Effect of morphodynamics on the spatial and temporal variation of macrofauna on three sandy beaches, Rio de Janeiro State, Brazil

Abstract

Three exposed sandy beaches were selected to compare £uctuations in density of the most abundant species, and to verify the in£uence of spatial and temporal variations on the community structure. Sampling was carried out every three months, from June 1993 to May 1995, on Fora, Prainha, and Boqueira¬ o Beaches. The ¢rst two beaches were classi¢ed by Dean's morphodynamic index () as intermediate, and the last as re£ective. Slope, beach width and median grain size were signi¢cantly di¡erent among the beaches.Two-way analysis of variance revealed signi¢cant di¡erences in species richness only among the beaches. No signi¢cant di¡erences in density of the macrofauna between beaches and season were observed. However, Prainha Beach showed a higher temporal variation of the density of the macrofauna (and higher standard deviation) than the other two beaches. Emerita brasiliensis (Crustacea: Decapoda), Excirolana braziliensis (Crustacea: Isopoda), and Pseudorchestoidea brasiliensis (Crustacea: Amphipoda) were the most abundant species. Canonical correspondence analysis calculated the in£uence of the temporal variation as 27.5%; the in£uence of the environmental variation on community structure was 20.9%. The results suggest that in spite of the long-term £uctuations in species density, the beaches did not have temporal di¡erences in the species richness and total density macrofauna during the study period.

Long or short? Investigating the effect of beach length and other environmental parameters on macrofaunal assemblages of Maltese pocket beaches

“…In fact, some authors, including, Dugan et al (2004), believe that biological interactions, including competitive ones, not only affect the distributions and zonation of intertidal macro-infauna but potentially also community structure. Studies by Veloso and Cardoso (2001) show that the abundance of the communities was also not related to any physical parameter and these authors suggested that certain biotic factors, such as food source, recruitment, predation and competition, are responsible for the differences in macrofaunal densities between beaches. In addition, Nucci et al (2001) have demonstrated a relationship between environmental heterogeneity and species richness.…”

Atlantorchestoidea brasiliensis (Crustacea: Amphipoda) as an indicator of disturbance caused by urbanization of a beach ecosystem

“…By contrast, studies on the life strategy of Atlantorchestoidea brasiliensis are still very few (VELOSO et al, 1997a,b;CARDOSO, 2002) in spite of its ecological importance (VELOSO et al, 1997a;CARDOSO, 2001) and the threat of its disappearance from urbanized beaches on the coast of Rio de Janeiro (VELOSO et al, 2006;2008). Information on its vertical distribution in the sediment, and experiments on its sensitivity to trampling are still sparse.…”

Composition, structure and zonation of intertidal macrofauna in relation to physical factors in microtidal sandy beaches at Río de Janeiro State, Brazil

“…The state of Rio de Janeiro in Brazil has an extensive coastline, with sandy beaches that vary in degree of wave exposure, grain size and beach slope, but despite these differences harbour the same communities (Veloso et al, 1997;Veloso and Cardoso, 2001). This apparent similarity makes this an interesting region to test for the influence of environmental parameters on the populations and communities.…”