On the structure of the inshore fish community of England and Wales

1989 ◽  
Vol 69 (1) ◽  
pp. 145-163 ◽  
Author(s):  
P. A. Henderson
Keyword(s):  
Fish Species ◽  
Fish Community ◽  
English Channel ◽  
Benthic Species ◽  
Power Station ◽  
England And Wales ◽  
Number Of Species ◽  
Power Stations

Records of fish captures on power station intake screens were used to analyse the structure of the English and Welsh inshore fish community. The study was undertaken as part of a programme to predict fish captures at future power station sites. It was found that 118 of the 122 fish species known to live inshore were recorded from the screens of 12 coastal power stations. The maximum number of species at one site was about 80, achieved at fully marine localities along the English Channel coast. This number declined with increasing latitude and decreasing salinity.Fish subdivide their use of the inshore habitat both spatially and temporally and the proportion of species complement within the major subdivisions of the habitat was remarkably similar at all sites. On average, 28 species were present simultaneously and these would include 4 pelagic, 8 demersal and 16 benthic species.

Is the introduction of benthic species necessary for open-water chemical reconstruction in diatom-based transfer functions?

2002 ◽  
Vol 59 (6) ◽  
pp. 938-951 ◽  
Author(s):  
Aline Philibert ◽  
Yves T Prairie
Keyword(s):  
Transfer Functions ◽  
Model Performance ◽  
Open Water ◽  
Partial Least Square ◽  
Least Square ◽  
Weighted Averaging ◽  
Benthic Species ◽  
Inference Models ◽  
Number Of Species ◽  
Chemical Conditions

Despite the overwhelming tendency in paleolimnology to use both planktonic and benthic diatoms when inferring open-water chemical conditions, it remains questionable whether all taxa are appropriate and necessary to construct useful inference models. We examined this question using a 75-lake training set from Quebec (Canada) to assess whether model performance is affected by the deletion of benthic species. Because benthic species are known to experience very different chemical conditions than their planktonic counterparts, we hypothesized that they would introduce undesirable noise in the calibration. Surprisingly, such important variables as pH, total phosphorus (TP), total nitrogen (TN), and dissolved organic carbon (DOC) were well predicted from weighted-averaging partial least square (WA-PLS) models based solely on benthic species. Similar results were obtained regardless of the depth of the lakes. Although the effective number of occurrence (N2) and the tolerance of species influenced the stability of the model residual error (jackknife), the number of species was the major factor responsible for the weaker inference models when based on planktonic diatoms alone. Indeed, when controlled for the number of species in WA-PLS models, individual planktonic diatom species showed superior predictive power over individual benthic species in inferring open-water chemical conditions.

scholarly journals The hydraulic management of the Barra Bonita reservoir (SP, Brazil) as a factor influencing the temporal succession of its fish community

2007 ◽  
Vol 67 (3) ◽  
pp. 433-445 ◽  
Author(s):  
ML. Petesse ◽  
M. Petrere Jr. ◽  
RJ. Spigolon
Keyword(s):  
Fish Species ◽  
Fish Community ◽  
Abundant Species ◽  
Anthropogenic Stress ◽  
Reservoir Level ◽  
Species List ◽  
Adaptation Capacity ◽  
Reproductive Structures ◽  
Temporal Succession ◽  
Reproductive Compensation

The temporal succession of fish communities allows evaluating the environmental conditions and the adaptation capacity of the fish species to anthropogenic stress in reservoirs. The fish community at Barra Bonita reservoir was sampled in two different periods of the year (dry and rainy) and in three different areas of the reservoir (fluvial, transition, and lentic). The species list was compared to another four lists, trying to detect the transformations of the fish community for the last 15 years. In order to evaluate the adaptation of the present fish community to the hydraulic management of reservoir, the trophic and reproductive structures were studied. Temporal succession analysis shows little change in fish richness of the communities. The number of fish species varies between 23 and 39 for a total of 68 registered species. From this, 27 can be considered constant, 14 accessory and 27 accidental; the main differences observed were for Anostomidae, Loricariidae and Characidae families. In relation to the hydraulic management, we found a fish community stabilized and adapted to environmental stress. This is characterized by the dominance of small-sized fish species of opportunistic diet and high reproductive compensation (r-strategists). The overlap of biological cycles of the most abundant species with the reservoir level fluctuations points to the period from September to March-April as critical for reproductive success and only the species with partial reproductive strategy or parental care are best succeeded. These results, interpreted in the context of the reservoir aging process, indicate that Barra Bonita reservoir is entering a transition phase, between the colonization and aging stages.

scholarly journals Comparing on site human and video counts at Igarapava fish ladder, south eastern Brazil

2006 ◽  
Vol 4 (2) ◽  
pp. 291-294 ◽  
Author(s):  
Mark D. Bowen ◽  
Simone Marques ◽  
Luiz G. M. Silva ◽  
Volney Vono ◽  
Hugo P. Godinho
Keyword(s):  
Fish Species ◽  
Accurate Method ◽  
Fish Passage ◽  
Southeastern Brazil ◽  
Human Observer ◽  
Full Spectrum ◽  
Prochilodus Lineatus ◽  
Number Of Species ◽  
Fish Ladder ◽  
Number Of Individuals

On site human observations and video images were collected and compared at the window of the Igarapava Dam fish ladder (IDFL), rio Grande , Southeastern Brazil, between March 1st and June 30th, 2004. We conducted four experiments with two humans (Observer 1 and Observer 2) observing fish passage in the IDFL window while a Sony 3CCD video camera (Observer 3) recorded fish passage at the same time. Experiments, each one hour in length, were distributed throughout the diel cycle using full spectrum lights. We identified fish species, the number of individuals for each species, and the real time that they passed. Counts from each human observer were compared to the video counts. The fish species most commonly observed in the window were - curimba (Prochilodus lineatus), mandi-amarelo (Pimelodus maculatus), piau-três-pintas (Leporinus friderici) and ferreirinha (Leporinus octofasciatus). The number of species and individuals were indistinguishable for the three observers. But, the number of species and individuals were significantly different among experiments. Thus, the three observers register the same number of species and count the same number of individuals even when these two response variables differ significantly among experiments. Based on these results, we concluded that the video count was an accurate method to assess fish passage at the IDFL.

scholarly journals Analysis of floodable areas of the Angara river

2020 ◽  
Vol 223 ◽  
pp. 03002
Author(s):  
Gachenko Andrey ◽  
Hmelnov Alexey
Keyword(s):  
Model Building ◽  
Hydroelectric Power Station ◽  
Application Software ◽  
Hydroelectric Power ◽  
Power Station ◽  
Terrain Model ◽  
Power Stations ◽  
Littoral Area ◽  
Bratsk Reservoir

In this work, the authors present a technology for riverside terrain model building that has been tested on a number of scientific projects to study the littoral area of tail race of the Irkutsk Hydroelectric Power Station and the Bratsk Reservoir. This model is used for forecasting changes in the reservoir shorelines associated with wastewater in the cascade of hydroelectric power stations. The technology described in the work was approved to solve a number of practical problems and showed its effectiveness. Specialized application software was developed and terrain data from various sources were used to specify and detail the end result.

scholarly journals PVsyst Software for Better Energy Efficiency of a Grid-Connected Photovoltaic Power Station

2021 ◽  
Vol 21 (2) ◽  
pp. 85-93
Keyword(s):  
Weather Station ◽  
Tracking Systems ◽  
Power Station ◽  
Solar Insolation ◽  
Power Stations ◽  
Photovoltaic Power ◽  
Solar Tracking ◽  
Orenburg Oblast ◽  
Solar Tracker

The paper presents a classification of solar tracking systems used in photovoltaic power stations (PVS) and their operating principles. A simulation model of a grid-connected 5-kW PVS has been developed in PVsyst, to which end the researchers selected PVS equipment and optimized the PV cell tilt angles. The paper further analyzes a grid-connected PVS in Orenburg Oblast in PVsyst under the following configurations: static PV cells, not tilted vs seasonally varied tilts; single-axis solar trackers with vertical and horizontal axes of rotation vs a dual-axis solar tracker. The analysis is based on solar insolation data for 2019 obtained from the research team’s HP-2000 weather station. Dual-axis solar tracker and single-axis vertical trackers are shown to have the best year-round generation, providing an increase of 13.2% and 11.5%, respectively, against the static PV cells (no change in tilt).

scholarly journals Species diversity, distribution and status of fishes in Chitwan district and adjacent areas, Nepal

2018 ◽  
Vol 30 ◽  
pp. 85-101
Author(s):  
Dilip Kumar Jha
Keyword(s):  
Species Diversity ◽  
Fish Species ◽  
Aquatic Systems ◽  
Adjacent Area ◽  
River Systems ◽  
Aquatic Resources ◽  
Number Of Species ◽  
Central Nepal ◽  
The People ◽  
First Time

Chitwan district is endowed with varied aquatic resources which harbor diverse fish species in central Nepal. A total of 111 fish species were collected from different sampling sites of several tributaries of Trisuli, Rapti and Narayani river systems in Chitwan district and adjacent areas from August 2011 to July 2016. These species belong to 9 orders, 27 families and 72genera. Among the orders, Cypriniformes had the highest number of species (49%) followed by Siluriformes (30%), Perciformes (12%), Synbranchiformes (3%), Osteoglossiformes (2%) while Anguiliformes, Beloniformes, Clupeiformes and Tetraodontiformes represented each by about 1%. Cyprinidae has the highest number of species (40%) among the families followed by Sisoridae (12%), Bagridae (7%), Cobitidae (5.4%), Schilbeidae (4.5%), Channidae (3.6%), Balitoridae (2.7%), Mastacembelidae (2.7%), Siluridae (2.7%), Notopteridae (1.8%), Ambassidae (1.8%), Nandidae (1.8%) and Mugilidae (1.8%). Other families accounted forabout 1% were Anguillidae, Belonidae, Clupeidae, Psilorhynchidae, Anabantidae, Gobiidae, Belontidae, Synbranchidae, Amblycipitidae, Pangasidae, Clariidae, Heteropneustidae, Chacidae and Tetraodontidae. The Botia geto was reported for the first time from Rapti river of Chitwan and adjacent area. Different fish species are naturally maintained in aquatic systems and support livelihoods of the people. Catches of major food fishes are declining due to overexploitation of resources, therefore, appropriate measures are needed at once to maintain and conserve the indigenous stock.

Long-term changes in muddy fine sand community of the Rance Basin: role of recruitment

2001 ◽  
Vol 81 (4) ◽  
pp. 553-564 ◽  
Author(s):  
Nicolas Desroy ◽  
Christian Retière
Keyword(s):  
Dominant Species ◽  
General Rule ◽  
Fine Sand ◽  
Mean Value ◽  
English Channel ◽  
Power Station ◽  
Tidal Power ◽  
Short Period

Dynamics of the Abra alba muddy fine sand community of the Rance Basin (western English Channel), initially sampled in one station by Retière at the beginning of the 1970s after the tidal power station built at the mouth of the estuary went into service, was reassessed from 1995 to 1997. Results showed a more ‘mature’ community in 1995–1997 with an increase in the number of species. After a short period, in spring 1995, during which the structure of the community was comparable to those described in 1972–1973, the assemblage was characterized by a great interannual structural stability. Densities of dominant species seem to fluctuate around a mean value comparable to the carrying capacity of the biota for these species. The recruitment of the dominant species with a long life span appears low compared to the densities of adults but seems sufficient to assure the replacement of individuals. Our results suggest that the pattern of massive recruitment followed by high mortality rates could not be the general rule and that a pattern of moderate recruitment followed by low post-settlement mortality of recruits should be more frequent.

scholarly journals Ekologi Trofik Komunitas Ikan di Perairan Segara Menyan, Subang, Jawa Barat (Trophic Ecology of the Fish Community in Segara Menyan Coastal Lagoon, Subang, West Java)

2015 ◽  
Vol 20 (3) ◽  
pp. 170 ◽  
Author(s):  
Ahmad Zahid ◽  
M.F. Rahardjo ◽  
Lenny S Syafei ◽  
Rini Susilowati
Keyword(s):  
Temporal Variation ◽  
Fish Species ◽  
Trophic Level ◽  
Coastal Lagoon ◽  
Fish Community ◽  
Trophic Ecology ◽  
Diet Breadth ◽  
Gut Contents ◽  
Trophic Guild ◽  
Spatio Temporal

Pengetahuan mengenai ekologi trofik merupakan dasar dalam memahami ekosistem secara keseluruhan yang dapat dijelaskan melalui pola hubungan trofik interspesies ataupun interserikat. Penelitian bertujuan untuk menjelaskan ekologi trofik meliputi indeks trofik dan jenis makanan dominan, serikat dan tingkat trofik, dan variasi spasial dan temporal komunitas ikan di estuari Segara Menyan. Pengambilan ikan contoh dilakukan setiap bulan pada zona berbeda. Ikan contoh dipisahkan berdasarkan waktu dan lokasi pengamatan, dianalisis isi saluran pencernaannya. Analisa data meliputi indeks vakuitas, jumlah total organisme makanan, jenis makanan dominan, luas relung makanan, dan tingkat trofik.  Pada pengamatan 106 spesies ikan, sebanyak 1-380 saluran pencernaan ikan diamati. Sebanyak lima dari 106 spesies memiliki nilai indeks vakuitas “0” dan jumlah makanan yang dikonsumsi bervariasi mulai dari empat hingga 27 jenis makanan. Secara umum, luas relung ikan adalah rendah berkisar 0,20-0,78 dan kebanyakan berada pada kisaran 0,20-0,48. Zooplankton merupakan jenis makanan paling dominan dikonsumsi oleh ikan. Komunitas ikan dikelompokkan dalam tujuh serikat trofik, yaitu detritivora, fitoplanktivora, zooplanktivora, zoobentivora, moluskivora, krustasivora, dan pisivora. Tingkat trofik komunitas ikan berkisar 2,05-4,73. Faktor perubahan ontogenetik, persediaan makanan, karakteristik habitat, dan ruaya beberapa spesies ikan memengaruhi variasi spasio-temporal jejaring makanan di Segara Menyan. Kata kunci: interaksi trofik, laguna, ikan, variasi spasio-temporal, serikat trofik Knowledge of trophic ecology is one way to understanding the whole ecosystem which explained by trophic relationship pattern (interspecies or interguild). The objective research was described of the trophic ecology, i.e. trophic index and dominant prey, trophic guild and trophic level, and spatio-temporal variation of fish community in Segara Menyan coastal lagoon. Fish were collected monthly for one year at three zones. Fish samples were placed in separate labelled plastic bags according to the time scale and location sampling, then gut contents were analyzed. The data of vacuity index, number of prey, prey dominant, diet breadth, and trophic level were analyzed. For each of 106 fish species, between 1 and 380 stomachs, were examined. The vacuity index was also different among species. Five of 106 species had a vacuity index of “0” and total number of food items consumed varied between fish species, ranging from three items to 27 items. The overall diet breadth (Bi) was relatively low among species, ranging from 0.20 to 0.78, with most of them between 0.20 and 0.48. Calanoid copepods comprised the most common food item consumed by all the fishes examined. Fishes occurring can be broadly categorized into seven different trophic guilds. The trophic level of fish communities ranged from 2.05 to 4.73. Spatio-temporal variation of food web was influenced of ontogenetic shift, food availability, habitat characteristic, and migration of some species in Segara Menyan coastal lagoon. Keywords: trophic interaction, lagoon, fishes, spatio-temporal variation, trophic guild

Characteristics of Rheinisch Brown Coals With Respect to Their Combustion and Fouling Behavior in Thermal Power Stations

1977 ◽  
Vol 99 (4) ◽  
pp. 679-683 ◽  
Author(s):  
K. Hein
Keyword(s):  
Thermal Power ◽  
Research Programme ◽  
Operating Parameters ◽  
Power Station ◽  
Power Stations ◽  
Excess Air ◽  
Thermal Power Stations ◽  
Brown Coals ◽  
First Results ◽  
Fouling Characteristics

In the paper first results of a several years’ research programme into the combustion and fouling characteristics of Rheinish brown coals are given. As described, fouling of the heat transfer surfaces causes severe difficulties for power station operation. The deposit formation is strongly dependent on both the composition of the inherent ash of the fuel and the extraneous impurities. The phenomenon of fouling can be influenced by operating parameters like excess air level and mixing between fuel and combustion air. The temperature of the heat receiving surface as well as its geometry play an important role.

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