Impacts of current and future large dams on the geographic range connectivity of freshwater fish worldwide

Proceedings of the National Academy of Sciences, Journal Year: 2020, Volume and Issue: 117(7), P. 3648 - 3655

Published: Feb. 3, 2020

Dams contribute to water security, energy supply, and flood protection but also fragment habitats of freshwater species. Yet, a global species-level assessment dam-induced fragmentation is lacking. Here, we assessed the degree occurrence ranges ∼10,000 lotic fish species worldwide due ∼40,000 existing large dams ∼3,700 additional future hydropower dams. Per river basin, quantified connectivity index (CI) for each by combining its range with high-resolution hydrography locations Ranges nondiadromous were more fragmented (less connected) (CI = 73 ± 28%; mean SD) than diadromous 86 19%). Current levels highest in United States, Europe, South Africa, India, China. Increases especially high tropics, declines CI ∼20 40 percentage points on average across Amazon, Niger, Congo, Salween, Mekong basins. Our can guide management at multiple scales various domains, including strategic planning, identification basins risk, prioritization restoration measures, such as dam removal construction bypasses.

Language: Английский

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A review of the relation between species traits and extinction risk

Biological Conservation, Journal Year: 2019, Volume and Issue: 237, P. 220 - 229

Published: July 12, 2019

Biodiversity is shrinking rapidly, and despite our efforts only a small part of it has been assessed for extinction risk. Identifying the traits that make species vulnerable might help us to predict status those less known. We gathered information on relationships between risk from 173 publications, across all taxa, spatial scales biogeographical regions, in what we think most comprehensive compilation date. aimed identify (1) taxonomical biases, (2) statistically robust generalizable predictors through use meta-analyses. Vertebrates Palaearctic are studied taxon region because higher accumulation data these groups. Among many have suggested be predictors, three had enough Two them potentially useful assessing lesser-known species: regardless taxon, with range narrow habitat breadth more extinction. Contrastingly, body size (the trait) did not present consistently positive or negative response. hypothesize relationship shaped by different aspects, namely phenomena represented depending taxonomic group. To increase understanding drivers extinction, further studies should focus understudied groups such as invertebrates fungi regions tropics expand number comparative analyses avoid current biases.

Language: Английский

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The hidden half: ecology and evolution of cryptobenthic fishes on coral reefs

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2018, Volume and Issue: 93(4), P. 1846 - 1873

Published: May 7, 2018

Teleost fishes are the most diverse group of vertebrates on Earth. On tropical coral reefs, their species richness exceeds 6000 species; one tenth total vertebrate biodiversity. A large proportion this diversity is composed cryptobenthic reef (CRFs): bottom-dwelling, morphologically or behaviourally cryptic typically less than 50 mm in length. Yet, despite and abundance, these both poorly defined understood. Herein we provide a new quantitative definition synthesise current knowledge diversity, distribution life history CRFs. First, use size distributions within families to define 17 core CRF as characterised by high prevalence (>10%) small-bodied (<50 mm). This stands strong contrast 42 fishes, which virtually no have evolved. We posit that small body has allowed CRFs diversify at extremely rates, primarily allowing for fine partitioning microhabitats facilitation allopatric reproductive isolation; yet, far from understanding documenting biodiversity Using rates description since 1758, predict approximately 30 will be described per year until 2050 (approximately twice annual rate compared fishes). Furthermore, 2031, more half fish consist These 'hidden half' reefs. Notably, global geographic coverage spatial resolution data communities uniformly poor, further emphasises remarkable reservoir yet discovered. Although may enabled extensive diversification families, also comes with suite ecological challenges affect fishes' capacities feed, survive reproduce; identify range life-history adaptations overcome limitations. In turn, bestow unique socio-ecological role CRFs, includes key trophodynamics cycling trophic energy provided microscopic prey larger consumers. size, ecology evolutionary make them critical component coral-reef food webs; our review shows highly susceptible variety anthropogenic disturbances. Understanding consequences changes ecosystems require us shed light frequently overlooked but abundant guild fishes.

Language: Английский

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Widespread winners and narrow-ranged losers: Land use homogenizes biodiversity in local assemblages worldwide

PLoS Biology, Journal Year: 2018, Volume and Issue: 16(12), P. e2006841 - e2006841

Published: Dec. 4, 2018

Human use of the land (for agriculture and settlements) has a substantial negative effect on biodiversity globally. However, not all species are adversely affected by use, indeed, some benefit from creation novel habitat. Geographically rare may be more negatively than widespread species, but data limitations have so far prevented global multi-clade assessments land-use effects narrow-ranged species. We analyse large, database to show consistent differences in assemblage composition. Compared with natural habitat, assemblages disturbed habitats average, especially urban areas tropics. All else being equal, this result means that human is homogenizing composition across space. Disturbed both reduced abundances increased Our results very important for conservation because typically at higher risk extinction Furthermore, shift also affect ecosystem functioning reducing contribution diversity species' responses environmental changes among local assemblages.

Language: Английский

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Demographic dynamics of the smallest marine vertebrates fuel coral reef ecosystem functioning

Science, Journal Year: 2019, Volume and Issue: 364(6446), P. 1189 - 1192

Published: May 23, 2019

Little fish make a big contribution Coral reefs represent one of the most biodiverse and rich ecosystems. Such richness conjures up images coral heads large colorful reef fishes. Brandl et al. show, however, that striking important parts ecosystem is almost never seen (see Perspective by Riginos Leis). Small cryptobenthic fish, like blennies, nearly 40% biodiversity. Furthermore, majority larvae settle locally, rather than being widely dispersed, have rapid turnover rates. high diversity densities could thus provide biomass base for larger, better-known fish. Science , this issue p. 1189 ; see also 1128

Language: Английский

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Rapid warming is associated with population decline among terrestrial birds and mammals globally

Global Change Biology, Journal Year: 2018, Volume and Issue: 24(10), P. 4521 - 4531

Published: July 22, 2018

Abstract Animal populations have undergone substantial declines in recent decades. These occurred alongside rapid, human‐driven environmental change, including climate warming. An association between population and change is well established, yet there has been relatively little analysis of the importance rates warming its interaction with conversion to anthropogenic land use causing declines. Here we present a global assessment impact rapid on 987 481 species terrestrial birds mammals since 1950. We collated spatially referenced trends at least 5 years’ duration from Living Planet database used mixed effects models assess these observed warming, use, body mass, protected area coverage. found that abundance for both are greater areas where mean temperature increased more rapidly, this effect pronounced birds. However, do not find strong or Our results identify link declines, thus supporting notion threat biodiversity.

Language: Английский

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Erosion of global functional diversity across the tree of life

Science Advances, Journal Year: 2021, Volume and Issue: 7(13)

Published: March 26, 2021

Among plants and vertebrates, extinction risk is universally higher for the largest species with slower paces of life.

Language: Английский

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Are we eating the world's megafauna to extinction?

Conservation Letters, Journal Year: 2019, Volume and Issue: 12(3)

Published: Feb. 6, 2019

Abstract Many of the world's vertebrates have experienced large population and geographic range declines due to anthropogenic threats that put them at risk extinction. The largest vertebrates, defined as megafauna, are especially vulnerable. We analyzed how human activities impacting conservation status megafauna within six classes: mammals, ray‐finned fish, cartilaginous amphibians, birds, reptiles. identified a total 362 extant species. found 70% species with sufficient information decreasing 59% threatened Surprisingly, direct harvesting for consumption meat or body parts is individual threat each classes examined, 98% (159/162) data available. Therefore, minimizing killing priority strategy might save many these iconic functions services they provide.

Language: Английский

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Assessing the impacts of climate change on biodiversity: is below 2 °C enough?

Climatic Change, Journal Year: 2019, Volume and Issue: 154(3-4), P. 351 - 365

Published: May 22, 2019

Large changes in biodiversity are expected to occur if climate change continues at its current pace. Adverse effects include species habitats and compositions, consequently ecosystem functioning. We assessed the magnitude of by performing a meta-analysis responses distributions change. focused on proportion local remaining their habitats. summarized 97 studies calculated two effect-size metrics from results quantify biodiversity. These fraction (FRS) area (FRA) with suitable for each species. Both calculate deviations original state together they indicate intactness. found an gradual decrease both FRS FRA significant reductions 14% 35% between 1 2 °C increase global mean temperatures. Strong impacts projected mammals plants 19%. The climate-change response varies strongly among taxonomic groups biomes. For some declines beyond 3 temperature increase. Although these estimates conservative, as we assume that unable disperse or adapt, conclude already moderate levels (i.e., 1–2 °C) is projected. Our research supports pledge limit 1.5 preferably lower protect

Language: Английский

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The megabiota are disproportionately important for biosphere functioning

Nature Communications, Journal Year: 2020, Volume and Issue: 11(1)

Published: Feb. 4, 2020

A prominent signal of the Anthropocene is extinction and population reduction megabiota-the largest animals plants on planet. However, we lack a predictive framework for sensitivity megabiota during times rapid global change how they impact functioning ecosystems biosphere. Here, extend metabolic scaling theory use simulation models to demonstrate that (i) are more prone due human land use, hunting, climate change; (ii) loss has negative ecosystem metabolism functioning; (iii) their will continue significantly decrease biosphere functioning. Global simulations show continued large alone could lead 44%, 18% 92% in terrestrial heterotrophic biomass, metabolism, fertility respectively. Our findings suggest policies emphasize promotion trees have disproportionate biodiversity, processes, mitigation.

Language: Английский

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