Dolphins in Danger, But from What?

Possibly due to a combination of stress, pollution and disease, thousands of dolphins have washed up, dead or dying, on the shores of Peru.

Article from: http://www.scientificamerican.com/article.cfm?id=massive-dolphin-die-off-in-peru-may-remain-a-mysteryImage from: Googe Images
 

Based on volunteers’ counts, an estimated 2,800 dolphins have been found in Peru since January. This is among the largest dolphin die-offs ever reported. Marine experts have offered several possible explanations, but none have been proven. It may remain a mystery. Some theories offer acoustic impact from oil testing or some type of virus or pathogen as the cause. This latest marine mammal stranding is one of 55 since 1991, 29 of which the National Oceanographic Atmospheric Administration in the U.S. classified as “undetermined.” The dolphins seemed to have suffered from middle-ear hemorrhage, fractures of the ear’s periodic bone, lung lesions, and bubbles in the blood. These symptoms would cause disorientation, intense pain, and difficulty breathing. However, most experts did not have enough evidence to determine anything conclusive. Stress or toxins could have made the dolphins vulnerable to viruses or other pathogens. They could have been introduced to organic pollutants, like PCBs, DDT, dioxins, or flame-retardants through the fish they consume. Dolphins with weakened immune systems could be more susceptible to diseases like leptospirosis, brucellosis, or distemper. In most cases like these, it is not one, but three or four factors which cause so much death. Two species of dolpin have been stranded on Peru’s shores. The majority are long-beaked common dolphins, most likely migrated from Central America. About 10 percent are Burmeister’s porpoises, a deepwater species. They migrate closer to the surface to calve, hence their presence near Peru. If seismic testing was occurring around the time of the stranding, oil leases under exploration off the coast of Peru might have something to do with it. Seismic testing uses air guns to map hydrocarbon deposits, which could impact marine mammals. Loud ocean noises may cause ear and organ damage and impact dive patterns, which can lead to decompression sickness or disorientation. If noise is the ultimate cause of this catastrophe, sonar could be another possible suspect. Ultimately, we may never know the real culprit(s).

We share this planet with an amazing variety of creatures. We will truly be lost when we no longer care about our fellow animals. This case is not just relevant because harm has come to one of our endangered species. Whatever has negatively affected these dolphins could place other marine animals and even humans in danger. The founder of the Scientific Organization for the Conservation of Aquatic Animals expressed concern for the residents of fishing villages along the coast of Peru. These villagers have been cutting meat off the carcasses for food. If the dolphins died from disease, the villagers could be at risk. Also, if we find that human action was the ultimate cause, I hope we can learn from this and prevent future atrocities.

I was horrified by this article and concerned that I had not already heard of this horrific mass dolphin death. Dolphins are my favorite animal. They’re highly intelligent, caring, and innocent. I found myself tearing up when I read this for the first time. I sincerely hope that we had nothing to do with this, but if we did, I hope we can ensure it never happens again.