scholarly journals Demersal fish assemblages of Faroe Bank: species composition, distribution, biomass spectrum and diversity

2002 ◽  
Vol 238 ◽  
pp. 211-225 ◽  
Author(s):  
E Magnussen
Keyword(s):  
Species Composition ◽  
Fish Assemblages ◽  
Demersal Fish ◽  
Composition Distribution

scholarly journals The demersal fish assemblages of the infra and circalittoral coastal rocky bottoms of the Aeolian Archipelago (Central Mediterranean Sea) studied by Remotely Operated Vehicle (ROV)

2020 ◽  
Author(s):  
IVAN CONSALVO ◽  
GABRIELE La MESA ◽  
SIMONEPIETRO CANESE ◽  
MICHELA GIUSTI ◽  
EVA SALVATI ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Fish Assemblages ◽  
Demersal Fish ◽  
Total Density ◽  
Depth Range ◽  
Remotely Operated Vehicle ◽  
Depth Ranges ◽  
Aeolian Archipelago ◽  
Rocky Bottoms

Demersal fish assemblages on the rocky bottoms of the Aeolian Archipelago were investigated using a Remotely Operated Vehicle (ROV) within the framework of research activities aimed at drawing up the zoning proposal of a new Italian national marine protected area. Visual assessments were conducted around the seven main islands by means of a total of 36 ROV transects. Video material was divided into 3 parts belonging to 3 Archipelago sectors (Western, Central and Eastern) and into 3 depth ranges (20-50, 51-120, 121-190). Thirty taxa of teleosts (29 species and 1 genus) belonging to 16 families were recorded. The assemblages were numerically dominated by some schooling fishes, such as Anthias anthias, Callanthias ruber and Chromis chromis, which exhibited a depth related partitioning of space, and three non-gregarious species, i.e. Serranus cabrilla, Coris julis and Lappanella fasciata. In terms of species composition, the assemblages observed in the sectors of the Archipelago largely overlapped. No significant sector-related differences were detected in fish species richness, diversity and total density. Species composition and the investigated assemblage parameters were significantly affected by depth. The pattern of variation in species richness among depth ranges changed depending on the archipelago sectors. No significant interaction between the factors depth range and sector was observed for species diversity and total density. Diversity values at 20-50 and 121-190 m depth were similar and significantly higher than that at 51-120 m depth. Fish total density showed a clear decreasing trend with increasing depth, though significant differences were detected between the 20-50 and 51-120 depth layers and the deepest one. Overall, the demersal fish assemblage of the Aeolian Archipelago was poorly diversified and depleted, most likely due to overfishing. This information highlighted the importance of the adoption of specific measures aimed at the recovery of overexploited resources and the restoration of the whole marine ecosystems.

scholarly journals Delineating the habitat of demersal fish assemblages with acoustic seabed technologies

2011 ◽  
Vol 68 (9) ◽  
pp. 1973-1985 ◽  
Author(s):  
Jeroen van der Kooij ◽  
Sven Kupschus ◽  
Beth E. Scott
Keyword(s):  
Species Composition ◽  
Fish Assemblages ◽  
Demersal Fish ◽  
Single Beam ◽  
Explanatory Variables ◽  
Acoustic Data ◽  
Spatial Management ◽  
Fish Habitats ◽  
The Relationship ◽  
Demersal Species

Abstract van der Kooij, J., Kupschus, S., and Scott, B. E. 2011. Delineating the habitat of demersal fish assemblages with acoustic seabed technologies. – ICES Journal of Marine Science, 68: 1973–1985. Habitats influence species distribution and, although the seabed is an important habitat factor for demersal species, traditional sampling methods often provide no practical solution to investigating the seabed over large areas. The ability of a multivariate method that utilizes single-beam acoustic seabed data combined with species composition data to define demersal fish habitats was tested. The best model explained 19.4% of the variance observed in the species data and was robust between years. Ten biotopes were identified, each containing species that, either alone or in combination with others, were indicative of that biotope. Using unclassified acoustic seabed data as explanatory variables, discrepancies between the numbers of acoustically distinct classes and species assemblages, as previously reported in the literature, were avoided, while utilizing their relationship with community structure. The study focused on the relationship between simultaneously recorded species composition and seabed data from fishing stations, but because continuous acoustic data along the survey tracks were available between stations, the model could be used to predict the spatial extent of the biotopes. Although the method was developed with the eventual aim of providing a meaningful foundation to the spatial management of mixed fisheries, it could also contribute to applications in spatial planning.

scholarly journals Analysis of demersal fish assemblages of the Tuscany and Latium coasts (north-western Mediterranean)

2002 ◽  
Vol 66 (S2) ◽  
pp. 233 ◽  
Author(s):  
Franco Biagi ◽  
Paolo Sartor ◽  
Gian Domenico Ardizzone ◽  
Paola Belcari ◽  
Andrea Belluscio ◽  
...  
Keyword(s):  
Species Composition ◽  
Continental Shelf ◽  
Fish Assemblages ◽  
Demersal Fish ◽  
Western Mediterranean ◽  
Similar Species ◽  
The European Union ◽  
The North ◽  
North Western ◽  
Trawl Surveys

A four-year time series (1994-1997) of groundfish trawl surveys performed within the European Union Project MEDITS (Mediterranean International Trawl Surveys), was analysed to identify and describe the fish assemblages along the continental shelf and slope of Tuscany and Latium (Italy), in the north-western Mediterranean. Cluster analysis was used to group samples with similar species composition in terms of abundance, biomass and frequency of occurrence. Results allowed the identification of four to five broad assemblages along the depth gradient: a strictly coastal group (< 50 m depth), two groups in the upper and lower part of the continental shelf (essentially 50-200 m), an epibathyal group (200-450 m) and a group derived from hauls made at depths greater than 450 m. Each assemblage corresponded to a faunistic association with relatively homogeneous and persistent species composition, biomass and density indices.

scholarly journals Assessing the impact of fisheries on demersal fish assemblages of the Mauritanian continental shelf, 1987–1999, using dominance curves

2005 ◽  
Vol 62 (3) ◽  
pp. 380-383 ◽  
Author(s):  
Didier Jouffre ◽  
Cheikh A. Inejih
Keyword(s):  
Species Composition ◽  
Continental Shelf ◽  
Fish Assemblages ◽  
Demersal Fish ◽  
Octopus Vulgaris ◽  
Taxonomic Information ◽  
Associated Species ◽  
The Impact ◽  
Trawl Surveys

Abstract The assemblages of demersal fish and associated species of the Mauritanian continental shelf are characterized on the basis of annual trawl surveys conducted during the period 1987–1999. Species composition is dominated by exploited species (Dentex spp., Pagellus bellottii, and Octopus vulgaris). Dominance curves (Abundance Biomass Comparison plots) were used to evaluate the impact of fisheries, which have increased in magnitude over several decades. The diagnosis of a “stressed” assemblage seems to converge with the results of a similar study conducted off Senegal, but here there was no trend in impact during the period of study. The sensitivity of the present results to the various ways of considering the available taxonomic information is also analysed.

scholarly journals KOMPOSISI JENIS, PENYEBARAN, DAN KEPADATAN STOK IKAN DEMERSAL LAUT DALAM DI PERAIRAN SAMUDERA HINDIA SELATAN JAWA DAN BARAT SUMATERA

2017 ◽  
Vol 13 (1) ◽  
pp. 43
Author(s):  
Ali Suman ◽  
Budi Iskandar Prisantoso ◽  
Fayakun Satria ◽  
Enjah Rahmat
Keyword(s):  
Species Composition ◽  
Deep Sea ◽  
Random Sampling ◽  
Demersal Fish ◽  
Total Catch ◽  
Composition Distribution ◽  
Trichiurus Lepturus ◽  
The Indian Ocean ◽  
Swept Area ◽  
Study Species

Penelitian bertujuan untuk mengkaji komposisi jenis, penyebaran, dan kepadatan stok ikan demersal laut di perairan ZEEI selatan Jawa dan barat Sumatera. Data yang dianalisis merupakan hasil survei yang dilakukan bulan September sampai dengan Oktober 2004 dengan menggunakan K.M. Baruna Jaya IV. Estimasi kepadatan stok dilakukan dengan menggunakan metode sapuan dengan pengambilan contoh acak bertingkat. Hasil penelitian menunjukkan bahwa komposisi jenis ikan demersal laut dalam di perairan selatan Jawa terdiri atas 169 spesies ikan, 31 spesies krustasea, dan 20 spesies Chepalopoda. Komposisi hasil tangkapan ikan didominasi oleh ikan ashiro (Lamprogrammus niger) sekitar 45% dan ikan layur (Trichiurus lepturus) sekitar 22%. Di perairan barat Sumatera ditemukan komposisi jenis hasil tangkapan meliputi 281 spesies ikan, 42 spesies krustasea, dan beberapa spesies Chepalopoda serta jenis yang dominan adalah ikan ashiro (Lamprogrammus niger) sekitar 20% dan Hoplosthethus sp. sekitar 17%. Jenis ikan demersal laut dalam yang memiliki penyebaran paling luas adalah Chlorophtalmus nigromarginatus di perairan selatan Jawa dan Diretmoides pauciradiatus di perairan barat Sumatera. Kelimpahan stok ikan demersal laut dalam tertinggi ditemui pada kedalaman 700 sampai dengan 1.100 m dan terendah didapatkan pada kedalaman 200 sampai dengan 400 m. Kepadatan stok ikan demersal laut dalam berkisar antara 0,8 sampai dengan 39,9 ton km-2 di perairan selatan Jawa dan berkisar 0,2 sampai dengan 7,4 ton km-2 di perairan barat Sumatera. The objective of this research is to study species composition, distribution, and stock density of deep sea demersal fish in the southern Java and western Sumatera of the Indian Ocean EEZ waters. The study was done based on the data collected from the survey conducted between September and October 2004 using Baruna Jaya IV research vessel. The study was basically conducted by applying swept area method with stratified random sampling. The results show that the species composition of deep sea demersal in southern off Java waters consisted of 169 in fishes, 31 in crustaceans, and 20 in chephalopods. The catch of deep sea demersal fish was dominated by ashiro (Lamprogrammus niger) about 45%and hair tail (Trichiurus lepturus) about 22%. Species composition of deep sea demersal fish in west off Sumatera waters consisted of 281 species of fishes, 42 species in crustaceans and some types of chepalopods. The dominant species was Lamprogrammus niger (ashiro) with about 20% of the total catch and Hoplosthethus sp. with about 17% of the total catch. The widest species distribution of is resource was Chlorophtalmus nigromarginatus in southern off Java waters and Diretmoides pauciradiatus in western off Sumatera waters. The highest abundances of deep sea resources were caught at the depth of 700 to 1,100 m and the lowest at the depth of 200 to 400 m. Stock density in southern off Java waters was 0.8 to 39.9 ton km-2 and about 0.2 to 7.4 ton km-2 in western off Sumatera waters.

Demersal fish assemblages on seamounts exploited by fishing in the Azores (NE Atlantic)

2020 ◽  
Author(s):  
Régis Santos ◽  
Wendell Medeiros‐Leal ◽  
Ana Novoa‐Pabon ◽  
Hélder Silva ◽  
Mário Pinho
Keyword(s):  
Fish Assemblages ◽  
Demersal Fish ◽  
Ne Atlantic
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