery rearing plans, hatchery versus wild origin, year class, and release site survival may be identified without applying traditional tags solely by collecting a fin clip from subsequent progeny recaptures. Another novel use of PBT has also allowed for novel experimental release strategies across life stages into the recovery area. By releasing specific full sibling families or groups of families at specific times and places, studies investigating habitat-related recruitment failure may be undertaken while simultaneously rebuilding the population. These experimental releases have gleaned valuable information about the spatial and temporal aspects of burbot recruitment failure. Methods, implementation into hatchery plans, and results will be presented as an example of the utility and power of integrating Parental Based Tagging into conservation aquaculture.
1:50PM How Might the Hatchery Environment Contribute to the Differences between Hatchery and Wild Salmonids and Centrarchids
  Steve Lochmann
Ideally, fish raised in hatcheries for stock enhancement would look and perform the same as their wild counterparts. This is often not the case. Hatchery fish differ from wild fish in a variety of ways. General areas of difference include morphology, physiology, degree of agonistic behavior, predator avoidance behavior, feeding, and reproductive characteristics. The salmonid and centrarchid literature was reviewed to look for trends between taxa with respect to the ways that hatchery and wild fish differ. There is general agreement between taxa regarding the nature of the difference between hatchery and wild fish. Efforts to mitigate the differences between hatchery and wild fish through hatchery protocols are also examined for salmonids and centrarchids.
2:10PM Using Bioelectrical Impedance Analysis to Measure, Monitor, Track and Compare Fish Health in the Hatchery and in the Wild
  Chuck Anderson, Cory Hartman, Keith Cox
New technologies can solve your problems. A problem that exists in aquaculture facilities is how to measure and track fish health in a real time basis. A new tool is emerging that could help measure fish health, energy content, protein and fat in both aquaculture and wild stocks. Bioelectrical impedance analysis (BIA) may provide solutions by measuring the cells of the fish. BIA has been in the medical and biological fields for 20+ years and has been used to track health, muscle contractions and overall tissue condition. Recently, data from BIA was integrated with cloud based software programs to provide instant real-time comparisons of measured parameters. The data presented here is of fish health in a facility and also in the wild. Comparisons of wild and hatchery fish are also compared. Results indicated that BIA measures of health were lower when the fish was wild, stressed or under restricted feeding. What makes this compelling is that it can be offered in a real-time basis and can be used by anyone anywhere.
2:30PM Successful Hormonal Induction of Spawning in Bonefish (Albula vulpes), Description of Early Ontogeny, and Characterization of Lipid Utilization
  Sahar Mejri, William Halstead, Anthony Cianciotto, Travis Van Leeuwen, Jon Shenker, Aaron Adams, Paul Wills
Bonefish (Albula vulpes L.) are a highly prized sportfish. Despite their economic importance, populations in the Florida Keys and Caribbean are in decline with much of their early life history undescribed. Using hormonal induction of A. vulpes, we successfully induced spawning and describe previously unknown stages of egg and larval development and lipid characterization and utilization for the species. Egg size increased following intraperitoneal injection of Carp pituitary extract as well as at spawning. Zygote and cleavage stages lasted 1 to 2 hours. The blastula, gastrula, and segmentation stages lasted 6 to 9 hours and the pharyngula stage lasted 2 to 4 hours and preceded hatching. Upon hatching at 26 hpf, larvae were morphologically primitive and had no mouth or teeth and the eye was undeveloped. Average total lipids in eggs, before fertilization, accounted for 171.2 µg mg-1 of wet mass. Eggs were characterized by high concentrations of storage lipids (e.g. wax esters-steryl esters (WE-SE) and triacylglycerol (TAG)) and structural lipids (e.g. phospholipids). During embryogenesis, WE-SE and TAG decreased and WE-SE was exhausted at 4 hph. Together, results provide previously undescribed early developmental stages for A.vulpes and will help focus restoration efforts concerning artificial propagation of A.vulpes in hatcheries.
2:50PM Refreshment Break
3:20PM Developing Trojan Sex Chromosome Carriers (YY Males) to Control Nuisance Fish Populations in the Southwest
  Chad Teal, Scott A. Bonar, Daniel J. Schill, Alex Erwin, Melanie Culver
Competition and predation from nonnative fish have had substantial impacts on native fish populations in the southwestern United States. Nonnative fish introductions have been implicated in nearly 50% of endangered species listings, second only to habitat loss. The Red Shiner (Cyprinella lutrensis) has been shown to compete with native cyprinids and other small bodied species. Green Sunfish (Lepomis cyanellus) are generalists that compete with more desirable game species and prey upon native fish. Traditional removal efforts are challenging and rarely capable of extirpating populations of these hardy species. Trojan sex chromosome eradication strategies have been modeled and show the collapse of target species’ populations. Efforts have begun at the University of Arizona to examine the feasibility of producing Trojan sex chromosome carrying (YY male) Red Shiner and Green Sunfish. To date, breeding, larval rearing, and sex reversal techniques have been developed at the UA Fisheries Propagation Lab. The development of genetic sex identification markers has started. Developing Trojan sex chromosome carriers for common nuisance fish species in the Southwest could lead to a more effective way of controlling these nonnative fish populations.
3:40PM Search for the Smoking Gun (PART I): Identifying and Addressing the Causes of Postrelease Morbidity and Mortality of Hatchery-Reared Snake River Sockeye Salmon Smolts
  Jesse Trushenski, Donald Larsen, Mollie Middleton, Michelle Jakaitis, Eric Johnson, Christine Kozfkay, Paul Kline
The Springfield Hatchery in southeast Idaho was established in 2013 to aid in recovery of ESA listed Snake River Sockeye salmon. Unexpectedly high mortality was observed in the first cohorts of Springfield-reared smolts upon release into Redfish Lake Creek (RFLC) headwaters. A series of iterative experiments was conducted to identify the cause of the mortality and to test various mitigation strategies. In our investigation, a difference in water chemistry was noted: Springfield Hatchery’s water source is “hard” with high Ca++ concentrations while water at RFLC is “soft” with very low Ca++. In manipulative experiments and field evaluations, we demonstrated that juvenile sockeye were profoundly affected by instantaneous transitions from high to low hardness water. Further, we established a causal link between differences in water chemistry, associated physiological stress, and mortality during smolt releases and outmigration. A variety of mitigation strategies, including water mixing and water softening were tested, but stepwise acclimation from high to medium, then medium to low hardness water proved to be the most biologically and logistically effective means of addressing the identified water chemistry differences. In Part II of these companion talks we’ll explore how fish reared under different strategies survived during release and downstream migration.
4:00PM Search for the Smoking Gun (PART II): Evaluation of Postrelease Morbidity and Mortality of Hatchery-Reared Snake River Sockeye Salmon Smolts
  Jesse Trushenski, Donald Larsen, Mollie Middleton, Michelle Jakaitis, Eric Johnson, Christine Kozfkay, Paul Kline
Unexpectedly high mortality rates were observed following release into, and during emigration from, Redfish Lake Creek in the first cohorts of Snake River Sockeye Salmon Oncorhynchus nerka juveniles reared at the Springfield Fish Hatchery despite typical in-hatchery performance and survival. Four strategies using varying acclimations times and release sites were tested in an effort to increase post-release survival. These strategies were in-transit acclimation using water softening (~ 5 h acclimation time), a multi-day stepwise acclimation that transitioned fish from hard to medium hardness water followed by release into either medium or low hardness water, and an unacclimated experimental control. The longer transitional period during which smolts adjust to reduced water hardness proved to be the most biologically and logistically effective means of addressing low post-release survival caused by water chemistry differences. Post-release survival estimates to Lower Granite Dam (~430 rkm downstream) and Bonneville Dam (~890 rkm downstream) indicated increased survival for acclimated groups. Although Snake River Sockeye Salmon smolt survival rates will undoubtedly fluctuate annually with changing environmental conditions, it is clear that the elevated morbidity and mortality observed in previous years can be addressed through acclimation of smolts to receiving water chemistry prior to release.
4:20PM Investigating an Ecological-Based Approach for Determining Hatchery Release Timing of Salmon
  Eric Lauver, Todd N. Pearsons
A primary goal of releasing Chinook Salmon smolts from a hatchery facility is for them to survive their outmigration in as high a number and in as good a condition as possible, and to do so without having negative impacts on non-target taxa of concern. Fish migration readiness (e.g., degree of smoltification), environmental factors (e.g., flow and passage conditions at hydro projects), and ecological interactions (e.g., competition and predation) should all be considered when scheduling releases. Because these factors may differ among years, optimal release times may also differ among years. However, parameters such as historic release dates, availability of staff, shifting workloads, and availability of equipment or other resources often determine when fish are released. A conceptual model for determining optimal release timing that considers the natural environment, fish readiness, and ecological interactions is presented. The conceptual model is evaluated via current-year and retrospective analysis of release timing relative to these metrics. An advantage we hope to realize by using a model-informed approach to set release time is continual improvement in the way we achieve optimal outmigration survival and ecological interactions, even as environmental changes occur.
4:40PM Examining Dispersal of Point Stocked Atlantic Salmon Fry Relative to Habitat Qualities in Streams in Eastern Maine, USA.
  Ernie Atkinson, Joseph Zydlewski
The Gulf of Maine Distinct Population Segment of Atlantic salmon has suffered from habitat loss and exploitation over the last century. Hatchery supplementation has unquestionably prevented the extirpation of the species, but stocking methods represent tradeoffs between survival, domestication and logistics. Fry stocking maximizes wild rearing opportunities which can be important for adaptation. These methods, however, are logistically demanding and require significant labor over a large spatial scale, over a short period dictated by the ontogeny of the fish. A critical unknown is the degree to which stocked fry disperse from their point of stocking. Greater dispersal as fry would obviate the need to physically distribute these fish while stocking, providing significant labor gains. We point stocked salmon fry in a reach of the East Machias River and assessed dispersal using electrofishing. Within the first two weeks, 78% had settled within the first 150 meters below the release point. At the end of the first growing season, there was no observed difference in abundance throughout the 2-kilometer study reach. The next step will be to repeat this work using hydraulically planted eyed eggs. Results of this study will inform decisions related to stocking intervals, habitat use, and stocking rates.
5:00PM Influence of Size-at-Stocking on Return-to-Creel of Hatchery Catchable Rainbow Trout
  Philip Branigan, Kevin A. Meyer, John Cassinelli
Catchable-sized hatchery trout (~250 mm TL; hereafter “standard” catchables) are an important component of cold water fisheries management programs, providing instantaneous fisheries once they are stocked in waters that cannot support wild trout populations or where catch rates are low. Recent investigations have indicated that the largest standard catchables in a raceway are caught by anglers at higher rates than smaller conspecifics, suggesting that increasing size at stocking (e.g., to 300 mm TL; hereafter “magnum” catchables) may substantially increase return-to-creel for anglers. However, costs of rearing catchables to larger size increases exponentially, thus balancing rearing costs and angler benefits can be challenging. We stocked “standard” and “magnum” catchable Rainbow Trout Oncorhynchus mykiss into 24 lakes and reservoirs and 19 streams across 3 years to evaluate size-at-stocking on angler catch, while monitoring rearing costs for each. Water bodies were stocked with equal numbers of magnums and standards that were marked with unique T-bar anchor tags. In lentic systems, magnums demonstrated a 107% increase in angler returns compared to standards, whereas magnums in lotic systems demonstrated a 53% increase over standards. The added cost to raise magnums was outweighed by the increased angler catch for lentic waters but not for lotic waters.

Organizers: Michelle L. “Mick” Walsh, Steve Lochmann, Valorie Titus
Supported by: AFS Fish Culture Section; TWS Hunting, Trapping, and Conservation Working Group

Location: Reno-Sparks CC Date: September 30, 2019 Time: 8:00 am - 5:20 pm