Resource polymorphism and diversity of Arctic charr

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Resource polymorphism and diversity of Arctic charr
Salvelinus alpinus in a series of isolated lakes

P. J. Woods*†‡§, D. Young, S. Sk´ ulason*, S. S. Snorrason†
and T. P. Quinn‡

*H´olar University College, H´aeyri 1, 551 Sauð´arkr´okur, Iceland, †University of Iceland, Sturlugata 7, Askja, 101 Reykjavík, Iceland, ‡University of  Washington, Box 355020, Seattle, Washington 98195, U.S.A. and National Park Service, Lake Clark National Park and Preserve, Port Alsworth, AK 99653, U.S.A.

(Received 5 April 2012, Accepted 30 October 2012)

Abstract
Morphological, dietary and life-history variation in Arctic charr Salvelinus alpinus were characterized from three geographically proximate, but isolated lakes and one large lake into which they drain in south-western Alaska. Polymorphism was predicted to occur in the first three lakes because
S. alpinus tend to become polymorphic in deep, isolated lakes with few co-occurring species. Only one morph was evident in the large lake and two of the three isolated lakes. In the third isolated lake, Lower Tazimina Lake, small and large morphs were found, the latter including two forms differing in growth rate. The small morph additionally differed from the two large forms by having
more gill rakers and a deeper body than same-sized individuals of the large morph, consuming more limnetic and fewer benthic resources, having a greater gonado-somatic index and maturing at a smaller size. The two large forms consumed only slightly different foods (more terrestrial insects were consumed by the medium-growth form; more snails by the high-growth form). Trends
in consumption of resources with body shape also differed between lakes. Variability in life history of S. alpinus in these Alaskan lakes was as broad as that found elsewhere. This variability is important for understanding lake ecosystems of remote regions where this species is commonly dominant.

© 2013 The Authors
Journal of Fish Biology © 2013 The Fisheries Society of the British Isles

Journal of Fish Biology (2013) 82, 569–587
doi:10.1111/jfb.12011, available online at wileyonlinelibrary.com

Key words: divergence; intraspecific

Single-nucleotide polymorphisms reveal distribution and migration of Chinook salmon (Oncorhynchus tshawytscha) in the Bering Sea and North Pacific Ocean (publication)

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Larson, W. A., F. M. Utter, K. W. Myers, W. D. Templin, J. E. Seeb, C. M. Guthrie, A. V. Bugaev, and L. W. Seeb. 2013. Single-nucleotide polymorphisms reveal distribution and migration of Chinook salmon (Oncorhynchus tshawytscha) in the Bering Sea and North Pacific Ocean Canadian Journal of Fisheries and Aquatic Sciences 70:128-141.

Abstract
We genotyped Chinook salmon (Oncorhynchus tshawytscha) from the Bering Sea and North Pacific Ocean for 43 singlenucleotide polymorphisms (SNPs) to investigate seasonal distribution and migration patterns. We analyzed 3563 immature fish from 22 spatiotemporal strata; composition analyses were performed using genotype data from spawning stocks spanning the species range. Substantial variation in stock composition existed among spatial and seasonal strata. We inferred patterns of seasonal migration based upon these data along with data from previous tag, scale, and parasite studies. We found that stocks from western Alaska and Yukon River overwinter on the Alaska continental shelf then travel to the middle and western Bering Sea during spring–fall. Stocks from California to Southeast Alaska were distributed in Gulf of Alaska year-round, with a substantial portion of this group migrating northward to the eastern Bering Sea during spring–fall. Proportions of Russian stocks increase when moving east to west in both the Bering Sea and North Pacific Ocean. These data can be used to better understand the impacts of fisheries and climate change on this valuable resource.

Fish assemblages respond to altered flow regimes via ecological filtering of life history strategies

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Mims, M.C., and J.D. Olden. 2013. Fish assemblages respond to altered flow regimes via ecological filtering of life history strategies. Freshwater Biology 58:50-62.

In riverine ecosystems, streamflow determines the physical template upon which the life history strategies of biota are forged. Human freshwater needs and activities have resulted in widespread alteration of the variability, predictability and timing of streamflow, and anticipating the biotic consequences of anthropogenic streamflow alteration is critical for successful environmental flow management. In this study, we examined relationships between dam characteristics, metrics of flow alteration and fish functional community composition according to life history strategies by coupling stream flow records and fish survey data in paired flow-regulated and free-flowing rivers across the conterminous United States. Our study demonstrated that river regulation by large dams has significant hydrological and biological consequences across the United States. We showed that on ecological time scales (i.e. the order of years to decades), dams are effectively changing the functional composition of communities that have established over millennia. Furthermore, the changes are directional and indicate a filtering by dams for some life histories (equilibrium strategists) and against other life histories (opportunists). Finally, our study highlights that dependence upon long-term flow records and availability of biotic
surveys extracted from national survey efforts limit our ability to guide environmental flow standards particularly in data-poor regions.

Relationship between effective population size, inbreeding and adult fitness-related traits in a steelhead (Oncorhynchus mykiss) population released in the wild.

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Relationship between effective population size, inbreeding and adult fitness-related traits in a steelhead (Oncorhynchus mykiss) population released in the wild.

Mol Ecol. 2013 Feb 4;

Authors: Naish KA, Seamons TR, Dauer MB, Hauser L, Quinn TP

Abstract
Inbreeding is of concern in supportive breeding programmes in Pacific salmonids, Oncorhynchus spp, where the number of breeding adults is limited by rearing space or poor survival to adulthood, and large numbers are released to supplement wild stocks and fisheries. We reconstructed the pedigree of 6602 migratory hatchery steelhead (Oncorhynchus mykiss) over four generations, to determine the incidence and fitness consequences of inbreeding in a northwest USA programme. The hatchery maintained an effective population size, N˜e = 107.9 from F(0) to F(2) , despite an increasing census size (N), which resulted in a decreasing N(e) /N ratio (0.35 in F(0) to 0.08 in F(2) ). The reduced ratio was attributed to a small broodstock size, nonrandom transfers and high variance in reproductive success (particularly in males). We observed accumulation of inbreeding from the founder generation (in F(4) , percentage individuals with inbreeding coefficients Δf > 0 = 15.7%). Generalized linear mixed models showed that body length and weight decreased significantly with increasing Δf, and inbred fish returned later to spawn in a model that included father identity. However, there was no significant correlation between Δf and age at return, female fecundity or gonad weight. Similarly, there was no relationship between Δf and reproductive success of F(2) and F(3) individuals, which might be explained by the fact that reproductive success is partially controlled by hatchery mating protocols. This study is one of the first to show that small changes in inbreeding coefficient can affect some fitness-related traits in a monitored population propagated and released to the wild.

PMID: 23379933 [PubMed – as supplied by publisher]

via pubmed: school of aquatic an… http://www.ncbi.nlm.nih.gov/PubMed/23379933?dopt=Abstract

Identifying Preservation and Restoration Priority Areas for Desert Fishes in an Increasingly Invaded World.

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Identifying Preservation and Restoration Priority Areas for Desert Fishes in an Increasingly Invaded World.

Environ Manage. 2013 Jan 26;

Authors: Pool TK, Strecker AL, Olden JD

Abstract
A commonly overlooked aspect of conservation planning assessments is that wildlife managers are increasingly focused on habitats that contain non-native species. We examine this management challenge in the Gila River basin (150,730 km(2)), and present a new planning strategy for fish conservation. By applying a hierarchical prioritization algorithm to >850,000 fish records in 27,181 sub-watersheds we first identified high priority areas (PAs) termed “preservation PAs” with high native fish richness and low non-native richness; these represent traditional conservation targets. Second, we identified “restoration PAs” with high native fish richness that also contained high numbers of non-native species; these represent less traditional conservation targets. The top 10 % of preservation and restoration PAs contained common native species (e.g., Catostomus clarkii, desert sucker; Catostomus insignis, Sonora sucker) in addition to native species with limited distributions (i.e., Xyrauchen texanus, razorback sucker; Oncorhynchus gilae apache, Apache trout). The top preservation and restoration PAs overlapped by 42 %, indicating areas with high native fish richness range from minimally to highly invaded. Areas exclusively identified as restoration PAs also encompassed a greater percentage of native species ranges than would be expected by the random addition of an equivalent basin area. Restoration PAs identified an additional 19.0 and 26.6 % of the total ranges of two federally endangered species-Meda fulgida (spikedace) and Gila intermedia (Gila chub), respectively, compared to top preservation PAs alone-despite adding only 5.8 % of basin area. We contend that in addition to preservation PAs, restoration PAs are well suited for complementary management activities benefiting native fishes.

PMID: 23354872 [PubMed – as supplied by publisher]

via pubmed: school of aquatic an… http://www.ncbi.nlm.nih.gov/PubMed/23354872?dopt=Abstract

Motion-guided attention promotes adaptive communications during social navigation.

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Motion-guided attention promotes adaptive communications during social navigation.

Proc Biol Sci. 2013;280(1754):20122003

Authors: Lemasson BH, Anderson JJ, Goodwin RA

Abstract
Animals are capable of enhanced decision making through cooperation, whereby accurate decisions can occur quickly through decentralized consensus. These interactions often depend upon reliable social cues, which can result in highly coordinated activities in uncertain environments. Yet information within a crowd may be lost in translation, generating confusion and enhancing individual risk. As quantitative data detailing animal social interactions accumulate, the mechanisms enabling individuals to rapidly and accurately process competing social cues remain unresolved. Here, we model how motion-guided attention influences the exchange of visual information during social navigation. We also compare the performance of this mechanism to the hypothesis that robust social coordination requires individuals to numerically limit their attention to a set of n-nearest neighbours. While we find that such numerically limited attention does not generate robust social navigation across ecological contexts, several notable qualities arise from selective attention to motion cues. First, individuals can instantly become a local information hub when startled into action, without requiring changes in neighbour attention level. Second, individuals can circumvent speed-accuracy trade-offs by tuning their motion thresholds. In turn, these properties enable groups to collectively dampen or amplify social information. Lastly, the minority required to sway a group’s short-term directional decisions can change substantially with social context. Our findings suggest that motion-guided attention is a fundamental and efficient mechanism underlying collaborative decision making during social navigation.

PMID: 23325772 [PubMed – in process]

via pubmed: school of aquatic an… http://www.ncbi.nlm.nih.gov/PubMed/23325772?dopt=Abstract

Centennial-scale fluctuations and regional complexity characterize Pacific salmon population dynamics over the past five centuries.

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Centennial-scale fluctuations and regional complexity characterize Pacific salmon population dynamics over the past five centuries.

Proc Natl Acad Sci U S A. 2013 Jan 15;

Authors: Rogers LA, Schindler DE, Lisi PJ, Holtgrieve GW, Leavitt PR, Bunting L, Finney BP, Selbie DT, Chen G, Gregory-Eaves I, Lisac MJ, Walsh PB

Abstract
Observational data from the past century have highlighted the importance of interdecadal modes of variability in fish population dynamics, but how these patterns of variation fit into a broader temporal and spatial context remains largely unknown. We analyzed time series of stable nitrogen isotopes from the sediments of 20 sockeye salmon nursery lakes across western Alaska to characterize temporal and spatial patterns in salmon abundance over the past ∼500 y. Although some stocks varied on interdecadal time scales (30- to 80-y cycles), centennial-scale variation, undetectable in modern-day catch records and survey data, has dominated salmon population dynamics over the past 500 y. Before 1900, variation in abundance was clearly not synchronous among stocks, and the only temporal signal common to lake sediment records from this region was the onset of commercial fishing in the late 1800s. Thus, historical changes in climate did not synchronize stock dynamics over centennial time scales, emphasizing that ecosystem complexity can produce a diversity of ecological responses to regional climate forcing. Our results show that marine fish populations may alternate between naturally driven periods of high and low abundance over time scales of decades to centuries and suggest that management models that assume time-invariant productivity or carrying capacity parameters may be poor representations of the biological reality in these systems.

PMID: 23322737 [PubMed – as supplied by publisher]

via pubmed: school of aquatic an… http://www.ncbi.nlm.nih.gov/PubMed/23322737?dopt=Abstract

Frequency and intensity of productivity regime shifts in marine fish stocks.

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Frequency and intensity of productivity regime shifts in marine fish stocks.

Proc Natl Acad Sci U S A. 2013 Jan 15;

Authors: Vert-Pre KA, Amoroso RO, Jensen OP, Hilborn R

Abstract
Fish stocks fluctuate both in abundance and productivity (net population increase), and there are many examples demonstrating that productivity increased or decreased due to changes in abundance caused by fishing and, alternatively, where productivity shifted between low and high regimes, entirely unrelated to abundance. Although shifts in productivity regimes have been described, their frequency and intensity have not previously been assessed. We use a database of trends in harvest and abundance of 230 fish stocks to evaluate the proportion of fish stocks in which productivity is primarily related to abundance vs. those that appear to manifest regimes of high or low productivity. We evaluated the statistical support for four hypotheses: (i) the abundance hypothesis, where production is always related to population abundance; (ii) the regimes hypothesis, where production shifts irregularly between regimes that are unrelated to abundance; (iii) the mixed hypothesis, where even though production is related to population abundance, there are irregular changes in this relationship; and (iv) the random hypothesis, where production is random from year to year. We found that the abundance hypothesis best explains 18.3% of stocks, the regimes hypothesis 38.6%, the mixed hypothesis 30.5%, and the random hypothesis 12.6%. Fisheries management agencies need to recognize that irregular changes in productivity are common and that harvest regulation and management targets may need to be adjusted whenever productivity changes.

PMID: 23322735 [PubMed – as supplied by publisher]

via pubmed: school of aquatic an… http://www.ncbi.nlm.nih.gov/PubMed/23322735?dopt=Abstract

Pesticides in urban streams and early life stages of pacific coho salmon.

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Pesticides in urban streams and early life stages of pacific coho salmon.

Environ Toxicol Chem. 2013 Jan 7;

Authors: King KA, Grue CE, Grassley JM, Fisk RJ

Abstract
Pesticides are frequently detected in urban streams and are believed to be primarily the result of homeowner use. Although concentrations in most cases are low (<1 µg/L), there is concern that pesticide inputs threaten efforts to restore and enhance salmon habitat. The authors exposed early life stages of coho salmon (Oncorhynchus kisutch) to a pesticide mixture (“cocktail”) representative of those pesticides most frequently reported in urban streams in western Washington State, USA. Life stages were continuously exposed to pulses of the cocktail simulating those in urban streams in fall and winter when coho salmon eggs and sac fry are present. Nominal concentrations of eight herbicides, two insecticides, a fungicide, and a breakdown product were the maximum detected. Fertilization, hatching success, survival, deformities, and growth of fry were not significantly affected. A reduction in fertilization success (19-25%) was not reproducible even when gametes were exposed to 100 times the maximum concentrations detected. Based on the end points examined in the present study, the results suggest that direct exposure to the pesticides most frequently detected in urban streams in western Washington does not impair early life stages of coho salmon and is not a major factor governing the recovery of salmon populations. The extent to which pesticide exposure would affect smoltification, outmigration, and ocean survival needs to be determined. Environ. Toxicol. Chem. © 2013 SETAC.

PMID: 23297254 [PubMed – as supplied by publisher]

via pubmed: school of aquatic an… http://www.ncbi.nlm.nih.gov/PubMed/23297254?dopt=Abstract

2013 Bevan Series

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The 2013 Bevan Series explores the medical, ecological, and ethical
issues around “Should we eat fish?” (dates and topics appended).
Speakers examine a diverse array of topics including whether pregnant
women should eat fish, heart health and fish intake, governance,
sustainability, energy use, and conservation.  The highly acclaimed
speakers include medical researchers, a chef, economist,
policy-makers, scientists, and a MacArthur Genius Award-winner.

We invite you to join us for 10 informative lectures and take your
place at the leading edge of marine conservation. All lectures are
free and open to the public.

When: Thursdays, 10 January – 14 March, 4:30 – 5:30pm
Location: Main auditorium, Fishery Sciences building (FSH 102)
School of Aquatic and Fishery Sciences, University of Washington.

Bevan Series schedule in 2013

  • 10 January, Barton Seaver: Conservation for cod and country: an economic and humanitarian imperative
  • 17 January, Emily Oken: Should pregnant women, nursing mothers, and young children eat fish?
  • 24 January, Peter Tyedmers: Energy use in fisheries: Achilles’ heel or Poseidon’s trident?
  • 31 January, Virginia Butler: The 10,000 year record of sustainable fisheries in the Pacific Northwest
  • 7 February, Rashid Sumaila: New threats to the flow of benefits from the global ocean
  • 14 February, Ted Ames: So what’s really happening with Gulf of Maine cod?
  • 21 February, Poul Degnbol: No seafood for the future without good governance: experiences from Europe
  • 28 February, Elizabeth McLanahan: Meltic Arctic ice: the new frontier for exploitation or conservation?
  • 7 March, David Siscovick: Fish intake and heart health: a clear picture or a new controversy?
  • 14 March, Eddie Allison: The piscivore’s dilemma

Organizer: Trevor A. Branch, Assistant Professor, School of Aquatic
and Fishery Sciences, University of Washington, tbranch@uw.edu,
206-221-0776

The Bevan website includes speaker affiliations, brief biographies,
and talk abstracts:
http://fish.washington.edu/seminars/bevan/schedule.php
Posters can be sent to your organization on request.

Funding for the Series is generously provided by Tanya Bevan, friends
of Don Bevan, Washington Sea Grant, NOAA’s Alaska Fisheries Science
Center and Northwest Fisheries Science Center, and the UW School of
Aquatic and Fishery Sciences.