Modelling the influence of environmental and weather factors on the density of the invader polychaete Boccardia proboscidea

GARAFFO GRISELDA V.; JAUBET MARÍA L.; SANCHEZ MARÍA A.; LLANOS ELIZABETH N.; VALLARINO EDUARDO A; ELIAS RODOLFO

MARINE ECOLOGY-PUBBLICAZIONI DELLA STAZIONE ZOOLOGICA DI NAPOLI I

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015

0173-9565

Stressed environments are more easily colonised by alien species. Currently, the intertidal zone around sewage discharges in a SW Atlantic shore (Mar del Plata, Argentina) is characterized by the presence of the invasive spionid Boccardia proboscidea. Understanding the links between both human and natural disturbances and the massive development of non-indigenous species will help prevent marine bioinvasions that are already favoured by global oceanic trade. The goal of this study was to build models for the density of B. proboscidea in the intertidal zone around sewage discharges of Mar del Plata, using environmental (pH, turbidity, temperature, salinity and total organic carbon content), weather (wind direction and storms record), spatial (sites) and temporal variables (season and year). Boccardia proboscidea density was investigated in relation to these variables using generalized linear models, and model averaging (multimodel inference) was used to obtain predicted density values. The highest predicted values of B. proboscidea density occurred at sites to the south of the sewage effluent and during spring. These sites are more affected by urban effluent discharges and they showed increased B. proboscidea density when the north wind was predominant. In addition, B.proboscidea density values were higher in sites with 20-22°C (seawater temperature), high total organic matter content (in sediments) and low salinity. Averaged model was only a good ?predictive model? in sites to the north of the outfall; however, it proved to be very useful as an "explanatory model" in all sites and it should be highly considered when making conservation and management decisions.