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.

Colonization by nearshore fish on small artificial reefs in Barkley Sound, British Columbia

1981 ◽  
Vol 59 (9) ◽  
pp. 1635-1646 ◽  
Author(s):  
Dominique Gascon ◽  
Roberta A. Miller
Keyword(s):  
Fish Community ◽  
Fish Assemblages ◽  
Artificial Reefs ◽  
Fish Community Structure ◽  
Factors Affecting ◽  
Barkley Sound ◽  
Reef Fish Community ◽  
Concrete Blocks ◽  
Rocky Habitats ◽  
Colonizing Ability

We investigated the structure of a temperate nearshore fish community by examining the development of fish assemblages on small artificial reefs of concrete blocks constructed in two series 6 months apart. In each series, a species equilibrium, of approximately six species, was rapidly reached within 6 months. Eight of the 30 species which had colonized the reefs from the surrounding rocky habitats were common on the reefs. Both juveniles and adults of all species were present, except for the rockfishes (Sebastes spp.) which were represented only by young individuals (1 to 3 years of age). Tagging indicated that the bottom-dwelling species (Gobiidae, Cottidae) remained permanently on the reefs, whereas a seasonal turnover in rockfish occurred.The communities inhabiting the reefs usually did not differ from each other within each series, whereas significant differences occurred between series. This difference was attributed to the differential colonizing ability of species. No evidence of interspecific competition was apparent among the species inhabiting the reefs.The results are discussed in light of some current models of coral reef fish community structure. Some possible factors affecting the differences observed between tropical and temperate waters are also discussed.

Modelling the distribution of fish around an artificial reef

2017 ◽  
Vol 68 (10) ◽  
pp. 1955 ◽  
Author(s):  
James A. Smith ◽  
William K. Cornwell ◽  
Michael B. Lowry ◽  
Iain M. Suthers
Keyword(s):  
Fish Assemblages ◽  
Spatial Scales ◽  
Artificial Reef ◽  
Positive Association ◽  
Spatial Arrangement ◽  
Fish Abundance ◽  
Artificial Reefs ◽  
Bottom Cover ◽  
Species Specific ◽  
Taxonomic Groups

Artificial reefs are a widely used tool aimed at fishery enhancement, and measuring the scale at which fish assemblages associate with these artificial habitat patches can aid reef design and spatial arrangement. The present study used rapidly deployed underwater video (drop cameras) to determine the magnitude and spatial scale of associations between a fish assemblage and a coastal artificial reef. Count data from drop cameras were combined with distance and bathymetry information to create a suite of explanatory generalised linear mixed models (GLMMs). The GLMMs showed that artificial reefs can influence surrounding fish abundance, but that the magnitude and scale is species specific. Three of the eight taxonomic groups examined showed a positive association with the artificial reef (with model fit poor for the remaining groups); and depth and bottom cover were also influential variables. The spatial scales of these associations with the artificial reef were small, and it was generally the presence of reef (i.e. a reef bottom type) that explained more variation in fish abundance than did distance to reef. The schooling baitfish yellowtail scad was an exception, and had elevated abundance >50m from the artificial reef. Further distribution modelling of artificial reefs will benefit species-specific design and management of artificial reefs.

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 Effects of reef attributes on fish assemblage similarity between artificial and natural reefs

2015 ◽  
Vol 72 (8) ◽  
pp. 2385-2397 ◽  
Author(s):  
Jennifer E. Granneman ◽  
Mark A. Steele
Keyword(s):  
Species Richness ◽  
Fish Species ◽  
Fish Assemblages ◽  
Size Structure ◽  
Assemblage Structure ◽  
Artificial Reefs ◽  
Giant Kelp ◽  
Substrate Structure ◽  
Density And Biomass ◽  
Natural Reefs

Abstract Artificial reefs are used to enhance populations of marine organisms, but relatively few studies have quantitatively evaluated which attributes of reef structure are most critical in determining whether assemblages of organisms on artificial reefs are similar to those on natural reefs. Using five pairs of artificial and natural reefs that spanned 225 km in the Southern California Bight, we evaluated how well fish assemblages on artificial reefs mimicked those on natural reefs and which attributes of reefs best predicted assemblage structure. Along underwater visual transects, we quantified fish species richness, density, and size structure, as well as substrate structure (rugosity and cover of substrate types), giant kelp density, and invertebrate density. Artificial reefs that were more similar in physical structure to natural reefs (low relief, low rugosity, and composed of small- to medium -sized boulders) supported fish assemblages that were similar to those on natural reefs. Fish species richness was not significantly different between artificial and natural reefs, but density and biomass tended to be higher on average on artificial reefs, body size was slightly smaller, and assemblage structure differed between the two reef types. Generally, artificial reefs extended higher off the seabed, were made of larger boulders, had higher rugosity, harboured more invertebrates, and supported less giant kelp. At both the within-reef (transect) and whole-reef scales, fish density and biomass were positively correlated with complex substrate structure, positively correlated with invertebrate density, and negatively correlated with giant kelp abundance, which was sparse or absent on most artificial reefs. Our results indicate that artificial reefs can support fish assemblages that are similar to those found on natural reefs if they are constructed to match the physical characteristics of natural reefs, or they can be made to exceed natural reefs in some regards at the expense of other biological attributes.

Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

2018 ◽  
Keyword(s):  
Species Richness ◽  
Fish Assemblages ◽  
Artificial Reef ◽  
Sea Bass ◽  
Artificial Reefs ◽  
Lutjanus Campechanus ◽  
Coverage Area ◽  
Management Objectives ◽  
Concrete Blocks ◽  
Total Fish

<em>Abstract</em>.—Twenty artificial reefs were deployed early in October 2005 approximately 20 km south of Dauphin Island, Alabama (USA), in the Hugh Swingle General Permit Area. Each reef consisted of 12 concrete blocks (20 cm long × 20 cm wide × 41 cm high) arranged on a plywood base (1.5 m<sup>2</sup> )and deployed on the bottom, 20 m deep. To quantify the epibenthic assemblage on the reefs, four removable bricks were attached to the reefs. Ten reefs were coated with copper-based, anti-fouling paint and 10 reefs were unpainted. Fish and epibenthic assemblages were compared between reef treatments (i.e., with and without copper-based paint). Reefs were surveyed 1 week after deployment in October 2005, then again in December 2005, May 2006, August 2006, and December 2006. During each survey, two scuba divers visually estimated the densities of all fish species and removed one of the removable bricks to identify and quantify the epibenthic organisms. The epibenthos (coverage area, biomass, diversity, species richness) and fish assemblages (total fish density, species diversity, species richness) were greater on unpainted reefs. Red Snapper <em>Lutjanus campechanus</em>, wrasses <em>Halichoeres </em>spp., Bank Sea Bass <em>Centropristis ocyurus</em>, and Atlantic Spadefish <em>Chaetodipterus faber </em>had higher densities on unpainted reefs. This study indicated that recruitment of fishes to artificial reefs was not just attraction to structure, but that growth of epibenthic assemblages had a significant influence on recruitment.

scholarly journals Dynamics of fish assemblages on a continuous rocky reef and adjacent unconsolidated habitats at Fernando de Noronha Archipelago, tropical western Atlantic

2011 ◽  
Vol 9 (4) ◽  
pp. 869-879 ◽  
Author(s):  
Paulo R. Medeiros ◽  
Ricardo S. Rosa ◽  
Ronaldo B. Francini-Filho
Keyword(s):  
Species Richness ◽  
Spatial Variation ◽  
Reef Fish ◽  
Fish Assemblages ◽  
Fish Abundance ◽  
Coralline Algae ◽  
Rocky Reef ◽  
Percent Cover ◽  
Western Atlantic ◽  
Bare Rock

In recent years, many studies investigated how density-dependent factors, such as shortages in microhabitat and food availability influence the structure of reef fish assemblages. Most of what is currently known, however, comes from comparisons of isolated patch reefs and from correlations between fish abundance and one or few microhabitat variables. In addition, most studies were done in the Caribbean and Indo-Pacific regions, whereas the South Atlantic region has been, to date, understudied. The present study evaluated spatial and temporal variations in reef fish abundance and species richness in a continuous rocky reef and adjacent unconsolidated habitats in a Southwestern Atlantic reef, using underwater techniques to assess both fish numbers and microhabitat variables (depth, rugosity, number of crevices and percent cover of live benthic organisms, bare rock, sand, and limestone). Higher species richness was observed at consolidated substratum stations on both sampling periods (May and October), but fish abundance did not show a significant spatial variation. Topographical complexity and percent cover of algae (except coralline algae) were amongst the most important determinants of species richness, and correlations between fish size and refuge crevice size were observed. The non-random patterns of spatial variation in species richness, and to a lesser extent, fish abundance, were related to differences in substratum characteristics and the inherent characteristics of fishes (i.e. habitat preferences) and not to geographical barriers restraining fish movement. This study highlights the importance of concomitantly assessing several microhabitat variables to determine their relative influence in reef fish assemblages.

scholarly journals Demersal Fish Assemblages in NE Atlantic Seagrass and Kelp

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 366
Author(s):  
Evie Furness ◽  
Richard K.F. Unsworth
Keyword(s):  
Species Richness ◽  
Fish Assemblages ◽  
Demersal Fish ◽  
Kelp Forests ◽  
Evidence Based ◽  
Ecological Value ◽  
Commercial Fish ◽  
Seagrass Meadows ◽  
The North ◽  
Commercial Species

Global fisheries are in decline, calling for urgent evidence-based action. One such action is the identification and protection of fishery-associated habitats such as seagrass meadows and kelp forests, both of which have suffered long-term loss and degradation in the North Atlantic region. Direct comparisons of the value of seagrass and kelp in supporting demersal fish assemblages are largely absent from the literature. Here, we address this knowledge gap. Demersal fish were sampled using a baited camera to test for differences between habitats in (1) the species composition of the fish assemblages, (2) the total abundance and species richness of fishes, and (3) the abundances of major commercial species. Seagrass and kelp-associated fish assemblages formed two significantly distinct groupings, which were driven by increased whiting (Merlangius merlangus) and dogfish (Scyliorhinus canicula) presence in seagrass and higher abundances of pollock (Pollachius pollachius) and goby (Gobiusculus flavescens) in kelp. The abundance, diversity, and species richness did not change significantly between the two habitats. We conclude that seagrass and kelp do support unique demersal fish assemblages, providing evidence that they have different ecological value through their differing support of commercial fish species. Thus, this study improves the foundation for evidence-based policy changes.

A comparison of the fish assemblages on natural and artificial reefs off Sal Island (Cape Verde)

2012 ◽  
Vol 93 (2) ◽  
pp. 437-452 ◽  
Author(s):  
Miguel N. Santos ◽  
Miguel T. Oliveira ◽  
João Cúrdia
Keyword(s):  
Species Richness ◽  
Fish Assemblages ◽  
Diversity Index ◽  
Cape Verde ◽  
Artificial Reefs ◽  
Visual Census ◽  
Mean Values ◽  
Marine Habitats ◽  
Fish Biodiversity ◽  
Santa Maria

Tourism is a growing activity in Cape Verde, which can lead to more intensive and uncontrolled fishing and diving activities, affecting the quality of marine habitats. To mitigate this biodiversity problem, a private diving operator, supported by the local authorities, decided to deploy the first artificial reefs (ARs) in the Archipelago just off Santa Maria Bay (Sal Island). To evaluate the ARs capacity to promote marine fish biodiversity in Santa Maria Bay, the fish assemblages were compared to those from nearby natural reefs (NRs), located at the same depth (10 and 28 m depth), by means of visual census. All study sites were surveyed by visual census in August 2009. A total of 64 species were recorded, mostly consisting of sedentary and/or benthophagous demersal species, followed by highly-sedentary benthic cryptic species. ‘Tchuklassa’ NR showed the highest species richness (58 species), while the lowest was recorded at ‘Santo Antão’ AR (48 species). An overall positive relationship was observed between habitat rugosity and mean species richness. The results showed a high percentage of common species on both reef types. Higher mean values of community descriptors (number of species, Shannon–Weaver diversity index, Simpson dominance index and equitability) and fish density were found on the ARs, with slightly higher densities recorded on the deeper reefs. These results suggest that ARs can have an important role promoting the local fish biodiversity and supporting local sustainable development of diving tourism.

scholarly journals Diel changeover of fish assemblages in shallow sandy habitats of lowland rivers of different sizes

2019 ◽  
pp. 41
Author(s):  
Michał Nowak ◽  
Artur Klaczak ◽  
Ján Koščo ◽  
Paweł Szczerbik ◽  
Jakub Fedorčák ◽  
...  
Keyword(s):  
Species Richness ◽  
Fish Assemblages ◽  
Drainage System ◽  
Fish Abundance ◽  
Late Afternoon ◽  
Lowland Rivers ◽  
Vistula River ◽  
Heterogeneous Habitats ◽  
Diel Dynamics ◽  
Point Bars

Diel dynamics of species richness and fish abundance were studied in three lowland rivers that differed significantly in size (discharge) in to the upper Vistula River drainage system (Poland). Shallow sandy habitats at point bars were repeatedly sampled with beach seining over 24-h periods. Species richness peaked at dusk and then decreased throughout the 24-h period in all the rivers. Overall fish abundance changed similarly in the smallest and the largest river, whereas in the mid-sized river it increased in the late afternoon hours. Some species (three gudgeon species, golden loach, and chub) were persistently nocturnal, whereas others (dace, bleak, and roach) shifted to diurnal activity in the mid-sized and large rivers. These differences in diel changes in the abundance of certain species might be explained in the context of variation in availability (i.e., proximity) of other, more heterogeneous habitats.

scholarly journals Inter-estuarine and temporal patterns of the fish assemblage of subtropical subestuaries along the Río de la Plata coast (Uruguay)

2017 ◽  
Vol 65 (2) ◽  
pp. 173-186 ◽  
Author(s):  
Alicia Acuña ◽  
Nathalie Muñoz ◽  
Rodrigo Gurdek ◽  
Irene Machado ◽  
Veronica Severi
Keyword(s):  
Species Richness ◽  
Fish Assemblage ◽  
Fish Assemblages ◽  
Diversity Indices ◽  
Fish Abundance ◽  
Freshwater Species ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
Southwest Atlantic ◽  
La Plata

ABSTRACT Fish assemblages in subestuaries have been poorly studied worldwide. In order to evaluate the inter-estuarine and temporal variability of the ichthyofauna of subestuaries along the Uruguayan coast of the Río de la Plata (RdlP), the Pando, Solís Chico and Solís Grande systems were sampled between 2011 and 2013. Fish biomass, abundance, species richness and diversity indices were analysed, defining fish assemblages characterised by a few species and great abundance. Estuarine resident and freshwater species represented 55.5% of the fish assemblage according to estuarine use guilds. Species occurrence was similar in the three subestuaries, but the relative abundances differed among them. The analysed community parameters showed a decreasing trend from west to east along the Uruguayan coast. Highest diversity and fish abundance were recorded in the Pando system located in the proximities of an important spawning area in the inner RdlP estuary. In the Solís Grande subestuary occurred the lowest species richness and fish abundance. The Solís Chico was characterised as a transitional subsystem. All three subestuaries showed an increase in species richness and abundance during high temperature periods, probably related to the life cycle of the species sharing habitats between the RdlP and the coastal subestuaries. This study constitutes the first step in assessing the fish assemblage patterns in coastal ecosystems of the RdlP and an approach about the ecological role of the subestuaries in the southwest Atlantic Ocean.

Sign in / Sign up

Export Citation Format

Share Document