Moving Forward or Standing Still: The Role of Captive Breeding in Species Recovery (hosted by AFS)

Symposium
ROOM: RSCC, C3
SESSION NUMBER: 7847
 
Captive breeding, rearing, and live gene banking programs have been instrumental in preventing the imminent extinction of species of birds, fish, and mammals. Linked programs with supplementation often play a key role in providing a demographic boost to threatened species in their native habitat. A key concern of these programs is maintaining adequate genetic diversity and fitness within populations so they can thrive in the wild and maintain the ability to respond to future environmental change. The joint national conference of AFS and TWS provides a unique opportunity to bring together researchers working with captive breeding and supplementation programs for a diverse range of vertebrate taxa ranging from r-selected to k-selected organisms, where diversity can be managed from the cohort level to the individual pedigree level. Presented in conjunction with the International Year of the Salmon, the goal of this symposium is to highlight current practices, advances, and challenges associated with captive breeding and supplementation programs and foster cross-taxa exchange of knowledge. We welcome presentations dealing with maintaining, measuring, and increasing genetic diversity and fitness within supplementation programs, as well as research designed to evaluate the effectiveness of these programs towards establishing self-sustaining populations in the wild.

8:00AM Can Conservation Targets for Imperiled Freshwater Fishes and Mussels be Achieved with Captive Breeding and Release Programs?
  Steven J. Cooke, Lisa Donaldson, D. Andrew R. Drake, Jessica Taylor, Joe Bennett, Trina Rytwinski
Captive breeding programs are one of the many tools used by conservation practitioners as a means of conserving, supporting, and supplementing populations of imperiled species. Captive breeding programs exist around the globe for freshwater mussels and fishes, but the availability of evidence exploring the effectiveness of these programs has not yet been explored using systematic map criteria. This systematic map aims to identify, collate and describe the evidence that exists on the effectiveness of captive breeding programs, for the purpose of achieving conservation targets for imperilled freshwater fishes and mussels in the wild. The outputs of this systematic map will help to inform conservation managers and policy makers who are responsible for protecting imperilled freshwater species by identifying existing information and highlighting key information gaps for captive breeding programs operating in temperate regions. We generated a systematic map to compile and map existing literature on the effectiveness of captive breeding programs for the conservation of imperiled freshwater fishes and mussels. We will share our findings from this review.
8:20AM Advancing Toward Recovery Using Captive Breeding in Snake River Sockeye Salmon
  John Powell, Dan Baker, Debbie Frost, Marc Garst, Desmond J. Maynard, W. Carlin McAuley, Barry Berejikian
Captive propagation provides a means to conserve genetic diversity and demographically support critically endangered species. A captive breeding program was established for Snake River Sockeye Salmon in 1991, which were listed as endangered under the U.S. Endangered Species Act later that year. The captive breeding program has been successful in preventing extinction and conserving 95% of the genetic diversity of the founding population from Redfish Lake, Idaho. Offspring from captive adults, in excess of broodstock needs, have been used to supplement wild populations in Redfish, Pettit and Alturas lakes. Over the 28 year program history more than 1.1 million eyed-eggs, 1.8 million parr, 4.3 million smolts, and 14,982 adults have been released into the basin. These eyed-egg, parr and smolt releases produced 6,157 returning anadromous adults. Natural production in basin lakes, augmented by releases of hatchery-reared and anadromous adults into Redfish and Pettit lakes, returned 1,234 anadromous adults. The Snake River Sockeye Salmon Captive Brood program has made a significant stride towards recovery and recolonization of basin lakes. Despite this marked increase in adult returns across the past quarter century challenges to recovery persist. Therefore, captive propagation remains a vital component in the recovery of this evolutionarily significant unit.
8:40AM Genetic Management of the Eagle Lake Rainbow Trout: An Endemic Strain of O. mykiss from a High Elevation Alkaline Lake Broodstock Population
  Jeff Rodzen, Paul Divine, Kristen Ahrens, Daphne Gille
The Eagle Lake Rainbow Trout (ELRT; Oncorhynchus mykiss aquilarum) is a subspecies of adfluvial rainbow trout isolated in, and endemic to, California’s Eagle Lake. The ELRT is a California Heritage Trout, a California Species of Special Concern and US Forest Service sensitive species. Eagle Lake is a high elevation alkaline lake fed by springs and seasonal creeks. Pine Creek has become the focus for restoring the ELRT’s historic spawning habitat. The primary threat to the ELRT is the lack of natural production. Eagle Lake is the sole broodstock source for this subspecies with juvenile fish being widely distributed for recreational angling within California and across other western states. Because of decades of various approaches to artificial spawning and lack of natural production, concerns regarding the genetic integrity of the Eagle Lake Rainbow Trout have been raised over time. A recent comprehensive genetic analysis has shown that the genetic composition has been consistent over the last several decades in spite of population size fluctuations and varied spawning and restocking practices. We also document some recent, yet limited, natural recruitment in Pine Creek, the primary tributary to Eagle Lake, in spite of a dense population of Brook Trout and suboptimal habitat conditions.
9:00AM Captive Propagation of Endangered Loach Minnow and Spikedace: Challenges and Successes
  Kristopher Stahr, Joshua Walters, Hannnah Smith
Loach Minnow Tiaroga cobitis and Spikedace Meda fulgida are two short-lived, small-bodied fishes endemic to the American Southwest, specifically the Gila River Basin of Arizona and New Mexico. Originally listed as threatened in 1986, Loach Minnnow and Spikedace were subsequently listed as endangered in 2012. Both species have been negatively impacted by introduction of non-native aquatic organisms and alteration to hydrologic regimes within their native range, resulting in population declines. As a primary facet of recovery efforts, each year Loach Minnow and Spikedace adults are collected in the wild and brought to the Arizona Game and Fish Department’s Aquatic Research and Conservation Center for captive propagation and subsequent repatriation. Captive spawning of these fishes historically has been challenging due to low numbers of wild broodstock available, the management of distinct genetic lineages, limited hatchery propagation infrastructure, and the inability to conduct robust propagation research. This paper outlines the steps taken to improve the propagation of Loach Minnow and Spikedace, and provides lessons for managers who are responsible for the captive breeding of imperiled organisms as part of species recovery.
9:20AM Development of a Cryopreservation Program to Improve Recovery of California Fishes
  Daphne Gille, Farhat Bajjaliya, Roger Bloom, Jeff Rodzen, Mark Clifford
Populations of native fishes in California are declining at an alarming rate. Nearly half of the endemic fish fauna are state or federally listed or species of special concern. A primary goal of California state hatcheries is to mitigate this trend and to enhance native fish resources through captive rearing. However, hatcheries frequently experience impediments to optimal performance such as loss of genetic diversity, broodfish availability, variable spawning success, and stochastic events. The California Department of Fish and Wildlife has initiated a cryopreservation program to bank genetic material (i.e., milt) from many native fish species to improve hatchery efficiency and conservation measures. We performed pilot studies evaluating the effectiveness of cryopreservation media to develop species-specific protocols that maximize post-thaw sperm motility and fertilizing ability. We then collected milt from hatcheries throughout the state. Development of these techniques and a cryopreservation archive will benefit California hatcheries by enabling mate pairing of genetically diverse fish at will, conservation of genetic variation for future generations, and protection against inbreeding and reduced fitness from inbreeding depression. Other practical benefits are flexibility of spawning time, ability to spawn when broodfish are scarce, reduction of milt waste from important individuals or species, and ease of transport.
09:40AM Break
1:10PM Spawn Matrixing Fails to Improve Survival in a Unique Cutthroat Trout Population Following Fire-Mediated Extirpation in the Wild
  Kevin Rogers, Seth Firestone, Andrew Whiteley
Fearing a debris flow might wipe out a small unique population of Cutthroat Trout following a wildfire in the headwaters of the Arkansas River, managers brought roughly half of the adult population into captivity to serve as a broodstock for subsequent repatriation efforts. A heavy rainstorm saturated the basin two months after the fire subsided, causing a massive debris flow that extirpated what remained of this high value population. With only 133 individuals surviving in captivity 22 months later, we evaluated if spawn matrixing could mitigate the effects of inbreeding and improve survival of the progeny. We genotyped each individual at 30 microsatellite loci to estimate relatedness, then fertilized half of the eggs from each gravid female with a related male and half with an unrelated male. These same two males were used to fertilize eggs from an unrelated female to create four families from four parents thereby controlling for egg and milt quality. A total of 28 families were created in this fashion and reared in individual hatching trays until survival to hatch and swim-up could be evaluated. Unexpectedly, survival was not influenced by relatedness in this study. Instead, egg quality was the primary driver of eventual fry survival.
1:30PM Managing Captive-Reared Chinook Salmon Maintained and Increased Genetic Diversity in Population
  Adrian Spidle, Sewall F. Young, Thomas Chance, Ned Currence
South Fork Nooksack spring Chinook salmon are required to recover for the Puget Sound ESU, listed as threatened under the US ESA, to be delisted. ~20,000 juvenile Chinook salmon were collected from 2007-2012. Genetic stock id verified approximately 4,000 were from the SF spring population targeted. Of the initial collection, 1,641 captive-reared fish were spawned from 2010-2017, with crosses chosen according to relatedness. Anadromous progeny of program fish were incorporated to the program beginning in 2014. In 2016 the first complete cohort of anadromous progeny had returned (ages 2-5 year olds). The program has succeeded in greatly increasing abundance of SF Nooksack Chinook salmon in the river. Ne estimated by the method of temporal variance in allele frequencies (1980s and 1990s baseline collections, initial juveniles retained for captive rearing, and 1st completed cohort anadromous progeny of program fish) showed a negative trend from the baseline collections to the juveniles taken into captive rearing. Ne estimates increased 180% over the point between the baseline collections and the 1st anadromous cohort, and 380% between the captive-reared juveniles and their 1st anadromous cohort, indicating genetic diversity taken into the program was maintained through the point of anadromous returns.
1:50PM Using Genetics to Test the Efficacy of Captive Propagation As a Recovery Strategy for the Endangered Houston Toad (Bufo [=Anaxyrus] houstonensis)
  Anjana Parandhaman, Madeleine Marsh, Shashwat Sirsi, Michael Forstner
The federally endangered Houston Toad (Bufo houstonensis) is endemic to east-central Texas and has continued to decline generally consequent to large-scale habitat loss. Population supplementation projects, via assurance colonies at the Houston Zoo, is one of the the management approaches used in recent attempts to arrest this decline, with recent efforts focusing on recovery sites in Bastrop County. This includes the acclimation and release of egg strands/juveniles into predator exclusion devices, to enable greater transition rates of neonates and juveniles to adult stages. Released eggstrands are monitored through to the emergent metamorph stage. These supplementation efforts are evaluated by determining naïve occupancy of the same sites through auditory surveys for chorusing adult male Houston Toads. Toads are captured, marked and a tissue sample is taken for genetic mark-recapture analyses. Chorusing males have increased in number at historically occupied sites and have been detected at previously unoccupied sites, that reflect supplemented sites in 2015 and 2016. The provenance of these adult toads, captured during nocturnal call surveys, is being determined with a pedigree analysis using microsatellite markers. Results suggest that captive propagation is successful, however this management approach should not be considered in isolation to ensure long-term persistence of the species.
2:10PM Captive Husbandry Maintains Representation of Boreal Toad Populations Locally Extirpated in the Wild
  Harry Crockett
Once abundant and widespread in the Southern Rocky Mountains (SRM), Boreal Toads experienced marked decline beginning around 1990. The mechanism driving decline and local extirpations was identified as chitridiomycosis (Bd) in 2001. At that time, with no known measures to prevent Bd spread or mitigate its effects, biologists collected toads from across the SRM for captive assurance at Colorado’s newly-completed native species hatchery. Toads are uniquely identified and segregated by source population. Currently, the hatchery houses roughly 1000 toads representing 25 wild populations, including at least five now likely extirpated in the wild. Hatchery-produced eggs, when available, provide tadpoles for reintroductions, the principal strategy for ensuring the species remains on the landscape. Populations included in the captive broodstock were chosen for maximum geographic representation, facilitating a nearest-neighbor approach to reintroductions. However, captive breeding success has been mixed, an increasingly urgent challenge as Bd continues to colonize wild populations. Of great interest, a few wild populations that initially crashed upon Bd colonization have persisted at greatly reduced abundance, suggesting a degree of disease tolerance in some individuals. Several of these populations are represented in the broodstock and are extremely valuable for concurrent research examining a possible genetic association with Bd tolerance.
2:30PM Broodstock Management to Support Multiple Facets of Kootenai River White Sturgeon and Burbot Restoration
  Shawn Young, Nathan R. Jensen, Ryan S. Hardy, Kevin McDonnell, Tyler J. Ross, Sarah Stephenson, Valerie Evans
The wild Kootenai River White Sturgeon (Acipenser transmontanus) and Burbot (Lota lota) populations are declining due to a lack of significant recruitment since the 1970s. Decades of persistent recruitment failure prompted the development of a conservation aquaculture program to ward off extirpation until habitat restoration may once again support natural recruitment. The Kootenai Tribe of Idaho has maintained a conservation aquaculture program for White Sturgeon since the 1990’s, and for Burbot since the 2000’s. The conservation aquaculture program is guided by a multi-agency adaptive management framework as part of an ecosystem-based restoration. The Kootenai Tribe’s hatcheries are designed to support three objectives of the overall restoration effort: 1.) population rebuilding 2.) maintain genetic diversity 3.) support post-release monitoring and evaluation of hatchery fish in a manner to inform the aquaculture and habitat restoration programs. The multi-faceted implementation has successfully supported and/or informed all three objectives using novel and elaborate rearing/release strategies, which are wholly dependent on properly designed broodstock plans. This presentation will describe how and why broodstock management plans for these two species are implemented to simultaneously rebuild population abundance and structure, while researching spatial and temporal aspects of the altered ecosystem that cause persistent recruitment failure.
2:50PM Refreshment Break
3:20PM Effects of Release Strategies on the Survival of Hatchery Reared Kootenai River White Sturgeon and Burbot
  Ryan S. Hardy, Kevin McDonnell, Tyler J. Ross, Shawn Young, Nathan R. Jensen, Sarah Stephenson
Kootenai River White Sturgeon (Acipenser transmontanus) and Burbot (Lota lota) populations have been declining due to a lack of significant recruitment since the 1970s. The reliance on hatchery-reared fish to maintain these shrinking populations in the Kootenai River, Idaho prompted the need to evaluate the efficacy of release strategy on post release growth, survival, and recruitment. The results of these analysis were directly utilized by the Kootenai Tribe of Idaho’s aquaculture program to adjust stocking densities and manage broodstock collection to meet in-river population targets. In addition, these results were integral in conserving genetic contribution of the declining populations while also providing adequate numbers to sustain natural production should limiting factors be improved. In this study, we evaluated estimates of annual survival by age, as well as size, location and season of release on survival, and provided an estimate on hatchery produced juvenile and adult abundance. This analysis provided the first age-specific estimates of annual survival for both sturgeon and Burbot in the basin. Monitoring and evaluation of population vital rates continues to be paramount in identifying optimal hatchery operations as well as to the continued success of this recovery effort.
3:40PM Low Summer Streamflow Limits Endangered Coho Salmon Recovery in Coastal California Streams
  Mariska Obedzinski, Andrew Bartshire, Nicolas Bauer, Sarah Nossaman Pierce, Andrew McClary, Gregg Horton, Aaron Johnson
In order to prevent extirpation of endangered Coho Salmon in the Russian River, California, near the southern extent of the species’ range, a conservation hatchery has been releasing juvenile Coho Salmon into historic tributaries since 2004. Extensive life cycle monitoring has helped document successes and identify bottlenecks. Since the inception of the program, released juveniles have survived the winter at an estimated probability of 0.25 and adult returns have increased from fewer than 10 per year to hundreds per year. Increases in wild juvenile Coho Salmon distribution throughout the watershed suggests successful spawning; however, extensive stream drying during the summer has led to extreme mortality of naturally-spawned fish and is preventing subsequent generations from completing their life cycles. Results from four years of wet/dry mapping and fish distribution data collection on 20 streams indicate that adults frequently spawn in reaches that become dry the following summer, and in many streams juveniles are observed in reaches that later become dry. With increasing frequency of drought in a highly populated region, creative solutions are needed to address streamflow impairment. Monitoring results are being used to prioritize habitat and streamflow enhancement efforts aimed at increasing the chances for long-term population recovery.
4:00PM Canceled Talk
 
4:20PM Colonization of Novel Habitat for Population Enhancement: An Atlantic Salmon Case Study
  Danielle Frechette, Julian Dodson, Melanie Dionne, Normand Bergeron
Colonization of vacant habitat as a means of population enhancement is increasingly being considered as part of salmonid recovery programs. Thorough understanding of how adult salmon use space during colonization is essential to ensuring that programs achieve desired conservation outcomes. We employed acoustic telemetry to examine movements and habitat use of adult Atlantic salmon translocated into novel habitat in a Quebec river as part of population enhancement program. A subset of returning adults was transported upstream of an impassible natural waterfall to increase available spawning and rearing habitat with the goal of reducing density-dependent effects on juvenile growth and survival. The majority of transported salmon remained in novel habitat. Post-transport fallback out of novel habitat occurred within 7 days of release and larger fish had a greater propensity to fallback. Fish sex, environmental conditions, and river morphology influenced movement patterns and habitat use by individuals that remained in colonization habitat. Results of spawning surveys and juvenile captures indicated that reduced spawning density resulted in increased juvenile size-at-age for both young-of-year and out-migrating smolts. Our findings provide a unique picture of colonization of unoccupied habitat by Atlantic salmon, which can be used to optimize future enhancement programs employing colonization or reintroduction.

 
Organizers: Danielle Frechette, Adrian Spidle
 
Supported by: NOAA NEFSC and International Year of the Salmon

Symposium
Location: Reno-Sparks CC Date: October 1, 2019 Time: 8:00 am - 4:40 pm