Study of polychaetes indicators of environmental conditions along ten years in intertidal areas of Mar del Plata (SW Atlantic).

MARIA DE LOS ANGELES SANCHEZ; JAUBET MARÍA LOURDES; GRISELDA VALERIA GARAFFO; MARIA SILVIA RIVERO; RODOLFO ELÍAS; EDUARDO ALBERTO VALLARINO

Lecce

Conferencia; 10th International Polychaeta Conference; 2010

<!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-1610611985 1107304683 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES; mso-fareast-language:ES;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:10.0pt; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt;} @page Section1 {size:595.3pt 841.9pt; margin:72.0pt 89.85pt 72.0pt 89.85pt; mso-header-margin:35.45pt; mso-footer-margin:35.45pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Macrobenthic communities have been used as indicators of environmental changes resulting from both natural and anthropogenic disturbances in marine ecosystems. Polychaetes play an important role in the functioning of benthic communities. They have been shown to be good indicators of species richness and community patterns in benthic invertebrate assemblages, and have recently been proposed as surrogates for marine biodiversity. The Mar del Plata city (38° S-57° W) is the greatest seaside resort of the Buenos Aires state, receiving about 2-3 million visitors during the summer. As a consequence, sewage discharge (average flow 2.8m3sec-1) increases up to 3.5m3.sec-1 during summer. The intertidal zone around Mar del Plata is characterized by dense mussel beds of small mytilid Brachidontes rodriguezii. The community and the polychaetes were successfully used in environmental impact assessment due to sewage discharges. The aims are evaluate the polychaetes along ten years around Mar del Plata’s sewage intertidal effluent and asses the short-term effect (before-after summer). Three areas, an Impacted and two Controls were analyzed from November 1997 to March 2008. Control areas include a very far location, Control 1, and Control 2 near (1,000m) to the outfall. Differences between stations and month (before-after summer) were tested against the main species. These analysis were assessed using Split plot (“year” was used like block). The results shows Syllis prolixa, Syllis gracilis and Leodamas (=Protoariciella) uncinata dominating the Control areas. In the other hand Capitella capitata, Alitta succinea, Boccardia polybranchia, Protocirrineris angelicolliatio and Caulleriella bremecae have been dominant in impacted areas. In 2008 a new Boccardia species have been dominating the impacted area as well as the Control 2 forming reef. This area has started to behave permanently as an impacted area. All the community and their associated flora and fauna that previously dominated the zone have been excluded by Boccardia.