Visually Estimating Fish Density at Artificial Structures in Lake Anna, Virginia

Shallow marine waters comprise diverse benthic types forming habitats for reef fish community, which important for the livelihood of coastal and small island inhabitants. Satellite imagery provide synoptic map of benthic habitat and further utilized to estimate reef fish stock. The objective of this research was to estimate reef fish stock in complex coral reef of Pulau Pari, by utilizing high resolution satellite imagery of the WorldView-2 in combination with field data such as visual census of reef fish. Field survey was conducted between May-August 2013 with 160 sampling points representing four sites (north, south, west, and east). The image was analy-zed and grouped into five classes of benthic habitats i.e., live coral (LC), dead coral (DC), sand (Sa), seagrass (Sg), and mix (Mx) (combination seagrass+coral and seagrass+sand). The overall accuracy of benthic habitat map was 78%. Field survey revealed that the highest live coral cover (58%) was found at the north site with fish density 3.69 and 1.50 ind/m2at 3 and 10 m depth, respectively. Meanwhile, the lowest live coral cover (18%) was found at the south site with fish density 2.79 and 2.18 ind/m2 at 3 and 10 m depth, respectively. Interpolation on fish density data in each habitat class resulted in standing stock reef fish estimation: LC (5,340,698 ind), DC (56,254,356 ind), Sa (13,370,154 ind), Sg (1,776,195 ind) and Mx (14,557,680 ind). Keywords: mapping, satellite imagery, benthic habitat, reef fish, stock estimation

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Temporal and spatial variation in adult and juvenile mobile fauna associated with natural and artificial coastal habitats

Marine Biology ◽

10.1007/s00227-021-03823-0 ◽

2021 ◽

Vol 168 (2) ◽

Author(s):

Alice E. Hall ◽

Roger J. H. Herbert ◽

Richard Stafford

Keyword(s):

Dicentrarchus Labrax ◽

Early Summer ◽

Coastal Habitats ◽

Artificial Structures ◽

Artificial Habitats ◽

Mobile Species ◽

Spatial And Seasonal Variation ◽

Black Bream ◽

Temporal And Spatial ◽

Natural Reefs

AbstractCoastal habitats are important for commercially exploited and protected species of fish and larger mobile invertebrates. The addition of artificial structures within the marine environment has the potential to alter the connectivity between habitats and to affect metapopulations of a region. Baited remote underwater videos (BRUV) were used to investigate the spatial and seasonal variation in abundance of adult and juvenile mobile species associated with subtidal natural and artificial habitats within Poole Bay on the south coast of England in 2019. Metrics included the relative maximum abundance (MaxN), number of species seen (S), assemblage structure and size range of fish. Higher values of MaxN and S were recorded on artificial structures in the spring and early summer; however, this pattern was reversed by mid-summer and early autumn when more fish were recorded on the natural reefs. Yet overall differences in MaxN and S between habitats were not significant. Differences in assemblage composition between habitats varied monthly, but this was mostly driven by particular sites. Although most fish observed were juveniles, there were some seasonal differences in the size of fish using natural and artificial sites, especially bib (Trisopterus luscus), black bream (Spondyliosoma cantharus), bass (Dicentrarchus labrax) and pollack (Pollachius pollachius). The artificial habitats in this region appeared to be important in certain months, so temporal studies of this type need to be incorporated within surveys, particularly those in proximity to protected areas.

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Zooplanktivore fish body growth responses to browning‐induced light limitation vary over ontogeny, but not with fish density

Ecology Of Freshwater Fish ◽

10.1111/eff.12605 ◽

2021 ◽

Author(s):

Renee M. van Dorst ◽

Anna Gårdmark ◽

Richard Svanbäck ◽

Magnus Huss

Keyword(s):

Body Growth ◽

Fish Density ◽

Light Limitation ◽

Growth Responses

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Influence of concrete properties on the initial biological colonisation of marine artificial structures

Ecological Engineering ◽

10.1016/j.ecoleng.2020.106104 ◽

2021 ◽

Vol 159 ◽

pp. 106104

Author(s):

Atteyeh S. Natanzi ◽

Bryan J. Thompson ◽

Paul R. Brooks ◽

Tasman P. Crowe ◽

Ciaran McNally

Keyword(s):

Artificial Structures ◽

Concrete Properties

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Substrate Selection of Ascidian Larva: Wettability and Nano-Structures

Journal of Marine Science and Engineering ◽

10.3390/jmse9060634 ◽

2021 ◽

Vol 9 (6) ◽

pp. 634

Author(s):

Euichi Hirose ◽

Noburu Sensui

Keyword(s):

The Body ◽

Substrate Selection ◽

Artificial Structures ◽

Substrate Preferences ◽

Nano Structures ◽

Hydrophobic Materials ◽

Faunal Communities ◽

Adhesive Organs ◽

Fouling Organisms ◽

Selection Of

Ascidians are marine sessile chordates that comprise one of the major benthic animal groups in marine ecosystems. They sometimes cause biofouling problems on artificial structures underwater, and non-indigenous, invasive ascidian species can potentially and seriously alter native faunal communities. Ascidian larvae are usually tadpole-shaped, negatively phototactic, and adhere on substrates by secreting a glue from their adhesive organs. Although larvae often prefer hydrophobic surfaces, such as a silicone rubber, for settlement, hydrophobic materials are often used to reduce occurrence of fouling organisms on artificial structures. This inconsistency may indicate that an attractive surface for larvae is not always suitable for settlement. Micro-scale structures or roughness may enhance the settlement of ascidian larvae, but settlement is significantly reduced by a nano-scale nipple array (or moth-eye structure), suggesting functional properties of similar structures found on the body surfaces of various invertebrates. The substrate preferences of larvae should be one of the important bases in considering measures against biofouling, and this review also discusses the potential uses of materials to safely reduce the impacts of invasive species.

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