Climate Change Effects on Fish Passability across a Rock Weir in a Mediterranean River

Climate change represents a major challenge for the management of native fish communities in Mediterranean rivers, as reductions in discharge may lead to a decrease in passability through small barriers such as weirs, both in temporary and perennial rivers. Through hydraulic modelling, we investigated how discharges from a large hydropower plant in the Tagus River are expected to affect the passability of native freshwater fish species through a rock weir (Pego, Portugal), equipped with a nature-like fish ramp. We considered not only mean daily discharge values retrieved from nearby gauging stations (1991–2005) for our flow datasets, but also predicted discharge values based on climatic projections (RCP) until the end of the century (2071–2100) for the Tagus River. Results showed that a minimum flow of 3 m3 s−1 may be required to ensure the passability of all species through the ramp and that passability was significantly lower in the RCP scenarios than in the historical scenario. This study suggests that climate change may reduce the passability of native fish species in weirs, meaning that the construction of small barriers in rivers should consider the decreases in discharge predicted from global change scenarios for the suitable management of fish populations.

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Climate change effects on the hydrology of the headwaters of the Tagus River: implications for the management of the Tagus–Segura transfer

Hydrology and Earth System Sciences ◽

10.5194/hess-22-6473-2018 ◽

2018 ◽

Vol 22 (12) ◽

pp. 6473-6491 ◽

Cited By ~ 8

Author(s):

Francisco Pellicer-Martínez ◽

José Miguel Martínez-Paz

Keyword(s):

Climate Change ◽

Water Resources ◽

River Basin ◽

Hydrological Model ◽

Water Cycle ◽

Economic Loss ◽

Climate Change Scenarios ◽

Resource Exploitation ◽

Climate Change Effects ◽

Tagus River

Abstract. Currently, climate change is a major concern around the world, especially because of the uncertainty associated with its possible consequences for society. Among them, fluvial alterations can be highlighted in basins whose flows depend on groundwater discharges and snowmelt. This is the case of the headwaters of the Tagus River basin, whose water resources, besides being essential for water uses within this basin, are susceptible to being transferred to the Segura River basin (both basins are in the Iberian Peninsula). This work studies the possible effects that the latest climate change scenarios may have on this transfer, one of the most important ones in southern Europe. In the first place, the possible alterations of the water cycle of the donor basin were estimated. To do this, a hydrological model was calibrated. Then, with this model, three climatic scenarios were simulated, one without climate change and two projections under climate change (Representative Concentration Pathways 4.5 (RCP 4.5) and 8.5 (RCP 8.5)). The results of these three hydrological modelling scenarios were used to determine the possible flows that could be transferred from the Tagus River basin to the Segura River basin, by simulating the water resource exploitation system of the Tagus headwaters. The calibrated hydrological model predicts, for the simulated climate change scenarios, important reductions in the snowfalls and snow covers, the recharge of aquifers, and the available water resources. So, the headwaters of the Tagus River basin would lose part of its natural capacity for regulation. These changes in the water cycle for the climate change scenarios used would imply a reduction of around 70 %–79 % in the possible flows that could be transferred to the Segura basin, with respect to a scenario without climate change. The loss of water resources for the Segura River basin would mean, if no alternative measures were taken, an economic loss of EUR 380–425 million per year, due principally to decreased agricultural production.

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Landscape resistance mediates native fish species distribution shifts and vulnerability to climate change in riverscapes

Global Change Biology ◽

10.1111/gcb.15281 ◽

2020 ◽

Vol 26 (10) ◽

pp. 5492-5508

Author(s):

Michael T. LeMoine ◽

Lisa A. Eby ◽

Chris G. Clancy ◽

Leslie G. Nyce ◽

Michael J. Jakober ◽

...

Keyword(s):

Climate Change ◽

Fish Species ◽

Species Distribution ◽

Native Fish ◽

Landscape Resistance ◽

Vulnerability To Climate Change ◽

Distribution Shifts

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Climate-change threats to native fish in degraded rivers and floodplains of the Murray–Darling Basin, Australia

Marine and Freshwater Research ◽

10.1071/mf11059 ◽

2011 ◽

Vol 62 (9) ◽

pp. 1099 ◽

Cited By ~ 57

Author(s):

Stephen R. Balcombe ◽

Fran Sheldon ◽

Samantha J. Capon ◽

Nick R. Bond ◽

Wade L. Hadwen ◽

...

Keyword(s):

Climate Change ◽

Water Resource ◽

Fish Species ◽

Flow Regimes ◽

Resource Development ◽

Native Fish ◽

Water Resource Development ◽

Tolerant Species ◽

Murray Darling Basin ◽

Impacts Of Climate Change

Many aquatic ecosystems have been severely degraded by water-resource development affecting flow regimes and biological connectivity. Freshwater fish have been particularly affected by these changes and climate change will place further stress on them. The Murray–Darling Basin (MDB), Australia, represents a highly affected aquatic system with dramatically modified flow regimes. This has impaired the health of its rivers, and potentially limited the adaptive capacity of its biota to respond to a changing climate. Here, we present our predictions of the potential impacts of climate change on 18 native fish species across their distributional ranges against the back-drop of past and continuing water-resource development (WRD). Because most of these species are found across a wide range of geographical and hydrological settings, we classified the MDB into 10 regions to account for likely variation in climate-change effects, on the basis of latitude, elevation and WRD. Cold water-tolerant species will be under greater stress than are warm water-tolerant species. In some regions, the negative impacts on exotic fish such as trout are likely to improve current conditions for native species. Because the impacts of climate change on any given species are likely to vary from region to region, regional fish assemblages will also be differentially affected. The most affected region is likely to occur in the highly disturbed Lower Murray River region, whereas the dryland rivers that are less affected in the northern MDB are likely to remain largely unchanged. Although climate change is a current and future threat to the MDB fish fauna, the continued over-regulation of water resources will place as much, if not more, stress on the remnant fish species.

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Climate change effects on the hydrology of the headwaters of the Tagus River: implications for the management of the Tagus-Segura transfer

10.5194/hess-2018-258 ◽

2018 ◽

Cited By ~ 1

Author(s):

Francisco Pellicer-Martínez ◽

José Miguel Martínez-Paz

Keyword(s):

Climate Change ◽

Water Resources ◽

River Basin ◽

Water Cycle ◽

Economic Loss ◽

Hydrological Modelling ◽

Climate Change Scenarios ◽

Resource Exploitation ◽

Climate Change Effects ◽

Tagus River

Abstract. Currently, climate change is a major concern around the world, especially because of the uncertainty associated with its possible consequences for society. Among these can be highlighted the fluvial alterations in basins whose flows depend on groundwater discharges and snow melt. This is the case of the headwaters of the Tagus River Basin, whose water resources, besides being essential for water uses within this basin, are susceptible to being transferred to the Segura River Basin (both basins are in the Iberian Peninsula). This work studies the possible effects that the latest climate change scenarios may have on this transfer, one of the most important in southern Europe. In the first place, the possible alterations of the water cycle of the donor basin were estimated. To do this, a hydrological model was calibrated. Then, with this model, three climatic scenarios were simulated, one without climate change and two projections under climate change (Representative Concentration Representative 4.5 (RCP 4.5) and RCP 8.5). The results of these three hydrological modelling scenarios were used to determine the possible flows that could be transferred from the Tagus River Basin to the Segura River Basin, by simulating the water resource exploitation system of the Tagus headwaters. These hydrological modelling predict, for the simulated climate change scenarios, important reductions in the snowfalls and snow covers, the recharge of aquifers and the available water resources. So, the headwaters of the Tagus River Basin would be the loss of part of its natural capacity for regulation. These changes in the water cycle for the climate change scenarios used would imply a reduction of around 80 % in the possible flows that could be transferred to the Segura Basin, with respect to a scenario without climate change. The loss of water resources for the Segura River Basin would mean, if no alternative measures were taken, an economic loss of 330–380 million euro per year, due principally to decreased agricultural production.

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Referee comment on "Climate change effects on the hydrology of the headwaters of the Tagus River: implications for the management of the Tagus-Segura transfer"

10.5194/hess-2018-258-rc1 ◽

2018 ◽

Author(s):

Anonymous

Keyword(s):

Climate Change ◽

Climate Change Effects ◽

Tagus River

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Climate Change Effects on Hydropower in Mozambique

Applied Sciences ◽

10.3390/app10144842 ◽

2020 ◽

Vol 10 (14) ◽

pp. 4842 ◽

Cited By ~ 2

Author(s):

Miguel Meque Uamusse ◽

Kamshat Tussupova ◽

Kenneth M Persson

Keyword(s):

Climate Change ◽

Power Plants ◽

Large Scale ◽

Feasibility Studies ◽

Hydropower Plant ◽

Small Hydropower ◽

Economic Implications ◽

Climate Change Effects ◽

Hydropower Potential ◽

The Impact

The impact of climate change on the production of hydropower in Mozambique is reviewed and regression analysis is applied to evaluate future climate scenarios. The results show that climate change will cause increased variability of precipitation and create flooding that can damage infrastructure such as hydropower dams. Climate change can also cause drought that will decrease surface water and reduce hydroelectric generation in Mozambique. Electricity generation is to a major extent performed through large-scale hydropower in Mozambique. To fulfill the sustainable development goals (SDGs) and an increased demand for electricity, several large and many small hydropower projects are planned and were built in the country. The economic lifetime of a hydropower plant is typically 100 years, meaning that the hydrologic regimes for the plants should be evaluated for at least this period. Climate change effects are rarely included in present feasibility studies. Economic implications associated with climate change phenomena are higher in Mozambique than in neighboring countries as its future electricity demand to a large extent is forecasted to be met by hydropower. The large hydropower potential in Mozambique should as well be considered when investing in new power plants in southern Africa.

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300 years of change for native fish species in the upper Danube River Basin - historical flow alterations versus future climate change

10.1101/2021.06.14.448400 ◽

2021 ◽

Author(s):

Martin Friedrichs-Manthey ◽

Simone Daniela Langhans ◽

Florian Borgwardt ◽

Thomas Hein ◽

Philipp Stanzel ◽

...

Keyword(s):

Climate Change ◽

Fish Species ◽

Future Climate ◽

Danube River ◽

Future Climate Change ◽

Native Fish ◽

Species Vulnerability ◽

Riverine Fish ◽

Anthropogenic Alterations ◽

Danube River Basin

River ecosystems belong to the most threatened ecosystems on Earth. Historical anthropogenic alterations have, and future climate change will further affect river ecosystems and the species therein. While many studies assess the potential effects of expected future changes on species, little is known about the severity of these changes compared to historical alterations. Here, we used a unique 300-year time series of hydrological and climate data to assess the vulnerability of 48 native fish species in the upper Danube River Basin. We calculated species-specific vulnerability estimates relative to the reference period (1970-2000) for the periods 1800-1830, 1900-1930, and 2070-2100, including two Representative Concentration Pathways (RCP 4.5 and 8.5) and identified the environmental drivers of vulnerability estimates. Models showed that future changes under RCP 4.5 would result in moderate species vulnerability compared to historical conditions, while under RCP 8.5, the vulnerability for all species increased substantially. In addition, species vulnerability was mainly driven by hydrology in the past and is likely to be driven by temperature in the future. Our results show that future climate change would alter environmental conditions for riverine fish species at a similar magnitude as historical anthropogenic hydrological river alterations have. Shedding light on such long-term historical and possible future anthropogenic alterations provides valuable insights for prioritising conservation actions for riverine fish species.

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Climate warming and invasive fish species: Will they replace native fish species in waters of temperate zones?

Biologia ◽

10.1515/biolog-2016-0101 ◽

2016 ◽

Vol 71 (7) ◽

Author(s):

Eva Záhorská

Keyword(s):

Climate Change ◽

Fish Species ◽

Native Species ◽

Life History Traits ◽

Native Fish ◽

High Plasticity ◽

Native Populations ◽

Increasing Temperature ◽

Change Of Life ◽

The Given

AbstractIt is well accepted that climate change will have a significant effect on aquatic environments and together with temperature as one of the most important variables, it will represent a major driver of shift in the ecosystem. The increasing temperature in waters of temperate zones will have stressful effect on coldwater adapted fish species that may lead to the shrink of their area of occurrence or even to their extinction. The fish species able to replace the disappearing native populations would be the ones characterized with high plasticity of phenotypes, and strong biological flexibility, which manifest in quick change of life-history traits. Such species are likely to track the changes in their environment relatively rapidly, whereas the responses of majority native species are slower. The given overview on this topic will try to predict and describe global effect of climate change on ecosystems, impact of invasive species on native fish communities and their possible replacement in the future.

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