Freshwater Populations, Interactions, and Networks

2018 ◽  
pp. 257-282
Author(s):  
David M. Harper ◽  
Nic Pacini
Keyword(s):  
Solar Energy ◽  
Life Histories ◽  
Patch Dynamics ◽  
Freshwater Ecosystems ◽  
Community Studies ◽  
Community Characteristics ◽  
Species List ◽  
Natural Change ◽  
Heat Of Evaporation ◽  
Numerical Dynamics

Freshwater ecosystems are never static and a species list alone hides that dynamism. Species come and go; populations wax and wane, so basic understanding of the numerical dynamics is necessary to separate ‘natural’ change from anthropogenic-induced change. Numerical changes in species or populations give clues, unravelling details of the changes. For example, quantifying life histories in changing populations or commonalities such as strategies in species changes is often necessary. Community characteristics, such as indices for vegetation or water quality, provide a different perspective on dynamics. Both population and community studies are now greatly assisted by environmental genetics, or eDNA. Ecosystems are made up of patches, as are landscapes, such that the patch dynamics often indicates much about the changing biological dynamics and networks. Energy to make ecosystems function is a small fraction of the solar energy that hits the earth; a far higher fraction is transformed by the vegetation of the ecosystem into latent heat of evaporation and is stored in water vapour. In its absence or reduction, that solar energy is transformed into heat, raising the temperature of the land and air.

scholarly journals Odonata (Insecta) from Nova Xavantina, Mato Grosso, Central Brazil: Information on species distribution and new records

Check List ◽  
2014 ◽  
Vol 10 (2) ◽  
pp. 299 ◽  
Author(s):  
Lenize Batista Calvão ◽  
Paulo De Marco Júnior ◽  
Joana Darc Batista
Keyword(s):  
Species Distribution ◽  
New Records ◽  
Freshwater Ecosystems ◽  
Species List ◽  
Mato Grosso ◽  
Central Brazil ◽  
Fixed Area ◽  
Freshwater Environments ◽  
Tropical Freshwater

Odonates are found in all freshwater environments, and are specially species rich in tropical freshwater ecosystems. Currently about 800 odonate species are known to Brazil, but only 29% of the Brazil territory have been surveyed for this group. Here we provide a species list with information on distribution and new records for Odonata in nine streams in Nova Xavantina, Mato Grosso, Central Brazil. We used the scan procedure with a fixed area for three days in each stream between 10:00 and 14:00h. We collected 1038 dragonfly specimens belonging to 67 species, which represents 8% of the known Brazil odonate fauna. Additionally, five new records for the study area are presented.

Carcass additions increase juvenile salmonid growth, condition, and size in an interior Columbia River Basin tributary

2020 ◽  
Vol 77 (4) ◽  
pp. 703-715 ◽  
Author(s):  
Matthew J. Kaylor ◽  
Seth M. White ◽  
Edwin R. Sedell ◽  
Dana R. Warren
Keyword(s):  
Body Size ◽  
Growth Rates ◽  
Life Histories ◽  
Freshwater Ecosystems ◽  
Steelhead Trout ◽  
Juvenile Salmonids ◽  
Early Fall ◽  
Juvenile Chinook ◽  
The Relationship

Numbers of anadromous fish returning to freshwater ecosystems have declined precipitously across much of western North America, reducing a potentially important resource subsidy for juvenile salmonids. We added carcasses to three sections of a Snake River tributary and assessed juvenile Chinook salmon (Oncorhynchus tshawytcha) and steelhead trout (Oncorhynchus mykiss) growth, body condition, size, and diet responses in summer and early fall. Juvenile salmonids consumed an abundance of eggs and carcass tissue, which increased energy rations. Within 3 weeks of carcass additions, juvenile Chinook and steelhead growth rates were 1.1–5 and 6–23 times greater in treatment reaches relative to control reaches, respectively. We used long-term tagging and detection data from this system to assess the relationship between juvenile Chinook size and emigration survival for two different juvenile life histories. The increased growth rates and body size in response to carcass additions, coupled with a positive relationship between body size and survival, suggest that juvenile salmonid rearing productivity and emigration survival may be limited by depressed returns of anadromous fishes in this system and potentially other tributaries of the Columbia Basin.

scholarly journals Marine trophic diversity in an anadromous fish is linked to its life-history variation in fresh water

2013 ◽  
Vol 9 (1) ◽  
pp. 20120824 ◽  
Author(s):  
Susan P. Johnson ◽  
Daniel E. Schindler
Keyword(s):  
Life History ◽  
Life Histories ◽  
Sockeye Salmon ◽  
Freshwater Ecosystems ◽  
Life History Variation ◽  
Trophic Diversity ◽  
Trade Offs ◽  
Salmon Population ◽  
Freshwater Habitats ◽  
Foraging Tactics

We used carbon and nitrogen stable isotopes from muscle tissues accrued in the ocean to examine whether marine foraging tactics in anadromous sockeye salmon ( Oncorhynchus nerka ) are linked to their ultimate freshwater life history as adults. Adults from large-bodied populations spawning in deep freshwater habitats had more enriched δ 15 N than individuals from small-bodied populations from shallow streams. Within populations, earlier maturing individuals had higher δ 15 N than older fish. These differences in δ 15 N suggest that the fish with different life histories or spawning habitats in freshwater either fed at different trophic positions or in different habitats in the ocean. We propose that, nested within interspecific diversity in the ecological attributes of salmon, population and life-history diversity in spawning adults is associated with variation in marine foraging tactics. These results further indicate that the trophic diversity of sockeye salmon in the ocean may be linked to trade-offs in ecological and evolutionary constraints they eventually experience as adults in freshwater ecosystems.

scholarly journals Development of Solar Accumulating Drying Equipment Based on the Theoretical Studies of Solar Energy Accumulation

2020 ◽  
Vol 63 (2) ◽  
pp. 174-192
Author(s):  
J. E. Safarov ◽  
Sh. A. Sultanova ◽  
G. T. Dadayev
Keyword(s):  
Heat Capacity ◽  
Solar Energy ◽  
Flat Surface ◽  
Phase Interface ◽  
Metal Plate ◽  
Theoretical Studies ◽  
State Technical ◽  
Heat Accumulator ◽  
Infrared Rays ◽  
Heat Of Evaporation

The process of heating a dewatered object in an infrared solar drying plant (with paraffin on the bottom) with solar energy storage is considered. To solve this problem, it is assumed that the heat capacity of paraffin exceeds the heat capacity of the dehydrated object. Infrared rays fall on the upper layer, and heat exchange takes place due to heat and mass transfer with the surface air located between the metal plate and the object to be dehydrated. The equations of thermal conductivity for a dewatered object are given, its relationship at the phase interface is determined using the equality of temperature and heat flow. For an exposure of overheating with a period of 6.5 h, the time of passage of the phase boundary in accordance with the law of motion of the spreading (hardening), was determined according to the formula of  ξ = α √6,5 h ≅ 12 h.The optimal thickness of the accumulating paraffin layer was ascertained. On the basis of the theoretical studies, experiments were conducted to study the temperature field of various heataccumulating materials in the laboratory of Tashkent State Technical University. It was found that of all heat-accumulating materials, paraffin has the best heat retention ability when its thickness is of 2–4 cm. The optimal variant of a solar accumulator drying plant with a heat accumulator, viz. paraffin has been designed. In particular, 2–4 cm of paraffin layer with a mass of 50 kg with a corresponding flat surface in terms of specific heat of evaporation is 2400 kJ/kg. The specific melting value of paraffin (150 kJ/kg) allows additional evaporation of 5.8 l of moisture when drying objects. The proposed solar accumulator drying plant can be used for dehydration of medicinal herbs.

scholarly journals Shifting Goalposts: Setting Restoration Targets for Waterbirds in the Murray-Darling Basin Under Climate Change

2021 ◽  
Vol 9 ◽  
Author(s):  
Gilad Bino ◽  
Kate Brandis ◽  
Richard T. Kingsford ◽  
John Porter
Keyword(s):  
Climate Change ◽  
Environmental Sustainability ◽  
Life Histories ◽  
River System ◽  
Biodiversity Loss ◽  
Environmental Water ◽  
Freshwater Ecosystems ◽  
Future Climate Change ◽  
Restoration Targets ◽  
Murray Darling Basin

The Murray-Darling Basin (the Basin) is the largest river system in Australia, supplying about 40% of the country’s irrigated agricultural output. Associated water resource development has come with a heavy price for the Basin’s freshwater ecosystems degrading them over decades. Australian governments are attempting to achieve environmental sustainability by returning water to the environment through buy-back of irrigation licences and improved water efficiencies. To determine effectiveness, basin-wide management objectives were established for key indicators, including waterbird populations and life histories which can effectively indicate ecosystem function and condition, driven by flow and flooding regimes. Ongoing monitoring of waterbird numbers indicates continued declines. We evaluated the feasibility of meeting established waterbird objectives under existing and predicted climates. We modelled long-term waterbird numbers using one of the world’s largest ongoing waterbird surveys (1983–2020), covering about 13.5% of the area of the entire Basin. Our findings suggest that under near future climate change projections, waterbird numbers will likely continue to decline, and remain below restoration targets set for the Basin. We discuss the current policy settings for using environmental water to support waterbird populations, recommending adjustments to restore the Basin’s waterbird populations and their wetlands in order to meet Australia’s conservation targets in relation to the ongoing global crisis of biodiversity loss.

Challenges for Diadromous Fishes in a Dynamic Global Environment

2009 ◽  
Author(s):  
Jon M. Honea
Keyword(s):  
Life Histories ◽  
Pacific Salmon ◽  
North Pacific Ocean ◽  
Terrestrial Ecosystems ◽  
Freshwater Ecosystems ◽  
Riparian Ecosystems ◽  
Nutrient Sources ◽  
Temporal And Spatial Variability ◽  
Ecological Importance ◽  
Animal Communities

<em>Abstract</em>.-We review the current understanding of major pathways, mechanisms, and consequences of salmon-borne marine-derived nutrients (MDN) in estuarine, freshwater, and riparian ecosystems. Semelparous Pacific salmon <em>Oncorhynchus </em>spp. acquire most of their body mass while at sea before returning to spawn and die in natal streams. The annual spawning migrations transport substantial quantities of MDN from the fertile North Pacific Ocean to relatively nutrient-poor coastal freshwater and terrestrial ecosystems. People have been long aware of the importance of salmon-borne MDN for the productivity of freshwater ecosystems in western North America, and the rapidly increasing knowledge base supports this notion. Nevertheless, many details associated with nutrient pathways, cycling processes, and the ecosystem-scale consequences of MDN transfer remain to be elucidated. The collective data suggest that freshwater portions of the salmon production system, as well as the dynamics of local terrestrial plant and animal communities, are intimately linked to MDN in complex ways. At the same time, the ecological importance of MDN, relative to other major nutrient sources, is temporally and spatially dependent and influenced by the life histories and abundances of salmonid stocks. Although interactions among climate cycles, salmon, riparian vegetation, predators, and MDN flowpaths and feedbacks are complex, they also form a wonderfully integrated ecological system with a high degree of resilience and productivity. Understanding this complex system and its inherent temporal and spatial variability requires a holistic scientific perspective that values important interactions among the salmonid life cycle, the physical setting, and the numerous linkages to other ecosystem components.

scholarly journals Eco-Assessment of Streams of Konya Closed River Basin (Turkey) Using Various Ecoregional Diatom Indices

2021 ◽  
Author(s):  
Abuzer Çelekli ◽  
Ömer Lekesiz ◽  
Tolga Çetin
Keyword(s):  
River Basin ◽  
Environmental Sustainability ◽  
Ecological Status ◽  
Freshwater Ecosystems ◽  
Diatom Species ◽  
Species List ◽  
Future Studies ◽  
Diatom Index ◽  
Diatom Indices ◽  
Dry Seasons

Abstract Ecological assessments of freshwater ecosystems based on diatom metrics are an important issue to attain environmental sustainability. The present study aimed to evaluate differences in the diatom-stressors relationship in relatively least disturbed streams in the Konya closed river basin using multivariate analyses and to bio-assess streams by application of different ecoregional diatom indices. Cocconeis euglypta, Cymbella excisa, Cocconeis placentula, and Achnanthidium minutissimum are the most contributing species to the dissimilarity of sampling stations between rainy and dry seasons and also between altitude (A2 800-<1600 m and A3 ≥1600 m) groups. A strong (82.8%) correlation between diatom species and stressors was expressed by the first two axes of canonical correspondence analysis. Diatom species displayed distinct responses to environmental variables (electrical conductivity, Ni, Cu, B, and altitude) playing important roles on the distribution of diatom species. Diatom indices indicated different ecological statuses of stations from a bad to a high. European diatom indices except Duero Diatom Index-DDI and Trophic Diatom Index-TDI showed well responses to the eco-assessment of streams and indicated high ecological status for the least disturbed sampling stations symbolized as S16, S20, S24, S25, S27-29, S37, and 39. These results were also supported by abiotic evaluation. Among diatom indices, although TIT was more competitive in the bio-assessment of streams, it is necessary to increase its species list by determining their trophic weights in future studies. This indicates that the revision of ecoregional specific diatom metrics with the enhancement of diatom species numbers according to their ecological preferences is needed to correctly interpret the water quality.

scholarly journals Stones in the road prevents effective implementation of eDNA-based freshwater quality monitoring in the Iberian Peninsula

2021 ◽  
Vol 4 ◽  
Author(s):  
Álvaro Fueyo ◽  
Javier Granero-Castro ◽  
Beatriz Villazán Peñalosa ◽  
Yaisell Borrell Pichs
Keyword(s):  
Iberian Peninsula ◽  
Dna Sequences ◽  
Mitochondrial Gene ◽  
Freshwater Ecosystems ◽  
Freshwater Species ◽  
Sequence Coverage ◽  
Global Biodiversity Information Facility ◽  
Species List ◽  
Family Level ◽  
Taxonomic Groups

The Water Framework Directive (WFD) monitoring requires the use of stressor-specific Multimetric Indices, intercalibrated and validated at river basin level, such as the IBMWP, which is one of the most widely used indices for the biomonitoring of rivers in the Iberian Peninsula. This qualitative index is based on the identification mainly at family level of 125 groups of macroinvertebrates. Currently, molecular biomonitoring systems (biomonitoring 2.0) is widely considered as a good alternative to conduct water quality assessments. The problem comes with the requirement of having complete DNA sequences databases for the targeted species within the indicator groups. In order to know the percentage of sequence coverage of the different taxonomic groups, is needed to know the number of freshwater species in each group. The fact that currently it is only necessary to identify them morphologically at family level to calculate the index means that there are no exhaustive lists of lower taxonomic ranges. In this study, we have studied the available taxonomic databases at species level for river macroinvertebrates in the Iberian Peninsula. For this purpose, species geographically referred to the Iberian Peninsula were extracted from three sources: two European (Freshwaterecology.info database and Weigand et al. (2019)) and one Iberian database/list (Múrria et al. 2020). The resultant species list was compared with GBIF (Global Biodiversity Information Facility) using its tool “Species Matching” to find synonyms and fuzzy names. The similarities and differences between databases were studied (considering the synonyms but not the fuzzy names) and a new list of 3586 species was constructed. Our analysis revealed that from 125 taxonomic groups covered by the IBMWP, there are no species collected for 11 of them (9%) and for another 34 groups (27%) there are less than 5 species collected in the databases. Then, using the BAGS software, all sequences of the mitochondrial gene COX1 were mined from BOLD database. From the 3586 species in the list, only 1900 (53%) have at least one sequence in BOLD. Therefore, conducting biomonitoring 2.0 in Iberian freshwater ecosystems is far from effective today. We need to overcome two big obstacles to reach the goal of using molecular biomonitoring in the Iberian Peninsula: a complete taxonomic list of quality indicators species by groups, and to sequence DNA barcodes from all relevant species.

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