Biological invasions: assessment of threat from ballast-water discharge in Patagonian (Argentina) ports

BOLTOVSKOY DEMETRIO; ALMADA PABLO; CORREA NANCY

ENVIRONMENTAL SCIENCE & POLICY

ELSEVIER SCI LTD

Lugar: Londres; Año: 2011 vol. 14 p. 578 - 583

1462-9011

Between July 2007 and December 2008 we surveyed 194 commercial vessels for compliance with ballast water (BW) regulations at 5 Argentine ports (four of them along the Patagonian coast). Our survey included inspection of the BW reporting forms and collection of BW samples for salinity and biological (plankton) analyses from 261 BW tanks. Most (77%) ships had some type of BW form on board, but the information in these forms was often unclear, incomplete or inconsistent and did not allow tracking the origin of the BW. Salinity of the BW was often in conflict with the reported geographic location of BW exchange, and the reported volumes of BW discharged in the ports surveyed appeared to be fictitious. Most (80%) BW tanks contained identifiable organisms, usually in very good state of preservation, totaling 408 plant and animal taxa, but only 3 of these had not been previously recorded in Argentina (two diatoms and one copepod). In spite of the fact that compliance with national and international regulations and guidelines on BW management is poor in the area, the number of recorded marine aquatic nonindigenous species (ANS) in Argentina is comparatively low (ca. 40). Several factors seem to buffer the Argentine coastline from ANS: (1) the low activity of most Patagonian ports; (2) the fact that most (61%) incoming ship traffic originates from domestic ports or areas unlikely to supply ANS; (3) the harsh environmental conditions (cold and turbulent, with few sheltered areas), and (4) the scarcity of hard substrates. In order to maintain its waters relatively free of ANS, Argentina needs to significantly increase its efforts at enforcing existing international and national legislation, and to revise and update its standards on BW management. We anticipate that the problems encountered are also characteristic of many other developing countries, both in South America and elsewhere, where compliance with IMO´s BW guidelines is still seldom tested or enforced.