Strontium isotopes simultaneously delineate fine-scale natal habitats and migrations of Pacific salmon harvested during a coastal commercial fishery.

We synthesized an expert review of climate change implications for hydroecological and terrestrial ecological systems in the northern coastal temperate rainforest of North America. Our synthesis is based on an analysis of projected temperature, precipitation, and snowfall stratified by eight biogeoclimatic provinces and three vegetation zones. Five IPCC CMIP5 global climate models (GCMs) and two representative concentration pathways (RCPs) are the basis for projections of mean annual temperature increasing from a current average (1961-Climatic Change (2015 1990) of 3.2°C to 4.9-6.9°C (5 GCM range; RCP4.5 scenario) or 6.4-8.7°C (RCP8.5), mean annual precipitation increasing from 3130 mm to 3210-3400 mm (3-9 % increase) or 3320-3690 mm (6-18 % increase), and total precipitation as snow decreasing from 1200 mm to 940-720 mm (22-40 % decrease) or 720-500 mm (40-58 % decrease) by the 2080s (2071-2100; 30-year normal period). These projected changes are anticipated to result in a cascade of ecosystem-level effects including: increased frequency of flooding and rain-on-snow events; an elevated snowline and reduced snowpack; changes in the timing and magnitude of stream flow, freshwater thermal regimes, and riverine nutrient exports; shrinking alpine habitats; altitudinal and latitudinal expansion of lowland and subalpine forest types; shifts in suitable habitat boundaries for vegetation and wildlife communities; adverse effects on species with rare ecological niches or limited dispersibility; and shifts in anadromous salmon distribution and productivity. Our collaborative synthesis of potential impacts highlights the coupling of social and ecological systems that characterize the region as well as a number of major information gaps to help guide assessments of future conditions and adaptive capacity.

Phylogeography and intraspecific genetic variation were studied in prochilodontids endemic to the Orinoco, Essequibo and Amazon River basins of northern South America. Portions of two protein-encoding mitochondrial (mt) DNA genes, ND4 and COI, were examined using singlestrand conformational polymorphisms (SSCPs) and nucleotide sequencing. Phylogeographic analysis indicated that the geographically widespread Prochilodus rubrotaeniatus is paraphyletic, with individuals from the Orinoco sharing most recent common ancestry with co-occurring Prochilodus mariae. A second Prochilodus rubrotaeniatus clade was composed of haplotypes found in the Rio Cuyunı´(Essequibo Basin) and tributaries of the Rio Negro (Amazon Basin). Intraspecific genetic analysis suggested that a complex set of processes have influenced patterns of genetic variation in prochilodontid lineages. Prochilodus rubrotaeniatus is monomorphic at both loci in the Rio Negro and probably recently colonized this basin from the Rio Essequibo. Only two of 55 P. mariae exhibited variant haplotypes, and both had resulted from nonsynonymous changes in the ND4 region. These observations were counter to neutral expectation and consistent with the action of natural selection on the mitochondrion. Overall, these analyses implicate vicariance, demography and selection for driving diversification of prochilodontids in northern South America. # 2004 The Fisheries Society of the British Isles

DS, Allendorf FW. Population structure and partial anadromy in Oncorhynchus mykiss from Kamchatka: relevance for conservation strategies around the Pacific Rim.Abstract -Conservation of life-history diversity found in Oncorhynchus mykiss requires knowledge of the underlying population structure and genetic basis of this variability. We analysed variation at 10 microsatellite loci from seven rivers across Kamchatka to identify population structure and to test for divergence between life-history forms. We found lower heterozygosity in Kamchatkan populations compared with North American populations, but population structure was substantial (region-wide F ST ¼ 0.11) and followed an isolation-by-distance pattern similar to that reported for older North American populations. We found no evidence for genetic divergence between resident and anadromous individuals in the Sopochnaya River or between typically anadromous individuals and 'half-pounders' in the Utkholok River. A review of other studies of reproductive isolation, in combination with our results, suggests: (1) that pristine populations of steelhead should be expected to exhibit partial anadromy; and (2) that managing anadromous and resident individuals separately without demonstrating reproductive isolation is biologically unsound.

Many studies exclude loci that exhibit linkage disequilibrium (LD); however, high LD can signal reduced recombination around genomic features such as chromosome inversions or sex-determining regions. Chromosome inversions and sex-determining regions are often involved in adaptation, allowing for the inheritance of co-adapted gene complexes and for the resolution of sexually antagonistic selection through sex-specific partitioning of genetic variants. Genomic features such as these can escape detection when loci with LD are removed; in addition, failing to account for these features can introduce bias to analyses. We examined patterns of LD using network analysis to identify an overlapping chromosome inversion and sex-determining region in chum salmon. The signal of the inversion was strong enough to show up as false population substructure when the entire dataset was analyzed, while the effect of the sex-determining region on population structure was only obvious after restricting analysis to the sex chromosome. Understanding the extent and geographic distribution of inversions is now a critically important part of genetic analyses of natural populations. Our results highlight the importance of analyzing and understanding patterns of LD in genomic dataset and the perils of excluding or ignoring loci exhibiting LD. Blindly excluding loci in LD would have prevented detection of the sex-determining region and chromosome inversion while failing to understand the genomic features leading to high-LD could have resulted in false interpretations of population structure.