Long‐term variability in spawning stock age structure influences climate–recruitment link for Barents Sea cod

Fisheries Oceanography, Journal Year: 2022, Volume and Issue: 32(1), P. 91 - 105

Published: Aug. 15, 2022

Fish populations may spawn a vast number of offspring, while only small and highly variable fraction new cohort survives long enough to enter into the fisheries as recruits. It is intuitive that size state spawning stock, adult part fish population, important for recruitment. Additionally, environmental conditions can greatly influence survival through vulnerable early life stages until To understand what regulates recruitment, an essential population dynamics, it thus necessary explain impact fluctuations in both stock environment, including interactions. Here, we examine if connection between environment recruitment affected by biomass, mean age diversity. Specifically, re-evaluate hypothesis stating from dominated young few classes more fluctuations. We expand upon earlier work on Barents Sea Atlantic cod, now with data series extended time backwards forwards cover period 1922-2019. While our findings are correlative cannot prove specific cause effect mechanism, they support strengthen evidence above. Furthermore, this study supports advice management should include considerations status.

Language: Английский

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Half a century of high-latitude fisheries oceanography research on the “recruitment problem” in Northeast Arctic cod (Gadus morhua)

ICES Journal of Marine Science, Journal Year: 2023, Volume and Issue: 80(5), P. 1179 - 1201

Published: May 23, 2023

Abstract Predicting recruitment in a reliable fashion is great challenge within operational fisheries advice. Here, we consulted the unique but undercommunicated IMR Cod Larva Project (1975–1990), its spin-offs, placed an international era of advancements over last 50 years to glance into future. Few initiatives this kind have applied such extensive research approaches, spanning from laboratory, mesocosm, tank, and field studies process modelling. The “critical period” concept appeared misleading, covering months rather than days early life history stages (ELHS) Northeast Arctic cod. Larval feeding success was strongly modified by improved encounter rates wind-induced turbulence. In addition, following maternal effect evidenced that dynamics stock demography prior spawning should be upheld promote success. Although now lower-trophic level models as well ELHS individual-based models, are still insufficiently reflecting needed spatiotemporal resolution. same problem applies climate/circulation models. Nevertheless, long-lasting has significantly mechanistic understanding also more predictable adult reproductive parameters. Based on “to-list list,” suggest avenues pursued further improve our ability predicting strength marine fish stocks.

Language: Английский

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Management strategies can buffer the effect of mass mortality in early life stages of fish

Journal of Applied Ecology, Journal Year: 2023, Volume and Issue: 60(10), P. 2056 - 2065

Published: Aug. 11, 2023

Abstract Mass mortality (MM) events affecting early life stages of fish can have strong and long‐term consequences for population abundance demography as well the economic activity supported by exploited stocks. Adaptive fishery management may help mitigate impacts ensure sustainable resource use following a MM event. Using state‐space cycle model, we simulated ‘what‐if’ scenarios on Northeast Arctic cod ( Gadus morhua ) eggs larvae. We compared expected catches, total stock biomass (TSB), interannual variability in catches over period 10 years after disturbance. further evaluated range mitigation strategies, namely reductions fishing varying duration (1–10 years) intensity (no reduction to full ban). A large led an increase no reductions, especially when applied immediately perturbation was characterized high mean age TSB. Severe substantially but are associated with variability. Fishing moderate between 1 4 would allow only slight Our findings demonstrate potential benefits adaptive approach fisheries highlight that actions exploitation stocks wake unexpected disturbances. Synthesis application . during potentially substantial effects population. Mitigation is more efficient affected has diverse structure strategy perturbation. measure average catch 1–4 event also increases slightly higher catches.

Language: Английский

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The effects of spatial and temporal variations in spawning on offspring survival in Northeast Arctic cod

ICES Journal of Marine Science, Journal Year: 2023, Volume and Issue: 81(3), P. 616 - 626

Published: March 15, 2023

Abstract Climate change and harvesting result in temporal spatial changes variability spawning, thus offspring ambient drift conditions. As a result, variable survival of thereby recruitment are expected. This is especially true for species with long reproduction migration as the case some Atlantic cod stocks. We utilize biophysical model simulations to analyze from spawning until age 1 resulting different scenarios spawning. find that 1.5–2 times higher when shifted southwards compared northerly shifts. In general, more sensitive shifts location than time. Early only favourable if concurrently farther north. A future scenario northward shift grounds beyond what has been observed historically suggests reduced increased sensitivity timing

Language: Английский

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Impact of temperature on Downs herring (Clupea harengus) embryonic stages: First insights from an experimental approach

PLoS ONE, Journal Year: 2023, Volume and Issue: 18(4), P. e0284125 - e0284125

Published: April 7, 2023

Among all human-induced pressures, ocean warming is expected to be one of the major drivers change in marine ecosystems. Fish species are particularly vulnerable during embryogenesis. Here, impact temperature was assessed on embryonic stages Atlantic herring (Clupea harengus), a high socio-economic interest, with particular focus under-studied eastern English Channel winter-spawning component (Downs herring). Key traits linked growth and development were experimentally evaluated at three temperatures (8°C, 10°C 14°C), from fertilization hatching, standardized controlled conditions. Overall negative impacts increased observed rate, mean egg diameter eyed stage, hatching rate yolk sac volume. A faster developmental stage frequency newly hatched larvae also higher temperature. Potential parental effects detected for four key (i.e. survival rate), despite limited number families. For instance, large variability among families shown (between 0 63%). relationships between maternal characteristics embryo therefore explored. We show that substantial proportion variance 31 70%) could explained by female attributes considered. More particularly, age, life history asymptotic average length Brody coefficient), condition important predictors traits. Overall, this study constitutes stepping-stone investigate potential consequences Downs recruitment provides first insights effects.

Language: Английский

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Maternal spawning experience and thermal effects on offspring viability of chub mackerel and their influence on reproductive success

Frontiers in Marine Science, Journal Year: 2022, Volume and Issue: 9

Published: Dec. 23, 2022

Maternal effects on offspring viability significantly contribute to the productivity and resilience of exploited marine fish populations. The temporal trend biomass chub mackerel ( Scomber japonicus ) in western North Pacific showed cyclic fluctuation patterns, but it has been rapidly increasing since 2011. Although there are several assumptions regarding mechanisms population dynamics this species these waters, is a contradiction thermal environmental conditions recruitment success. We explored maternal age and/or previous spawning experience egg traits captive response conditions. Moreover, from relationship between growth rate temperature experienced by fish, temperatures wild specimens were assessed. sizes eggs spawned females aged 1–3 years negatively correlated with temperature, size nutrition significant larger nutrient-rich 2- or 3-year-old (repeat spawners) than those 1-year-old (first-time at given temperature. Such temperature- maternal-age-dependent reflected standard length first-feeding larvae. starvation tolerance larvae after hatching body also evident derived showing longer heights females. Further, grew faster tested temperatures. process ontogenetic development until 25 days positively Meanwhile, estimated ranged 18.0 20.3°C. These findings suggested that opposing responses mackerel, main recruit may be restricted within range available for spawning. discuss reproductive success accordance life history traits.

Language: Английский

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Spatial, temporal, and demographic variability in patagonian toothfish (Dissostichus eleginoides) spawning from twenty-five years of fishery data at South Georgia

Deep Sea Research Part I Oceanographic Research Papers, Journal Year: 2023, Volume and Issue: 203, P. 104199 - 104199

Published: Nov. 22, 2023

Patagonian toothfish (Dissostichus eleginoides) are a commercially important species that support longline fishery at the subantarctic island of South Georgia (CCAMLR Subarea 48.3). Understanding life history is key to successful management and sustainability this fishery. Using catch data from past 25-years, 1997 2021, we provide an updated assessment spatial, temporal, demographic variability spawning Georgia. Our findings confirm occurs in vicinity shelf-break Georgia, with significant hotspots detected Shag Rocks, midway along both northern southern shelf breaks, eastern end island. The location these were consistent over 25-years examined. Based on between 2007, when fishing occurred routinely all around 40% hotspot locations overlapped regions where Benthic Closed Areas (BCAs) established 2008. With this, can estimate approximately located within, already protected by, existing network BCAs. There was evidence timing exhibited bimodality peak April being observed first two years time series. This fell outside seasonally restricted season for many subsequent years. These discussed context historic, current, possible future regulatory changes

Language: Английский

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Spatiotemporal variation in the size structure of the chub mackerel, Scomber japonicus, over half a century in the East Asian Marginal Seas

Regional Studies in Marine Science, Journal Year: 2023, Volume and Issue: 68, P. 103263 - 103263

Published: Oct. 27, 2023

Language: Английский

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Large biomass reduction effect on the relative role of climate, fishing, and recruitment on fish population dynamics

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: April 18, 2024

Many species around the world have collapsed, yet only some recovered. A key question is what happens to populations post collapse. Traditionally, marine fish collapses are linked overfishing, poor climate, and recruitment. We test whether effect on biomass change from these drivers remains same after a used regression model analyse of harvesting, recruitment, climate variability before collapse across 54 world. The most salient result was in fishing that became weaker sea temperature recruitment effects were more variable systems. strongest changes pelagic habitats. resultant sensitivity external indicates whilst may be rebuilt, responses variables known affect stocks changed Our results show general applied many provides useful insights, but not all respond similarly calling for stock-specific models. Stocks environmental differently collapse, so caution needed when using pre-collapse knowledge advise population dynamics management.

Language: Английский

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Accounting for Salmon Body Size Declines in Fishery Management Can Reduce Conservation Risks

Fish and Fisheries, Journal Year: 2024, Volume and Issue: 26(1), P. 113 - 130

Published: Nov. 11, 2024

ABSTRACT Changes in population demographic structure can have tangible but unknown effects on management effectiveness. Fishery of Pacific salmon is often informed by estimates the number spawners expected to produce maximum sustainable yield ( S MSY ), implicitly assuming that reproductive output per spawner does not change over time. However, many populations experienced long‐term trends age, sex and length compositions resulted smaller body sizes mature fish. We present an empirically based simulation approach for evaluating implications declining resulting from shifting demographics. simulated with or without trends, selective unselective harvests, harvest policies assessment methods did account explicitly when estimating . A strategy evaluation showed reduced harvests run exhibited negative trends. Reduced abundances increased conservation risks (higher probability falling below abundance threshold) could be partially mitigated using stock‐recruitment analyses total egg mass instead abundance, via precautionary where target escapements were higher than , especially fisheries selectively removed large Explicit accounting stock‐recruit up 25% 20% lower compared traditional toward smaller, younger male‐biased runs population. Conservation may critical sustaining productive fish their benefits ecosystems people.

Language: Английский

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