PAHs distribution in water column of the inner zone of the Bahía Blanca estuary and its relationship with Chlorophyll a, Particulate Organic Matter and Ammonium (enviado)

ARIAS, A.H.; SPETTER, C.V.; FREIJE, R.H.; MARCOVECCHIO, J.H.

Bahía Blanca

Simposio; Estuarine Coastan and Shelf Science symposium, ECSA44; 2008

Estuarine Coastal and Shelf Science-Instituto Argentino de Oceanografía

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in the marine coastal environments and are counted among the major groups of anthropogenic environmental pollutants due to their bioaccumulative potential, carcinogenicity and high persistence. The Bahia Blanca Estuary presents an intensive human activity at the north shoreline: oil, chemical and plastic factories, two commercial harbours, a tourist area, a fishing / recreational port and a big industrial city with more of 350000 inhabitants. This work presents the first comprehensive survey of PAHs in estuarine water column and provides useful information on their levels of concentration and its relationships with water chemistry. 30 samples of sub-superficial water were collected and analyzed for 17 PAHs, Chlorophyll a, Phaeopigments, Particulate Organic Matter (POM) and Ammonium concentration between March and December of 2005. Water PAH´s highest concentrations occurred in early spring a period in which the typical phytoplankton bloom has just finished. These high levels positively correlated with dissolved Ammonium and Phaeopigments increasing levels whereas Chlorophyll a and POM concentrations were shown to negatively correlate. On the opposite, minimum values and erratic distributions of water PAH´s coexisted with the period of highest phytoplankton activity. Results were discussed and different hypothesis on water PAHs fate and distributions respect to the dynamics of the analyzed environmental factors were outlined.