A couple of years ago thousands of dolphins stranded and died on the coast of Peru and the reason was and remain a mystery.
Interviewing Barbara Fraser, environmental reporter in Peru for my thesis, she mentioned the dolphins during the interview, and said that this might remain a mystery. I remember reading about it in a short notice in a Swedish newspaper when it happened, but nothing more than that. Barbara, on the other hand, have written an excellent article to read to be enlightened in the subject.
The marine eco system are easily forgotten, might be since we are land animals ourself. But it is important that every now and then think about the seas and what we are doing to them as fishing and oil-drilling. The latter could be the reason to the mass death of the dolphins since they easily get disoriented by sounds. It could also be an enhancement of chemicals, due to the fact that the dolphins are high in the foodchain and by this logic then have higher levels of the substance in their body. Mass- deaths have occurred before in the 80s and 90s, due to DDT and equal chemicals.
Some claim natural causes as the reason, but I am not convinced.
Canon 5D Mark iii, 24-105 mm Canon lens, editing in Lightroom
The marine eco system found in Parachas. Exploited by tourism but viewed as untouched.