scholarly journals Effects of Physicochemical Variables of Superficial Waters on the Abundance of the North African Freshwater Crab Potamon algeriense (Bott, 1967)

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Soufiane Fadlaoui ◽  
Ouahid El Asri ◽  
Mustapha Bouterfas ◽  
Mohammed Melhaoui
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Suspended Matter ◽  
Mountain Stream ◽  
Freshwater Crab ◽  
Physicochemical Variables ◽  
The North ◽  
Global Quality ◽  
Nitrite Nitrate

The large number of pollutants discharged into the aquatic environment may influence the physicochemical and biological qualities of the aquatic ecosystem. This study discloses the global quality of the surface waters and the effect of physicochemical variables on the abundance of the African freshwater crab Potamon algeriense inhabiting Zegzel watercourse, a mountain stream in the northeast of Morocco. Physicochemical variables including streamflow, water temperature, pH, dissolved oxygen, suspended matter, chloride, calcium, magnesium, ammonia, nitrite, nitrate, orthophosphate, and organic matter were evaluated monthly for one year (October 2017–September 2018). The evaluation of the physicochemical quality showed that the waters of all the stations studied are between the excellent and good quality classes concerning all the physicochemical variables and highlights also two variations with a tendency towards degradation, one spatial from upstream to downstream and the other seasonal from the wet to the dry period. The abundance of crabs was recorded to exhibit a positive correlation with dissolved oxygen, calcium (N = 44) (p < 0.01), and magnesium. However, a negative correlation has been noticed for streamflow (N = 1) (p < 0.01), water temperature, pH, suspended matter, chloride, ammonia, nitrite, nitrate, orthophosphate, and organic matter. The results obtained reveal that besides the biotic variables, the distribution of P. algeriense also depends on these specific environmental variables.

Effet de certains paramètres physico-chimiques sur les relations prédateurs–proies dans les populations de copépodes cyclopoïdes des mares temporaires d'eau douce

1986 ◽  
Vol 64 (1) ◽  
pp. 8-11
Author(s):  
Louise Vallières ◽  
Antoine Aubin
Keyword(s):  
Organic Matter ◽  
Body Size ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Feeding Ecology ◽  
Mineral Content ◽  
Abiotic Factors ◽  
Size Class ◽  
Regression Analyses ◽  
Physical And Chemical

Copepod populations of three temporary freshwater pools (Alnus unit, Carex unit, and Molinia unit) were studied using a standard approach (species versus abiotic factors) and a holistic one (body size and feeding ecology). Multiple regression analyses of data indicate that the physical and chemical features of water (temperature, pH, dissolved oxygen, mineral content, and depth) explain 62 to 98% of the variability of carnivorous copepods, while the abundance of their prey accounts for much less. No size class of prey seems to be preferred. The abundance of decaying organic matter, typical of such pools, would result in an overabundance of prey. Predators would then be under the control of nonalimentary factors.

Impact of hypolimnetic oxygenation on profundal macroinvertebrates in a eutrophic lake in central Alberta. I. Changes in macroinvertebrate abundance and diversity

1997 ◽  
Vol 54 (9) ◽  
pp. 2157-2169 ◽  
Author(s):  
W P Dinsmore ◽  
E E Prepas
Keyword(s):  
Dissolved Oxygen ◽  
Water Temperature ◽  
Eutrophic Lake ◽  
Water Bodies ◽  
Macroinvertebrate Communities ◽  
South Basin ◽  
The North ◽  
Hypolimnetic Oxygenation ◽  
Abundance And Diversity ◽  
The Impact

Hypolimnetic oxygenation from 1988 to 1991 in the north basin of Amisk Lake increased mean summer (June-August) dissolved oxygen (DO) concentrations in the deep hypolimnion (25 m) from <0.4 mg ·L-1 during pretreatment years (1980-1987) to 2.7 mg ·L-1 during treatment. Mean summer hypolimnetic temperatures at 25 m also increased from 6.3 (pretreatment) to 8.1°C (treatment). Profundal (15-25 m) Chironomus spp. abundance in the treated basin increased from <100 to >2000 ·m-2 from 1988 to 1991 whereas Chaoborus spp., Tubificidae, and other taxa remained uncommon at similar depths. Shannon-Weaver indices of diversity decreased as oxygenation progressed, in contrast with previous studies. Similar patterns in densities and diversity were observed in the south basin of Amisk Lake, although the increase in DO concentrations was smaller relative to the north basin. The impact of increased water temperature on macroinvertebrates appeared minor relative to the effects of increased DO concentrations. No changes in macroinvertebrate communities were noted in a nearby reference lake during the study period. Responses to hypolimnetic oxygenation in Amisk Lake differed markedly from those reported for smaller, single-basined water bodies.

scholarly journals MODELO MATEMÁTICO DEL ECOSISTEMA DE LA CIÉNAGA GRANDE DE SANTA MARTA

2016 ◽  
Vol 32 ◽  
Author(s):  
Yuri S. Tuchkovenko ◽  
Luis Alfredo Calero
Keyword(s):  
Mathematical Model ◽  
Organic Matter ◽  
Spatial Distribution ◽  
Dissolved Oxygen ◽  
Coastal Lagoon ◽  
Two Dimensional ◽  
Balance Equations ◽  
Dead Organic Matter ◽  
Shallow Reservoir ◽  
Nitrite Nitrate

The structure of the chemical – biological block of two-dimensional mathematical model of ecosystem and shallow reservoir and his methods of calibration is described in detail. The model includes the balance equations for the following components of ecosystem: phytoplankton, bacteria, zooplankton, dead (organic) matter, phosphate, ammonium, nitrite, nitrate and dissolved oxygen. Results of calculations of spatial distribution of several components of the ecosystem for the Ciénaga Grande de Santa Marta coastal lagoon (Colombia) in various seasons of year are given.

scholarly journals CHANGES IN CONCENTRATIONS OF ORGANIC MATTER IN THE MOUTHS OF THE DOTNUVELE AND SMILGA RIVERS

2018 ◽  
Author(s):  
Stefanija MISEVIČIENĖ
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Anthropogenic Activities ◽  
Precipitation Amount ◽  
Ecological Status ◽  
Sources Of Pollution ◽  
Temperature And Precipitation ◽  
Quality Of Water ◽  
The Difference

The quality of water in rivers of central Lithuania is often bad due to intensive anthropogenic activities. When rivers flow through the town’s territory, concentrated pollution, such as rainwater, industrial and productional waste water discharges, contributes to diffuse sources of pollution. If biogenic substances are the main indicators for diffuse pollution, organic matter, expressed as BOD, is the indicator for concentrated pollution. The article provides the 2013 – 2017 monitoring data on the changes of organic matter in the water of the Dotnuvele and Smilga Rivers and discusses the reasons for fluctuations in concentrations of BOD7. The aim of the research is to investigate the changes in the organic matter of the Dotnuvele and Smilga Rivers, depending on meteorological factors. For chemical analysis, water samples were taken quarterly. Water analysis was carried out by the ASU Chemical Analytical Laboratory of Water Resources Engineering Institute. The amount of organic matter (BOD7) is calculated as the difference in oxygen content after 7 days of incubation, while the amount of dissolved oxygen (O2) in the water is determined by the electrochemical probe method. The concentrations of BOD7 and O2 in the water of both rivers is compared with the criteria for assessing the ecological status of surface water bodies. The research has shown that the dissolved oxygen concentrations in rivers’ water are strongly influenced by water temperature and precipitation. The lower the temperature, the more of the dissolved oxygen is found in rivers’ water (r = -0.64). A lower precipitation amount, which reaches the rivers, increases the amount of dissolved oxygen in them (r = -0.45). The increase of BOD7 concentrations in rivers’ water was caused by higher precipitation amount (r = 0.46), higher air (r = 0.41) and lower water temperature (r = -0.41). The ecological status of the Dotnuvele River was usually good, while Smilga was average.

scholarly journals Detection of low bottom water oxygen concentrations in the North Sea; implications for monitoring and assessment of ecosystem health

2010 ◽  
Vol 7 (4) ◽  
pp. 1357-1373 ◽  
Author(s):  
N. Greenwood ◽  
E. R. Parker ◽  
L. Fernand ◽  
D. B. Sivyer ◽  
K. Weston ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
North Sea ◽  
Particulate Organic Matter ◽  
Ecosystem Health ◽  
Bottom Water ◽  
Dissolved Oxygen Concentration ◽  
The North ◽  
The North Sea

Abstract. This paper presents new results from high temporal resolution observations over two years (2007 and 2008) from instrumented moorings deployed in the central North Sea, at the Oyster Grounds and on the northern slope of Dogger Bank (North Dogger). The water column was stratified in the summer at both sites, leading to limited exchange of the water in the bottom mixed layer. Data from these moorings revealed the variable nature of summer oxygen depletion at the Oyster Grounds. The combination of in situ and ship-based measurements allowed the physical and biological conditions leading to decreasing dissolved oxygen concentrations in bottom water to be examined. In 2007 and 2008, the concentration of dissolved oxygen in the bottom water at both sites was observed to decrease throughout the summer period after the onset of stratification. Depleted dissolved oxygen concentration (6.5 mg l−1, 71% saturation) was measured at the North Dogger, a site which is not significantly influenced by anthropogenic nutrient inputs. Lower oxygen saturation (5.2 mg l−1, 60% saturation) was measured for short durations at the Oyster Grounds. The seasonal increase in bottom water temperature accounted for 55% of the decrease in dissolved oxygen concentration at the Oyster Grounds compared to 10% at North Dogger. Dissolved oxygen concentration in bottom water at the Oyster Grounds was shown to be strongly influenced by short term events including storms and pulses of particulate organic matter input. In contrast, dissolved oxygen concentration in bottom water at the North Dogger reflected longer seasonal processes such as a gradual temperature increase over the summer and a more steady supply of particulate organic matter to the bottom mixed layer. The differences between the study sites shows the need for an improved understanding of the mechanisms driving these processes if the use of oxygen in marine management and ensuring ecosystem health is to be meaningful and successful in the future. These high frequency observations provide greater understanding of the nature of the depletion in bottom oxygen concentration in the North Sea.

Relations Between Annual Dredging Activities, Suspended Matter Concentrations, and the Development of the Tidal Regime in the Ems Estuary

1983 ◽  
Vol 40 (S1) ◽  
pp. s289-s300 ◽  
Author(s):  
V. N. de Jonge
Keyword(s):  
Organic Matter ◽  
Suspended Matter ◽  
Morphological Changes ◽  
River Rhine ◽  
Ems Estuary ◽  
Secchi Disc ◽  
Tidal Regime ◽  
The North ◽  
Tenfold Increase ◽  
Natural Equilibrium

This paper challenges Kühl and Mann's suggestion (1973) that an increase in organic matter in the Ems Estuary between 1950 and 1970 caused a five- to tenfold increase in the turbidity in that period. Their hypothesis is refuted because: (a) during that period the discharge of organic matter via both the River Ems and the River Westerwoldsche A did not change significantly; (b) the increase in particulate organic carbon in the western Dutch Wadden Sea and possibly also in the Ems Estuary resulting from eutrophication of the North Sea by the River Rhine during 1950–70 is unlikely to have been more than twofold; and (c) Secchi-disc data do not support the five- to tenfold increase in turbidity. It is suggested that dredging is probably responsible for the increase in turbidity because the volume of material dredged annually increased fourfold between 1950 and 1970. The mean annual concentration of suspended matter increased by a factor ranging from 1.3 to 2.1 between 1954 and the period 1970 to 1979. The fluctuations in concentrations of suspended matter showed a statistically significant correlation with the distance dredged annually and not with the volume dredged annually. This indicated that the relation depended more on how "extensive" rather than on how "intensive" the dredging was. The fluctuations in concentrations of suspended matter are caused by the intensified erosion and sedimentation cycle that is initiated after the local natural equilibrium between channel morphology and current pattern is disturbed. This explanation is supported by the morphological changes that occurred in part of the study area between 1975 and 1979. Further support for this hypothesis was found in the changes of the tidal regime in the estuary. It is postulated that the complete cessation of dredging would probably be accompanied by the concentrations of suspended solids falling from the 1979 levels to values nearer those obtained in 1954. The biological implications of the processes described are discussed.Key words: dredging, suspended matter, tidal regime, Ems Estuary, turbidity

scholarly journals Features of the Oceanological Values Fields in the Sivash Bay (The Sea of Azov)

2020 ◽  
Vol 37 (6) ◽  
Author(s):  
P. D. Lomakin ◽  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Suspended Matter ◽  
Water Area ◽  
Total Suspended Matter ◽  
Western Coast ◽  
Colored Dissolved Organic Matter ◽  
Marine Hydrophysical Institute ◽  
The North ◽  
Azov Sea

Purpose. The study is aimed at revealing the structural regularities and variability of the fields of temperature, salinity, the colored dissolved organic matter and total suspended matter concentrations, and also the factors that form them in the Sivash Bay. Besides, the results obtained are to be compared with the already known features of the fields of the values under investigation which are typical of the Azov-Black Sea coastal zone; and the response in the considered fields to the North Crimean Canal damming is to be assessed. Methods and Results. Based on the data of 8 expeditions carried out by Marine Hydrophysical Institute in 2013–2016, the structural regularities and variability of the fields of temperature, salinity, the colored dissolved organic matter and total suspended matter concentrations, and the factors that form the fields of these values in the Sivash Bay were revealed. The quantitative indicators of changes in the fields of the considered values, which arose after the North Crimean Canal was dammed, are represented. Conclusions. In the region under study, a number of constantly acting factors that determine formation of special, not typical of the coastal area, features of the oceanological values fields are identified, namely: the influence of the Azov Sea and the North Crimean Canal waters, the rivers inflowing to the water area of the Sivash western coast, the isolated lakes, the swampy shallow bays and the isolated, relatively deep, parts of the coastline. Three years after the North Crimean Canal was dammed, in the northwestern Sivash salinity increased by 20 PSU. The opinion that Sivash is not a typical sea bay, but a connected with the Azov Sea reservoir with the signs of a salt swamp is confirmed

Windstorm disturbance effects on mountain stream ecosystems and the Plecoptera assemblages

Biologia ◽  
2015 ◽  
Vol 70 (9) ◽  
pp. 1215-1227 ◽  
Author(s):  
Iľja Krno ◽  
Tomáš Lánczos ◽  
Ferdinand Šporka
Keyword(s):  
Organic Matter ◽  
Water Temperature ◽  
Species Abundance ◽  
River Basins ◽  
Mountain Stream ◽  
Functional Feeding Groups ◽  
Channel Stability ◽  
Forested Areas ◽  
Disturbed Forest ◽  
Annual Water

Abstract Within the investigated river basins the deforestation ranged from 0-45.5%, dependent on the amount of windstorm damage. Our water temperature readings revealed that the canopy elimination above the streams in the areas damaged by the windstorm caused increase in daily and annual water temperature and also wider daily water temperature range, than those in the undisturbed reference stream, which caused the decline of cold stenotherm species abundance. The stream basins deforestation was collinear with FPOM and UFPOM concentrations, water temperature gradient and nitrate concentrations. Statistical analysis showed that size of stream, conductivity, catchment area and discharge were negatively correlated with the stonefly mesotherm ratio and nitrate contents. Higher average concentrations of nutrients (like NO−3) in samples from some streams are a consequence of their mobilization from disturbed forest soils due to the windstorm. Most streams located in the deforested area were found by us in a higher trophic status, especially due the particulate organic matter (POM) content and biofilms amount, what caused increase in some functional feeding groups occurrence (collectorgatherers, scrapers and mainly predators). Stream degradation positively correlated with the percentage of deforested area, ratio of eurytherm taxa, transported organic matter, dissolved organic matter, and biofilms occurrence. The conductivity values measured in water samples were collinear with alkalinity and pH values and increased with watersheds areal extent. We established environmental variables influenced by the windstorm event along the catchment degradation gradient using measurable characteristics of stonefly assemblages and metrics. The proportion of the Leuctridae family and the Nemoura genus expressed as the LN index (1) shows a negative correlation with part undisturbed forested areas and channel stability, and positive correlation with stream erosion (expressed as the TAM quantity) in river basins. Proportion of shredders among the investigated streams was significantly higher in deforested streams, and shows lower stability of stonefly community in these habitats, where significantly fluctuate channel stability, water temperature and discharge of these streams.

scholarly journals KANDUNGAN BAHAN ORGANIK SEDIMEN DAN KADAR H2S AIR DI DALAM DAN DI LUAR TEGAKAN MANGROVE DESA BEDONO, KABUPATEN DEMAK

2018 ◽  
Vol 7 (1) ◽  
pp. 78-85
Author(s):  
Halimatus Sa’diyah ◽  
Norma Afiati ◽  
Pujiono Wahyu Purnomo
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Organic Material ◽  
Organic Materials ◽  
Current Speed ◽  
Survey Method ◽  
Water Sampling ◽  
Mangrove Area ◽  
Surrounding Environment

Kawasan mangrove dapat memproduksi bahan organik dari proses dekomposisi serasah yang jatuh yang menjadi penyuplai nuterien ke lingkungannya. Proses tersebut menggunakan oksigen terlarut yang apabila oksigen terlarut habis maka proses tersebut beralih ke proses dekomposisi secara anaerob yang menyebabkan terbentuknya senyawa H2S. Penelitian ini bertujuan untuk mengetahui perbedaan kandungan bahan organik sedimen dan kadar H2S air di dalam dan di luar kawasan mangrove serta untuk mengetahui hubungan kandungan kadar H2S air dengan bahan organik sedimen dan oksigen terlarut di kawasan mangrove desa Bedono. Metode penelitian adalah metode survey. Penelitian ini dilakasanakn pada bulan Mei- Juni 2017 di lokasi yang mewakili kawasan mangrove dan lingkungan sekitarnya. Data yang diukur adalah suhu air, kecerahan, kedalaman, kecepatan arus, oksigen terlarut, pH, bahan organik sedimen dan H2S air yang dilaksanakan empat kali dengan selang pengukuran dua minggu. Hasil yang didapat yaitu suhu air 28-31oC, kecerahan 14,5-68 cm, kedalaman 33-165 cm, kecepatan arus 0-0,1 m/s, oksigen terlarut , pH 5-6, bahan organik sedimen 7,73-20,27%, H2S air 0,003-0,037 mg/l. Kandungan bahan organik sedimen dan kadar H2S air tertinggi di dalam kawasan mangrove dengan rata-rata 16,36% dan 0,031 mg/l, dan terendah di luar kawasan mangrove dengan rata-rata 9,78% dan 0,01 mg/l. Kadar H2S tinggi di dalam kawasan mangrove dan lebih rendah di luar kawasan mangrove. Kadar H2S air dengan bahan organik sedimen dan oksigen terlarut berhubungan linier dengan persamaan H2S= 0,027 + 0,001BOS- 0,006 DO (r= 0,7246, BOS= Bahan Organik Sedimen, DO= Dissolved Oxygen). Mangroves produce organic matter from the decomposition of falling leaves, twigs etc, which supply nutrient to the environment. The process uses dissolved oxygen; when dissolved oxygen exhausted, it switches into anaerobic decomposition which causes the formation of H2S compounds. This study aims to knowing differences in sediment organic materials and H2S within and adjacent of mangrove areas and to determine the relation of H2S with sediment organic materials and dissolved oxygen in the mangrove areas of Bedono. Survey method is refered, and the study was conducted in May - June 2017 on locations representing mangrove areas and the surrounding environment. The data measured are water temperature, brightness, depth, current speed, dissolved oxygen, pH, sediment organic materials and H2S in the water. Sampling was conducted four times every fortnight. The result of the water temperature is  28-31 ° C, brightness 14.5 to 68 cm, 33-165 cm depth, current speed 0-0.1 m/s, dissolved oxygen 2-5,2 mg/l, pH 5-6, sediment organic material 7,73 to 20.27%, H2S 0.003 to 0.037 mg/l. Sediment organic materials and H2S were highest within the mangrove area, with an average 16.36% and 0.031 mg/l, and the lowest outside of mangrove area with an average 9.78% and 0.01 mg/l. H2S higher in the inside of  the mangrove areas compared to the outside of it. The relation of H2S with sediment organic materials and dissolved oxygen is linearly related according to the equation H2S= 0.027+ 0.001SOM- 0.006DO (r= 0.7246, SOM= Sediment Organic Materials, DO= Dissolved Oxygen).

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