Penguin die-off in Chile

The affected birds were Magellanic Penguins

Approximately 1500 dead penguins have been recovered from the shores of a Chilean Bay some 1200 miles north of Antarctica. The birds showed no outward evidence of exposure to oil, and a cause of the mass mortality has yet to be determined. Numerous carcasses have been transported to Chilean veterinary schools for necropsies and additional diagnostics.

It will likely not surprise readers of this blog that fatal interaction with fisheries has been proposed as a likely culprit. Local fishermen have been setting shallow nets overnight, fishing for Southern Rays Bream and Sea Bass. There has been abundant speculation that the migrating penguins may simply have been in the wrong place at the wrong time and drowned en masse. Several authorities have pointed out, however, that previous penguin die-offs due to drowning in fishing nets have never involved more than 80 animals. The scale of this mortality event may point to some other cause or contributing factor.

Penguin expert and professor Dee Boersma of the University of Washington points to another possible consideration: climate change. She has found that warmer waters displace the fish on which the penguins feed, and that the birds must travel an average of 25 miles farther to feeding grounds than when the waters were cooler. Such shifts may impact the birds’ nutritional state, increasing their susceptibility to disease. It could potentially drive them to compete for food near fishing nets, placing them at risk of entanglement.

Far too little is known at this point to draw any conclusions, and SEANET will continue to follow this story. Should we hear of any results from the necropsies or other investigations, we will post them right here in the blog.