Macrobenthic Distribution Patterns at a Sewage disposal site...

ELIAS RODOLFO; VALLARINO EDUARDO; SCAGLIOLA MARCELO; FEDERICO IGNACIO ISLA

journal of coastal research

CERF

Lugar: West Palm Beach; Año: 2004 p. 227 - 332

The inner shelf (5?15 m depth) off Mar del Plata (Argentina, Southwestern Atlantic) was studied to assess the influ- ence of an intertidal sewage effluent on macrobenthic populations and to provide baseline information for a future monitoring program. Bottom samples were obtained with van Veen grabs at 49 stations. Macrobenthic organisms retained in a 0.5 mm mesh screen were used for biological analysis. Very fine sand-bottoms with a Natica?Owenia association occur in shallower sites, while patchy coarse sand bottoms plus gravel-sized shell debris inhabited by an association of patchy populations of Melita?Prionospio?Kalliapseudes?Caulleriella characterize the rest of the area. Low organic matter content in the area (from 0.78 to 2.05 %), and absence of any known indicator species (such as Prionospio spp.) in relation to distance to effluent, suggest that local benthic populations remain relatively undisturbed in spite of the heavy input of organic matter. The major factor contributing to this situation is the high hydrodynamics of the area.