%0 Journal Article %T Human impact on the benthic macrofauna of two beach environments with different morphodynamic characteristics in southern Brazil %A Jenyffer Vierheller Vieira %A Carlos Alberto Borzone %A Luciano Lorenzi %A Fabiano Grecco de Carvalho %J Brazilian Journal of Oceanography %D 2012 %I Universidade de S?o Paulo %R 10.1590/s1679-87592012000200004 %X Pollution, exploitation of resources, erosion and recreational activities produce the most common impacts that somehow alter the natural balance of beach ecosystems. The aim of this study was to compare the richness and abundance of the benthic macrofauna of two sectors, one non-urbanized and the other urbanized, on each of two morphodynamically different beaches. Sectors of each beach were analyzed taking into account morphodynamic, anthropogenic (recreational activities) and ecological aspects. Morphodynamically, one of the beaches presented sediment formed of fine sand with a gentle slope and morphodynamism with dissipative characteristics. The other was of sediment formed of medium sand with a steep profile and of intermediate to reflective morphodynamic characteristics. On both beaches during the summer, the urbanized sector was frequented by a greater number of users than the non-urbanized sector. On the beach with dissipative morphodynamism, negative relationships were observed between user abundance and the species Bledius bonariensis, Donax hanleyanus, Thoracophelia furcifera, Excirolana armata, Phoxocephalopsis sp. and Tholozodium rhombofrontalis. On the beach with intermediate to reflective morphodynamics, low abundances of Atlantorchestoidea brasiliensis and Excirolana braziliensis were recorded in the urbanized sector. Thus the results of this study suggest the use of certain species as indicators of human impacts on beach ecosystems. Polui o, explora o de recursos, eros o e atividades recreativas s o os impactos mais comuns que de alguma forma alteram o equil¨ªbrio natural do ecossistema praial. O objetivo deste trabalho foi comparar a riqueza e a abundancia da macrofauna bent nica entre um setor n o urbanizado e outro urbanizado de duas praias morfodinamicamente distintas. Os setores de cada praia foram analisados levando em considera o aspectos morfodinamicos, antr¨®picos (atividades recreativas) e ecol¨®gicos. Morfodinamicamente, uma das praias apresentou sedimentos formados por areia fina, suave inclina o e morfodinamismo com caracter¨ªsticas dissipativas. A outra praia apresentou sedimentos formados por areia m¨¦dia, perfil ¨ªngreme e caracter¨ªsticas morfodinamicas entre intermedi¨¢rias a refletivas. Em ambas as praias, durante o ver o, o setor urbanizado apresentou maior abundancia de usu¨¢rios do que o setor n o urbanizado. Na praia com morfodinamismo dissipativo, rela es negativas foram observadas entre a abundancia de usu¨¢rios e a dos organismos Bledius bonariensis, Donax hanleyanus, Thoracophelia furcifera, Excirolana armata, Phoxoc %K Praias arenosas %K Morfodinamica %K Macroinfauna %K Atividade recreativa %K Sandy beaches %K Morphodynamics %K Macroinfauna %K Recreational activity %U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592012000200004