Hundreds of dolphins and thousands of pelicans have been found dead on the beaches of the Peruvian coastline. While it is not entirely rare for such a dynamic coastline to experience its fair share of animal sightings and deaths, the sheer number involved in this case (as well as the fact that a couple of different species are involved) has left scientists and government officials scratching their heads.
Already the bodies of more than 4,450 pelicans and almost 900 dolphins have littered the country’s beaches, raising health concerns and forcing the Peruvian Ministry of Health to close many of the beaches that occupy the 1,500-mile coastline, from its capital city of Lima and northward. In the past, similar cases of mass pelican deaths have been recorded—most notably in 1982-1983 and 1997-1998 when El Nino was deemed largely to blame for warmer ocean temperatures. And scientists believe that this year is no different.
Carlos Bocanegra, a biologist at the National University of Trujillo, believes that a warming ocean is responsible this time around—temperatures in the region have averaged 10 degrees Fahrenheit (6 degrees Celsius) warmer than the same time last year. According to Bocanegra, as the water warms, populations of anchovies (the pelicans preferred meal) move to deeper water, making it harder for younger pelicans to dive down and feed. Of the 10 dying pelicans Bocanegra examined, the digestive tracks were found to be either empty or contained the remains of fish that are not a usual part of their diets.
Further evidence that this is the case has come from fisherman in the northern region of Lambayeque, who claimed that since the end of January daily catches of anchovetas drew in noticeably less and less than the average five tons a day.
Yet even with a clearer idea surrounding the death of the birds, the dead dolphins continue to remain largely a mystery. Many coastal areas around the world are no strangers to dead dolphins washing up on the shoreline; however, the numbers that Peru has seen are higher than usual and thus a reason for concern. Initially, scientists believed that this anomaly could have been a result of agrochemical runoff from rivers that introduce heavy metals and pesticides into the ocean. However, testing has gone on to overrule much of these claims.
What is perhaps most plausible is that the dolphins were affected by a controversial method of locating oil deposits on the ocean floor which utilizes shock waves produced by sonar explosions. Between February 8 and April 8 of this year, BPZ Energy (a Houston-based energy company) has been conducting seismic testing in an area off the northern coast of Peru. The company has gone on to deny claims that their work may be involved in the dolphin deaths, but conservationists are not easily convinced.
Carlos Yaipen, of the sea mammal conservation group Orca, testified at a congressional hearing that autopsies of the dolphins found that dolphins in the area suffered from internal hemorrhages, collapsed livers, and broken bones in the ears—evidence that strongly points to such sonic damage. “In microscopic exams we found fatty tissue with a great quantity of surrounding bubbles and hemorrhages,” explained Yaipen. “This happens when there is a strong sound in the fatty tissue, in the mandibular fat where sounds are received.”
As the quest for answers continues, one thing that remains certain is that Peru’s coastal protection programs could use some work. An economist who has worked closely with public interest groups involved with coastal preservation, Juan Carlos Sueiro, says that this mass of deaths brings attention to Peru’s lack of readiness for crises like this. “Peru doesn’t have a policy of coastal territory management,” Sueiro explained. “It is probably the most backward in the entire region.
Many hope that this new attention on the South American country will put the pressure on the government to improve their ability to protect their coastlines by strengthening their management of the coastal territory. To petition the Peruvian Health Ministry to do so, sign the petition here.
Photo Credit: commons.wikimedia.org/wiki/File:Several_Peruvian_pelicans_in_Pan_de_Azucar_National_Park_in_Chile_September_2009.jpg