Structural Changes in Macroinvertebrate Communities Associated with Reduction in the Management of Coastal Saltpans

Saltpans with different management levels were studied for macroinvertebrate community and abiotic variables like water depth, water conductivity, and organic matter in sediments. Significant variation was observed between saltpans, between ponds within saltpans, and between periods within ponds for abundance, and also between saltpans for biomass. Environmental variables varied significantly between saltpans and between ponds. Significant positive correlations occurred between depth and total abundance, between depth and Corixidae abundance, and also between organic matter in sediments and diversity. Significant negative correlations were observed between depth and diversity and between organic matter in sediments and total abundance. Multidimensional Scaling and Canonical Correspondence Analysis confirmed results of analysis of variance and correlations. Invertebrate communities were numerically dominant as also revealed by ABC method. Abandoned saltpan ponds show the largest changes in water depth, with communities dominated by some opportunist species, varying within short temporal scales, which is typical from highly disturbed systems.

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Analyzing of UVLC system considering the effect of water depth

Journal of Optical Communications ◽

10.1515/joc-2021-0030 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Mustafa B. Al-Deen ◽

Mazin Ali A. Ali ◽

Zeyad A. Saleh

Keyword(s):

Coastal Water ◽

Water Depth ◽

Bit Error Rate ◽

Multiple Input Multiple Output ◽

Visible Light Communications ◽

New Approach ◽

Multiple Input ◽

Input Multiple Output ◽

Depth Water

Abstract This paper presents a new approach to discover the effect of depth water for underwater visible light communications (UVLC). The quality of the optical link was investigated with varying water depth under coastal water types. The performance of the UVLC with multiple input–multiple output (MIMO) techniques was examined in terms of bit error rate (BER) and data rate. The theoretical result explains that there is a good performance for UVLC system under coastal water.

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Is it possible to predict habitat use by spawning salmonids? A test using California golden trout (Oncorhynchus mykiss aguabonita)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f99-081 ◽

1999 ◽

Vol 56 (9) ◽

pp. 1576-1584 ◽

Cited By ~ 28

Author(s):

Roland A Knapp ◽

Haiganoush K Preisler

Keyword(s):

Oncorhynchus Mykiss ◽

Water Depth ◽

Parametric Model ◽

Water Velocity ◽

Habitat Characteristics ◽

Nonparametric Model ◽

Habitat Features ◽

Substrate Size ◽

Depth Water ◽

Spawning Sites

It is widely believed that stream salmonids select spawning sites based on water depth, water velocity, and substrate size. Attempts to predict spawning locations using these habitat features have met with little success, however. In this study, we used nonparametric logistic regression to determine what habitat features were associated with the locations chosen by spawning California golden trout (Oncorhynchus mykiss aguabonita). From this nonparametric model, we developed a parametric model that incorporated the habitat features most strongly associated with spawning sites and used this model to calculate the probability of use by spawning golden trout for specific stream locations. The overall nonparametric model was highly significant and explained 62% of the variation in spawning location. Four of the eight habitat variables, substrate size, water depth, water velocity, and stream width, had highly significant effects and alone explained 59% of the variation in spawning location. The results of a cross-validation procedure indicated that the parametric model generally provided a good fit to the data. These results indicate that location-specific probabilities of use were predictable based on easily measured habitat characteristics and that nonparametric regression, an approach still rarely used in ecological studies, may have considerable utility in the development of fish-habitat models. Given the escalating pace at which fish habitats are being altered, such models are increasingly important in predicting the effects of these alterations on populations.

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Trophic state of benthic deep-sea ecosystems from two different continental margins off Iberia

Biogeosciences ◽

10.5194/bg-10-2945-2013 ◽

2013 ◽

Vol 10 (5) ◽

pp. 2945-2957 ◽

Cited By ~ 10

Author(s):

A. Dell'Anno ◽

A. Pusceddu ◽

C. Corinaldesi ◽

M. Canals ◽

S. Heussner ◽

...

Keyword(s):

Organic Matter ◽

Water Depth ◽

Surface Waters ◽

Deep Sea ◽

Nutritional Value ◽

Trophic State ◽

Phytoplankton Bloom ◽

Continental Margins ◽

Organic C ◽

Deep Sea Sediments

Abstract. The bioavailability of organic matter in benthic deep-sea ecosystems, commonly used to define their trophic state, can greatly influence key ecological processes such as biomass production and nutrient cycling. Here, we assess the trophic state of deep-sea sediments from open slopes and canyons of the Catalan (NW Mediterranean) and Portuguese (NE Atlantic) continental margins, offshore east and west Iberia, respectively, by using a biomimetic approach based on enzymatic digestion of protein and carbohydrate pools. Patterns of sediment trophic state were analyzed in relation to increasing water depth, including repeated samplings over a 3 yr period in the Catalan margin. Two out of the three sampling periods occurred a few months after dense shelf water cascading events. The benthic deep-sea ecosystems investigated in this study were characterized by high amounts of bioavailable organic matter when compared to other deep-sea sediments. Bioavailable organic matter and its nutritional value were significantly higher in the Portuguese margin than in the Catalan margin, thus reflecting differences in primary productivity of surface waters reported for the two regions. Similarly, sediments of the Catalan margin were characterized by significantly higher food quantity and quality in spring, when the phytoplankton bloom occurs in surface waters, than in summer and autumn. Differences in the benthic trophic state of canyons against open slopes were more evident in the Portuguese than in the Catalan margin. In both continental margins, bioavailable organic C concentrations did not vary or increase with increasing water depth. Overall, our findings suggest that the intensity of primary production processes along with the lateral transfer of organic particles, even amplified by episodic events, can have a role in controlling the quantity and distribution of bioavailable organic detritus and its nutritional value along these continental margin ecosystems.

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MIM and nonlinear least‐squares inversions of AEM data in Barataria basin, Louisiana

Geophysics ◽

10.1190/1.1598104 ◽

2003 ◽

Vol 68 (4) ◽

pp. 1126-1131 ◽

Cited By ~ 2

Author(s):

Melissa Whitten Bryan ◽

Kenneth W. Holladay ◽

Clyde J. Bergeron ◽

Juliette W. Ioup ◽

George E. Ioup

Keyword(s):

Least Squares ◽

Water Depth ◽

Least Squares Method ◽

Nonlinear Least Squares ◽

Image Method ◽

Water Conductivity ◽

Near Surface ◽

Barataria Basin ◽

Airborne Electromagnetic Survey ◽

Nonlinear Least Squares Method

An airborne electromagnetic survey was performed over the marsh and estuarine waters of the Barataria basin of Louisiana. Two inversion methods were applied to the measured data to calculate layer thicknesses and conductivities: the modified image method (MIM) and a nonlinear least‐squares method of inversion using two two‐layer forward models and one three‐layer forward model, with results generally in good agreement. Uniform horizontal water layers in the near‐shore Gulf of Mexico with the fresher (less saline, less conductive) water above the saltier (more saline, more conductive) water can be seen clearly. More complex near‐surface layering showing decreasing salinity/conductivity with depth can be seen in the marshes and inland areas. The first‐layer water depth is calculated to be 1–2 m, with the second‐layer water depth around 4 m. The first‐layer marsh and beach depths are computed to be 0–3 m, and the second‐layer marsh and beach depths vary from 2 to 9 m. The first‐layer water conductivity is calculated to be 2–3 S/m, with the second‐layer water conductivity around 3 to 4 S/m and the third‐layer water conductivity 4–5 S/m. The first‐layer marsh conductivity is computed to be mainly 1–2 S/m, and the second‐ and third‐layer marsh conductivities vary from 0.5 to 1.5 S/m, with the conductivities decreasing as depth increases except on the beach, where layer three has a much higher conductivity, ranging up to 3 S/m.

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Aquatic Macroinvertebrate Assemblages in Rivers Under the Influence of Mining Activities

10.21203/rs.3.rs-568053/v1 ◽

2021 ◽

Author(s):

Axel Eduardo Rico-Sánchez ◽

Alexis Joseph Rodríguez-Romero ◽

Jacinto Elías Sedeño-Díaz ◽

Eugenia López-López ◽

Andrea Sundermann

Keyword(s):

Heavy Metals ◽

Structural Changes ◽

Cost Effective ◽

Diversity Indices ◽

Aquatic Macroinvertebrates ◽

Conservation Strategies ◽

Mining Activities ◽

Macroinvertebrate Communities ◽

Negative Effects ◽

Central Plateau

Abstract Mining is one of the main pollution issues worldwide, causing the greatest disturbances to the environment. Industrial and artisanal mining activities are widespread in Mexico, being a major global producer of various metals. This study aimed to assess the ecological impairments resulting from mining activities using the aquatic macroinvertebrates assemblages (MA). A multiple co-inertia analysis (MCOA) was applied to determine the relationships between environmental factors, habitat quality, heavy metals, and aquatic macroinvertebrates in two rivers of the Central Plateau, Mexico. The results revealed three contrasting environmental conditions and different MA. High concentrations of heavy metals, nutrients, and salinity limit the presence of various families of seemingly sensitive macroinvertebrates, these factors were identified as the drivers of structural changes in the MA, showing that not only mining activities, but also agriculture, and villages in the basin, exert negative effects to the macroinvertebrate communities. Diversity indices showed that the lowest diversity matched with both, the most polluted and the most saline rivers. The rivers studied displayed a high alkalinity and hardness, which can lead to the formation of metal precipitates and thus acting as a protection to aquatic biota. Aquatic biomonitoring in rivers, impacted by mining and other human activities, is critical for detecting the effect of metals and other pollutants to improve management and conservation strategies. This study supports the design of cost-effective and accurate water quality biomonitoring protocols in developing countries.

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Evaluating the interaction of biofilms, organic matter and soil structures at the pore scale

10.5194/ismc2021-59 ◽

2021 ◽

Author(s):

Alexander Prechtel ◽

Simon Zech ◽

Alice Lieu ◽

Raphael Schulz ◽

Nadja Ray

Keyword(s):

Organic Matter ◽

Structural Changes ◽

Effective Diffusivity ◽

Computational Domain ◽

Pore Scale ◽

Gas Phases ◽

Soil Structures ◽

Ldg Method ◽

Conventional Models ◽

Diffusive Processes

<div class="description js-mathjax"> <p>Key functions of soils, such as permeability or habitat for microorganisms, are determined by structures at the microaggregate scale. The evolution of elemental distributions and dynamic processes can often not be assessed experimentally. So mechanistic models operating at the pore scale are needed.<br />We consider the complex coupling of biological, chemical, and physical processes in a hybrid discrete-continuum modeling approach. It integrates dynamic wetting (liquid) and non-wetting (gas) phases including biofilms, diffusive processes for solutes, mobile bacteria transforming into immobile biomass, and ions which are prescribed by means of partial differential equations. Furthermore the growth of biofilms as, e.g., mucilage exuded by roots, or the distribution of particulate organic matter in the system, is incorporated in a cellular automaton framework (CAM) presented in [1, 2]. It also allows for structural changes of the porous medium itself (see, e.g. [3]). As the evolving computational domain leads to discrete discontinuities, we apply the local discontinuous Galerkin (LDG) method for the transport part. Mathematical upscaling techniques incorporate the information from the pore to the macroscale [1,4].<br />The model is applied for two research questions: We model the incorporation and turnover of particulate OM influencing soil aggregation, including &#8216;gluing&#8217; hotspots, and show scenarios varying of OM input, turnover, or particle size distribution. <br />Second, we quantify the effective diffusivity on 3D geometries from CT scans of a loamy and a sandy soil. Conventional models cannot account for natural pore geometries and varying phase properties. Upscaling allows also to quantify how root exudates (mucilage) can significantly alter the macroscopic soil hydraulic properties.</p> </div> <div id="field-23"> <p>[1]&#160; Ray, Rupp, Prechtel (2017). AWR (107), 393-404.<br />[2] Rupp, Totsche, Prechtel, Ray (2018). Front. Env. Sci. (6) 96.<br />[3] Zech, Dultz, Guggenberger, Prechtel, Ray (2020). Appl. Clay Sci. 198, 105845.<br />[4] Ray, Rupp, Schulz, Knabner (2018). TPM 124(3), 803-824.</p> </div>

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Biogeochemical processes in the Barents sea

10.29006/978-5-6045110-0-8/(23) ◽

2021 ◽

pp. 287-306

Author(s):

A.Yu. Lein ◽

◽

A.S. Savvichev ◽

Keyword(s):

Organic Matter ◽

Water Column ◽

Methane Concentration ◽

Barents Sea ◽

Biogeochemical Processes ◽

Total Abundance ◽

The North ◽

The Barents Sea ◽

Continental Origin ◽

Biomass Of Microorganisms

Biogeochemical processes involving microorganisms play an important role in marine sedimentogenesis. The study of biogeochemical processes in the Barents Sea was carried out from 1997 with interruptions until 2019. Using a complex of geological-geochemical, microbiological, radioisotope and stable isotope methods, it was possible to obtain a quantitative estimate of the total abundance and biomass of microorganisms, rates of biogeochemical processes, methane content and organic matter suspended. In the course of work in four expeditions, it was found that in the surface (0–10 m) water column south of 74° N the magnitude of the total abundance and the biomass of microorganisms increased by 2019 by about 5 times compared to 1998. To the north, in colder waters, the total abundance and the biomass of organisms were lower than in the southern region of the sea. The methane concentration in the surface layer of the water column at the border with the atmosphere did not change much for 20 years (1976–1997) and increased noticeably from 1997 to 2017, from 3.3 to 15.8 nM. The increase in FFM, the biomass of organisms and the concentration of methane in the water column is associated with the melting of glaciers, with the release of organic matter of continental origin released from ice into the water. The results of the work indicate changes in the ecosystem of the Barents Sea.

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ANALISIS KELIMPAHAN TOTAL BAKTERI COLIFORM DI PERAIRAN MUARA SUNGAI SAYUNG, MOROSARI, DEMAK (Analysis of Total Abundance of Coliform Bacteria at the Sayung River Estuary, Morosari, Demak)

SAINTEK PERIKANAN Indonesian Journal of Fisheries Science and Technology ◽

10.14710/ijfst.14.1.30-35 ◽

2018 ◽

Vol 14 (1) ◽

pp. 30

Author(s):

Lani Febriana Safitri ◽

Niniek Widyorini ◽

Oktavianto Eko Jati

Keyword(s):

Water Quality ◽

Organic Matter ◽

Dissolved Oxygen ◽

Random Sampling ◽

River Estuary ◽

Total Coliform ◽

Coliform Bacteria ◽

Total Abundance ◽

Average Abundance ◽

Total Coliform Bacteria

Perairan Muara Sungai Sayung terletak di wilayah Kabupaten Demak sebelah barat. Perairan ini telah dipengaruhi oleh berbagai aktivitas manusia yang menyebabkan terjadinya penurunan kualitas perairan. Bakteri Coliform merupakan bakteri gram negatif yang berbentuk batang dan tidak membentuk spora. Bakteri ini merupakan bakteri indikator terjadinya pencemaran perairan maupun indikator keberadaan bakteri patogen lainnya. Perhitungan total bakteri Coliform perlu dilakukan untuk mengetahui adanya pencemaran limbah organik yang terjadi di Perairan Muara Sungai Sayung, Morosari, Demak. Tujuan dari penelitian ini adalah untuk mengetahui kelimpahan total bakteri Coliform, dan status perairan di Perairan Muara Sungai Sayung, Morosari, Demak. Penelitian ini juga bertujuan untuk mengetahui hubungan dari jumlah total bakteri Coliform dengan bahan organik terlarut dan oksigen terlarut (DO). Pelaksanaan penelitian ini dilakukan pada bulan Mei 2018. Metode yang digunakan dalam penelitian ini adalah metode survei dan teknik pengambilan sampel menggunakan metode random sampling yang dilakukan pada lima stasiun. Hasil penelitian menunjukkan bahwa kelimpahan rata-rata total bakteri Coliform yang diperoleh berkisar antara 4 x 103 – 550 x 10 3/100ml. Kelimpahan rata-rata total bakteri Coliform yang diperoleh pada setiap stasiun menunjukkan bahwa kandungan total bakteri Coliform telah melebihi baku mutu air menurut Keputusan Menteri Lingkungan Hidup Nomor 51 Tahun 2004. Keberadaan total bakteri Coliform memiliki hubungan yang lemah dengan kandungan bahan organik terlarut, sedangkan keberadaan total bakteri Coliform memiliki hubungan yang cukup dengan oksigen terlarut (DO) di perairan Muara Sungai Sayung Morosari, Demak. Sayung River Estuary is located in the western part of Demak Regency. This estuary has been affected by various human activities which have led to a decline in water quality. Coliform bacteria are a gram-negative bacteria that are rod-shaped and do not form spores. This bacterium is an indicator bacteria of water pollution and an indicator of the presence of other pathogenic bacteria. Total Coliform bacteria calculation needs to be carrid out to find out if there any contamination of organic waste in Sayung River Estuary, Morosari, Demak.. The purpose of this research was to determine total abundance of Coliform bacteria, water quality in Sayung River Estuary, Morosari, Demak and relationship between the total abundance of Coliform bacteria with dissolved organic matter and dissolved oxygen (DO). This research was carried out in May 2018. The method that used in this research were survey method and the sampling technique was random sampling method in five stations. The results showed that the average abundance of total Coliform bacteria obtained ranged between 4 x 103 - 550 x 103 / 100ml. Average abundance of total Coliform bacteria obtained at each station shows that the total content of Coliform bacteria has exceeded the water quality standard according to Minister of Environment Decree number 51 of 2004. The total presence of Coliform bacteria has a weak relationship with the content of dissolved organic matter, while the total number of Coliform bacteria have sufficient relationship with dissolved oxygen (DO) in the Sayung River Estuary,Morosari, Demak.

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Assessing macroinvertebrate communities in relation to environmental variables: the case of Sambandou wetlands, Vhembe Biosphere Reserve

Applied Water Science ◽

10.1007/s13201-019-1103-9 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 3

Author(s):

Tatenda Dalu ◽

Rivoningo Chauke

Keyword(s):

Community Structure ◽

Water Depth ◽

Environmental Variables ◽

Anthropogenic Activities ◽

Biosphere Reserve ◽

High Water ◽

Macroinvertebrate Community ◽

Macroinvertebrate Communities ◽

Negative Effect ◽

Macrophyte Cover

AbstractThe Vhembe Biosphere Reserve, South Africa, contains many wetlands that serve as wildlife habitats and provide vital ecosystem services. Some of the wetlands are continuously being degraded or destroyed by anthropogenic activities causing them to disappear at an alarming rate. Benthic macroinvertebrates are known as good water quality bioindicators and are used to assess aquatic ecosystem health. The current study investigated habitat quality using macroinvertebrate community structure and other biotic variables (i.e. phytoplankton, macrophytes) in relation to environmental variables in the Sambandou wetlands using canonical correspondence analysis (CCA). A total of fifteen macroinvertebrate families were identified over two seasons. The CCA highlighted seven variables, i.e. pH, phosphate concentration, temperature, ammonium, macrophyte cover, conductivity and water depth, which were significant in structuring macroinvertebrate community. Picophytoplankton and microphytoplankton concentrations decreased from winter to summer, whereas nanophytoplankton concentration increased from winter to summer. Thus, the dominance of small-sized phytoplankton indicated nutrient limitation and decreased productivity, whereas winter sites 2 and 3 were dominated by large-celled phytoplankton, highlighting increased productivity. Winter sites were mostly negatively associated with CCA axis 1 and were characterised by high temperature, phosphate and ammonium concentrations, macrophyte cover, pH and conductivity. Summer sites were positively associated with axis 1, being characterised by high water depth and pH levels. The results obtained highlighted that agricultural activities such as cattle grazing and crop farming and sand mining/poaching had a negative effect on macroinvertebrate community structure.

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