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 Coral Fishes Community On The Artificial Coral Reefs Of Kareko Waters, North Lembeh Island District, Bitung City, North Sulawesi

2017 ◽  
Vol 5 (2) ◽  
pp. 145
Author(s):  
Gisela Awuy ◽  
Ari B. Rondonuwu ◽  
Alex Denny Kambey
Keyword(s):  
Species Richness ◽  
Coral Reefs ◽  
Diversity Index ◽  
Artificial Reef ◽  
Scuba Diving ◽  
Reef Fishes ◽  
Artificial Reefs ◽  
Total Density ◽  
Visual Census ◽  
North Sulawesi

The aim of this research is to determine the species richness, individual abundance, and the ecology index of the coral fishes on the artificial reef of Kareko waters,  District of North Lembeh - Bitung City. The data is collected using “Visual Census” technique by scuba diving. The amount of the reef fishes found in the artificial coral reefs were 53 species. The abundance species in the artificial reefs which made from metal were 34 species and which made from concrete were 35 species. The total of number individuals of coral fishes from 47 species is 210.50 individuals/30m2. The total density was 7,017 individuals/m2. The highest relative density on iron-made reefs was found in Dascyllus trimaculatus (15.73%) and and which made from concrete were Dascyllus reticulatus (10.85%).  Based on H’, H’max, and H’min, the diversity Index  of coral fishes in both artificial reefs including high.Keywords : Coral Fishes, Artificial Reef, Kareko ABSTRAKTujuan penelitian ini yaitu untuk mengetahui kekayaan spesies, kelimpahan individu, dan indeks ekologi ikan karang pada terumbu buatan di Perairan Kareko. Kecamatan Lembeh Utara, Kota Bitung. Pengambilan data dilakukan dengan menggunakan teknik “Sensus Visual” dengan melakukan penyelaman SCUBA. Jumlah spesies ikan karang yang ditemukan pada terumbu buatan yaitu 53 spesies. Kekayaan spesies di terumbu buatan yang terbuat dari besi berjumlah 34 spesies, sedangkan di terumbu buatan beton berjumlah 35 spesies. Kelimpahan individu total ikan karang dari 47 spesies yaitu 210,50 individu/30 m2 sedangkan kepadatan/densitas total adalah 7,017 individu/m2. Kepadatan relative tertinggi untuk terumbu buatan besi ditemukan pada jenis Dascyllus trimaculatus (15,73%) dan untuk terumbu buatan beton ditemukan pada jenis Dascyllus reticulatus (10,85%). Berdasarkan nilai H’, H’max, and H’min, indeks keanekeragaman ikan karang pada kedua jenis terumbu buatan tergolong tinggi.Keywords : Coral Fishes, Artificial Reef, Kareko

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.

scholarly journals Coral Fishes At Artificial Reef In Bunaken National Park Arakan, South Minahasa Regency

2017 ◽  
Vol 5 (2) ◽  
pp. 155
Author(s):  
Riezky H. S. Wuwumbene ◽  
Ari B. Rondonuwu ◽  
Victor N. R. Watung
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Diversity Index ◽  
Artificial Reef ◽  
Data Retrieval ◽  
Artificial Reefs ◽  
Visual Census ◽  
Reef Fish Species ◽  
The Village

Artificial reefs already placed in the coast of the village of Arakan, South Minahasa regency since June 2015. Artificial reef, that would be the location of research are concrete and iron, mostly be the medium of coral transplantation. The pupose of the research are (1). To know the species coral reef fish (2). To know the number of each species and the density of the coral reef fish (3). To know the structure of coral reef fish communities. Data retrieval be done use with Visual Census Method in the 51 squaremeter area (lenght = 8,5 m, width = 6 m). This research find 15 families with 29 coral reef fish species and 1341  individual. The diversity index of artificial reefs with moderate diversity index and relative abudance is found in species Dascyllus trimaculatus 34,731 %,  Plotosus lineatus 21,593 %, and Dascyllus reticulatus 21,174 %.Keywords: Artificial reef, Community Structure, Arakan. ABSTRAKTerumbu buatan sudah diletakan pada perairan desa Arakan Kabupaten Minahasa Selatan pada bulan Juni 2015. Terumbu buatan yang menjadi lokasi penelitian berjenis beton dan besi, model yang terbuat dari besi lebih banyak diarahkan sebagai media transplantasi karang. Penelitian ini bertujuan untuk (1) Mengetahui kekayaan spesies ikan karang (2) Mengetahui kelimpahan individu dan kepadatan relatif ikan karang (3) Mengetahui struktur komunitas ikan karang. Pegambilan data dilakukan menggunakan metode Sensus Visual dengan luas pengamatan pada terumbu buatan  seluas 51 m2 (panjang = 8,5 meter dan lebar = 6 meter). Penelitian ini menemukan 15 famili dengan 29 spesies ikan karang dan kelimpahan individu total 1341 individu. Indeks keanekaragaman di daerah terumbu buatan dengan nilai indeks keanegaraman yang sedang dengan indeks dominasi rendah dan kelimpahan relatif terdapat pada spesies Dascyllus trimaculatus dengan nilai 34,731 %, Plotosus lineatus dengan nilai 21,593 %, dan Dascyllus reticulatus dengan nilai 21,174 %.Kata Kunci : Terumbu Buatan, Struktur Komunitas, Arakan.

scholarly journals Performance of a baited underwater video system vs. the underwater visual census technique in assessing the structure of fish assemblages in a Mediterranean marine protected area

2021 ◽  
Vol 22 (3) ◽  
pp. 480
Author(s):  
GABRIELLA LA MANNA ◽  
IVAN GUALA ◽  
DANIELE GRECH ◽  
FRANCESCO PERRETTI ◽  
FABIO RONCHETTI ◽  
...  
Keyword(s):  
Species Richness ◽  
Protected Area ◽  
Fish Assemblages ◽  
Marine Protected Area ◽  
Fish Fauna ◽  
Underwater Video ◽  
Visual Census ◽  
Underwater Visual Census ◽  
Species Richness And Abundance ◽  
High Level

Accurate, rapid and cost-effective fish assemblage monitoring is fundamental for marine protected area (MPA) management as a pivotal tool to verify whether and to what extent MPA conservation objectives have been achieved and to redefine these objectives in the framework of an adaptive management. Recently, there has been a sharp increase in the number of video-based methods to study fish fauna, such as baited remote underwater video (BRUV) systems, that, depending on the objectives of the monitoring, can provide complementary or additional data to the more commonly used underwater visual census (UVC). Even though BRUV systems have been widely used in a wide range of geographic contexts and habitats, their use in the Mediterranean basin is still sporadic and the evaluation of the efficiency of BRUV systems and whether they can be used to complement other techniques needs investigation. Thus, the objective of this study was to assess the performance of a BRUV system in a Mediterranean MPA and to evaluate its effectiveness in assessing the structure of fish assemblages (abundance and species richness) by comparing estimates with those obtained by the UVC technique. The fish fauna were monitored by BRUV and UVC in the Capo Caccia – Isola Piana Marine Protected Area (Sardinia, Italy), in July and October-November 2020, at four sampling sites and two areas, hundreds of meters apart, for each site. Overall, 46 taxa and a total of 3620 individuals were observed by BRUV, while 36 taxa and a total of 2995 individuals were observed by UVC. The species first observed in front of the camera’s field of view and able to reach the maximum abundance were the planktivores (Chromis chromis and Oblada melanura) followed by several carnivorous species belonging to the families Labridae, Serranidae and Sparidae, and lastly two carnivores (Mullus surmuletus and Mugilidae spp.) and some high-level predators (Dentex dentex, Seriola dumerili, Sphyraena viridensis, Dicentrarchus labrax). The maximum species richness and abundance were reached between 39 and 50 min. The cumulative species richness increased until around 30 min. Species richness was higher during the BRUV compared to the UVC monitoring. The consistency in findings between BRUV and UVC and a better performance of BRUV in detecting some species (mainly high-level predators), supports BRUV as an additional technique for describing and quantifying species richness and abundance also in the Mediterranean Sea. Based on the results of this study, the advantages/disadvantages, shortcomings, suggestions and resources needed for the two techniques are outlined.

scholarly journals Fish species richness in shallow environments of the Island of Santa Catarina, Southern Brazil

2018 ◽  
Vol 7 ◽  
pp. e20018001
Author(s):  
André Pereira Cattani ◽  
Olímpio Rafael Cardoso ◽  
Gisela Costa Ribeiro ◽  
Marcelo Soeth ◽  
Maurício Hostim-Silva ◽  
...  
Keyword(s):  
Species Richness ◽  
Fish Assemblages ◽  
Abiotic Factors ◽  
Fish Fauna ◽  
Sandy Beaches ◽  
Mean Value ◽  
Taxonomic Structure ◽  
Rocky Shores ◽  
Santa Catarina ◽  
Mean Values

The Island of Santa Catarina is a mosaic of ecosystems of great importance for fish fauna, highlighting the presence, in the same island, of estuaries, lagoons, mangroves, rocky shores and sandy beaches. This study aimed to compare, based on species richness, fish assemblages between different ecosystems. Between 1981 and 2011, there were collected a total of 165 taxa of fish, distributed in 54 families, in six sampling sites, using casting net, sweep net, beach trawl and gill net. According to the species accumulation curve, that show the increase of the number of different species with the increase of the number of samples, for all sites, the curves of species recorded followed patterns similar to curves obtained by the Jacknife index. However, the number of species has stabilized only for samples collected in Saco dos Limões, Itacorubi Mangrove and Ratones Mangrove. Comparing the mean values of richness between sites, the highest mean value was found in Saco dos Limões, followed by Índio Beach, Conceição Lagoon, North Bay , Itacorubi and Ratones Mangroves. Using the list of species as reference, despite the differences in abundance and richness between sites, the taxonomic structure is similar between sampling sites, which supports the hypothesis that the assemblages are occurring in all sites and the differences are primarily related to the patterns of reproduction and recruitment of species and secondarily influenced by abiotic factors, especially the temperature and salinity.

scholarly journals Can the Diving Industry Promote Marine Conservation and Enhance Environmental Awareness? (Sal Island, Cape Verde Case)

2018 ◽  
Vol 11 (1) ◽  
pp. 52-72
Author(s):  
Miguel Tiago Oliveira ◽  
Karim Erzini ◽  
Luís Bentes ◽  
Miguel Neves Santos
Keyword(s):  
Species Identification ◽  
Online Survey ◽  
Marine Conservation ◽  
Cape Verde ◽  
Artificial Reefs ◽  
Marine Biodiversity ◽  
Cape Verdean ◽  
Identification Guide ◽  
Natural Reefs ◽  
Santa Maria

Introduction:The growth in tourism in the Cape Verdean Sal Island has been a cause as well as a consequence of a number of investments (both by the State and the private entities) to create synergies for that sector, ensuring and promoting the island’s touristic attractiveness. Such increases in the number of visitors, allied with the island’s marine biodiversity - that make up much of its economic potential - have caused the growth of the diving industry, which has become one of the biggest attractions for tourists. In light of the scarcity of scientific studies on the impacts associated with this activity and means for diver engagement, the local diving operators have proposed the development of several tools.Method:An Underwater Species Identification Guide and four underwater routes were proposed for four popular scuba diving sites off Santa Maria Bay (Sal Island, Cape Verde): “Kwarcit”, “Sargo”, “Três Grutas” and “Tchuklassa”. To better understand how the diving industry could promote environmental education, conservation and enhance biodiversity awareness among divers, we also established the diver tourists’ profile using an online survey.Results:A total of 347 respondents, of which 85% have higher education, showed that 67% stay more than seven nights in Cape Verde. Moreover, natural reefs are the 1stdive site to be visited, while artificial reefs preference increases after a second dive on the man-made reefs. The majority would recommend the use of the Underwater Species Identification Guide and the underwater routes.The results showed that divers strongly embrace the use of new tools for better understanding of diving site biodiversity and that the diving industry can play an important role in the enhancement of biodiversity awareness.

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.

Effects of an anti-salt intrusion dam on tropical fish assemblages

2010 ◽  
Vol 61 (3) ◽  
pp. 288 ◽  
Author(s):  
Tuantong Jutagate ◽  
Amonsak Sawusdee ◽  
Thanitha Thapanand-Chaidee ◽  
Sovan Lek ◽  
Gaël Grenouillet ◽  
...  
Keyword(s):  
Species Richness ◽  
Chlorophyll A ◽  
Environmental Conditions ◽  
Fish Assemblages ◽  
Diversity Index ◽  
Tropical Fish ◽  
Food Sources ◽  
Salt Intrusion ◽  
Open Phase ◽  
Salinity Gradients

Following the construction of an anti-salt intrusion dam in Pak Panang River, Thailand, changes in the environmental conditions and fish assemblages were monitored both in the estuary and in the river. The present study was conducted during two different phases: when the sluices were open; and when they were closed. Salinity in the estuary declined (P < 0.001), but increased in the river during the open phase (P = 0.002). In the river, the pH increased (P < 0.001) during the closed phase, but was relatively constant in the estuary. No differences were found for water temperatures, chlorophyll a and abundance of phytoplankton. During the closed phase, the abundance of zooplankton was higher in the estuary, but the abundance of benthos in the river declined. Ninety-four fish species were collected. Species richness and the diversity index did not differ in the estuary, but were significantly different in the river; abundance was higher during the open phase. Fish moved between the two systems during the open phase and changes in fish assemblages correlated with salinity gradients and food sources. Sluice regulation to allow fish to move between the river and the estuary is recommended.

scholarly journals Decline of arable flora diversity in Istria (from the year 2005 to the year 2017)

2018 ◽  
Vol 6 (1) ◽  
pp. 385-398 ◽  
Author(s):  
Edita Štefanić ◽  
Vesna Kovačević ◽  
Slavica Antunović
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Diversity Index ◽  
Vascular Plant ◽  
Regional Scale ◽  
Recent Survey ◽  
Row Crops ◽  
Mean Values ◽  
Wiener Diversity Index ◽  
Weed Flora

Changes in floristic composition of weed flora were assessed comparing two phytocoenological surveys carried out during vegetation seasons in 2005 and in 2017 on the Istrian Peninsula. A total of 50 fields (row crops, cereals, alfalfa fields, orchards/vineyards and ruderal areas) were surveyed for each of the sampling time using Braun-Blanquet cover-abundance scale. Altogether 175 vascular plant species were recognized in both investigations. The most abundant species in 2005 were Avena fatua, Setaria verticilata, Lolium multiflorum and Veronica persica. In the recent survey these species became very rare or were even not detected in some habitats. In contrast, some species with very low relative abundance or not recorded in the earlier survey were found abundant in 2017. These are: Pastinaca sativa, Conyza canadensis, Picris echioides, Polygonum aviculare, and Heliotropium europaeum. The species richness was significantly higher in the earlier survey when 143 (82%) weeds were detected compared to only 97 species (55%) found in 2017. Only 64 species were found in both surveys, and these were considered frequent weeds. The comparison of weed communities from the earlier to the recent survey reflects the reduction of the weed flora at the regional scale, as well as at the field scale. The mean values of Shannon-Wiener diversity index were also higher in the earlier period and it decreased over time, particularly in row crops, cereals and ruderal habitats. This decrease was related to decline of species richness, and to the increase in inequality in the relative abundance of species. On the whole, canonical correspondence analysis indicated the major variations in species composition between different habitats.

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