Distribution and abundance of soft-bottom molluscs in Port Phillip Bay, Victoria, Australia

1974 ◽  
Vol 25 (3) ◽  
pp. 371 ◽  
Author(s):  
GCB Poore ◽  
S Rainer
Keyword(s):  
Distribution Patterns ◽  
Sediment Type ◽  
Soft Bottom ◽  
Surface Deposit ◽  
Suspension Feeders ◽  
Feeding Types ◽  
Marginal Areas ◽  
Feeding Type ◽  
Faunal Density ◽  
Main Determinants

The distribution of soft-bottom molluscs of Port Phillip Bay, Vic., is examined in terms of abundance, the distribution of feeding types and patterns of diversity, and related to environmental variables such as depth and sediment type. Six feeding types were distinguished among the 105 species collected. Infaunal suspension feeders dominated in marginal sandy substrates while surface deposit feeders dominated in the silt and clay sediments of the Central region and Corio Bay. Epifaunal suspension feeders, grazers, scavengers and predators were less abundant and were seldom dominant. Numbers of individuals and species, and diversity, varied widely but were generally higher in marginal areas. Four areas of the Bay were recognized on the basis of similarities in distribution patterns, the distribution of species numbers, of diversity and of the dominant feeding type: the Nepean sand banks, the deep water Central and Corio regions, marginal areas, and the shallow seagrass sand flats. The main determinants of mollusc distributions were substrate and food supply, while purely hydrological effects were limited to nearshore areas. Regional differences in diversity were related to sample size by correlation and regression; low faunal density caused diversity in the Exchange region to be considerably underestimated.

Macroalgal distribution patterns in a shallow, soft-bottom lagoon, with emphasis on the nonnativeGracilaria vermiculophylla andCodium fragile

2006 ◽  
Vol 29 (3) ◽  
pp. 465-473 ◽  
Author(s):  
Mads Solgaard Thomsen ◽  
Karen J. McGlathery ◽  
Anna Christina Tyler
Keyword(s):  
Distribution Patterns ◽  
Soft Bottom

Distribution, biomass and community structure of demersal fishes of the Gulf of Carpentaria, Australia

1994 ◽  
Vol 45 (3) ◽  
pp. 375 ◽  
Author(s):  
SJM Blaber ◽  
DT Brewer ◽  
AN Harris
Keyword(s):  
Community Structure ◽  
Abiotic Factors ◽  
Fish Fauna ◽  
Distribution Patterns ◽  
Demersal Fish ◽  
Fish Distribution ◽  
Sediment Type ◽  
Principal Coordinates Analysis ◽  
Main Site ◽  
Principal Coordinates

The demersal fish fauna of the Gulf of Carpentaria was surveyed during November and December 1990. Over 300 species from 85 families were caught by trawling a systematic grid of 107 stations. The absolute mean biomass was 124.8 kg ha-1 (s.e. =44.1) for day trawls and 53.7 kg ha-1 (s.e. =6.0) for night trawls. The overall mean catch rates were 421.3 kg h-1 (s.e. = 128.5) for day trawls and 198.6 kg h-1 (s.e. =21.5) for night trawls. Biomasses were twice as high in the prawn-trawling grounds of Albatross Bay, the south-eastern gulf and Groote Eylandt as they were elsewhere in the gulf. Twenty-five species made up 75% of the biomass; the dominant families were Haemulidae, Carangidae, Leiognathidae and Nemipteridae. Community-structure and distribution patterns were analysed by numerical classification techniques and principal-coordinates analysis. These indicated six main site groups and 15 fish community groups, based on fish species occurrences and biomasses. There was a relationship between fish distribution patterns and depth of water but not other abiotic factors recorded (sediment type, salinity, temperature and turbidity).

scholarly journals Diversity and ecology of Pilargidae (Annelida: Polychaeta) from the Gulf of Carpentaria and Arafura Sea, northern Australia

Zoosymposia ◽  
2009 ◽  
Vol 2 (1) ◽  
pp. 537-550
Author(s):  
SHONA A. HOCKNULL ◽  
CHRISTOPHER J. GLASBY
Keyword(s):  
Species Composition ◽  
Distribution Patterns ◽  
Sediment Type ◽  
Geological History ◽  
Northern Australia ◽  
Sediment Types ◽  
Arafura Sea ◽  
History Of ◽  
Unit Depth ◽  
Sand And Gravel

This study identifies to species or species units 572 lots (>1000 specimens) of pilargids from six localities in the Arafura Sea and Gulf of Carpentaria (including the ports at Gove and McArthur River). We analyze the taxonomic data against geomorphic unit, depth, and sediment type. Preliminary results show that pilargid fauna of northern Australia comprises 13 species in seven genera (Ancistrosyllis, Cabira, Litocorsa, Loandalia, Pilargis, Sigambra, and Synelmis). Although all four localities have a similar diversity of species (six or seven species each), the species composition differs between each region: Litocorsa annamita and Synelmis rigida were found in all sediment types in the Arafura Sea and Gulf of Carpentaria; Ancistrosyllis cf. hartmanae (mud and sand dominated sediments only) and Sigambra pettiboneae (all sediment types) were restricted to the inshore localities of Gove and McArthur River; Loandalia gladstonensis and Sigambra sp. 2 were found on the shelf and in the inshore habitats of the Gulf of Carpentaria only; Litocorsa sp. ‘arafura’, Sigambra sp. ‘arafura’ and Synelmis gibbsi were found only in the Arafura Sea, with sediments dominated by sand and gravel; and Cabira sp. 1 and Sigambra cf. tentaculata were found at all locations, in all sediment types. Based on these distribution patterns and the Recent Quaternary geological history of the area, hypotheses of post-glacial colonization of the Gulf of Carpentaria are presented. The pilargid species composition in northern Australia is also compared to neighboring Indo-west Pacific regions.

scholarly journals Ecological network analysis with benthic indices to assess ecological and functional status of soft-bottom subtidal habitat in the English Channel

2018 ◽  
Author(s):  
Aurore Raoux ◽  
Jean-Philippe PEZY ◽  
Jean-Claude Dauvin ◽  
Nathalie NIQUIL
Keyword(s):  
Network Analysis ◽  
Ecological Status ◽  
Sediment Type ◽  
English Channel ◽  
Ecological Network ◽  
Soft Bottom ◽  
Ecological Network Analysis ◽  
Sea Bed ◽  
Ecopath Model ◽  
Benthic Indices

The eastern part of the English Channel (north-eastern Atlantic) in a megatidal environment is one of the most impacted area in the world wide ocean. To the traditional fish activities and maritime transports with dredging and deposit spoil sediment which impact the ecosystem, aggregate extractions and implementation of offshore wind farms increase the pressures in this shallow epicontinental sea. The soft-bottom sea bed was mainly covered by sandy gravels and gravelly sand located offshore under high tidal currents while medium sand and muddy fine sand were deposit along the coast in area with weak currents. A large number of benthic indices had been recently developed mainly to the implementation of the European Water Framework Directive, but to structural assessment, development of more integrate method such as Ecological Network Analysis with the Ecopath model permit to furnish a functional assessment of the benthic habitats. Several studies in diverse sediment type under human pressures or future activities with reef and protected scenarios within an offshore windfarm permit to evaluate the suitability of structural and functional indices to reveal spatio-temporal statutes and changes of the Ecological Status of the benthic ecosystems

Ice algae resource utilization by benthic macro- and megafaunal communities on the Pacific Arctic shelf determined through lipid biomarker analysis

2020 ◽  
Vol 651 ◽  
pp. 23-43 ◽  
Author(s):  
CW Koch ◽  
LW Cooper ◽  
JM Grebmeier ◽  
K Frey ◽  
TA Brown
Keyword(s):  
Organic Carbon ◽  
Sea Ice ◽  
Feeding Strategy ◽  
Food Sources ◽  
Ice Algae ◽  
Surface Deposit ◽  
Suspension Feeders ◽  
Deposit Feeders ◽  
Lipid Biomarker ◽  
Biomarker Analysis

We studied ice algae utilization by benthic fauna from the northern Bering and Chukchi Seas using highly branched isoprenoid (HBI) biomarkers. We assessed whether various food acquisition strategies influence the observed HBI signatures. The proportion of phytoplankton to ice algae-sourced HBIs was determined through the H-Print approach that is presumed to reflect the percentage of sea ice organic carbon (iPOC) incorporated into tissues, relative to phytoplankton organic carbon. Cluster analysis separated 3 groups based on location and feeding strategy that were significantly influenced by annual sea ice persistence. Ice algae utilization was most significant in the northeast Chukchi Sea, where seasonal sea ice was present the longest. General feeding strategy was determined to be a significant factor in the degree of ice algae utilization. Predominant deposit feeders (both surface and subsurface) used more ice algae relative to suspension feeders. Organic carbon incorporated by predominant suspension feeders was primarily phytoplankton-based. The vast majority of all organisms sampled (~90%) incorporated a measurable quantity of iPOC. Sipunculids and brittle stars had the highest relative dependence on ice algae, while other taxa displayed plastic dietary responses, including the suspension/surface deposit feeder Macoma calcarea. This study indicates that ice algae are widely utilized in Pacific Arctic benthic food webs, but most benthic organisms displayed flexibility in consuming the available food sources. The elevated utilization of ice algae by deposit feeders may prove to be a disadvantage for these organisms if they cannot adapt to the ongoing decline of iPOC as seasonal sea ice declines.

Spatio-temporal sublittoral macrobenthic distribution and dominant species in Guanabara Bay, Rio de Janeiro, Brazil

2020 ◽  
Author(s):  
L. A. Pessoa ◽  
P. C. Paiva ◽  
R. R. Paranhos ◽  
C. A. Echeverría ◽  
Marcos A. V. Freitas
Keyword(s):  
Annual Cycle ◽  
Temporal Distribution ◽  
Distribution Patterns ◽  
Rainfall Regime ◽  
Guanabara Bay ◽  
Soft Bottom ◽  
Gravity Corer ◽  
Structural Variables ◽  
High Dominance ◽  
Spatio Temporal

Abstract Soft-bottom macrobenthic invertebrates are sensitive to natural or anthropogenic changes in aquatic ecosystems. The distribution patterns of sublittoral macrobenthic species in Guanabara Bay were studied from 2005 to 2007. Samples were collected at ten stations during six surveys throughout the rainfall regime (dry, early and late rainy). Ten replicates were collected at each station by Gravity corer or skin diving. Van Dorn bottles (bottom water) and by Ekman sediment sampler (granulometry) provided material for abiotic data. Stations were grouped into sectors (Entrance, Intermediary and Inner) based on abiotic data and location. The Redundancy Analysis (RDA) and Parsimonious RDA for all years and each annual cycle showed indicator taxa with high dominance in each sector. PERMANOVA indicated a regular seasonality between the surveys for the first annual cycle (p <0.05), and an atypical pattern for the second (p> 0.05), possibly due the low rainfall observed during this period. The mosaic of soft-bottom substrates infers structural variables, and patterns of temporal distribution were basically influenced by parameters those indicating pollution and the SACW (South Atlantic Central Water) intrusion, as well as ecological attributes among species, such as: predation, competition. The Ervilia concentrica and Cypridinidae could be used as indicators for anthropic and natural impacts in the Guanabara Bay for the Entrance sector, while Cyprideis salebrosa and Cyprideis sp. for the Intermediary sector and Heleobia australis for the Inner sector.

Changes in the benthic community of china clay waste deposits in Mevagissey Bay following a reduction of discharges

1981 ◽  
Vol 61 (3) ◽  
pp. 789-804 ◽  
Author(s):  
P. Keith Probert
Keyword(s):  
Benthic Community ◽  
Species Interactions ◽  
Suspended Solid ◽  
Soft Bottom ◽  
Fine Grained ◽  
China Clay ◽  
Suspended Solid Concentration ◽  
Amphiura Filiformis ◽  
Faunal Density ◽  
Deposit Feeding

Macrobenthic infauna was sampled in Mevagissey Bay, off the south coast of Cornwall, England, when the bay was receiving fine-grained mineral waste from the china clay industry at a rate of about 450000 tons per annum. Quintuplicate 0·1 m2 grab samples, washed on a 0·5 mm mesh, were taken on 15 occasions over two years at a station about 1 km from the outfall and at a water depth of 13 m. The fauna had a range of density of 755–2144 individuals/0–5 m2 and in composition resembled a partially impoverished Echinocardium cordatum/Amphiurafiliformis community. Population densities of Goniada maculata (Polychaeta), Cingula semicostata (Gastropoda), Nucula turgida, Mysella bidentata, Venus striatula and Tellina fabula (Bivalvia) showed no clear trends during the two years' sampling. Magelona filiformis (Polychaeta), Abra alba and Phaxas pellucidus (Bivalvia), Acrocnida brachiata and Amphiura filiformis (Ophiuroidea) declined in abundance, whereas the densities of Nephtys hombergi (Polychaeta) and Labidoplax digitata (Holothurioidea) increased. L. digitata became the commonest species, with a peak density of 708 individuals/0·5 m2. A month after sampling began the rate of waste discharged was reduced from 700000 tons per annum, but this did not appear to improve conditions for the benthic community. Total faunal density remained relatively stable but species diversity declined. It is argued that the suspended solid concentration was unlikely to have adversely affected the predominantly deposit-feeding community, but that persistent sediment instability continued to be a source of stress. Nevertheless, the observed major changes of community structure were similar to natural fluctuations of coastal soft-bottom populations resulting from species interactions and differences of larval success.

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