We asked this earlier and we are asking again, ‘What is happening to our world?’ Are we gradually inching towards extinction? Has Mother Nature started unleashing her fury on us? Has the countdown begun for the Armageddon? May be!
From ever-increasing biotic crisis and sudden appearance and disappearance of thousands of dead fish on Australian beach – there is something wrong that is again and again giving us hints of our impending doom. Now there is something new – Cape fur seals killing blue sharks!
Events off the South African coasts have left marine biologists all confused! That’s the place where you can find the cute and cuddly looking Cape fur seals and the deadly-looking blue sharks.
These animals, the Arctocephalus pusillus or Cape fur seals and the Prionace glauca or the blue sharks call these waters their home and have historically been living there with a kind of a mutual agreement to leave each other alone. So, the seals didn’t bother the sharks and the sharks didn’t bother the seals.
These Cape fur seals are smaller than the blue sharks and both of them happened to feed on similar menu of crustaceans, squids and smaller fish. Since neither of the two marine animals had any conflict of interest, they left each other happy. However, things changed 11 years back when Chris Fallows, a marine biologist saw something unusual.
It was back in 2004 when Fallows was out there in the waters photographing the exotic marine life, he noticed off the Cape Town coast, that a Cape fur seal attacked and killed a blue whale. It was a surprise but Fallows didn’t pay enough attention thinking of it as an isolated incident.
8 years later in 2012, Fallows witnessed the same thing again. Only this time, there were 5 blue sharks under attack from a group of these smaller Cape fur seals. It was only then some more incidents were reported of cape fur seals killing blue sharks.
This was pretty unusual. So, Fallows teamed up with some other marine experts and started investigating the unusual behavior of the seals. The purpose of the investigation was to find the root cause. They found something and published their reports in African Journal of Marine Science.
From Florida-based Rosenstiel School of Marine and Atmospheric Science, marine biologist Dr. Hammerschlag came up with an interesting observation. He noticed that the blue sharks were attacked by the Cape fur seals right underneath their bodies and feasted on their guts. What could possibly be the cause for targeting those organs in specific? Well, those organs from blue sharks store maximum energy. So basically, blue shark guts have become a source of energy for these fur seals.
The more pressing concern however is, ‘Why are the seals killing these sharks in the first place when they have been leaving in peace before?’ In an attempt to explain this unusual behavior of the seals, Dr. Hammerschlag hypothesizes that the seals are actually sticking with the survival of the fittest strategy. They are simply cherry-picking and eliminating competition for ever-depleting food resources. And… what is causing this depletion? We humans are to blame ourselves for this! Pollution and over-fishing are the primary causes, thinks Dr. Hammerschlag.
He actually warned that because of this unnatural behavior of the seals, the balance in marine ecosystem is getting disturbed. We really don’t know what consequences we are to face. These fur seals that once primarily lived on diet menu made up of birds, cephalopods and a wide variety of small fish have now turned in vicious shark killers. This definitely is not a good sign.
Will we as humans ever learn to accept our mistakes and do whatever is necessary to reverse the damage we have already done? We need to remember that we are intelligent by nature’s design and that doesn’t give us the authority turn against nature. The consequences will be devastating, not for nature but for us.