River flow controls ecological processes and invertebrate assemblages in subsurface flowpaths of an ephemeral river reach

2008 ◽  
Vol 65 (8) ◽  
pp. 1532-1544 ◽  
Author(s):  
Thibault Datry ◽  
Scott T. Larned
Keyword(s):  
Microbial Activity ◽  
River Flow ◽  
Riparian Zone ◽  
Taxon Richness ◽  
Ecological Processes ◽  
Zone Length ◽  
Nutrient Sources ◽  
Subsurface Zones ◽  
Invertebrate Assemblages ◽  
Reactive Phosphorus

We present the first measurements of solutes, invertebrates, and microbial activity in the semi-perched hyporheic, parafluvial, and riparian flowpaths of an ephemeral river channel. Dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP) concentrations decreased as water from an adjacent river mainstem moved through the flowpaths. DOC, DON, and DOP processing rates decreased with increasing mainstem flow and increased with parafluvial zone length. These patterns suggest that the surface water zones of perched river systems are organic nutrient sources to subsurface flowpaths and that parafluvial zones of these systems are strong sinks for organic matter. No longitudinal changes were detected in NO3–concentrations, and relationships between NO3–processing and hydrological variables were not significant. NO3–concentrations were uniformly high, and microbial activity and DOC and dissolved reactive phosphorus (DRP) concentrations were low, suggesting that biological NO3–removal was carbon- or phosphorus-limited. Invertebrate assemblages also varied between subsurface zones: density and taxon richness in the hyporheic and parafluvial zones were higher than in the riparian zone, and evenness was higher in the riparian zone than in the hyporheic or parafluvial zones. Distinct invertebrate assemblages in riparian zones may reflect greater hydrologic stability compared with hyporheic and parafluvial zones.

Freshwater, Fish and the Future: Proceedings of the Global Cross-Sectoral Conference

2016 ◽  
Keyword(s):  
Puerto Rico ◽  
Freshwater Fish ◽  
Water Use ◽  
Large Scale ◽  
River Flow ◽  
Fish Assemblages ◽  
Physical Habitat ◽  
Resource Exploitation ◽  
Ecological Processes ◽  
Tropical Island

<em>Abstract.</em> —Freshwater tropical island environments support a variety of fishes that provide cultural, economic, and ecological services for humans but receive limited scientific, conservation, and public attention. Puerto Rico is a Caribbean tropical island that may serve as a model to illustrate the interactions between humans and natural resources in such complex ecosystems. The native freshwater fish assemblage of Puerto Rico is distinct from mainland assemblages in that the assemblage is not diverse, all species are diadromous, and they may be exploited at multiple life stages (e.g., postlarva, juvenile, adult). Primary large-scale drivers of recent water-use policy include economic growth, human population density, and urbanization, with climate change as an overarching influence. Watershed and riparian land use, water quality, river flow and instream physical habitat, river habitat connectivity, exotic species, and aquatic resource exploitation are important proximate factors affecting the ecosystem and fisheries. Research on ecological processes and components of the stream and river fish assemblages has expanded the knowledge base in the past decade with the goal of providing critical information for guiding the conservation and management of the lotic resource to optimize ecosystem function and services. The greatest challenge facing Caribbean island society is developing policies that balance the needs for human water use and associated activities with maintaining aquatic biodiversity, ecological integrity and services, and sustainable fisheries. Achieving this goal will require broad cooperation and sustained commitment among public officials, agency administrators, biologists, and the public toward effective resource management.

scholarly journals Response of Cladocera Fauna to Heavy Metal Pollution, Based on Sediments from Subsidence Ponds Downstream of a Mine Discharge (S. Poland)

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 810 ◽  
Author(s):  
Agnieszka Pociecha ◽  
Agata Z. Wojtal ◽  
Ewa Szarek-Gwiazda ◽  
Anna Cieplok ◽  
Dariusz Ciszewski ◽  
...  
Keyword(s):  
Water Exchange ◽  
River Flow ◽  
Water Discharge ◽  
Aquatic Systems ◽  
Strongly Correlated ◽  
Alona Affinis ◽  
Mine Discharge ◽  
Invertebrate Assemblages ◽  
High Concentrations ◽  
S Poland

Mining is recognized to deeply influence invertebrate assemblages in aquatic systems, but different invertebrates respond in different ways to mining cessation. Here, we document the response of the cladoceran assemblage of the Chechło river, S. Poland (southern Poland) to the cessation of Pb-Zn ore mining. The aquatic system includes the river and associated subsidence ponds in the valley. Some ponds were contaminated during the period of mining, which ceased in 2009, while one of the ponds only appeared after mining had stopped. We used Cladocera to reveal how the cessation of mine water discharge reflected on the structure and density of organisms. A total of 20 Cladocera taxa were identified in the sediment of subsidence ponds. Their density ranged from 0 to 109 ind./1 cm3. The concentrations of Zn, Cd, Cu and Pb were much higher in sediments of the ponds formed during peak mining than in the ponds formed after the closure of the mine. Statistical analysis (CCA) showed that Alonella nana, Alona affinis, Alona sp. and Pleuroxus sp. strongly correlated with pond age and did not tolerate high concentrations of heavy metals (Cu and Cd). This analysis indicated that the rate of water exchange by the river flow and the presence of aquatic plants, affect species composition more than pond age itself.

Microbial-derived phospholipid fatty acids approve the link of stable isotope depth pattern to peatland hydrology

2020 ◽  
Author(s):  
Miriam Groß-Schmölders ◽  
Axel Birkholz ◽  
Kristy Klein ◽  
Jens Leifeld ◽  
Christine Alewell
Keyword(s):  
Stable Isotope ◽  
Microbial Activity ◽  
Turning Point ◽  
Phospholipid Fatty Acid ◽  
Microbial Community Composition ◽  
Microbial Metabolism ◽  
Nutrient Sources ◽  
Peatland Hydrology ◽  
Peatland Restoration ◽  
Peatland Degradation

&lt;p&gt;Ongoing peatland degradation calls for an efficient method to indicate peatland hydrology and the success of restoration effort. In previous studies we found specific depth patterns of 13C and 15N depending on peatland hydrology (drained, rewetted or natural), but were unable to find an explanation of these patterns. As degradation is mostly connected to drainage we assumed an increase of microbial activity. This microbial activity should then be imprinted in stable isotope signatures (15N, 13C) due to differences in microorganism communities, their metabolic pathways and nutrient sources. We aimed to find a link between our investigated isotope depth patterns to microbial community composition. Therefore, we conducted a phospholipid fatty acid (PLFAs) analysis. As a marker for bacteria we used PLFAs i-C15:0 and a-C-15:0 as well as the C18:2,9c as a marker for fungi. We studied two nutrient poor peatlands in Northern Europe: Lakkasuo (Central Finland) and Deger&amp;#246; Stormyr (Northern Sweden). At all locations cores were taken from adjacent drained (or rewetted) and natural sites. At Lakkasuo drained site, we found a high humification index (HI, after van Post), shown by less plant residuals and a high amount of matrix. For Deger&amp;#246; Stormyr the picture looks different. Above the drained horizon (high HI) peat was light, with a smaller amount of matrix and lots of plant residuals (low HI), like it was also seen in the natural cores. At the drained (and rewetted) sites we found distinct peaks in microbial PLFA concentrations, which correlate to the stable isotope peaks (&quot;turning point&amp;#8221;) we found before. At the 15N turning point, in the center of the drained horizon, overall microbial-derived PLFA abundance is also the highest. Furthermore, the overall microbial-derived PLFA abundance is positively correlated with 15N values (r&lt;sup&gt;2&lt;/sup&gt;=0.5). Fungi-derived PLFAs are negatively correlated (r&lt;sup&gt;2&lt;/sup&gt;=0.4) to 13C. Fungi-derived PLFAs showed the highest amount at the uppermost part of the drained horizon and low amounts in the waterlogged conditions below the drained horizon, whereas 13C showed lowest values at the surface and high values below the drained horizon. Our results suggest, that fungi dominate microbial metabolism in the upper, aerobic peat horizon. Downwards the drained horizon conditions slowly switch to oxygen limitation. Thus, fungal-derived PLFAs decrease whereas bacterial-derived PLFAs are increasing. The highest diversity of microbial-derived PLFAs is indicated by the 15N turning point. Below this point, oxygen is increasingly limited and concentrations of all microbial-derived PLFAs are decreasing down to the 13C turning point and the onset of the permanently waterlogged, anaerobic horizon. Cores from rewetted peatlands show no depth trend of 15N values above the formerly drained horizon and a low amount of microbial-derived PLFAs. Hence, we conclude that stable isotope values reflect microbial metabolism processes, which differ between drained, rewetted and natural peatlands. Additionally, stable isotope patterns reflect a switch in the predominant communities from fungi to bacteria within a drained horizon. Summing up, the PLFA analysis approved that stable isotope measurements can serve as a cost and work efficient monitoring tool for peatland history as well as peatland restoration success.&lt;/p&gt;

scholarly journals Spatiotemporal dynamics of terrestrial invertebrate assemblages in the riparian zone of the Wewe river, Ashanti region, Ghana

2020 ◽  
Vol 15 (1) ◽  
pp. 331-345
Author(s):  
Collins Ayine Nsor ◽  
Samuel K. Oppong ◽  
Emmanuel Danquah ◽  
Michael Ochem ◽  
Osei Owusu Antobre
Keyword(s):  
Ecosystem Health ◽  
Riparian Zone ◽  
Spatiotemporal Dynamics ◽  
Geometric Series ◽  
Invertebrate Community ◽  
Wet Season ◽  
Disturbed Habitat ◽  
Ashanti Region ◽  
Terrestrial Invertebrate ◽  
Invertebrate Assemblages

AbstractThis study assessed invertebrate response to disturbances in the riparian zone of the Wewe river, using geometric series, rarefaction, Renyi diversity, and CCA models. We sampled 2,077 individuals (dry season) and 2,282 (wet season) belonging to 16 invertebrate orders. The severely disturbed habitat registered the highest individuals (n = 1,999), while the least was the moderately disturbed habitat (n = 740). Seasonal assemblages were not significantly different. Fire, farming, tree felling, and erosion explained 66.8% and 60.55% in the dry and wet seasons, respectively, of variations in invertebrate assemblages. This suggests threats to the invertebrate community and the riparian ecosystem health by anthropogenic interventions.

scholarly journals Small invertebrates in bivalve-cultivated and unmodified habitats of nearshore ecosystems

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Stuart H. Munsch ◽  
Julie S. Barber ◽  
Jeffery R. Cordell ◽  
Peter M. Kiffney ◽  
Beth L. Sanderson ◽  
...  
Keyword(s):  
West Coast ◽  
Benthic Invertebrates ◽  
Coastal Communities ◽  
Ecological Processes ◽  
Bottom Culture ◽  
Nearshore Ecosystems ◽  
The Us ◽  
Invertebrate Assemblages ◽  
Us West ◽  
Epibenthic Invertebrates

AbstractMany nearshore ecosystems are modified by aquaculture, including bivalve culture to produce food and restore extirpated populations. Small invertebrates in nearshore ecosystems support fundamental ecological processes, but the effects of bivalve culture on invertebrates are incompletely understood. Here, we compared invertebrate assemblages from multiple studies of bivalve-cultivated and unmodified nearshore habitats along the US west coast. In general, unmodified eelgrass and nearby off-bottom culture habitats with eelgrass present were inhabited by a greater abundance, richness, and diversity of epibenthic invertebrates than bottom culture and bare (mud, sand) habitats that both lacked eelgrass. Findings of individual studies suggested: minor differences in epibenthic invertebrate assemblages associated with various aquaculture practices; restoring native oysters to mudflats did not detectably alter epibenthic invertebrate abundances; epibenthic invertebrates were more abundant on shell hash introduced to mudflats than unmodified mudflats; and benthic invertebrates were less abundant, rich, and diverse in habitats cultured on bottom by Manila clams. Considering the range of these patterns, there appears to be potential for coastal communities to restore extirpated bivalve populations or develop bivalve culture practices that meet objectives to grow food while maintaining nearshore ecosystems’ fundamental processes supported by robust invertebrate assemblages.

scholarly journals An underground tale: contribution of microbial activity to plant iron acquisition via ecological processes

2013 ◽  
Vol 113 (1) ◽  
pp. 7-18 ◽  
Author(s):  
Chong Wei Jin ◽  
Yi Quan Ye ◽  
Shao Jian Zheng
Keyword(s):  
Microbial Activity ◽  
Iron Acquisition ◽  
Ecological Processes

Field evidence for geophysical detection of subsurface zones of enhanced microbial activity

2004 ◽  
Vol 31 (23) ◽  
Author(s):  
Eliot A. Atekwana ◽  
Estella Atekwana ◽  
Franklyn D. Legall ◽  
R. V. Krishnamurthy
Keyword(s):  
Microbial Activity ◽  
Field Evidence ◽  
Subsurface Zones

Ecological processes mediate the effects of the invasive bloom-forming diatom Didymosphenia geminata on stream algal and invertebrate assemblages

Hydrobiologia ◽  
2019 ◽  
Vol 847 (1) ◽  
pp. 177-190 ◽  
Author(s):  
J. P. Bray ◽  
C. Kilroy ◽  
P. Gerbeaux ◽  
F. J. Burdon ◽  
J. S. Harding
Keyword(s):  
Ecological Processes ◽  
Didymosphenia Geminata ◽  
Invertebrate Assemblages

scholarly journals Observational gridded runoff estimates for Europe (E-RUN version 1.0)

2016 ◽  
Author(s):  
Lukas Gudmundsson ◽  
Sonia I. Seneviratne
Keyword(s):  
Cross Validation ◽  
River Flow ◽  
Climate Variable ◽  
Data Bases ◽  
Ecological Processes ◽  
Wide Range ◽  
Terrestrial Water ◽  
Monthly Runoff ◽  
Derived Data ◽  
Combining Information

Abstract. River runoff is an essential climate variable as it is directly linked to the terrestrial water balance and controls a wide range of climatological and ecological processes. Despite its scientific and societal importance, there are to date no pan-European observation-based runoff estimates available. Here we employ a recently developed methodology to estimate monthly runoff rates on regular spatial grid in Europe. For this we first collect an unprecedented collection of river flow observations, combining information from three distinct data bases. Observed monthly runoff rates are first tested for homogeneity and then related to gridded atmospheric variables (E-OBS version 11) using machine learning. The resulting statistical model is then used to estimate monthly runoff rates (December 1950–December 2014) on a 0.5° × 0.5° grid. The performance of the newly derived runoff estimates is assessed in terms of cross validation. The paper closes with example applications, illustrating the potential of the new runoff estimates for climatological assessments and drought monitoring. The newly derived data are made publicly available at doi:10.1594/PANGAEA.845725.

Modelling of point and diffuse pollution: application of the Moneris model in the Ipojuca river basin, Pernambuco State, Brazil

2013 ◽  
Vol 68 (2) ◽  
pp. 357-365 ◽  
Author(s):  
Alessandra Maciel de Lima Barros ◽  
Maria do Carmo Sobral ◽  
Günter Gunkel
Keyword(s):  
River Basin ◽  
River Flow ◽  
Developed Countries ◽  
Diffuse Pollution ◽  
Geographical Information ◽  
Intermittent Flow ◽  
Nitrogen And Phosphorus ◽  
Nutrient Sources ◽  
Nutrient Emissions ◽  
Point And Diffuse Sources

Emissions of pollutants and nutrients are causing several problems in aquatic ecosystems, and in general an excess of nutrients, specifically nitrogen and phosphorus, is responsible for the eutrophication process in water bodies. In most developed countries, more attention is given to diffuse pollution because problems with point pollution have already been solved. In many non-developed countries basic data for point and diffuse pollution are not available. The focus of the presented studies is to quantify nutrient emissions from point and diffuse sources in the Ipojuca river basin, Pernambuco State, Brazil, using the Moneris model (Modelling Nutrient Emissions in River Systems). This model has been developed in Germany and has already been implemented in more than 600 river basins. The model is mainly based on river flow, water quality and geographical information system data. According to the Moneris model results, untreated domestic sewage is the major source of nutrients in the Ipojuca river basin. The Moneris model has shown itself to be a useful tool that allows the identification and quantification of point and diffuse nutrient sources, thus enabling the adoption of measures to reduce them. The Moneris model, conducted for the first time in a tropical river basin with intermittent flow, can be used as a reference for implementation in other watersheds.

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