A molecular-telemetric approach to Atlantic salmon reintroductions: how human intervention can promote the establishment of new populations

With increases to the number of species and populations impacted by human activities, the need for human involvement in their maintenance and/or conservation has grown in turn. This involvement increasingly takes the form of re-introductions, relocations, or supplementation of populations in decline or that have been lost. As a result, reintroduction biology has become a quickly growing field of research that attempts to answer the many questions related to reintroductions and translocations. When and how to release individuals into the wild, at what age should they be released, and in what situations is the introduction of new individuals sufficient to establish new populations. To advance our understanding of species reintroductions and address some of these questions in situ, adaptive management experiments and new techniques were developed for the Atlantic salmon reintroduction program in the Lake Champlain basin. These experiments assessed the suitability of commonly used methods in salmonid reintroduction and supplementation for re-establishing or strengthening self-sustaining populations and meta-population structure through direct comparisons of long-term survival, spawning returns, and dispersal rates. Concurrently, to address how changes in the species composition of Lake Champlain have affected the ability of reintroduced salmon to establish themselves, radio telemetry was employed to monitor spawning migrations through a challenging, high velocity section of the Boquet River, a tributary to Lake Champlain. In doing so, new, transferrable radio telemetric techniques for continuous fine scale monitoring were developed. In comparing alternative rearing/release techniques to the standard method of producing large 1+ parr through the use of elevated rearing temperatures, several significant trends were apparent. First, while fry (age 0+) are commonly held to exhibit reduced survival to adulthood relative to 1+ parr, once natural mortality during the first year was accounted for, fry returns exceeded those of standard production parr while their dispersal rates were more consistent with Atlantic salmon meta-populations. Second, all three alternative parr rearing/release methods reduced straying rates relative to standard methods. Third, while advancing release dates lowered parr-to-adult survival relative to standard procedures, using seasonal water temperatures prior to release significantly improved both survival and spawning returns. Once released, growing salmon fed on alewife, an invasive prey species containing thiaminase, which lowered thiamine levels among mature adults, potentially impacting energy levels and swimming performance. At a challenging, high velocity section of the Boquet River, we detected a significant effect of this thiamine deficiency on downstream movement rates from both high and low flow sections of the river as well as an effect of thiamine supplementation, particularly among male salmon. To confirm this, however, a new telemetric technique was required. We therefore developed a technique that successfully estimated the location of tagged salmon to within several meters using readily available equipment and statistical models. Overall, these results will assist the reintroduction efforts in Lake Champlain and their implications are highly transferrable to the reintroduction/supplementation of other at-risk or extirpated populations. The methods developed below are readily implementable and provide positive returns on investment, both over the short- and long-term, while representing a step forward for the reintroduction of species of high economic, cultural, and ecological importance

Concurrent habitat and life history influences on effective/census population size ratios in stream-dwelling trout

Lower effective sizes (Ne) than census sizes (N) are routinely documented in natural populations, but knowledge of how multiple factors interact to lower Ne/N ratios is often limited. We show how combined habitat and life-history influences drive a 2.4- to 6.1-fold difference in Ne/N ratios between two pristine brook trout (Salvelinus fontinalis) populations occupying streams separated by only 750 m. Local habitat features, particularly drainage area and stream depth, govern trout biomass produced in each stream. They also generate higher trout densities in the shallower stream by favoring smaller body size and earlier age-at-maturity. The combination of higher densities and reduced breeding site availability in the shallower stream likely leads to more competition among breeding trout, which results in greater variance in individual reproductive success and a greater reduction in Ne relative to N. A similar disparity between juvenile or adult densities and breeding habitat availability is reported for other species and hence may also result in divergent Ne/N ratios elsewhere. These divergent Ne/N ratios between adjacent populations are also an instructive reminder for species conservation programs that genetic and demographic parameters may differ dramatically within species

Children's Perception of Wolverine in the North Slave Region of the Northwest Territories, Canada

The public’s level of knowledge and opinions towards certain species can greatly impact their willingness to support present or future conservation or management programs. When public opinion is mixed, as is often the case with wild carnivores, an accurate assessment of perceptions and knowledge can identify areas of concern and help guide public outreach efforts. When such outreach programs focus on children they can be particularly effective for two reasons: 1) the opinions of children towards wild animals are often more flexible than the ingrained beliefs of adults, and 2) it is the younger generation that will be called upon to support long-term conservation efforts in the future. To assess the degree of knowledge and the current state of opinion among children towards a little known and often negatively perceived Arctic species, the wolverine (Gulo gulo), we conducted surveys with school children between the ages of 8 – 12 years old in seven schools within the North Slave Region of the Northwest Territories. Results from 151 completed surveys confirm that the majority of children lack general knowledge about this species, though the overall level of knowledge was higher in small, rural communities than the larger capital city of Yellowknife. Negative values were among the most commonly expressed values we observed, but so too was an appreciation for the ecological role that wolverines play in nature. The results of this study can be used to implement new educational programs aimed at increasing the overall level of acceptance of the wolverine and similar carnivores, and to encourage the public’s willingness to support conservation efforts for this often negatively perceived species.Le niveau de connaissances et d’opinions des populations au sujet d’une espèce donnée peut avoir une grande incidence sur les programmes de gestion ou de conservation actuels ou futurs de l’espèce en question. Lorsque l’opinion publique est mixte, comme c’est souvent le cas avec les carnivores sauvages, l’évaluation précise des perceptions et des connaissances peut permettre de déterminer les sujets de préoccupation et de guider les efforts de sensibilisation du public. Quand de tels programmes de sensibilisation visent les enfants, ils peuvent être particulièrement efficaces pour deux raisons :1) les opinions des enfants envers les animaux sauvages sont souvent plus flexibles que celles détenues par les adultes, et 2) c’est la jeune génération qui sera appelée à soutenir les efforts de conservation à long terme. Pour évaluer le degré de connaissances et les opinions actuelles des enfants envers une espèce arctique peu connue et souvent négativement perçue, le carcajou (Gulo gulo), nous avons mené des enquêtes auprès d’élèves de huit à douze ans dans sept écoles de la région North Slave des T.N.-O. Les résultats des 151 questionnaires remplis confirment que la majorité des enfants possèdent peu de connaissances générales sur cette espèce, bien que le niveau global de connaissances était plus élevé dans les petites collectivités rurales que dans la capitale de Yellowknife. Les valeurs négatives figuraient parmi les valeurs les plus courantes exprimées dans le cadre des enquêtes, bien que la valeur écologique du rôle du carcajou dans la nature ait également été mise en évidence. Les résultats de cette étude peuvent être utilisés pour mettre en œuvre de nouveaux programmes éducatifs visant à accroître le niveau général d’acceptation du carcajou ou d’autres carnivores de ce genre, ainsi que pour encourager le public à soutenir les efforts de conservation de cette espèce souvent mal comprise. &nbsp

Minor shifts towards more natural conditions in captivity improve long-term survival among reintroduced Atlantic salmon

Elevating winter water temperatures is a common practice when rearing salmonids for supplementation or reintroduction. Doing so elevates developmental rates, producing larger juveniles with greater smolt-to-adult survival, but does not guarantee improved adult returns to stocked tributaries. To test whether more natural developmental conditions improve adult returns to stocked tributaries, three consecutive cohorts of yearling (age 1+) landlocked Atlantic salmon (Salmo salar) were released into two tributaries of Lake Champlain. Cohorts were reared under two winter thermal conditions (seasonal surface water and above-seasonal groundwater) and (or) two release times (early and normal). Relative to standard hatchery practices, modelled returns to experimental tributaries increased over replicate cohorts by 286% on average following exposure to seasonal rearing temperatures, but decreased by 89% on average when release dates were advanced. By utilizing cost-effective shifts towards hatchery rearing techniques that more closely resemble natural growth conditions, we demonstrate how hatchery programs may improve long-term survival and returns for fish species with complex life histories involved in supplementation and reintroduction programs.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Data from: Novel, continuous monitoring of fine-scale movement using fixed-position radiotelemetry arrays and random forest location fingerprinting

1. Radio-tag signals from fixed-position antennas are most often used to indicate presence/absence of individuals, or to estimate individual activity levels from signal strength variation within an antenna’s detection zone. The potential of such systems to provide more precise information on tag location and movement has not been explored in great detail in an ecological setting. 2. By reversing the roles that transmitters and receivers play in localization methods common to the telecommunications industry, we present a new telemetric tool for accurately estimating the location of tagged individuals from received signal strength values. The methods used to characterize the study area in terms of received signal strength are described, as is the random forest model used for localization. The resulting method is then validated using test data before being applied to true data collected from tagged individuals in the study site. 3. Application of the localization method to test data withheld from the learning dataset indicated a low average error over the entire study area (< 1m) while application of the localization method to real data produced highly probable results consistent with field observations. 4. This telemetric approach provided detailed movement data for tagged fish along a single axis (a migratory path) and is particularly useful for monitoring passage along migratory routes. The new methods applied in this study can also be expanded to include multiple axes (x, y, z) and multiple environments (aquatic and terrestrial) for remotely monitoring wildlife movement

Environmental, anthropogenic, and dietary influences on fine scale movement patterns of Atlantic salmon through challenging waters.

Partial barriers to migration can affect migratory fish population dynamics and be influenced by many biotic, abiotic, and anthropogenic factors, including nutritional deficiencies. We investigated how such variables (including a thiamine deficiency) impact fine-scale movement of landlocked Atlantic salmon, by treating returning spawners with thiamine and observing their attempts to climb a human-altered, high velocity stretch of river using fine-scale radio telemetry. Multiple re-entries into a river section, along with water temperature, strongly influenced movement rates. High or increasing discharge encouraged downstream movement; males abandoned migratory attempts at a higher rate than females. Although thiamine-injected salmon exhibited greater migratory duration, this did not produce a measurable improvement in passage performance, possibly due to the difficulty associated with this section of river - among 24 tagged salmon staging 10.9 attempts each and lasting 1.5 days/attempt on average, only three traversed the entire reach. This study provides new insights into how biotic and abiotic variables affect fish movement, while suggesting limits to the potential for human intervention (thiamine injections) to assist passage through partial migratory barriers.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author