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

scholarly journals Demersal fish assemblages and habitat characteristics on the continental shelf and upper slope of the north-western Mediterranean

2000 ◽  
Vol 80 (6) ◽  
pp. 981-988 ◽  
Author(s):  
Montserrat Demestre ◽  
Pilar Sánchez ◽  
Pere Abelló
Keyword(s):  
Continental Shelf ◽  
Fish Species ◽  
Fish Assemblages ◽  
Demersal Fish ◽  
Western Mediterranean ◽  
Habitat Characteristics ◽  
Species Assemblages ◽  
The North ◽  
Benthic Sediments ◽  
Upper Slope

Continental shelf and upper slope fish communities were studied along the Catalan coast based on 66 experimental bottom otter trawls. A total of 79 demersal fish species were studied by means of cluster analysis and multi-dimensional scaling (MDS) ordination for community structure. Analysis revealed the existence of five major location clusters. Similarity percentage analysis (SIMPER) was determined by comparing the dissimilarity between two groups of samples using the discriminating species. Geomorphological characteristics, bottom substratum and depth showed direct influences on species assemblages. High correlation between the biotic data samples and depth was observed. The fish species assemblages identified five main demersal fish associations which corresponded with the five location clusters and with five benthic sediments (mud of the upper slope, sand and gravel, mud of the shelf, muddy-sand and sand with rocky outcrops).

Structure and dynamics of demersal fish assemblages over three decades (1985–2012) of increasing fishing pressure in Guinea

2016 ◽  
Vol 38 (2) ◽  
pp. 189-206 ◽  
Author(s):  
ML Camara ◽  
B Mérigot ◽  
F Leprieur ◽  
JA Tomasini ◽  
I Diallo ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Demersal Fish ◽  
Fishing Pressure ◽  
Structure And Dynamics

Subtidal assemblages associated with a geotextile reef in south-east Queensland, Australia

2005 ◽  
Vol 56 (2) ◽  
pp. 133 ◽  
Author(s):  
Rhys A. Edwards ◽  
Stephen D. A. Smith
Keyword(s):  
Fish Assemblages ◽  
Benthic Communities ◽  
Artificial Reef ◽  
Demersal Fish ◽  
Diverse Range ◽  
Marine Habitats ◽  
Sessile Invertebrates ◽  
Hard Structures ◽  
Asymmetrical Design ◽  
Natural Reefs

In marine habitats, the use of geotextile materials as a ‘soft-engineering’ solution is increasingly being considered as an alternative to hard structures. However, very little is known about biological assemblages that develop on geotextile structures. This study provides the first ecological comparison of subtidal assemblages between Narrowneck Artificial Reef (NAR), a geotextile reef in south-east Queensland, Australia, and three nearby natural reefs. Benthic community structure, fish assemblages and habitat complexity were compared between reef types using an asymmetrical design. Although natural reefs supported distinct biotic assemblages, as a class, these reefs differed significantly from NAR. The artificial reef was dominated by macroalgae and supported fewer benthic categories, whereas the natural reefs were characterised by a diverse range of sessile invertebrates. Benthic and demersal fish assemblages were less diverse on NAR, but pelagic fish assemblages were similar on both reef types. The substratum of NAR was less complex than that of the natural reefs; this physical variable was correlated with some of the differences in benthic communities and benthic and demersal fish assemblages. It is likely that the key determinants of the biotic patterns observed in this study are interactions between the age of NAR and the physical properties of geotextile substratum.

The effect of marine seismic surveys on the movement, abundance and community structure of demersal fish assemblages on the North West Shelf

2020 ◽  
Vol 60 (2) ◽  
pp. 480
Author(s):  
Mark G. Meekan ◽  
Conrad W. Speed ◽  
Robert D. McCauley ◽  
Jayson M. Semmens ◽  
Stephen J. Newman ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Demersal Fish ◽  
Seismic Survey ◽  
Survey Study ◽  
Control Zone ◽  
High Exposure ◽  
North West ◽  
Air Gun ◽  
Study Results ◽  
Demersal Fishes

In 2018, the Australian Institute of Marine Science (AIMS) and its partners, conducted an experiment to investigate the effect of exposure to a 3D seismic survey on demersal fishes. The experiment involved the use of a commercial seismic vessel equipped with a 2600 cubic inch air-gun array, sailing a racetrack pattern with eight operational (high exposure zone) and eight inactive (vessel control zone) sail lines, with a 500 m sequential line separation and ≈18 m shot point spacing. The high exposure and vessel control lines were separated by 35 km. Demersal fishes were observed in five sampling surveys over a 6-month period (three surveys before and two after exposure), using acoustic telemetry and stereo baited remote underwater videos systems (BRUVS). The telemetry component included the capture, tagging with acoustic transmitters and release of 387 red emperor (Lutjanus sebae) within two telemetry receiver arrays. These arrays, one in each zone, comprised 37 and 39 acoustic receivers over ≈32 km2, to record movements of tagged fish. The receivers provided near-continuous data on tag locations, and, hence, movement of fish in the area, until removal in December 2018. During each sampling survey, BRUVS were deployed at various distances from the area of the seismic survey. Study results are currently being finalised for presentation.

scholarly journals Vulnerability of Demersal Fish Assemblages to Trawling Activities: A Traits-Based Index

2020 ◽  
Vol 7 ◽  
Author(s):  
Silvia de Juan ◽  
Hilmar Hinz ◽  
Paolo Sartor ◽  
Sergio Vitale ◽  
Luis Bentes ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Demersal Fish

scholarly journals The influence of offshore windpower on demersal fish

2006 ◽  
Vol 63 (5) ◽  
pp. 775-784 ◽  
Author(s):  
Dan Wilhelmsson ◽  
Torleif Malm ◽  
Marcus C. Öhman
Keyword(s):  
Species Richness ◽  
Power Plants ◽  
Fish Assemblages ◽  
Demersal Fish ◽  
Fish Abundance ◽  
Artificial Reefs ◽  
Fish Community Structure ◽  
Blue Mussels ◽  
Fish Aggregation ◽  
Surrounding Areas

Abstract A significant expansion of offshore windpower is expected in northwestern Europe in the near future. Little is known about the impacts it may have on the marine environment. Here, we investigate the potential for wind turbines to function as artificial reefs and fish aggregation devices (FADs), i.e. whether they would locally increase fish densities or alter fish assemblages. Fish communities and habitat composition were investigated using visual transects at two windpower farms off the southeastern coast of Sweden, central Baltic Sea. Fish abundance was greater in the vicinity of the turbines than in surrounding areas, while species richness and Shannon–Wiener diversity (H′) were similar. On the monopiles of the turbines, fish community structure was different, and total fish abundance was greater, while species richness and diversity (H′) were lower than on the surrounding seabed. Blue mussels and barnacles covered most of the submerged parts of the turbines. On the seabed, more blue mussels and a lesser cover of red algae were recorded around the power plants than elsewhere. Results from this study suggest that offshore windfarms may function as combined artificial reefs and fish aggregation devices for small demersal fish.

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