Peculiarities of the Pontogammarus robustoides (Amphipoda, Gammaridae) Adaptive Reactions to the Water Temperature Increasing in the Model Ecosystem – Microcosm

The crustaceans’ family Gammaridae populations’ adaptive reactions with a water temperature increasing to the critical values were studied in the model ecosystem – the microcosm. The experiment included investigation of such indexes as population dimensional composition, precopulatory activity, number of oviparous females, embryogenesis duration, and energy metabolism at the different phases of thermocycle. Obtained data revealed optimal and critical for gammarid’s viability temperature conditions of environment. It is assumed that under conditions of climate change, when water temperature sharp fluctuations take place, in the Kyiv reservoir (Dnipro River, Ukraine) coastal shallow water crustacean’s family Gammaridae components of the invertebrates associations the structural and functional changes are expected. Temperature increasing to the critical values will promote the animals migration processes intensification; incapable of this animals will perish. Gammarids with ability to migrate in direction of areas with more favorable for their viability conditions will have a significant advantage.

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Surface Water Temperature Predictions at a Mid-Latitude Reservoir under Long-Term Climate Change Impacts Using a Deep Neural Network Coupled with a Transfer Learning Approach

Water ◽

10.3390/w13081109 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1109

Author(s):

Nobuaki Kimura ◽

Kei Ishida ◽

Daichi Baba

Keyword(s):

Climate Change ◽

Surface Water ◽

Water Temperature ◽

Transfer Learning ◽

Air Temperature ◽

Climate Models ◽

Temporal Variations ◽

Training Data ◽

Surface Water Temperature

Long-term climate change may strongly affect the aquatic environment in mid-latitude water resources. In particular, it can be demonstrated that temporal variations in surface water temperature in a reservoir have strong responses to air temperature. We adopted deep neural networks (DNNs) to understand the long-term relationships between air temperature and surface water temperature, because DNNs can easily deal with nonlinear data, including uncertainties, that are obtained in complicated climate and aquatic systems. In general, DNNs cannot appropriately predict unexperienced data (i.e., out-of-range training data), such as future water temperature. To improve this limitation, our idea is to introduce a transfer learning (TL) approach. The observed data were used to train a DNN-based model. Continuous data (i.e., air temperature) ranging over 150 years to pre-training to climate change, which were obtained from climate models and include a downscaling model, were used to predict past and future surface water temperatures in the reservoir. The results showed that the DNN-based model with the TL approach was able to approximately predict based on the difference between past and future air temperatures. The model suggested that the occurrences in the highest water temperature increased, and the occurrences in the lowest water temperature decreased in the future predictions.

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Water Temperature and Hydrological Modelling in the Context of Environmental Flows and Future Climate Change: Case Study of the Wilmot River (Canada)

Water ◽

10.3390/w13152101 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2101

Author(s):

Christian Charron ◽

André St-Hilaire ◽

Taha B.M.J. Ouarda ◽

Michael R. van den Heuvel

Keyword(s):

Climate Change ◽

Water Temperature ◽

Environmental Flows ◽

Low Flow ◽

Future Climate Change ◽

Climate Change Scenarios ◽

Water Abstraction ◽

Surface Water Flow ◽

Modelling Studies ◽

Rcp 8.5

Simulation of surface water flow and temperature under a non-stationary, anthropogenically impacted climate is critical for water resource decision makers, especially in the context of environmental flow determination. Two climate change scenarios were employed to predict streamflow and temperature: RCP 8.5, the most pessimistic with regards to climate change, and RCP 4.5, a more optimistic scenario where greenhouse gas emissions peak in 2040. Two periods, 2018–2050 and 2051–2100, were also evaluated. In Canada, a number of modelling studies have shown that many regions will likely be faced with higher winter flow and lower summer flows. The CEQUEAU hydrological and water temperature model was calibrated and validated for the Wilmot River, Canada, using historic data for flow and temperature. Total annual precipitation in the region was found to remain stable under RCP 4.5 and increase over time under RCP 8.5. Median stream flow was expected to increase over present levels in the low flow months of August and September. However, increased climate variability led to higher numbers of periodic extreme low flow events and little change to the frequency of extreme high flow events. The effective increase in water temperature was four-fold greater in winter with an approximate mean difference of 4 °C, while the change was only 1 °C in summer. Overall implications for native coldwater fishes and water abstraction are not severe, except for the potential for more variability, and hence periodic extreme low flow/high temperature events.

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Responses of Benthic Macroinvertebrate Communities of Two Tropical, High-Mountain Lakes to Climate Change and Deacidification

Diversity ◽

10.3390/d13060243 ◽

2021 ◽

Vol 13 (6) ◽

pp. 243

Author(s):

Javier Alcocer ◽

Luis A. Oseguera ◽

Diana Ibarra-Morales ◽

Elva Escobar ◽

Lucero García-Cid

Keyword(s):

Climate Change ◽

Species Richness ◽

Water Temperature ◽

Water Level ◽

Environmental Changes ◽

Mountain Lakes ◽

High Mountain ◽

Macroinvertebrate Communities ◽

High Mountain Lakes ◽

La Luna

High-mountain lakes are among the most comparable ecosystems globally and recognized sentinels of global change. The present study pursued to identify how the benthic macroinvertebrates (BMI) communities of two tropical, high mountain lakes, El Sol and La Luna, Central Mexico, have been affected by global/regional environmental pressures. We compared the environmental characteristics and the BMI communities between 2000–2001 and 2017–2018. We identified three principal environmental changes (the air and water temperature increased, the lakes’ water level declined, and the pH augmented and became more variable), and four principal ecological changes in the BMI communities [a species richness reduction (7 to 4), a composition change, and a dominant species replacement all of them in Lake El Sol, a species richness increase (2 to 4) in Lake La Luna, and a drastic reduction in density (38% and 90%) and biomass (92%) in both lakes]. The air and water temperature increased 0.5 °C, and lakes water level declined 1.5 m, all suggesting an outcome of climate change. Contrarily to the expected acidification associated with acid precipitation, both lakes deacidified, and the annual pH fluctuation augmented. The causes of the deacidification and the deleterious impacts on the BMI communities remained to be identified.

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Attraction of an artificial reef: a migratory demersal flounder remains in shallow water under high temperature conditions in summer

Environmental Biology of Fishes ◽

10.1007/s10641-021-01153-0 ◽

2021 ◽

Author(s):

Hiromichi Mitamura ◽

Hideaki Nishizawa ◽

Yasushi Mitsunaga ◽

Kotaro Tanaka ◽

Junichi Takagi ◽

...

Keyword(s):

High Temperature ◽

Shallow Water ◽

Artificial Reef ◽

Temperature Conditions

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Combined Effects of Climate Change and Bank Stabilization on Shallow Water Habitats of Chinook Salmon

Conservation Biology ◽

10.1111/cobi.12168 ◽

2013 ◽

Vol 27 (6) ◽

pp. 1201-1211 ◽

Cited By ~ 3

Author(s):

JEFFREY C. JORGENSEN ◽

MICHELLE M. MCCLURE ◽

MINDI B. SHEER ◽

NANCY L. MUNN

Keyword(s):

Climate Change ◽

Shallow Water ◽

Chinook Salmon ◽

Combined Effects ◽

Bank Stabilization

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Seasonal Dynamics in the Number and Composition of Coliform Bacteria in Drinking Water Reservoirs

10.1101/2021.02.16.428560 ◽

2021 ◽

Author(s):

Carolin Reitter ◽

Heike Petzoldt ◽

Andreas Korth ◽

Felix Schwab ◽

Claudia Stange ◽

...

Keyword(s):

Climate Change ◽

Drinking Water ◽

Microbial Community ◽

Water Temperature ◽

Surface Waters ◽

Coliform Bacteria ◽

List Type ◽

Water Production ◽

Water Reservoirs ◽

Drinking Water Production

AbstractWorldwide, surface waters like lakes and reservoirs are one of the major sources for drinking water production, especially in regions with water scarcity. In the last decades, they have undergone significant changes due to climate change. This includes not only an increase of the water temperature but also microbiological changes. In recent years, increased numbers of coliform bacteria have been observed in these surface waters. In our monitoring study we analyzed two drinking water reservoirs (Klingenberg and Kleine Kinzig Reservoir) over a two-year period in 2018 and 2019. We detected high numbers of coliform bacteria up to 2.4 x 104 bacteria per 100 ml during summer months, representing an increase of four orders of magnitude compared to winter. Diversity decreased to one or two species that dominated the entire water body, namely Enterobacter asburiae and Lelliottia spp., depending on the reservoir. Interestingly, the same, very closely related strains have been found in several reservoirs from different regions. Fecal indicator bacteria Escherichia coli and enterococci could only be detected in low concentrations. Furthermore, fecal marker genes were not detected in the reservoir, indicating that high concentrations of coliform bacteria were not due to fecal contamination. Microbial community revealed Frankiales and Burkholderiales as dominant orders. Enterobacterales, however, only had a frequency of 0.04% within the microbial community, which is not significantly affected by the extreme change in coliform bacteria number. Redundancy analysis revealed water temperature, oxygen as well as nutrients and metals (phosphate, manganese) as factors affecting the dominant species. We conclude that this sudden increase of coliform bacteria is an autochthonic process that can be considered as a mass proliferation or “coliform bloom” within the reservoir. It is correlated to higher water temperatures in summer and is therefore expected to occur more frequently in the near future, challenging drinking water production.HighlightsColiform bacteria proliferate in drinking water reservoirs to values above 104 per 100 mlThe genera Lelliottia and Enterobacter can form these “coliform blooms”Mass proliferation is an autochthonic process, not related to fecal contaminationsIt is related to water temperature and appears mainly in summerIt is expected to occur more often in future due to climate changeGraphical abstract

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Environmental Change Threatens Freshwater Insect Communities in Northwest Africa: A Meta-Analysis

Frontiers in Environmental Science ◽

10.3389/fenvs.2021.671715 ◽

2021 ◽

Vol 9 ◽

Author(s):

Nils Kaczmarek ◽

Ralf B. Schäfer ◽

Elisabeth Berger

Keyword(s):

Climate Change ◽

Water Temperature ◽

Negative Binomial ◽

Small Body ◽

Future Research ◽

Insect Communities ◽

Data Set ◽

Temperature Conductivity ◽

Northwest Africa ◽

The Impact

A climatic shift from temperate to arid conditions is predicted for Northwest Africa. Water temperature, salinity, and river intermittency are likely to increase, which may impact freshwater communities, ecosystem functioning, and related ecosystem services. Quantitative data and information on the impact of climate change on insect communities (e.g., richness, taxonomic and trait composition) are still scarce for Northwest Africa. In this study, we extracted information on freshwater insect occurrence and environmental variables in Northwest Africa from the results of a literature search to study potential consequences of changing climatic conditions for these communities. Our data set covered 96 families in 165 sites in Morocco and Algeria. We quantified the impact of several explanatoryvariables (climate, altitude, water temperature, conductivity, intermittency, flow, aridity, dams, and land cover) on richness, taxonomic and functional trait composition using negative binomial regression models and constrained ordination. Family richness in arid sites was on average 37 % lower than in temperate sites in association with flow, river regulation, cropland extent, conductivity, altitude, and water temperature. With 36 % of the studied temperate sites predicted to turn arid by the end of the century, a loss of insect families can be predicted for Northwest Africa, mainly affecting species adapted to temperate environments. Resistance and resilience traits such as small body size, aerial dispersal, and air breathing promote survival in arid climates. Future research should report insect occurrences on species level to allow for better predictions on climate change effects.

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Latitudinal patterns in intertidal ecosystem structure in West Greenland suggest resilience to climate change

10.1101/2021.01.05.419028 ◽

2021 ◽

Author(s):

Jakob Thyrring ◽

Susse Wegeberg ◽

Martin E Blicher ◽

Dorte Krause-Jensen ◽

Signe H&oslashgslund ◽

...

Keyword(s):

Climate Change ◽

Ascophyllum Nodosum ◽

Tidal Range ◽

Environmental Drivers ◽

Small Scale ◽

Ecosystem Structure ◽

Assemblage Composition ◽

West Greenland ◽

Functional Changes ◽

Time Substitution

Climate change has ecosystem-wide cascading effects. Little is known, however, about the resilience of Arctic marine ecosystems to environmental change. Here we quantify and compare large-scale patterns in rocky intertidal biomass, coverage and zonation in six regions along a north-south gradient of temperature and ice conditions in West Greenland (60-72°N). We related the level and variation in assemblage composition, biomass and coverage to latitudinal-scale environmental drivers. Across all latitudes, the intertidal assemblage was dominated by a core of stress-tolerant foundation species that constituted >95% of the biomass. Hence, canopy-forming macroalgae, represented by Fucus distichus subsp. evanescens and F. vesiculosus and, up to 69 °N, also Ascophyllum nodosum, together with Semibalanus balanoides, occupied >70% of the vertical tidal range in all regions. Thus, a similar functional assemblage composition occurred across regions, and no latitudinal depression was observed. The most conspicuous difference in species composition from south to north was that three common species (the macroalgae Ascophyllum nodosum, the amphipod Gammarus setosus and the gastropod Littorina obtusata) disappeared from the mid-intertidal, although at different latitudes. There were no significant relationships between assemblage metrics and air temperature or sea ice coverage as obtained from weather stations and satellites, respectively. Although the mean biomass decreased >50% from south to north, local biomass in excess of 10 000 g ww m-2 was found even at the northernmost site, demonstrating the patchiness of this habitat and the effect of small-scale variation in environmental characteristics. Hence, using the latitudinal gradient in a space-for-time substitution, our results suggest that while climate modification may lead to an overall increase in the intertidal biomass in north Greenland, it is unlikely to drive dramatic functional changes in ecosystem structure in the near future. Our dataset provides an important baseline for future studies to verify these predictions for Greenlands intertidal zone.

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