scholarly journals Influence of habitat connectivity and seasonality on the ichthyofauna structure of a riverine knickzone

2018 ◽  
Vol 108 (0) ◽  
Author(s):  
Eduardo M. Brambilla ◽  
Virginia S. Uieda ◽  
Marcos G. Nogueira
Keyword(s):  
Rainy Season ◽  
Power Plants ◽  
High Water ◽  
Abundant Species ◽  
Fish Diversity ◽  
Hydroelectric Power ◽  
Two Factors ◽  
Dry Conditions ◽  
Flood Pulses ◽  
Imminent Threat

ABSTRACT Knickzones are originated from basaltic outcroppings, present runs, riffles and pools and are highly influenced by flood pulses, which maintain their natural dynamic. However, the construction of hydroelectric power plants alters or eliminate the dynamism of this area and can affect the resident fauna that may be dependent on it. The aim of this study was to evaluate the organization of a knickzone’s ichthyofauna considering the influence of seasonality and connectivity of habitats. The study was performed in a knickzone located in the Sapucaí-Mirim River, Southeast Brazil. We sampled four rocky pools connected to the river and three isolated pools, during rainy and dry conditions. The analysis of the two factors (connectivity and seasonality) and of their interaction showed a significant influence only for seasonality on ichthyofauna structure, with higher values of abundance in the rainy season. The species that most contributed to the high dissimilarity between seasons were Knodus moenkhausii (50% of contribution) and Astyanax bockmanni (21%). The former is the most abundant species in the rainy season and the later in the dry season. The alteration between low and high water level occurs frequently in knickzones, as it is a rocky shallow platform in the middle of a river, with floods occurring seasonally or in stochastic short-term periods. This hydrological seasonal dynamic, high limnological variability and complex interactions of different habitats (pools, runs and rapids) explain the particular ichthyofauna structure in such small area. Our results also indicate the potential importance of basaltic knickzones for regional fish diversity conservation, especially due to the imminent threat by intensive hydropower reservoir construction.

scholarly journals Genetic monitoring of the endangered Pyrenean desman (Galemys pyrenaicus) in the Aude River, France

2020 ◽  
Vol 146 (1) ◽  
Author(s):  
François Gillet ◽  
Bruno Le Roux ◽  
Frédéric Blanc ◽  
Aurélie Bodo ◽  
Christine Fournier-Chambrillon ◽  
...  
Keyword(s):  
Power Plants ◽  
Hydroelectric Plant ◽  
Local Population ◽  
High Water ◽  
Iucn Red List ◽  
Suitable Habitat ◽  
Hydroelectric Power ◽  
Long Distance ◽  
The Impact ◽  
Galemys Pyrenaicus

The Pyrenean desman (Galemys pyrenaicus) is a small semi-aquatic mammal endemic to the Pyrenean Mountains and the northern half of the Iberian Peninsula. This species is currently considered as vulnerable in the IUCN Red List and has been suffering from habitat loss and fragmentation for decades but little is known about the impact of water flow modifications induced by hydroelectric power plants. In order to address this issue we monitored Pyrenean desman individuals living in a harnessed section of the Aude River, by genotyping both faeces samples and hair of live-trapped animals. During a three-year study (2011-2013), a total of 39 individuals were identified using 24 microsatellite loci, 28 from faeces and 11 from trapped animals. Several long distance movements were evidenced up to at least 15 km, a distance that has never previously been reported. These movements might be related to modifications of the river bed caused by very high water flows that occurred during the repair of the Nentilla hydroelectric plant. The local population density suggests that the Aude River provides suitable habitat for the Pyrenean desman, and preservation of this habitat should be a priority for the conservation of this species.

scholarly journals Peces de la Laguna Cormorán, Parque Nacional Sangay, Ecuador

2017 ◽  
Vol 9 (15) ◽  
Author(s):  
Fernando Anaguano-Yancha
Keyword(s):  
Aquatic Ecosystem ◽  
Rainy Season ◽  
Transition Period ◽  
Species Abundance ◽  
Abundant Species ◽  
Dry Season ◽  
Fish Diversity ◽  
Astyanax Fasciatus ◽  
The Family ◽  
Rhamdia Quelen

AbstractI conducted a fish inventory at the Cormoran Lagoon, in the icthyogeographic area Upano–Zamora, during October 2011 (dry season), February 2012 (transition period), and May 2012 (rainy season). Fish were sampled using four trammels (20 m length, 1.5 m height), 40 fishing lines, and a hand net. A total of 599 individuals of 16 species and six families were captured. The order Characiformes was the most abundant and diverse, and Lebiasina elongata (Lebiasinidae) and Astyanax fasciatus (Characidae) were the most abundant species. Species abundance gradually decreased as the rainy season arrived. Elevational ranges of the genus Chaetostoma (Chaetostoma microps) and of the family Heptapteridae (Rhamdia quelen) are increased to 1783 m in Ecuador. Fish diversity at Cormoran Lagoon still needs more studies. It is necessary to carry out taxonomic, ecological, and biogeographic studies that contribute to the knowledge of fish diversity in this tropical aquatic ecosystem. It is posible that some species are endemic, specially in the genera Astroblepus and Bryconamericus.  ResumenSe realizó un inventario de peces en la laguna Cormorán, en la zona ictiogeográfica Upano–Zamora, durante octubre 2011 (época de seca), febrero 2012 (época de transición) y mayo 2012 (época de lluvias). Los peces fueron muestreados usando cuatro trasmallos (20 m de largo, 1,5 m de alto), 40 anzuelos y una red de mano. Un total de 599 individuos de 16 especies y seis familias fueron capturados. El orden Characiformes fue el más abundante y diverso, y Lebiasina elongara (Lebiasinidae) y Astyanax fasciatus (Characidae) fueron las especies más abundantes. La abundancia de especies disminuyó paulatinamente conforme llegaba la época de lluvias. Se extienden los rangos altitudinales del género Chaetostoma (Chaetostoma microps) y de la familia Heptapteridae (Rhamdia quelen) hasta 1783 m en Ecuador. La ictiofauna de la laguna Cormorán todavía necesita mayores de estudios. Es necesario realizar estudios taxómicos, ecológicos y biogeográficos que contribuyan al conocimiento de la diversidad de peces de este ecosistema acuático tropical. Es posible que algunas especies encontradas en este estudio sean endémicas, especialmente en los géneros Astroblepus y Bryconamericus. 

scholarly journals Analytical Approach to Sampling Estimation of Underwater Tunnels Using Mechanical Profiling Sonars

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1900
Author(s):  
Vitor Augusto Machado Jorge ◽  
Pedro Daniel de Cerqueira Gava ◽  
Juan Ramon Belchior de França Silva ◽  
Thais Mancilha ◽  
Waldir Vieira ◽  
...  
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Hydroelectric Power ◽  
Large Power ◽  
Unmanned Underwater Vehicles ◽  
Power House ◽  
Simulated Environment ◽  
Sonar Sensor ◽  
Power Plant Operation ◽  
Plant Power

Hydroelectric power plants often make use of tunnels to redirect the flow of water to the plant power house. Such tunnels are often flooded and can span considerable distances. Periodical inspections of such tunnels are highly desirable since a tunnel collapse will be catastrophic, disrupting the power plant operation. In many cases, the use of Unmanned Underwater Vehicles (UUVs) equipped with mechanical profiling sonars is a suitable and affordable way to gather data to generate 3D mapping of flooded tunnels. In this paper, we study the resolution of 3D tunnel maps generated by one or more mechanical profiling sonars working in tandem, considering synchronization and occlusion problems. The article derives the analytical equations to estimate the sampling of the underwater tunnels using mechanical profiling sonars (scanning sonars). Experiments in a simulated environment using up to four sensors simultaneously are presented. We also report experimental results obtained by a UUV inside a large power plant tunnel, together with a first map of this environment using a single sonar sensor.

scholarly journals Deep-Water Cartilaginous Fishes in the Central Mediterranean Sea: Comparison between Geographic Areas with Two Low Impact Tools for Sampling

2021 ◽  
Vol 9 (7) ◽  
pp. 686
Author(s):  
Angela Carluccio ◽  
Francesca Capezzuto ◽  
Porzia Maiorano ◽  
Letizia Sion ◽  
Gianfranco D’Onghia
Keyword(s):  
Adriatic Sea ◽  
Fish Habitat ◽  
Conservation Status ◽  
Abundant Species ◽  
Cartilaginous Fish ◽  
Fish Diversity ◽  
Ionian Sea ◽  
Central Mediterranean ◽  
The North ◽  
North Western

Baited lander represents a low impact technique, an alternative to the traditional trawl sampling for collecting data on fish diversity and abundance, especially for threatened species such as Chondrichthyes living in sensitive habitats. In this study, distribution and abundance of cartilaginous fish were compared between two geographic areas, the southern Adriatic Sea and the north-western Ionian Sea, with two low impact sampling gears, an experimental bottom longline and a baited lander. Species diversity was evaluated by applying ecological indices and difference in mean abundances were tested using multivariate analysis. A total of 13 species of cartilaginous fish were collected. Significant differences in the assemblage recorded in the same area using different sampling tools were detected and no significant differences were detected among different areas explored with the same method. Using longline, the most abundant species collected in both areas was Galeus melastomus, while using lander, the most observed species were Dalatias licha in the southern Adriatic Sea and Hexanchus griseus in the north-western Ionian Sea. According to IUCN classification, of the 13 species collected, 2 are near threatened and 5 are threatened. A better governance of sensitive habitats coinciding with the essential fish habitat for these species would ensure them a better conservation status.

Water quality impacts of small hydroelectric power plants in a tributary to the Pantanal floodplain, Brazil

2021 ◽  
Author(s):  
Rúbia Fantin Cruz ◽  
Stephen K. Hamilton ◽  
Hans M. Tritico ◽  
Ibraim Fantin‐Cruz ◽  
Daniela Maimoni Figueiredo ◽  
...  
Keyword(s):  
Water Quality ◽  
Power Plants ◽  
Hydroelectric Power ◽  
Hydroelectric Power Plants
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