Do you know whatís killing the southern right whales around Argentina? If you do, please speak up because scientists are perplexed as to why the population is suddenly struggling. Although they are able to offer up a few theories, nothing is concrete at this point, and marine experts will need answers in order to help the whalesí survival,†according to National Geographic.
Between 1971 and 2002, 145 southern right whales died. In the past decade alone, however, 485 such whales have died, amounting to a drastic 70% increase. Even more startling is the fact that 89% of the whales that die are still babies.
Last year was the worst for the southern right whale yet. A full 1/3 of the speciesí babies were found dead. Of the 116 dead whales located, 113 were still calves. Obviously, the southern right whaleís existence is in major jeopardy when the whales have difficulty surviving through infancy.
Here are some of the theories for this crisis that experts are considering:
When a population dies off in such great numbers, disease is usually a major factor. Though signs of disease have been found in some of the dead calves, it has not occurred at nearly a high enough rate to attribute the whole crisis to this factor.
Since the 1980s, kelp gulls learned a new way of feeding themselves: eating live whales. Itís gross, but itís true Ė the gulls will peck at the skin of whales and devour it. Once a wound has been created, the birds tend to feast on the same spot, potentially causing major injury.
While adults seem to have learned how to shake the birds from doing much damage while they surface, the youngest whales arenít as savvy about getting the gulls off their backs. Most of the dead calves scientists examine are covered in bird-created lesions, though itís difficult to ascertain whether they contributed to the whalesí deaths.
The whalesí food chain may be tainted. Krill eat algae, which is often infected with toxins. While some of the toxins are naturally occurring, some of it is likely due to pollutants and a heavy factory presence on the Argentinian coast.
When the whales, in turn, eat this krill, they are absorbing the toxins that are present in their prey. Though the toxins are probably not enough to kill adult whales, the youngest whales would be more susceptible to the impact and could die from the exposure.
On the flip side, it may be a lack of food that is doing the whales the most harm. Scientifically it has been hard for experts to determine whether whales have had access to enough food, but they have tried examining blubber thickness and the baleen (where food enters the mouth and water seeps back out) to monitor the diet. Though more research will need to be conducted, there are early indicators that babies arenít finding enough food to meet their appetites.
In fact, the lack of food might start to be problematic before the calves are even born. Mother whales gorge on krill during their pregnancy since they wonít wind up eating for months after giving birth. If the mothers donít store up enough food in preparation for this event, they are unable to pass along adequate nutrients when breastfeeding their young.
Currently, scientists suspect that a number of these theoretical factors are contributing to the deaths of southern right whales. Unlike the northern right whale, the southern species is not yet considered endangered. Nonetheless, the southern right whale is now at a fraction of the population it once boasted, and if the mortality continues to trend at its current rate, it could join its northern brethren in similar peril. Hopefully, experts will be able to pinpoint the most aggravating causes to help protect these beautiful creatures.
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