Spatial and temporal patterns in the sandy beach surf zone benthos of the tropical east Pacific
Vanagt, T.; Fockedey, N.; Vandepitte, L.; Cornejo-Rodriguez, M.P.; Calderón, J.; Vincx, M.; Degraer, S. (2007). Spatial and temporal patterns in the sandy beach surf zone benthos of the tropical east Pacific, in: Vanagt, T. De rol van swash in de ecologie van macrofauna op Ecuadoriaanse zandstranden, met speciale aandacht voor de surfende gastropode Olivella semistriata = The role of swash in the ecology of Ecuadorian sandy beach macrofauna, with special reference to the surfing gastropod Olivella semistriata. pp. 231-253 In: Vanagt, T. (2007). De rol van swash in de ecologie van macrofauna op Ecuadoriaanse zandstranden, met speciale aandacht voor de surfende gastropode Olivella semistriata = The role of swash in the ecology of Ecuadorian sandy beach macrofauna, with special reference to the surfing gastropod Olivella semistriata. PhD Thesis. Universiteit Gent. Faculteit Wetenschappen. Vakgroep Biologie: Gent. XVII, 289 pp., more |
| Keywords | Aquatic communities > Benthos
Spatial variations
Temporal variations
Topographic features > Beach features > Surf zone
Topographic features > Landforms > Coastal landforms > Beaches
ISE, Ecuador [Marine Regions]
Marine/Coastal |
| Authors | | Top | - Vanagt, T., more
- Fockedey, N., more
- Vandepitte, L., more
- Cornejo-Rodriguez, M.P.
| - Calderón, J.
- Vincx, M., more
- Degraer, S., more
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| Abstract | Despite the importance of benthos in the sandy shore ecosystem, studies comprising the different macrobenthic groups of sandy beaches are almost non-existant. In this paper, the sublittoral fringe of nine sandy beaches along the tropical East Pacific coast of Ecuador was sampled for epi-, hyper- and endobenthos on four occasions (August 1999 - May 2000). Spatial and temporal patterns within and in between these three macrobenthic groups were investigated. The endobenthos showed the highest average densities (754 ind/m²), whereas the hyperbenthos had the highest average species richness (15 higher taxonomic groups or 43 morphospecies). Lowest total densities were found in epibenthos (0.04 ind/m²). Within the endo- and hyperbenthos, five beach groups could be observed, which were different for hyper- and endobenthos. Endobenthic assemblages were primarily distinguished based on differences in beach related physical factors such as beach morphology and sedimentology. For the hyperbenthos, the opposite was true: they were mainly structured by temporal factors; local abiotic beach parameters were not as influential as for the endobenthos. Within the epibenthos, there was an unexplained trend of higher densities and species richness towards beaches with antropogenic impact. The use of density data did not allow us to find clear structural links between the three benthic groups. We conclude that when studying surf zone systems, for example within the framework of environmental impact studies, one should bear in mind that (1) different benthic groups can show different spatial and temporal patterns, (2) temporal patterns are not geographically homogeneous within one region and (3) the structuring function of environmental variables differs considerably between the macrobenthic subgroups. |
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