Assessing urban contamination using intertidal polychaetes on sandy beaches

AGUSTINA FERRANDO, JOSE LUIS ESTEVES Y RODOLFO ELÍAS

Holiday Inn Bay the Bay

Conferencia; Ninth International Polychaete Conference; 2007

University of Maine

Several impacts affect the marine environments, being their assessment one of the major goals in any study. Due to their scarce or null mobility, the macrobenthos, and polychaetes in particular, are fundamental tools for assessing environment health. In this study we analize infaunal organisms at 3 urban sandy beaches of Puerto Madryn (outfall of a Fisheries factory, and two pluvial effluents in Moreno and 28 de julio streets), and two control sites. Five replicated corers in lower and middle intertidal zone, and environmental variables of intersticial water and sediments were obtained every 3 months. Preliminary data of November 2005 show anthropogenic-induced disturbance. Highly significative differences were recorded between S (species number) in levels, while N (mean Abundance), H´ (Shannon) and  J´ (Pielou) show no significant differences. Highly significant differences were detected among sites (mean abundances in Fisheries was 3,927 individuals, and 1,033 individuals in 28 de julio, but low abundance in Moreno (125 individuals) and in the two control sites at Doradillo 1 y 2 (227 and 198 individuals). Polychaetes are always dominant. High values of Ammonium, Phosphates, Nitrites and organic matter were related to Fisheries and 28 de Julio, as well as Boccardia polybranchia and Capitella “capitata” sp., but high Eh, Nitrate and dissolved oxygen were related to Moreno with Paraonides sp. an in Control sites with an unidentified Psammodrilidae (probability a new species, according to Lobo Orensanz). Its clear the impact in urban areas, in relation to effluents, and the proper use of polychaetes as indicators of environmental health.