scholarly journals Composition and relative abundance of fish species in the lower White Salmon River, Washington, prior to the removal of Condit Dam

2011 ◽  
Author(s):  
M. Brady Allen ◽  
Patrick J. Connolly
Keyword(s):  
Relative Abundance ◽  
Fish Species ◽  
Salmon River

scholarly journals Freshwater Fish Species of the Oorlogskloof River, Northern Cape Province, South Africa

Our Nature ◽  
2013 ◽  
Vol 10 (1) ◽  
pp. 8-16
Author(s):  
P.P. Ramollo ◽  
M. Schumann ◽  
W.A.J. Pretorius
Keyword(s):  
South Africa ◽  
Freshwater Fish ◽  
Relative Abundance ◽  
Fish Species ◽  
Freshwater Fishes ◽  
Endangered Fish ◽  
Freshwater Fish Species ◽  
Northern Cape

The freshwater fish of Oorlogskloof River were sampled in March 2010. The study aimed to determine the distribution and relative abundance of freshwater fish in the Oorlogskloof River. A total of 4643individuals represented by five fish species belonging to two families were sampled. The Barbus anoplus was only sampled in the upper reaches of the Oorlogskloof River gorge while endangered Labeobarbus capensis appeared downstream in the Oorlogskloof River. Barbus serra dominated the fish species in the system. The invasion of Tilapia sparmanni in this system was confirmed during the survey andthe species appeared to be widespread throughout the system. At this stage it does not appear to be posing a serious threat to the endangered fish species. The Oorlogskloof River can be considered as a potential refuge site for the conservation of some endemic and threatened freshwater fishes of South Africa.DOI: http://dx.doi.org/10.3126/on.v10i1.7746

scholarly journals Impact of the Low Head Dam/Barrage on Fisheries – A Case Study of Giri River of Yamuna Basin (India)

2015 ◽  
Vol 17 (2) ◽  
pp. 119-138
Author(s):  
Harcharan Singh Rumana ◽  
Veliachamy Jeeva ◽  
Sudhir Kumar
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Fish Species ◽  
Habitat Heterogeneity ◽  
Diversity Index ◽  
River System ◽  
Western Himalayas ◽  
Diversity Pattern ◽  
Low Head ◽  
Longitudinal Stretch

Abstract Shannon’s diversity index H’ = pi log2 pi was calculated for 16 fish species. The index was resolved into its components, species richness and relative abundance, to determine which components played a larger role in the determination of diversity pattern. Changes in diversity were correlated with species richness (r), habitat heterogeneity, and hydrological regimes in a longitudinal stretch of 35 km along the river Giri, a major tributary of the Yamuna River system, in Western Himalayas. Abundance differs with change in habitat structures, habitat preference of fish species and water regimes. The decrease in diversity in the lower stretch of about 3-4 km upstream of the barrage was found to be associated with habitat fragmentation and as well as d/s with loss of biotic integrity of aquatic ecosystem due to water scarcity. Species richness was found to be maximum at upper and middle reaches (elevation 650-800 m, msl) of the river, whereas it was low in lower reaches. Change in water chemistry was also noticed at Jatan barrage-low head dam due to impoundment of river water. It is inferred that the regulation of water has an impact on species richness and relative abundance, and on habitat heterogeneity which has decreased due to the change in environmental condition.

scholarly journals The Composition and Relative Abundance of Fish Species in a Mangrove Creek in the Niger Delta, Nigeria, Based on Different Types of Gear

2011 ◽  
Vol 54 (3) ◽  
pp. 136-141
Author(s):  
Blessing Julius Oribhabor ◽  
Mfon Timothy Udo ◽  
Lawrence Etima ◽  
Ahmed Sardauna Adisa-Bolantab
Keyword(s):  
Relative Abundance ◽  
Fish Species ◽  
Niger Delta ◽  
Visual Observation ◽  
Species Assemblage ◽  
Benthic Species ◽  
Mangrove Creek ◽  
Different Types ◽  
Sarotherodon Melanotheron ◽  
Permanent Residents

The composition and relative abundance of fish species assemblage of a mangrove creek in the Niger Delta, Nigeria based on different types of gear was assessed at four stations between November 2004 and June 2006. The overall community structure was made up of 25 species of 16 families. Visual observation showed that tilapia species comprising of Sarotherodon melanotheron and Tilapia guineensis were the most dominant species. Samples from baited entrance traps indicated that S. melanotheron dominated T. guineensis. Samples from baited hook and line, and cast net showed dominance of P. elongatus followed by P. quadrifilis. (The baited hook and line is commonly used by the fishers because it is effective in catching diversity of species, except that it is unable to catch bottom feeders such as mullets and tilapia species). Funnel entrance trap had the highest species selectivity, catching only tilapia species. Cast net was more selective in species catch than baited hook and line, but it was effective in catching both pelagic and benthic species. Among the fish species, members of the families: Sciaenidae, Polynemidae, Ariidae, Monodactylidae and Cichlidae were permanent residents; Carangidae, Luthjanidae and Serranidae were temporary residents; while Elopidae, Gobiidae, Dasyatidae, Cynoglossidae, Sphyraenidae and Trichiuridae were rare species. Keywords: composition

scholarly journals KERAGAAN ALAT TANGKAP DAN JENIS IKAN DI PERAIRAN SUNGAI SIAK, PROVINSI RIAU

2017 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Khoirul Fatah ◽  
Makri Makri
Keyword(s):  
Relative Abundance ◽  
Fish Species ◽  
Diversity Index ◽  
Macrobrachium Rosenbergii ◽  
Fish Diversity ◽  
Fishing Activity ◽  
Fish Yield ◽  
Monthly Data ◽  
Long Line ◽  
Fishing Gears

Sungai Siak merupakan salah satu Sungai besar yang mengalir di Provinsi Riau yang memiliki banyak fungsi salah satu dari fungsi tersebut adalah usaha penangkapan ikan. Kegiatan penangkapan ikan di Sungai Siak menggunakan alat tangkap yang bersifat tradisional dan dilakukan secara kelompok atau perorangan. Penelitian ini bertujuan untuk mengetahui jumlah dan jenis alat tangkap jenis ikan, kelimpahan relatif, dan keanekaragaman jenis ikan yang ada di perairan Sungai Siakpada tahun 2008. Pengambilan data dilakukan di perairan Sungai Siak mulai dari Kuala Tapung sampai Muara Mandau. Pengambilan data alat tangkap dilakukan terhadap nelayan yang sedang mengoperasikan alat tangkap tersebut, sedang pengambilan data jenis dan hasil tangkapan ikan dilakukan secara langsung di lapangan. Pengumpulan data bulanan jenis dan hasil tangkapan dibantu oleh nelayan setempat sebagai enumerator. Hasil penelitian menunjukan terdapat delapanjenis alat tangkap yang beroperasi di Sungai Siak mulai dari Kuala Tapung sampai Muara Mandau yaitu jaring, rawai, tajur, luka, pengilar, belad, dan jala. Alat tangkap jaring dan jala jumlah dan sebarannya paling banyak ditemukan di sepanjang Sungai Siak mulai dari Kuala Tapung sampai Muara Mandau, lalu disusul alat tangkap belad. Untuk jenis ikan ditemukan 60 jenis ikan yang tertangkap dari berbagai jenis alat tangkap, ikan tersebut berasal dari 12 famili dan satu jenis krustacea yaitu udang galah (Macrobrachium rosenbergii), dari 12 famili tersebut kelimpahan relatif didominansi oleh famili Cyprinidae dan Engraulidae baik pada bulan Juni, Agustus, dan Oktober. Jika dilihat dari nilai Indeks keanekaragaman pada beberapa stasiun Sungai Siak mempunyai nilai indeks berkisar antara 0,5-3,0. Siak River one of the biggest river at Riau Province has a multipurpose function including fisheries. Fishing activity at the river used a traditional gear which was operated by individual or group fisherman. A study aimed to investigate number and type of fishing gears, fish species caught, relative abundance and fish diversity of the Siak River was conducted from Kuala Tapung until Muara Mandau in 2008. Data of fishing were collected from the fisherman operated the fishing gears. Monthly data on fish species caught and fish yield were collected directly by enumerator. Results of the study showed that eight kinds of fishing gears, namely gillnets, long line, hand line, traps (luka, pengilar, and belad), filtering device, and cast net were operated. The dominant fishing gear operated was gillnet and cast net and filtering device in the next. About sixty fish species from the twelve families and giant freshwaters prawn (Macrobrachium rosenbergii) were caught using those fishing gears. During June, August, and October, the relative abundance of the fish species was dominated by family of Cyprinidae and Engraulidae. The fish diversity index of the Siak River ranged from 0.5-3.0.

scholarly journals KEANEKARAGAMAN JENIS IKAN DI SUNGAI DIGOEL DISTRIK EDERA KABUPATEN MAPPI

2018 ◽  
pp. 1-14
Author(s):  
Robert S. Buhdy ◽  
Norce Mote ◽  
Edy HP. Melmambessy
Keyword(s):  
Species Diversity ◽  
Relative Abundance ◽  
Fish Species ◽  
Diversity Index ◽  
Survey Method ◽  
Fishing Gear ◽  
Species Diversity Index ◽  
Dominance Index ◽  
Abundance Index ◽  
Evenness Index

Fisheries production in the mainland waters of Mappi Regency is larger (27.48%) compared to marine fisheries (8.53%).  Edera District is one of the districts in Mappi District which contributes to the potential of fisheries specifically for mainland waters. This study aims to determine the diversity of fish species in the Digoel River, Edera District, Mappi Regency. The fishing gear used is gill nets, stocking nets, fixed lines, fishing rods and spoon nets (tanggo).  The study was conducted in August - October 2017 using the survey method. The variables analyzed were the species diversity index, evenness index, dominance index and relative abundance index.  The results of the study obtained 28 species of fish which were divided into 8 orders of 20 families and 28 species. The value of the diversity of fish species is moderate, the Evenness value is relatively stable and evenly distributed, the type of dominance in Di shows that there is no dominance of species and the relative abundance of Kr is medium. Keywords:  Digoel River; Diversity; Evenness; Dominance and Relative Abundance.

Short-Term Response of a Coastal Wetland Fish Assemblage to Tidal Regime Restoration in Oregon

2017 ◽  
Vol 8 (1) ◽  
pp. 193-208 ◽  
Author(s):  
Brook P. Silver ◽  
J. Michael. Hudson ◽  
Samuel C. Lohr ◽  
Timothy A. Whitesel
Keyword(s):  
Relative Abundance ◽  
Fish Species ◽  
Fish Assemblage ◽  
Coho Salmon ◽  
Threespine Stickleback ◽  
Freshwater Species ◽  
Tidal Regime ◽  
Long Term Monitoring ◽  
Term Monitoring

Abstract Bandon Marsh National Wildlife Refuge, Oregon, completed construction of a large-scale tidal marsh restoration project on the Ni-les'tun Unit within the Coquille River estuary in 2011. To understand the initial effects of restoration construction and establish a baseline for long-term monitoring, we documented the assemblage of fish species 3 y before and 2 y after restoration construction. The overall fish assemblage in the Ni-les'tun Unit was substantially different after restoration construction, with an increased abundance, frequency, and richness of estuarine and diadromous fish species. Threespine Stickleback Gasterosteus aculeatus and species of Sculpin (family Cottidae) dominated the Ni-les'tun Unit and control area in both relative abundance and capture frequency throughout this study. Among salmonids, Coastal Cutthroat Trout Oncorhynchus clarkii and Coho Salmon Oncorhynchus kisutch had the highest frequency of occurrence and relative abundance both before and after restoration construction. Fish occupied newly constructed channels within 2 y. Species found in new channels included freshwater species (e.g., juvenile salmonids), introduced species (e.g., Mosquitofish Gambusia affinis), and estuarine species (e.g., Sculpin, Threespine Stickleback, and Shiner Perch Cymatogaster aggregata). Changes were likely due to improved access and changing habitat created by the reintroduced tidal regime. We recommend long-term monitoring to assess the trajectory of the biological response to the restoration over time.

scholarly journals Impacts of low-head hydropower plants on cyprinid-dominated fish assemblages in Lithuanian rivers

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tomas Virbickas ◽  
Paolo Vezza ◽  
Jūratė Kriaučiūnienė ◽  
Vytautas Akstinas ◽  
Diana Šarauskienė ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Fish Species ◽  
Fish Assemblages ◽  
Rutilus Rutilus ◽  
Environmental Flow ◽  
Low Flow ◽  
Exceedance Probability ◽  
Hydropower Plants ◽  
Before And After ◽  
Low Head

AbstractThe meso-scale habitat simulation model MesoHABSIM was applied in three Lithuanian lowland rivers to study the effect of low-head hydropower plants (HPPs) on the fish habitats. Stream flow time series on a daily scale for the period 1970–2015 were used to describe flow regime downstream of HPPs for periods before and after their installation. Conditional habitat suitability criteria were developed for 4 species of cyprinid fish, schneider (Alburnoides bipunctatus), dace (Leuciscus leuciscus), roach (Rutilus rutilus) and vimba (Vimba vimba) to simulate their available habitat at different water discharges. Modelling results showed that HPPs have a significant impact on habitat availability in the low flow period in dry years below HPPs due to insufficient released flow. The environmental flow, as prescribed by the Lithuanian national law, is estimated between 80 and 95% exceedance probability of the mean minimum discharge of 30 days. This flow leads to a significant reduction in frequency and duration of available suitable habitats for vimba and schneider during low flow period. The roach habitat is the least affected. The results of habitat modelling are in line with the actual data on the occurrence and relative abundance of considered fish species in the studied river stretches. A general comparison of the relative abundance of modelled fish species in 42 natural river stretches and 20 stretches below the HPPs also showed that the relative abundance of roach is significantly higher, and that of schneider is significantly lower in river sections below the HPPs than the abundance in natural river sections. All results indicate that the current environmental flow does not secure survival of certain fish species. The applicability of the average low flow release during summer could be a plausible alternative to the current environmental flow in order to maintain ecosystem health and services.

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