scholarly journals Community structure and carbonate production of a temperate rhodolith bank from Arvoredo Island, southern Brazil

2004 ◽  
Vol 52 (3-4) ◽  
pp. 207-224 ◽  
Author(s):  
Douglas F. M. Gherardi
Keyword(s):  
Community Structure ◽  
Coralline Algae ◽  
Carbonate Content ◽  
Production Rates ◽  
Percentage Cover ◽  
Coralline Red Algae ◽  
Carbonate Production ◽  
Random Dispersal ◽  
Long Run ◽  
Main Bank

A small (100,000 m²) rhodolith bank located at the Arvoredo Marine Biological Reserve (Santa Catarina, Brazil) has been surveyed to determine the main bank components, the community structure, and carbonate production rates. Data from five photographic transects perpendicular to Arvoredo Island shore were complemented with sediment samples and shallow cores, all collected by scuba diving. The main bank component is the unattached, nongeniculate, coralline red algae Lithophyllum sp., used as substrate by the zoanthid Zoanthus sp. Percentage cover of living and dead coralline algae, zoanthids and sediment patches account for nearly 98% of the investigated area. Classification and ordination of samples showed that differences in the proportion of live and dead thalli of Lithophyllum sp. determine the relative abundances of zoanthids. Results also indicate that similarity of samples is high and community gradients are subtle. Significant differences in percentage cover along transects are concentrated in the central portion of the bank. Low carbonate content of sediments from deeper samples suggests low rates of recruitment and dispersal of coralline algae via fragmentation. However, carbonate production of Lithophyllum sp ranging from 55-136.3 g m-2 yr-1 agrees with production rates reported for other temperate settings. In the long run, rhodolith density at Arvoredo Is. is likely to be dependent upon random dispersal of spores and/or fragments from other source areas.

scholarly journals Slow Community Development Enhances Abiotic Limitation of Benthic Community Structure in a High Arctic Kelp Bed

2021 ◽  
Vol 8 ◽  
Author(s):  
Christina Bonsell ◽  
Kenneth H. Dunton
Keyword(s):  
Community Structure ◽  
Community Development ◽  
Benthic Community ◽  
Beaufort Sea ◽  
High Arctic ◽  
Coralline Algae ◽  
Physical Factors ◽  
Crustose Coralline Algae ◽  
Benthic Community Structure ◽  
Kelp Bed

We examined the patterns of propagule recruitment to assess the timescale and trajectory of succession and the possible roles of physical factors in controlling benthic community structure in a shallow High Arctic kelp bed in the Beaufort Sea, Alaska. Spatial differences in established epilithic assemblages were evaluated against static habitat attributes (depth, distance from river inputs) and environmental factors (temperature, salinity, current speed, underwater light) collected continuously over 2–6 years. Our measurements revealed that bottom waters remained below freezing (mean winter temperatures ∼−1.8°C) and saline (33–36) with negligible light levels for 8–9 months. In contrast, the summer open water period was characterized by variable salinities (22–36), higher temperatures (up to 8–9°C) and measurable irradiance (1–8 mol photons m–2 day–1). An inshore, near-river site experienced strong, acute, springtime drops in salinity to nearly 0 in some years. The epilithic community was dominated by foliose red algae (47–79%), prostrate kelps (2–19%), and crustose coralline algae (0–19%). Strong spatial distinctions among sites included a positive correlation between cover by crustose coralline algae and distance to river inputs, but we found no significant relationships between multi-year means of physical factors and functional groups. Low rates of colonization and the very slow growth rates of recruits are the main factors that contribute to prolonged community development, which augments the influence of low-frequency physical events over local community structure. Mortality during early succession largely determines crustose coralline algal and invertebrate prevalence in the established community, while kelp seem to be recruitment-limited. On scales > 1 m, community structure varies with bathymetry and exposure to freshwater intrusion, which regulate frequency of primary and physiological disturbance. Colonization rates (means of 3.3–69.9 ind. 100 cm–1 year–1 site–1) were much lower than studies in other Arctic kelp habitats, and likely reflect the nature of a truly High Arctic environment. Our results suggest that community development in the nearshore Beaufort Sea occurs over decades, and is affected by combinations of recruitment limitation, primary disturbance, and abiotic stressors. While seasonality exerts strong influence on Arctic systems, static habitat characteristics largely determine benthic ecosystem structure by integrating seasonal and interannual variability over timescales longer than most ecological studies.

Carbonate production rates of encruster communities on a lagoonal patch reef: Vabbinfaru reef platform, Maldives

2014 ◽  
Vol 65 (8) ◽  
pp. 720 ◽  
Author(s):  
K. M. Morgan ◽  
P. S. Kench
Keyword(s):  
Coral Cover ◽  
Patch Reef ◽  
Coralline Algae ◽  
Carbonate Production ◽  
Sedimentary Environments ◽  
Reef Health ◽  
Global Estimates ◽  
Range Of Values ◽  
Encrusting Organisms ◽  
Reef Platform

Coral reefs are formed by the growth and calcification of primary coral framework and secondary encrusting organisms. Future scenarios of reef health predict global declines in coral cover and an increase in the relative importance of encrusting organisms to gross reef calcification. Numerous coral growth studies are available; however, there are few quantitative estimates of secondary carbonate production on reefs. The present study used vertically orientated PVC pipe to generate rates of carbonate production (g cm–2 year–1) by encruster communities on Vabbinfaru reef platform, Maldives (4°18′35″N, 73°25′26″E). Maximum carbonate production by encrusters was 0.112 g cm–2 year–1 (mean ± s.d.: 0.047 ± 0.019 g cm–2 year–1). Encruster community composition was dominated by non-geniculate coralline algae (mean ± s.d.: 76 ± 14.2%), with other encrusting taxa being quantitatively unimportant to total substrate cover (mean ± s.d.: 9 ± 16.7%). Rates of encruster calcification at Vabbinfaru fell within the range of values reported for other reef-building provinces. There is a particular need for more quantitative field-based measurements of reef-organism calcification rates because such values strengthen regional and global estimates of gross carbonate production and have direct implications for net reef accretion and the development of reef sedimentary environments.

scholarly journals Reef Flat Community Structure of Atol das Rocas, Northeast Brazil and Southwest Atlantic

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Adriana C. Fonseca ◽  
Roberto Villaça ◽  
Bastiaan Knoppers
Keyword(s):  
Community Structure ◽  
Reef Flat ◽  
Temporal Stability ◽  
Coralline Algae ◽  
Brazilian Coast ◽  
Southwest Atlantic ◽  
Green Macroalgae ◽  
Red Macroalgae ◽  
Sw Atlantic ◽  
Definition Of

This study was conducted during 1999 to 2002 and addresses the community structure and some ecological aspects of the benthic reef flat assemblages of Atol das Rocas, located offshore the NE brazilian coast. It corresponds to the sole atoll of the SW Atlantic, which characterized by a shallow topography and is almost completely built by coralline algae. The turf forming red macroalgaeDigenea simplexand the crustose corallineHydrolithon pachydermumwere the dominant species of the reef flat. The crustose green macroalgaeDictyosphaeria ocellataand the turf forming red macroalgaeGelidiella acerosawere the subdominant species. Biomass values ofD. simplexwere about twice higher than the other species, pointing out to its relevance in the community structure of this reef zone. Biodiversity indices indicated a high equitability within the few species observed and a relative temporal stability of the community structure. Some local spatial variations were found in the community structure of the reef flat zone, enabling the definition of three subhabitats. The patterns of distribution and abundance of the benthic organisms seem to be related to the environmental conditions of the reef flat, such as low water turbulence, lengthy periods of aerial exposure, and low herbivore pressure.

scholarly journals Nongeniculate coralline red algae (Rhodophyta: Corallinales) in coral reefs from Northeastern Brazil and a description of Neogoniolithon atlanticum sp. nov.

Phytotaxa ◽  
2014 ◽  
Vol 190 (1) ◽  
pp. 277 ◽  
Author(s):  
FREDERICO T. S. TÂMEGA ◽  
Rafael Riosmena-Rodriguez ◽  
RODRIGO MARIATH ◽  
Marcia Figueiredo
Keyword(s):  
Coral Reefs ◽  
Critical Evaluation ◽  
Taxonomic Status ◽  
First Record ◽  
Abundant Species ◽  
Northeastern Brazil ◽  
Type Material ◽  
Coralline Algae ◽  
Coralline Red Algae ◽  
Western Atlantic

A taxonomic reassessment of coralline algae (Corallinales, Rhodophyta) associated with reef environments in the Abrolhos Bank, northeastern Brazil, was developed based on extensive historical samples dating from 1999–2009 and a critical evaluation of type material. Our goal was to update the taxonomic status of the main nongeniculate coral reef-forming species. Our results show that four species are the main contributors to the living cover of coral reefs in the Abrolhos Bank: Lithophyllum stictaeforme, Neogoniolithon atlanticum sp. nov., Porolithon pachydermum and Spongites fructiculosus. Comparison of the type material to modern collections has shown that Lithophyllum congestum is a heterotypic synonym of L. stictaeforme. However, L. stictaeforme and P. pachydermum were the most abundant species at the studied sites, a finding consistent with other coral reefs in the region. This is the first record of S. fructiculosus in the southwestern Atlantic. This review provides the baseline data needed for the monitoring and management of the southernmost limits of coral reefs in the western Atlantic Ocean.

scholarly journals Subtidal littering: Indirect effects on soft substratum macrofauna?

2008 ◽  
Vol 9 (2) ◽  
pp. 35 ◽  
Author(s):  
I. AKOUMIANAKI ◽  
P. KONTOLEFAS ◽  
S. KATSANEVAKIS ◽  
A. NICOLAIDOU ◽  
G. VERRIOPOULOS
Keyword(s):  
Community Structure ◽  
Sediment Surface ◽  
Long Run ◽  
Significant Difference ◽  
Before And After ◽  
Soft Substratum ◽  
One Year ◽  
The Impact ◽  
Control Surfaces ◽  
Macrofauna Community

Changes in macrofauna community structure, abundance and species richness were examined both before and one year after the deployment of plastic and glass bottles at littered (litter density: 16 items / 100 m2) and non-littered (control) surfaces at three unimpacted coastal areas of the western Saronikos Gulf (Greece). In parallel, LOI% at the adjacent sediments and changes in the composition of feeding types of the megaepifauna that colonized the litter were examined across treatments. Significant changes in macrofauna community structure were demonstrated between before and after littering. At only one of the sites was there detected a significant difference in macrofauna community structure between control and littered plots after littering. This difference was linked with a significant increase in the abundance of opportunistic polychaete species and LOI% levels in the sediment surface due to the entrapment of macrophytal debris within the littered surface. The study did not show a consistent direct response of macroinfauna community to litter and the associated megafauna. Unlike the megafauna attracted by litter items, soft-substratum macrofauna is less responsive to the addition of novel hard substrates in adjacent sediments. Alternatively, it could be that the impact of littering with small items triggers a macrofauna response detectable in the long-run.

scholarly journals Bacterial Communities Associated With Healthy and Bleached Crustose Coralline Alga Porolithon onkodes

2021 ◽  
Vol 12 ◽  
Author(s):  
Fangfang Yang ◽  
Zhiliang Xiao ◽  
Zhangliang Wei ◽  
Lijuan Long
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Communities ◽  
Larval Settlement ◽  
Crustose Coralline Alga ◽  
Coralline Algae ◽  
Pocillopora Damicornis ◽  
Crustose Coralline Algae ◽  
Settlement And Metamorphosis ◽  
Relative Abundances

Crustose coralline algae (CCA) play vital roles in producing and stabilizing reef structures and inducing the settlement and metamorphosis of invertebrate larvae in coral reef ecosystems. However, little is known about the bacterial communities associated with healthy and bleached CCA and their interactions with coral larval settlement. We collected samples of healthy, middle semi-bleached, and bleached CCA Porolithon onkodes from Sanya Bay in the South China Sea and investigated their influences on the larval settlement and metamorphosis of the reef-building coral Pocillopora damicornis. The larval settlement/metamorphosis rates all exceeded 70% when exposed to healthy, middle semi-bleached, and bleached algae. Furthermore, the compositions of bacterial community using amplicon pyrosequencing of the V3–V4 region of 16S rRNA were investigated. There were no obvious changes in bacterial community structure among healthy, middle semi-bleached, and bleached algae. Alphaproteobacteria, Bacteroidetes, and Gammaproteobacteria were dominant in all samples, which may contribute to coral larval settlement. However, the relative abundances of several bacterial communities varied among groups. The relative abundances of Mesoflavibacter, Ruegeria, Nautella, and Alteromonas in bleached samples were more than double those in the healthy samples, whereas Fodinicurvata and unclassified Rhodobacteraceae were significantly lower in the bleached samples. Additionally, others at the genus level increased significantly from 8.5% in the healthy samples to 22.93% in the bleached samples, which may be related to algal bleaching. These results revealed that the microbial community structure associated with P. onkodes generally displayed a degree of stability. Furthermore, bleached alga was still able to induce larval settlement and metamorphosis.

scholarly journals ANALISIS KONDISI LAMUN (SEAGRASS) DI PERAIRAN PULAU PRAMUKA, KEPULAUAN SERIBU

2015 ◽  
Vol 13 (1) ◽  
pp. 22-32
Author(s):  
Septi Dwi Fajarwati ◽  
Asma Irma Setianingsih ◽  
Muzani Muzani
Keyword(s):  
Water Quality ◽  
Community Structure ◽  
Ph Value ◽  
Secondary Data ◽  
Quality Analysis ◽  
Quality Data ◽  
Primary Data ◽  
Seagrass Habitat ◽  
Percentage Cover ◽  
Water Quality Data

ABSTRACT This research aims to analyze the condition of seagrass ecosystem to see water quality data of the seagrass habitat and percentage cover of seagrass in the waters of the Pramuka Island, Seribu Islands. The research was conducted over two months from October to November 2014.This research used a descriptive method with field survey approach. The population in this study is the seagrass in Waters Pramuka Island. Determining the location with purposive sampling of the sampling is divided into three stations is North, East and South. Data collection techniques include primary data and secondary data. Primary data is data of seagrass (type, percentage cover and density of seagrass) and data of seagrass habitat environmental parameters (water temperature, current speed, brightness, depth, salinity, substrate, TSS, DO, pH) were obtained by direct measurement in the field, while secondary data include the general state of the research sites. Data analysis techniques used in this study using analysis of community structure of seagrass and water quality analysis. The results showed that seagrass species found in the Pramuka Island there are 6 types of seagrass Cymodocea rotundata, Cymodocea serrulata, Enhalus acoroides, Halophila ovalis, Halodule uninervis, Thalassia hemprichii. Conditions of seagrass in the waters of the Pramuka Island included into the category of less healthy-poor seagrass. At station 1 percentage by 31% classified seagrass less healthy conditions, while the other two stations are stations 2 and 3 belong to the category of the poor condition of seagrass, with each percentage cover of seagrass 19.4% and 20.3%. Of all water quality parameters measured, all the parameters are still in normal circumstances, but there are some parameters whose value is high at some stations TSS and pH value is high at station 2 with a value of TSS 18 mg/l and a pH value of 8.2. Water quality and seagrass communities in station 1 is still in good condition for the growth of seagrass, because at this station is an unspoiled area away from human activity, while the stations 2 and 3 have undergone changes in community structure of seagrass because at this station has several anthropogenic activities that disrupt the lives of seagrass, mostly from human activities such as domestic sewage and hoarding/reclamation, which affects the condition of seagrass at station 2 and 3 are poor seagrass. Keyword: Seagrass, Water Quality, Pramuka Island

Community structure of a rhodolith bed from cold-temperate waters (southern Australia)

2008 ◽  
Vol 56 (5) ◽  
pp. 437 ◽  
Author(s):  
A. S. Harvey ◽  
F. L. Bird
Keyword(s):  
Community Structure ◽  
Red Algae ◽  
Growth Form ◽  
The Other ◽  
Growth Forms ◽  
Free Living ◽  
Coralline Red Algae ◽  
Reliable Identification

Rhodolith beds are aggregations of free-living non-geniculate coralline red algae (Corallinales, Rhodophyta), with a high biodiversity of associated organisms. This is the first detailed study of a rhodolith-bed community from the cold-temperate waters of southern Australia. This bed, located at 1–4-m depth in Western Port, Victoria, is composed of four rhodolith-forming species (Hydrolithon rupestre (Foslie) Penrose, Lithothamnion superpositum Foslie, Mesophyllum engelhartii (Foslie) Adey and Neogoniolithon brassica-florida (Harvey) Setchell & Mason). M. engelhartii has a foliose growth form and the other three species have fruticose growth forms. Detailed descriptions are provided for all species, allowing reliable identification. Comparisons with other rhodolith beds and reported rhodolith-forming species, both in Australia and worldwide, are also provided. The invertebrate cryptofaunal community was quantified for two rhodolith-forming species. The density of cryptofauna inhabiting foliose and fruticose rhodolith growth forms did not differ significantly and neither did abundance of individual phyla. Mean density of fauna was 0.4 invertebrates cm–3, the majority of which were polychaete worms. Comparisons of fauna associated with other rhodolith beds are also provided. A study of the vitality of the rhodolith bed showed dead rhodoliths are more abundant than live rhodoliths. Possible reasons for reduced bed vitality are explored.

Community structure of nongeniculate coralline red algae (Corallinales, Rhodophyta) in three boulder habitats in southern Australia

Phycologia ◽  
1999 ◽  
Vol 38 (2) ◽  
pp. 138-148 ◽  
Author(s):  
Sabine Daume ◽  
Sascha Brand-Gardner ◽  
William J. Woelkerllng
Keyword(s):  
Community Structure ◽  
Red Algae ◽  
Coralline Red Algae
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