An overview of fish stocking in Brazil

Neotropical Ichthyology, Journal Year: 2023, Volume and Issue: 21(3)

Published: Jan. 1, 2023

Abstract Fish stocking is a common management strategy in Brazil, yet no assessment has examined its real extent and features. The present work investigated fish practices Brazil between 2010 2019 to characterize propagule pressure, species composition, the use of non-native species, geographical temporal trends, environment types, responsible agencies. Based on information disseminated internet, study detected 1,155 events (ca. 115 events/year). In total, ca. 56.4 million were stocked, with an average 90 thousand fish/event. We found all Brazilian regions involving 436 municipalities 21 states. Most occurred Northeast region (66.3%), which received alone 41 fish. Reservoirs primary target environment, public sector conducted most events. involved 63 taxa, including 14 taxa three hybrids. Considering that informed 62.4% released summed 19.7 These results provide broad overview reveal this action widely disseminated. Its frequent use, associated lack proper criteria illegal raise concerns about technical aspects, outcomes, potential environmental impacts.

Language: Английский

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DHA and EPA levels in a piscivorous fish changed by preying upon stocked salmon fry

Scientific Reports, Journal Year: 2023, Volume and Issue: 13(1)

Published: Sept. 15, 2023

Increases in prey population size can affect the physiology and ecology of upper-trophic level organisms. This phenomenon is known as a bottom-up effect. For example, increased abundance resources trigger physiological (internal) changes predators, such improvements nutritional status. However, these aspects effects have not been considered. In this study, we tested hypothesis that white-spotted charr Salvelinus leucomaenis, salmonid fish, increases body stores omega-3 fatty acids, especially docosahexaenoic acid (DHA) eicosapentaenoic (EPA), by preying upon stocked hatchery-reared masu salmon Oncorhynchus masou fry streams. The dynamics contents inhabiting salmon-stocked unstocked streams clearly support hypothesis: (DHA, EPA, total acid) after stocking streams, but addition, DHA with increasing vice versa for EPA. impacts human activities, fish stocking, on freshwater ecosystems are matter serious concern conservation. Future attempts to gain comprehensive understanding should consider only community also physiology.

Language: Английский

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Single generation epigenetic change in captivity and reinforcement in subsequent generations in a delta smelt (Hypomesus transpacificus) conservation hatchery

Molecular Ecology, Journal Year: 2024, Volume and Issue: 33(15)

Published: July 5, 2024

Abstract A refugial population of the endangered delta smelt ( Hypomesus transpacificus ) has been maintained at Fish Conservation and Culture Laboratory (FCCL) UC Davis since 2008. Despite intense genetic management, fitness differences between wild cultured fish have observed FCCL. To investigate molecular underpinnings hatchery domestication, we used whole‐genome bisulfite sequencing to quantify epigenetic hatchery‐origin smelt. Differentially methylated regions (DMRs) were identified from 104 individuals by comparing methylation patterns in different generations (G1, G2, G3) with their parents (G0). We discovered a total 132 significant DMRs p < .05) G0 G1, 201 G3. Our results demonstrate substantial emerged hatchery‐reared early hatchery, higher proportion hypermethylated fish. The rearing environment was found be stronger predictor individual clustering based on than family, sex or generation. study indicates reinforcement status successive environment, as evidenced an increase decrease hypomethylated over time. Lastly, our demonstrated heterogeneity inherited pattern families across generations. These insights highlight long‐term consequences practices landscape, potentially impacting populations.

Language: Английский

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Swinging back from the brink? Polygamous mating strategies revealed for an iconic threatened freshwater fish

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 919, P. 170808 - 170808

Published: Feb. 7, 2024

Catastrophic fish death events are increasing in frequency and severity globally. A series of major recent deaths the semi-arid lower Darling-Baaka river system (LDBR) Australia emblematic these issues with tens millions native perishing. In 2018-2019 there was a event for Australia's largest freshwater fish, Murray cod (Maccullochella peelii). To aid recovery guide restoration activities local populations, it is essential to gather information on mating strategies effective population size following event. After deaths, we collected larvae during 2020 2021 breeding seasons used single nucleotide polymorphisms (SNPs) provide insight estimate size. Larvae were detected both years along entire length LDBR. Sixteen percent inferred individuals found contribute multiple pairings, confirming complex polygamous system. high polygamy evident within between 100 % identified among parents that produced offspring 95 involved spawning years. Post-larval samples 2016 co-analysed further inform kinship patterns. Again, monogamy rare no confirmed cases same male-female pair contributing or seasons. Effective based after estimated at 721.6 (CI 471-1486), though this has likely declined subsequent catastrophic LDBR March 2023. Our data into variability strategies, anticipate knowledge will assist planning conservation actions ultimately help recover species crisis.

Language: Английский

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Replicated whole‐lake experiment reveals the ineffectiveness of stocking five example fish species in small lakes

Fisheries Management and Ecology, Journal Year: 2024, Volume and Issue: unknown

Published: April 5, 2024

Abstract Fish stocking is common practice in fisheries management, but its effectiveness to support or increase stock size catches debated. In Lower Saxony, Germany, a controlled, replicated experiment of five native fish species eight gravel pit lakes <20 ha was conducted examine the potential additive effects releases on abundance, indexed by catch per unit effort (CPUE) electrofishing and gillnet samples. were stocked twice four study lakes, while remaining control not subjected any over 6‐year period. Recapture rates individually marked fishes extremely low all species. Consequently, did species‐specific total community abundance. additional experiments separate ponds species, except bream ( Abramis brama ), showed high survival at least one year, indicating general material. marking with passive integrated transponders affect survival, for roach Rutilus rutilus can thus be ruled out as an explanation post‐stocking mortality. We conclude that failed enhance stocks small lakes.

Language: Английский

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Evaluating the impact of captive ancestry on the growth and survival of Delta Smelt in a captive environment

Aquaculture Reports, Journal Year: 2024, Volume and Issue: 36, P. 102169 - 102169

Published: June 1, 2024

Delta Smelt Hypomesus transpacificus, is an endangered fish endemic to the California San Francisco Bay-Delta, USA. Extreme declines of wild population have prompted use cultured supplement since 2021 prevent extinction species. However, evidence adaptation captivity in conservation hatchery has raised concerns about captive-bred for supplementation and how these may differ from Smelt. We conducted a study over two consecutive years investigate effects varying levels captive ancestry on growth survival different domestication index (DI) groups, capturing high DI low values. Fish were monitored larval adult life-stages determine differences between groups. Our findings indicate that can significant influence as we observed reduced at multiple life-stages. The results suggest released hatchery-reared affect performance their offspring natural environment. Further studies might be necessary develop better management strategy enhance efforts.

Language: Английский

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A stochastic hormesis Ricker model and its application to multiple fields

Chaos Solitons & Fractals, Journal Year: 2024, Volume and Issue: 185, P. 115131 - 115131

Published: June 17, 2024

Language: Английский

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A Resilience History of the Columbia River Basin and Salmonid Species: Regimes and Policies

Environments, Journal Year: 2023, Volume and Issue: 10(5), P. 76 - 76

Published: May 2, 2023

We view the history of Columbia River Basin through a resilience lens from point salmonids, as keystone species for river basin ecosystems and social systems. rely on concept multiple stable states depicted in stability landscape, scientific theory, but equally metaphor mental model. Using evidence-based plausibility arguments concerning existence, creation, potential critical transitions between regimes, we describe change over centuries. argue that transition occurred taking state system its historic regime into novel stabilized by new feedbacks institutional configurations. By using space defined four variables used policy deliberations salmon recovery tie our results to historical contemporary management issues. Knowledge (a) which is currently occupied (b) regimes are possible both crucial effective formation. draw distinctions positions held federal agencies, tribal civil society organizations current affairs recommendations, raising questions about appropriate use decision support systems public process making.

Language: Английский

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Go west: Population genomics reveals unexpected population fluctuations and little gene flow in Western hemisphere populations of the predatory lady beetle, Hippodamia convergens

Evolutionary Applications, Journal Year: 2023, Volume and Issue: 17(1)

Published: Dec. 29, 2023

Abstract Hippodamia convergens —the convergent lady beetle, has been used extensively in augmentative biological control of aphids, thrips, and whiteflies across its native range North America, was introduced into South America the 1950s. Overwintering H . populations from western United States are commercially collected released current eastern USA, with little knowledge effectiveness control. Here we use a novel ddRADseq‐based SNP/haplotype discovery approach to estimate range‐wide population diversity, differentiation, recent evolutionary history. Our results indicate (1) significant differentiation among American , (2) no detectable admixture between them, despite repeated augmentation, (3) continued size expansion range. These contradict previous findings using microsatellite markers. In light these new findings, implications for discussed. Additionally, because quantifying non‐target effects is difficult problem migratory beetles, our could serve as cornerstone improving predicting efficacy future releases

Language: Английский

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Evaluation of genetic consequences of stocking on the southern‐margin populations of white‐spotted charr

Ecology and Evolution, Journal Year: 2024, Volume and Issue: 14(8)

Published: Aug. 1, 2024

Abstract Coldwater‐adapted freshwater fishes, especially their populations along warm‐range margins, are most vulnerable to the climate oscillations associated with global warming. Stocking is a major strategy for avoiding extinction of these species. However, while stocking can reverse decline isolated populations, it may also result in loss genetic diversity native local population due introgressive replacement hatchery genes. To plan an adequate conserving locally adapted impacts on lineages should be evaluated from small river branches wide‐ranging drainage areas. We investigated structure white‐spotted charr ( Salvelinus leucomaenis ) within its southern range (Lake Biwa basin, Japan). By applying genome‐wide SNP analysis population's structure, we assessed extent introgression resulting stocking. White‐spotted Lake watershed constitutes distinctive group, which apparent differentiation was observed. The hatchery‐reared fish line commonly used supplementation catchment discernable population, enabling us analyze across entire area. Admixed individuals were observed stocked sites that showed relatively high heterozygosity and nucleotide diversity. much lower than populations. history as well road availability contributed substantially Populations remained upstream regions tested rivers. low when compared supplementation. Our results shed light suggest conventional methods cannot preserve unique biodiversity distribution margin.

Language: Английский

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