More than 400 dead dolphins were washed ashore on a Northern Peru beach in the month of January. Coming in from the Pacific Ocean, this is the second time in two years so many of the sea mammals have been discovered. In 2012, there were twice as many dead dolphins lining the coast of Peru.
The United States had reported almost 300 dolphin deaths along the east coast through the month of August. That number for an entire eight months was considered dangerously high for the Atlantic dolphin population. Almost doubling the deaths in Peru has biologists very concerned.
The Peruvian Sea Institute, known as Imparpe, sent a team of technician to examine the troubling trend. In just the last week of January, they discovered as many as 220 dolphins washed ashore. Prior to that, more than 200 dolphins had been discovered by biologists.
Sea animal deaths are very hard to determine the cause of death. Mass deaths especially pose a problem for biologists because there could be a number of causes. Viruses, like the morbillivirus that killed 740 Atlantic dolphins on the US eastern shore in 1987, are often to blame for deaths in such large numbers. But without performing proper autopsies on the animals, there is no way to know for sure.
Technician Jaime de la Cruz, who led the search along the Lambayeque region of Peru’s coast, is concerned that fatal toxins could be the cause. If that is the case, it is almost impossible to determine the source. Toxins are transmitted to the dolphins through smaller fish they consume. The dead dolphins will also be examined for respiratory diseases, pesticides, and other digestive possibilities. De la Cruz expects the autopsies to take as long as two weeks. Poisoning from fisherman has already been ruled out, though fishing nets are responsible for some of the deaths.
Autopsies in 2012 of the 870 dolphins found in Peru were inconclusive. It is difficult to perform the necessary tests and research on the recovered bodies because Peru has limited marine biology resources. Of the one hundred different chemical reagents available to test marine animals toxicology, Peruvian laboratories only possess three or four. If the results turn up empty, it does not mean that the cause of death wasn’t chemical. It just means Imparpe technicians did not have the proper tools.
Of primary concern is the current mating and feeding season. The abnormally high number of dead dolphins could seriously endanger the overall population and future generations of dolphins.