MonicaMarine mammal stranding events have always existed. More and more countries are implementing stranding teams to specialize in these kinds of events, which are still not completely understood.
Have you heard about the mass stranding event that just happened in Tasmania?
Stranding events have already been recorded with up to 300 stranded whales per year. However, this time the numbers were OVERWHELMING.
Around 470 Pilot Whales beached themselves in Tasmania. First, a pod of 270 individuals stranded on Tuesday and as if that wasn’t a big enough number, another 200 individuals beached themselves on Wednesday.
First of all, if you are not sure of what place I’m talking about, you can see here a map of where the stranding event happened.
Then, I thought I would share with you a little information about why whales and dolphins beach themselves and why this massive stranding event might have happened.
Well, we yet don’t know the exact cause but over the years researchers have been able to develop different theories regarding the causes of these kind of events.
Some possible causes of whale strandings:
Navigation error:
Toothed whales (as Pilot Whales are) use echolocation to orientate themselves. Navigation error is probably what happened in Tasmania where the coastline is quite shallow and affected by tidal changes. The whales seem to have failed to detect the proximity of the shore, might have entered a shallow bay, not finding the exit and ended up beaching themselves.
Old or sick:
A whale could get stranded because its sick, old, could be infested with parasites or be poisoned by toxins. Sometimes they also strand because they are injured for natural reasons, as well as being entangled or hit by boats.
Sound pollution:
This may affect the whales in a few different ways. Sound pollution (coming from human activities) might interfere with the communication between the individuals as well as confuse the individuals orientation.
Why is this? The sounds being produced through human activities (military sonar, ships, seismic testing, drilling) start overlapping those produced by the whales. Imagine when you are at a concert and you have to shout to speak to your friend and often you are still unable to understand! Well, that’s exactly what is happening with the whales when humans disturb their environment with other noise.
Escaping from a predator:
This could be another possible reason. Escaping from predators without really thinking exactly about where they are going, leading them to getting lost.
The only ‘good thing’ about this stranding event is that it will allow researchers to collect a lot of data from the carcasses of these pilot whales and hopefully find out a lot of new information. Information which is usually impossible to get when a whale is out in its natural habitat, spending most time in the deep waters.
Why so many? Why Pilot Whales?
You might be wondering why this stranding event involved such a high number of individuals.
Well, Pilot Whales are known to be very sociable and always live in very large pods. It seems like when something bad happens and a few of the whales get stranded on shore, the others just follow.
Also, something beautiful and at the same time sad has been noticed to happen during the rescue of these whales in Tasmania. When rescuers would free a whale, that whale would tend to come back to shore again, being “attracted” by the calls of distress of the rest of the pod. This made the rescuers work even harder, but demonstrated once again the strong bonds that exist between individuals of the same pods.
What happens to their body when they are out of the water?
Pilot whales can reach lengths of 7m and weigh up to 3600kg. When on land, they loose the buoyancy that they usually have in the water and with their weight and pressure they often risk to crush their own organs, causing severe injuries or death. These animals are characterized by a thick layer of blubber (fat) used to keep them warm in the ocean; when on land, they are unable to regulate their body temperature and are at very high risk of overheating. For this reason, it is very important for rescuers to keep them wet and cool as much as possible.
Rescuers were able to save about 110 whales with the number of dead whales being 360 animals that had stranded.
Pilot whales are not considered endangered, although the exact population numbers are not known. So, it is very difficult for researchers to know the impacts of loosing such high numbers of individuals could have.
The team of rescuers certainly did the best that they could in the most unexpected an unprecedented whale stranding event.
Support Project Jonah in however way you can and if you want to contribute in helping marine mammals, don’t hesitate to contact them. There is a lot of work that needs to be done and everyone can help!
