Chronic oiling affecting Magellanic penguins in South America: a review

RUOPPOLO, VALERIA; BOERSMA, P. DEE; GARCIA BORBOROGLU, PABLO; REYES, LAURA; PINHO DA SILVA, RODOLFO

Hamburgo

Conferencia; 7th Effects of oil on Wildlife Conference; 2003

IFAW/IBRRC

Every year, during the austral winter, oiled penguins are found on shore along their migration route from Argentina to Brazil (Boersma et al., 1990). Incidental releases of oil by spills or ship wrecks are a possible source of petroleum but oil-contaminated ballast water and tank washing at sea seem to be the main sources of pollution (Boersma, 1987; Gandini et al., 1994). Oil affecting Magellanic penguins (Spheniscus magellanicus) along the Atlantic coast of South America has been documented since the early seventies (Jehl, 1975). Gandini et al. (1994) estimated that 42,000 penguins died each year due to chronic oil pollution along the coast of Chubut Province, in Argentina. In 1997 tanker routes were moved farther offshore by law enforcement, north and south tanker routes were separated to reduce the probability of accidents resulting from boat collisions. Although fewer penguins are now oiled along the coast of Argentina, many are still being oiled along the coasts of Uruguay and Brazil. Where this oil is coming from is not known, but the problem seems to be major, as annually there are several rescue centers cleaning oiled penguins along its distribution range. Other species of seabirds are affected, but penguins are the most common sight. Beached bird surveys have been a powerful tool in demonstrating the impact of chronic oiling in the Magellanic penguin (Knaus, 1990; Gandini, et al., 1994) and have to be encouraged, along with new preventive measures against oil spills and effective control, as Magellanic penguin populations are declining.