Towards vibrant fish populations and sustainable fisheries that benefit all: learning from the last 30 years to inform the next 30 years

Reviews in Fish Biology and Fisheries, Год журнала: 2023, Номер 33(2), С. 317 - 347

Опубликована: Март 4, 2023

A common goal among fisheries science professionals, stakeholders, and rights holders is to ensure the persistence resilience of vibrant fish populations sustainable, equitable in diverse aquatic ecosystems, from small headwater streams offshore pelagic waters. Achieving this requires a complex intersection management, recognition interconnections people, place, that govern these tightly coupled socioecological sociotechnical systems. The World Fisheries Congress (WFC) convenes every four years provides unique global forum debate discuss threats, issues, opportunities facing fisheries. 2021 WFC meeting, hosted remotely Adelaide, Australia, marked 30th year since first meeting was held Athens, Greece, provided an opportunity reflect on progress made past 30 provide guidance for future. We assembled team individuals involved with Adelaide reflected major challenges faced over years, discussed toward overcoming those challenges, then used themes emerged during identify issues improve sustainability world's next years. Key future needs identified include: rethinking management systems modelling approaches, modernizing integrating assessment information systems, being responsive flexible addressing persistent emerging threats fisheries, mainstreaming human dimension governance, policy compliance, achieving equity inclusion also number cross-cutting including better understanding role as nutrition hungry world, adapting climate change, embracing transdisciplinarity, respecting Indigenous knowledge thinking ahead foresight science, working together across scales. By reflecting about future, we aim our mutual sustaining sustainable benefit all. hope prospective can serve guide (i) assess towards lofty (ii) refine path input new voices approaches stewardship.

Язык: Английский

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Variation in Salmon Migration Phenology Bolsters Population Stability but Is Threatened by Drought

Ecology Letters, Год журнала: 2025, Номер 28(2)

Опубликована: Фев. 1, 2025

ABSTRACT Intrapopulation variation in movement is common nature but its effects on population dynamics are poorly understood. Using data from 3270 individually‐marked fish representing nine cohorts of coho salmon ( Oncorhynchus kisutch ) California, we show that bimodal intrapopulation the timing juvenile down‐migration their natal habitat and subsequent residence non‐natal affects growth, emigration timing, abundance stability adult returns. Non‐natal (early down‐migrants) exhibited more variable growth earlier to estuary than (late down‐migrants). While rearing was common, were overrepresented among returns, total returns 1.4 times stable alone. Our results demonstrate migratory behaviour bolsters stability. However, reduced low water years, suggesting drought exacerbates instability by reducing critical variation.

Язык: Английский

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Drought-Induced, Punctuated Loss of Freshwater Mussels Alters Ecosystem Function Across Temporal Scales

Frontiers in Ecology and Evolution, Год журнала: 2019, Номер 7

Опубликована: Июль 18, 2019

Punctuated, mass mortality events are increasing for many animal taxa and often related to climatic extremes such as drought. Freshwater mussels experiencing increased linked hydrologic Because play important functional roles in rivers it is understand the ecosystem effects of these die-offs. Here, we address how caused by drought may impact stream function. We first present a conceptual model, based on literature, mussel should affect different functions across various ecological time scales, from hours decades. Next, highlight two case studies drought-linked, mussel-mass southern U.S. then results an experiment performed quantifying punctuated die-off. Finally, combine our experimental with field data recent die-off predict losses will influence Based presented studies, mesocosm experiment, extrapolated nutrient pulse due die-off, conclude that ecosystems extensively altered following events. Mussel loss governed severity, location within river network, species-specific tolerances. In short term, decomposing carrion die-offs releases large nutrients into water which stimulates food web productivity. long overall biomass, traits more sensitive species decline, leads decreases function take decades recover. Drought human demand make likely future unlikely recover without changes management restoration populations through propagation. Our research provides example abundant, long-lived organism has cascading long-term impacts ecosystems.

Язык: Английский

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Categorising use patterns of non-marine environments by elasmobranchs and a review of their extinction risk

Reviews in Fish Biology and Fisheries, Год журнала: 2019, Номер 29(3), С. 689 - 710

Опубликована: Авг. 2, 2019

Язык: Английский

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Extreme drought causes fish recruitment failure in a fragmented Great Plains riverscape

Ecohydrology, Год журнала: 2019, Номер 12(6)

Опубликована: Июнь 5, 2019

Abstract Dryland stream fishes are adapted to highly connected habitats with unpredictable hydrologic conditions, including frequent low flows and sometimes extreme drought. The flow recruitment hypothesis predicts that some spawn in main channel during when water temperatures prey densities high. However, drought periods might be disruptive even among whose life histories otherwise benefit from lower flows. We studied dynamics of six (family Cyprinidae) at 15 sites a fragmented Great Plains riverscape Kansas, USA, 2 years tracked the chronology gonadal development age 0 test by broadcast planktonic ova would less successful compared demersal or adhesive ova. found all taxa were reproductively active but was evident for only four. two species which not evident, peppered chub ( Macrhybopsis tetranema ) silver storeriana ), confirmed suspected pelagic‐broadcast spawning have declined other dewatered riverscapes. Our data highlight potential within isolated fragments cause complete near‐complete failure fishes, especially those small population sizes. Failed may related mode, characteristics, both. work informs management fish diversity drought‐prone riverscapes establishing mechanistic linkages drought, recruitment, assemblage structure.

Язык: Английский

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Analysis of Smallholders’ Livelihood Vulnerability to Drought across Agroecology and Farm Typology in the Upper Awash Sub-Basin, Ethiopia

Sustainability, Год журнала: 2021, Номер 13(17), С. 9764 - 9764

Опубликована: Авг. 31, 2021

Assessing the magnitude of smallholder farmers’ livelihood vulnerability to drought is an initial step in identifying causal factors and proposing interventions that mitigate impacts drought. This study aimed assess smallholders’ upper Awash sub-basin, Ethiopia. Household (HH) climate data were used for indicators related sensitivity, exposure, adaptive capacity define The was compared among studies agroecological zone (AEZ) farm typologies. result illustrated a diverse index (VI) ranging from −1.956 −4.253 AEZ. highest VI estimated lowland AEZ, while lowest midland could be accounted by fact farmers shown exposure (0.432) sensitivity (0.420) (0.288). A closer look at typology, each showed substantial diversity drought, implying potential aggregations Accordingly, livestock on-farm-income-based marginal off-farm-income-based typologies higher than intensive-irrigation-farming-based typology. Based on result, we concluded procedures resilience-building efforts should better target AEZ prioritize focus region typology tailor technologies farms. Although emphasizes importance irrigation-based strategy, overall enhancement needs action areas such as reducing households, improving usage technologies, diversify options, and, hence, long-term wealth accumulation strengthen toward impacts.

Язык: Английский

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Dynamic contributions of intermittent and perennial streams to fish beta diversity in dryland rivers

Journal of Biogeography, Год журнала: 2019, Номер 46(10), С. 2311 - 2322

Опубликована: Авг. 5, 2019

Abstract Aim To determine the role of flow intermittence and species origin in shaping freshwater fish beta diversity across dryland riverscapes. Location Verde Little Colorado River basins, United States. Methods Fish was investigated two large rivers with marked differences basin‐wide intermittence. Local site (continually flowing perennial vs. periodically intermittent) (native non‐native) contributions to were compared within each basin over multiple decades (1987–2013) relation changing hydrologic conditions. Metacommunity dynamics quantified using changes alpha‐ (local), beta‐ gamma‐ (regional) through time. Results Beta‐diversity patterns varied Intermittent sites most influential where lower (Verde River), whereas higher (Little River). In intermittent sites, native tended be than non‐native contributions. The relative β‐diversity invariant annual regimes, whether atypically or average flows, but somewhat related intra‐annual variation. Native increased years high conditions River. Over time, decreased River, indicating taxonomic homogenization, remained relatively unchanged Main Conclusions Investigations beta‐diversity components time are considered pivotal for conservation prioritization planning. We found that both streams play complementary roles supporting diversity, their increase as wide availability habitat type decreases. Moreover, overall consistent supported diversity. Despite weakening policy protections streams, these habitats critical local persistence regional biodiversity.

Язык: Английский

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No quarter: Lack of refuge during flow intermittency results in catastrophic mortality of an imperiled minnow

Freshwater Biology, Год журнала: 2020, Номер 65(12), С. 2108 - 2123

Опубликована: Сен. 8, 2020

Abstract Many once‐perennial rivers have become intermittent. Channel drying can result in fish mortality if refuges are not available. Understanding where occur and fishes use these provide insight for species persistence help stakeholders manage limited resources. Streamflow diversions the Rio Grande of New Mexico >60 km losses aquatic habitat, affecting up to 30% range imperiled silvery minnow ( Hybognathus amarus ). Potential include areas with perennial flow below diversion dams, isolated pools, irrigation return flows. We examined spatial temporal patterns both adult young‐of‐year collected pools that formed during streamflow intermittency from 2009 2019. hypothesised that: (1) would be more numerous persisted longer; (2) they located closer upstream flow, due movement escape drying; (3) increased rate habitat loss each day pools. During 12 years study, we counted 3,985 intermittency. related counts pool maximum depth, occurred day, distance was an barrier. In 2016, 290 until complete desiccation or reconnection continuous flows occurred, factors influenced persistence. Deeper longer, but depth had a small positive effect on no Adults were whereas downstream Rate channel little numbers stranded when faster. On average, <4 days 263 dried completely before returned. Only 66 4,749 did dry completely. appear intermittency; instead, became shrinking persist long enough act as fishes. Lack refuge catastrophic through there management actions, such translocating fish. To increase intermittency, conservation actions should match response by ensuring availability perennial‐water at appropriate scale.

Язык: Английский

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Nowhere to swim: interspecific responses of prairie stream fishes in isolated pools during severe drought

Aquatic Sciences, Год журнала: 2020, Номер 82(2)

Опубликована: Март 19, 2020

Язык: Английский

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Regional, multi-decadal analysis on the Loire River basin reveals that stream temperature increases faster than air temperature

Hydrology and earth system sciences, Год журнала: 2022, Номер 26(9), С. 2583 - 2603

Опубликована: Май 17, 2022

Abstract. Stream temperature appears to be increasing globally, but its rate remains poorly constrained due a paucity of long-term data and difficulty in parsing effects hydroclimate landscape variability. Here, we address these issues using the physically based thermal model T-NET (Temperature-NETwork) coupled with EROS semi-distributed hydrological reconstruct past daily stream streamflow at scale entire Loire River basin France (105 km2 52 278 reaches). increased for almost all reaches seasons (mean =+0.38 ∘C decade−1) over 1963–2019 period. Increases were greatest spring summer, median increase + 0.38 (range =+0.11 +0.76 ∘C) +0.44 (+0.08 +1.02 per decade, respectively. Rates increases greater than air across majority reaches. Spring summer typically southern part (up +1 largest rivers (Strahler order ≥5). Importantly, could exert joint influence on trends, where accompanied by similar trends +0.71 decreases −16 % decade−1). Indeed, reaches, positive anomalies exhibited synchrony negative streamflow, highlighting dual control exerted hydroclimatic drivers. Moreover, temperature, time series common change points occurring late 1980s, suggesting temporal coherence between changes drivers rapid response. Critically, riparian vegetation shading mitigated up 0.16 decade−1 smaller streams (i.e. < 30 km from source). Our results provide strong support basin-wide rising reduced streamflow. We suggest that some climate change-induced can through restoration maintenance forests.

Язык: Английский

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