What on earth is going on with the dolphins?
Just this week I read about some 900 dead dolphins washing ashore in Northern Peru, saw the viral video once again of that pod of dolphins stranding in Brazil in front of beachgoers, and to top it all off, heard that the mystery surrounding the death of two captive dolphins in Switzerland last November was finally resolved when a toxicology report found traces of a heroin substitute that led to a possible overdose.
In our neck of the woods, we also dealt with our own dolphin crisis this year when an unprecedented 214 Common dolphins stranded in Cape Cod beaches. International Fund for Animal Welfare’s Katie Moore is a dolphin expert and leads the team that rescued 74% of the dolphins that stranded alive and I sat down with her to learn more:
MB: When did you first hear about the dolphin strandings in Peru? How bad is it?
KM: We learned about the strandings in Peru a few months ago. We have been in direct contact with the National Oceanic and Atmospheric Administration Fisheries Service who’s been looking into the unfolding event and have been in direct contact with their counterparts in Peru. The confirmed death of close to 900 dolphins is logically concerning and something that needs our very close attention.
MB: This dolphin die-off in Peru was happening roughly at the same time as all the strandings your team was responding to in Cape Cod, and in both cases Common dolphins were the species. Are these events linked?
KM: From what we've heard and read on Peru, and it's important to note that we have not been directly involved in the research and investigation efforts underway in South America, the strandings there have had some similarities but some clear differences from what we've experienced in Cape Cod. Like you pointed out, one of the similarities is that strandings on both locations have involved species of Common dolphins.
On the other hand in Peru, most, if not all of the estimated close to 900 animals have been found dead whereas here on the Cape, we found a fair proportion of the animals still alive. Our team and volunteers arrived on scene to find 98 of them alive and of those we were able to successfully release 73 back to the ocean. We fit all of our released dolphins with ID tags to make sure they’re doing well in the wild and during this event we deployed 19 satellite tags which have provided some great data to analyze.
Unlike the coast of Peru, Cape Cod is historically a world hot-spot for mass strandings. We see this every year, although never in such numbers like this last winter. We’re currently working hard to enter and edit all of the data we generated during this event, continue to await the results of many sample analyses from different labs that are doing these specialized screenings and we ultimately hope to be able to piece together a better understanding of what may have been driving this event.
Like us, the Peruvian authorities have been collecting a lot of data from the animals and at this point from what they’ve been able to see, we are less inclined to think that this has anything to do with human interference or acoustic trauma and more inclined to think that this may be disease related. Authorities in Peru are leaning towards morbillivirus as the possible culprit. This virus can spread quickly between dolphins and porpoises and closely resembles distemper in dogs, but we haven’t seen any of the results yet so can’t confirm that this would be the case.
MB: More than 1,500 brown pelicans and boobies have been reported dead along roughly the same coastline in Peru. Do you think there is a connection between the dolphin deaths and the sea birds?
KM: Specialists in Peru seem to think that these events are not related. With regards to the seabird die-off a lack of prey, in this case anchovies, is singled out as the likely trigger. Peru has one of the world’s largest fisheries and reportedly lands a remarkable percentage of the world’s anchovy catch.
From a scientific standpoint we can’t dismiss or confirm that there is a connection between these mortality events until we have conclusive data. It’s important to point out that collecting viable samples is incredibly challenging in such a remote and tropical location where the heat can increase the rate of decomposition and render samples useless in just a few hours.
We know that changes in the ocean environment like rising sea temperatures can cause a domino effect and lead to harmful impacts in the entire food-chain. Environmental contamination by humans and biotoxins are also important to keep in mind in an event like this.
MB: How worried should we be? Is this a sign that the ocean environment is somehow collapsing before our eyes?
KM: I think in today’s world there are a lot of insults to the environment that we need to look at. We see the news of these larger events like the dolphin die-off in Peru or the Deepwater Horizon oil spill in the Gulf two years ago, but there are oil spills, unsustainable fishing practices, uninhibited pollution, increasing ocean noise, you name it, occurring up and down the coast every single day and that have a very serious and real cumulative impact. It’s easy to put these smaller but chronic incidents out of sight and out of mind but they are crucially important and need to be addressed.