scholarly journals The evolutionary basis of premature migration in Pacific salmon highlights the utility of genomics for informing conservation

2016 ◽  
Author(s):  
Daniel J. Prince ◽  
Sean M. O’Rourke ◽  
Tasha Q. Thompson ◽  
Omar A. Ali ◽  
Hannah S. Lyman ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Genetic Differentiation ◽  
Pacific Salmon ◽  
Single Locus ◽  
Physiological Adaptation ◽  
Evolutionary Significance ◽  
Adaptive Variation ◽  
Adaptive Genetic Variation ◽  
Conservation Units ◽  
Connected Populations

AbstractThe delineation of conservation units (CUs) is a challenging issue that has profound implications for minimizing the loss of biodiversity and ecosystem services. CU delineation typically seeks to prioritize evolutionary significance and genetic methods play a pivotal role in the delineation process by quantifying overall differentiation between populations. While CUs that primarily reflect overall genetic differentiation do protect adaptive differences between distant populations, they do not necessarily protect adaptive variation within highly connected populations. Advances in genomic methodology facilitate the characterization of adaptive genetic variation, but the potential utility of this information for CU delineation is unclear. Here we use genomic methods to investigate the evolutionary basis of premature migration in Pacific salmon, a complex behavioral and physiological adaptation that exists within highly-connected populations and has experienced severe declines. Strikingly, we find that premature migration is associated with the same single locus across multiple populations in each of two different species. Patterns of variation at this locus suggest that the premature migration alleles arose from a single evolutionary event within each species and were subsequently spread to distant populations through straying and positive selection. Our results reveal that complex adaptive variation can depend on rare mutational events at a single locus, demonstrate that CUs reflecting overall genetic differentiation can fail to protect evolutionarily significant variation that has substantial ecological and societal benefits, and suggest that a supplemental framework for protecting specific adaptive variation will sometimes be necessary to prevent the loss of significant biodiversity and ecosystem services.

scholarly journals Abundance and composition of the medium to large-sized mammals in a private area of a REDD+ project in Acre, Brazil

2018 ◽  
Vol 18 (3) ◽  
Author(s):  
André Luis Moura Botelho ◽  
Luiz Henrique Medeiros Borges ◽  
Brian McFarland
Keyword(s):  
Gene Flow ◽  
Ecosystem Services ◽  
Relative Abundance ◽  
Rare Species ◽  
Camera Traps ◽  
Large Mammals ◽  
Conservation Areas ◽  
Conservation Units ◽  
Key Species ◽  
Tapirus Terrestris

Abstract: The implementation of private areas focused on conservation of species and habitats, combined with REDD+ policies, has become an important ally for biodiversity conservation, expanding the conservation areas of the most varied habitats, covering key groups such as large mammals, which are extremely important for the maintenance of ecosystem services. In the upper region of the Purus River in Acre, Brazil, an inventory was carried out using camera-traps, of medium and large mammals community in a private REDD+ area, known as the Purus Project. A total of 19 species of mammals were recorded with an effort of 1859 trap-nigths, including rare, endangered and key species. It is estimated that the richness for the area is of 22 species. Endangered and rare species such as the tapir (Tapirus terrestris) and the short-eared dog (Atelocynus microtis) presented high rates of relative abundance compared to other Conservation Units (UCs). The richness of medium to large-sized mammals recorded in the Purus Project underscores the importance of REDD+ in private areas for the conservation of this group, given the challenges for inclusion and creation of new protected areas. REDD+ projects in privates' areas become an important component for conservation of species and the connection between public conservation units favoring the spread of species and populations between areas, and consequently the gene flow.

Shifting habitat mosaics and fish production across river basins

Science ◽  
2019 ◽  
Vol 364 (6442) ◽  
pp. 783-786 ◽  
Author(s):  
Sean R. Brennan ◽  
Daniel E. Schindler ◽  
Timothy J. Cline ◽  
Timothy E. Walsworth ◽  
Greg Buck ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Pacific Salmon ◽  
Spatial Scales ◽  
River Basins ◽  
River Network ◽  
Strontium Isotope ◽  
Climate Forcing ◽  
Fish Production ◽  
Habitat Mosaics ◽  
Relative Productivity

Watersheds are complex mosaics of habitats whose conditions vary across space and time as landscape features filter overriding climate forcing, yet the extent to which the reliability of ecosystem services depends on these dynamics remains unknown. We quantified how shifting habitat mosaics are expressed across a range of spatial scales within a large, free-flowing river, and how they stabilize the production of Pacific salmon that support valuable fisheries. The strontium isotope records of ear stones (otoliths) show that the relative productivity of locations across the river network, as both natal- and juvenile-rearing habitat, varies widely among years and that this variability is expressed across a broad range of spatial scales, ultimately stabilizing the interannual production of fish at the scale of the entire basin.

scholarly journals Interspecific gene flow and vicariance in Northern African rear-edge white oak populations revealed by joint analysis of microsatellites and flanking sequences.

2021 ◽  
Author(s):  
Lepais Olivier ◽  
Abdeldjalil Aissi ◽  
Errol Véla ◽  
Yassine Beghami
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Population Size ◽  
Evolutionary History ◽  
Evolutionary Significance ◽  
Interspecific Gene Flow ◽  
Continental Scale ◽  
Rear Edge ◽  
Flanking Sequences ◽  
Edge Populations

Rear-edge populations represent reservoirs of potentially unique genetic diversity but are particularly vulnerable to global changes. While continental-scale phylogeographic studies usually do not cover these populations, more focused local scale study of rear-edge populations should help better understand both past evolutionary history and its consequences for the persistence and conservation of these potentially unique populations. We studied molecular variation at 36 sequenced nuclear microsatellites in 11 rear-edge Quercus faginea and Q. canariensis populations across Algeria to shed light on taxonomic relationship, population past evolutionary history and recent demographic trajectory. We used descriptive approach and simulation-based inference to assess the information content and complementarity of linked microsatellite and flanking sequence variations. Genetic differentiation among populations classified into eight well-defined genetic clusters do not allow to unambiguously delineate two species. Instead, continuous level of genetic differentiation indicates interspecific gene flow or drift in isolation. Whereas the analysis of microsatellite variation allowed inferring recent interspecific gene flow, additional nucleotide variation in flanking sequences, by reducing homoplasy, pointed towards ancient interspecific gene flow followed by drift in isolation. The assessment of the weight of each polymorphism in the inference demonstrates the value of linked variation with contrasted mutational mechanisms and rates to refine historical demographic inference. Past population size decline inferred in some of these oak populations as well as low contemporary effective population size for most populations is a concern for the persistence of these populations of high evolutionary significance and conservation value.

Pacific Salmon: Ecology and Management of Western Alaska’s Populations

2009 ◽  
Keyword(s):  
Pacific Salmon ◽  
Conservation Strategy ◽  
The Arctic ◽  
Evolutionary Potential ◽  
Evolutionary Processes ◽  
Conservation Units ◽  
Process Step ◽  
Evolutionary Trajectories ◽  
Dynamic Relationships

<em>Abstract.</em>—The legacy of Pacific salmon <em>Oncorhynchus </em>spp. can be described as the genetic resources that are the product of past evolutionary events and which represent the future evolutionary potential of the species. A key step in conserving this legacy is identifying conservation units—major chunks of biodiversity that collectively comprise the evolutionary legacy. A variety of methods exist for defining conservation units, but all should follow a two-step process. Step One is describing the (often hierarchical) structure of biodiversity within each species—that is, the evolutionary relationships among populations and metapopulations or larger conservation units. In theory, this is an objective, data-driven exercise. Step Two involves considering questions such as, “Which level in the hierarchy is best for identifying conservation units?” and “How much biodiversity do we need to conserve?” These questions do not have a single ‘correct’ answer; instead, they must be informed by societal values. In Step Two, therefore, it is important to articulate clear program goals to provide a context for addressing these difficult questions. But defining conservation units is only part of a coherent, long-term conservation strategy; evolution is dynamic, whereas simply conserving certain fixed types promotes stasis. Therefore, equally important is the conservation of evolutionary <em>processes</em>, which are the dynamic relationships between salmon and their ecosystems that help shape their evolutionary trajectories. Evolutionary processes include patterns of connectivity, dispersal, and gene flow; sexual selection and natural selection; and interactions with physical and biological features of the habitat. Conserving evolutionary processes requires consideration of the same two steps outlined above. Reflecting on the long-term goals of the Arctic-Yukon-Kuskokwim Sustainable Salmon Initiative will help to focus efforts to identify important units for conservation and vital evolutionary processes for Alaska salmon.

Regional population structuring and conservation units in the platypus (Ornithorhynchus anatinus)

2013 ◽  
Vol 61 (5) ◽  
pp. 378 ◽  
Author(s):  
Stephen H. Kolomyjec ◽  
Tom R. Grant ◽  
Christopher N. Johnson ◽  
David Blair
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Large Scale ◽  
Wide Distribution ◽  
Conservation Units ◽  
Genetic Structuring ◽  
The North ◽  
Contemporary Gene Flow ◽  
Ornithorhynchus Anatinus ◽  
Southern Island

The platypus (Ornithorhynchus anatinus) has a wide distribution in Australia, encompassing the southern island of Tasmania and a broad latitudinal range of the mainland from the temperate south to the tropical north. We used 12 microsatellite markers from 235 individuals sampled from 13 river systems to examine patterns of genetic differentiation and gene flow throughout the species’ range. Using a Bayesian approach we identified three large-scale groupings that correspond closely to geographically distinct regions of the species’ distribution: the tropical northern mainland, the subtropical and temperate southern mainland, and Tasmania. Six additional clusters were found within the regional groups, three in the northern, two in the southern mainland regions, and the last in Tasmania. These clusters coincided with major river drainages. Genetic differentiation was generally high, with pairwise Fst values ranging from 0.065 to 0.368 for regions and 0.037 to 0.479 for clusters. We found no evidence of contemporary gene flow among the three clusters in the north, but some migration may occur between the larger clusters in the south. Due to the high genetic structuring and lack of gene flow between these three regional populations of the platypus we recommend their treatment as evolutionarily significant units (ESUs) within the platypus species. We have also detailed several smaller management units (MUs) existing within our study area based on subregional clusters and geographically significant features.

How different is different? Defining management and conservation units for a problematic exploited species

2009 ◽  
Vol 66 (9) ◽  
pp. 1617-1630 ◽  
Author(s):  
Andrea M. Bernard ◽  
Moira M. Ferguson ◽  
David L.G. Noakes ◽  
Bruce J. Morrison ◽  
Chris C. Wilson
Keyword(s):  
New York ◽  
Fishery Management ◽  
Lake Ontario ◽  
Evolutionary Significance ◽  
Lake Whitefish ◽  
Conservation Units ◽  
Phylogenetic Groups ◽  
Spawning Aggregations ◽  
The Status ◽  
Lake Simcoe

Discontinuous genetic structure is widely used to delineate local, regional, and phylogenetic groups within species for conservation and management purposes. We used microsatellite markers to assess the genetic distinctiveness of putative stocks and populations of lake whitefish ( Coregonus clupeaformis ) in Ontario waters. Analysis of spawning aggregations in eastern Lake Ontario showed fish from Chaumont Bay, New York, to be weakly differentiated from spawning whitefish in and near the Bay of Quinte, Ontario. No significant differences were found between lake- and bay-spawning aggregations within the Bay of Quinte. These same genetic tools were used to test the distinctiveness and evolutionary significance of Lake Simcoe lake whitefish as a designatable unit (DU) under guidelines established by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Although there was marked differentiation among populations from across Ontario, the Lake Simcoe population was closely allied with lake whitefish populations from Lake Ontario and Lake Huron, suggesting that a distinct status is not warranted on genetic grounds. This work demonstrates how assessing hierarchical diversity under COSEWIC’s framework can provide key information of the status of exploited populations for fishery management.

Evaluation of visual survey methods for monitoring Pacific salmon (Oncorhynchus spp.) escapement in relation to conservation guidelines

2008 ◽  
Vol 65 (2) ◽  
pp. 212-226 ◽  
Author(s):  
Kendra R Holt ◽  
Sean P Cox
Keyword(s):  
Coho Salmon ◽  
Pacific Salmon ◽  
Survey Methods ◽  
Effective Means ◽  
Area Under The Curve ◽  
Cost Effective ◽  
Trend Detection ◽  
Conservation Units ◽  
Visual Survey ◽  
Wide Range

Canada’s Wild Salmon Policy requires that biological status of conservation units of Pacific salmon (Oncorhynchus spp.) be assessed regularly in relation to abundance-based benchmarks. Visual survey methods, in which periodic counts of spawning fish are made throughout a season, will likely be used for this purpose because they provide a cost-effective means of monitoring interannual trends in escapement. Trend detection performance for visual survey methods depends mainly upon consistency in (i) the ability of observers to detect fish and (ii) the annual timing of fish presence in the survey area. We developed a Monte Carlo simulation procedure to evaluate the ability of four visual survey methods (peak count, mean count, trapezoidal area-under-the-curve (AUC), and likelihood AUC) to detect 30% declines in coho salmon (Oncorhynchus kisutch) escapement over 10 years (i.e., the magnitude of trend that would warrant listing a coho population as threatened using the listing criteria of the Committee on the Status of Endangered Wildlife in Canada (COSEWIC)) given realistic levels of variability in these two factors. The mean count outperformed all other approaches across a wide range of scenarios about true population dynamics and survey designs, suggesting that a simple mean count method is suitable for monitoring coho escapements in relation to COSEWIC guidelines.

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