Effects of morphodynamics and across-shore physical gradients on benthic macroinfauna on two sandy beaches in south-eastern Brazil

2014 ◽  
Vol 94 (4) ◽  
pp. 671-680 ◽  
Author(s):  
Joaquim N.S. Santos ◽  
Rafaela de S. Gomes ◽  
Ruan Managna Vasconcellos ◽  
Débora de Souza Silva ◽  
Francisco Gerson Araújo
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Species Richness ◽  
Sandy Beaches ◽  
Assemblage Structure ◽  
Wave Period ◽  
South Eastern ◽  
Eastern Brazil

We examined the benthic macroinfauna at three strata during two seasons (winter and summer) on two sandy beaches (dissipative and reflective) in south-eastern Brazil. The hypothesis raised is that effects of morphodynamics and zonation determine the structure of macroinfauna, with dissipative beaches having comparatively higher species richness and density than the reflective beaches. Flamengo beach (dissipative) had higher species richness but lower density compared to Grumari beach (reflective). A high dissimilarity in assemblage structure (91.75%) was detected between the two beaches. Zonation in the occurrence of macroinfauna was detected for the two beaches in the two examined seasons. At Grumari beach, Emerita brasiliensis occurred mainly in stratum 1 (intertidal swept zone) while Saccocirus sp. occurred in stratum 2 (infralittoral at 0.5 m depth), whereas at Flamengo beach E. brasiliensis and Enoploides sp. had the highest density in stratum 1 (intertidal swept zone) whereas Scolelepis goodbodyi and Donax uncinata dominated in stratum 3 (infralittoral at 1.0 m depth). Scolelepis goodbodyi, Dispio uncinata, Enoploides sp., Nematoda and Trileptium sp. were associated with higher a Dean parameter and content of organic matter at Flamengo beach. In contrast, Hastula sp., Donax sp., Pisionidens indica, Hemipodus californiensis, Saccocirus sp. and Phyllodocidae were associated with the higher wave period and grain size of Grumari beach. The hypothesis that macroinfauna structure differs between the beaches and strata was confirmed, with the dissipative beaches having comparatively higher richness but lower density than the reflective beaches.

scholarly journals Diversity and distribution of crustaceans from 13 sheltered sandy beaches along São Sebastião Channel, south-eastern Brazil

2001 ◽  
Vol 81 (3) ◽  
pp. 475-484 ◽  
Author(s):  
P.R. Nucci ◽  
A. Turra ◽  
E.H. Morgado
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Clay Content ◽  
Fine Sand ◽  
Sandy Beaches ◽  
Matter Content ◽  
Sediment Grain Size ◽  
Crustacean Species ◽  
South Eastern ◽  
Eastern Brazil

The crustacean species composition in the intertidal zones of 13 sheltered unconsolidated marine beaches in south-eastern Brazil is described. Fifty-three crustacean species were collected, adding 46 species to the total reported by previous studies in the same region. Decapods dominated the community, in contrast to exposed sandy beaches where peracarids normally predominate. The species were distributed irregularly among the beaches. Richness varied markedly among sites, and was positively related to a combination of factors such as fine sand grains, high organic matter content, and relatively low silt–clay content. The presence of rock fragments enabled both rocky shore and sandy beach crustaceans to occur on the same beaches. Richness and abundance of crustaceans showed no clear relationship to sediment grain size and slope, in contrast to the norm for exposed sandy beaches. The dominance of the tanaid Kalliapseudes schubarti in some areas may be a result of organic matter pollution in the region. These beaches showed higher species richness than typical sheltered and exposed sandy beaches, indicating that this sheltered, highly heterogeneous seascape is an important area for conservation.

Environmental effects on the structure of polychaete feeding guilds on the beaches of Sepetiba Bay, south-eastern Brazil

2012 ◽  
Vol 93 (4) ◽  
pp. 973-980 ◽  
Author(s):  
Gustavo Mattos ◽  
Ricardo S. Cardoso ◽  
André Souza Dos Santos
Keyword(s):  
Grain Size ◽  
Sandy Beach ◽  
Sandy Beaches ◽  
Feeding Guilds ◽  
Feeding Guild ◽  
Beach Sediment ◽  
Sepetiba Bay ◽  
Importance Index ◽  
Eastern Brazil ◽  
Macrofauna Communities

Several studies have been conducted to explain patterns of the abundance, richness and diversity of sandy-beach macrofauna; however, such analyses have ignored the overall functional structure of macrofauna communities. Few studies have examined polychaete feeding guilds on sandy beach environments. To examine the effects of environmental factors on polychaete feeding guilds on sandy beaches, 12 sandy beaches from five islands in Sepetiba Bay were sampled. A total of 24 polychaete morphospecies, grouped among 21 families, were identified in these sandy beaches. The polychaete species were classified into 10 feeding guilds, and the SDT guild (suspended-deposit feeders, discretely motile, with tentacles) was the most abundant feeding guild, with 34.2% of total number of organisms. The highest trophic importance index and index of trophic diversity values were recorded on the sheltered beaches. A canonical correspondence analysis showed that the exposure rate, beach length, and grain size of the beach sediment significantly affected the polychaete feeding guild distribution and abundance. We can conclude that sheltered beaches have a higher diversity of feeding guilds than exposed beaches and that the biological descriptors of the feeding guilds are directly associated with the grain size of the sediment.

scholarly journals Monsoonal forcing controlled cold water coral growth off south-eastern Brazil during the past 160 kyrs

2020 ◽  
Author(s):  
André Bahr ◽  
Monika Doubrawa ◽  
Jürgen Titschack ◽  
Gregor Austermann ◽  
Dirk Nürnberg ◽  
...  
Keyword(s):  
Organic Matter ◽  
Continental Slope ◽  
Deep Water ◽  
Cold Water ◽  
Nepheloid Layer ◽  
High Northern Latitude ◽  
South Eastern ◽  
The Past ◽  
Eastern Brazil ◽  
Water Ecosystems

Abstract. Cold-water corals (CWC) constitute important deep-water ecosystems that are increasingly under environmental pressure due to ocean acidification and global warming. The sensitivity of these deep-water ecosystems to environmental change is demonstrated by abundant paleo-records drilled through CWC mounds that reveal a characteristic alteration between rapid formation and dormant or erosive phases. Previous studies have identified several parameters such as food supply, oxygenation, and carbon saturation state of bottom water as central for driving or inhibiting CWC growth, yet there is still a large uncertainty about the relative importance of the different environmental parameters. To advance this debate we have performed a multi-proxy study on a sediment core retrieved from the 25 m high Bowie Mound, located in 866 m water depth on the continental slope off south-eastern Brazil, a structure built up mainly by the CWC Solenosmilia variabilis. Our results indicate a multi-factorial control on CWC growth and mound formation at Bowie Mound during the past ~160 kyrs, which reveals distinct formation pulses during glacial high northern latitude cold events (Heinrich Stadials, HS) largely associated with anomalous continental wet periods. The ensuing enhanced run-off elevated the terrigenous nutrient and organic matter supply to the continental margin, and might have boosted marine productivity. The dispersal of food particles towards the CWC colonies during HS was facilitated by the highly dynamic hydraulic conditions along the continental slope that prevailed throughout glacial periods. These conditions caused the emplacement of a pronounced nepheloid layer above Bowie Mound aiding the concentration and along-slope dispersal of organic matter. Our study thus demonstrates a yet unrecognized impact of continental climate variability on a highly vulnerable deep-marine ecosystem.

Helminth communities of Leptodactylus latrans (Anura: Leptodactylidae) from the Atlantic rainforest, south-eastern Brazil

2013 ◽  
Vol 89 (2) ◽  
pp. 250-254 ◽  
Author(s):  
G.M. Toledo ◽  
D.H. Morais ◽  
R.J. Silva ◽  
L.A. Anjos
Keyword(s):  
Species Richness ◽  
Parasite Species ◽  
Parasitic Infection ◽  
Nematode Species ◽  
Atlantic Rainforest ◽  
Generalist Species ◽  
South Eastern ◽  
Helminth Communities ◽  
Eastern Brazil ◽  
Disturbed Environment

AbstractThe helminth fauna associated with Leptodactylus latrans, a large frog living in a disturbed environment of Atlantic rainforest in south-eastern Brazil, was evaluated. We found eight helminth taxa, including five nematode species, Falcaustra mascula, Oswaldocruzia subauricularis, Physaloptera sp., Rhabdias sp. and an unidentified cosmocercid, two trematodes, Gorgoderina parvicava and Haematoloechus fuelleborni, and one larval cestode. The overall prevalence of infection was 63.2% with a mean intensity of 11.3 ± 3.8. The cosmocercid nematode and O. subauricularis showed the highest prevalences, although the trematode G. parvicava was the most abundant and dominant parasite species. Host size positively influenced both the intensity of infection and parasite species richness. Our data suggest that the juvenile individuals of L. latrans are more susceptible to parasitic infection than the adults. The comparison of the similarity of this community component with that found in other studies in South America shows that, as well as the characteristics of the host, the sampling area also influences the parasitic fauna. Therefore, the results of this study agree that the helminth communities of frogs have relatively low species richness and dominance of generalist species.

Distribution of anuran species among montane streams in south-eastern Brazil

2003 ◽  
Vol 19 (3) ◽  
pp. 219-228 ◽  
Author(s):  
Paula Cabral Eterovick
Keyword(s):  
Species Richness ◽  
Behavioural Flexibility ◽  
Predator Species ◽  
Serra Do Cipó ◽  
South Eastern ◽  
Predator Diversity ◽  
Anuran Species ◽  
Eastern Brazil ◽  
Stream Size ◽  
Montane Streams

The composition of anuran assemblages was studied in 16 streams at the Serra do Cipó, south-eastern Brazil, in which 26 anuran species were found. Volume and isolation level of stream sections of 150 m were estimated; tadpoles, adult anurans, and potential tadpole predators were searched for over 16 consecutive months. Stream size, isolation, richness and diversity of tadpole predators, and some additional physical and biotic variables were measured and related to anuran species richness. Smaller streams tended to shelter more anuran species than larger ones, but neither stream size nor stream isolation explained variations in anuran species richness. Anuran species richness tended to increase with tadpole predator diversity. Tadpole species richness was influenced by predator species richness, and was highest when there were seven types of tadpole predators present. The distribution of few anuran species could be clearly related to particular physical and biotic variables. The behavioural flexibility of anurans and the similarity among streams may have contributed to this pattern.

Species richness, distribution pattern, and conservation status of amphibians in Cross River National Park, south‐eastern Nigeria

Biologia ◽  
2021 ◽  
Author(s):  
Lotanna Micah Nneji ◽  
Adeniyi C. Adeola ◽  
Babatunde E. Adedeji ◽  
Omotoso Olatunde ◽  
Abiodun B. Onadeko ◽  
...  
Keyword(s):  
Species Richness ◽  
Distribution Pattern ◽  
National Park ◽  
Conservation Status ◽  
Cross River ◽  
South Eastern
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