Episode 21 – My shark “experience”…
This past week I had the wonderful opportunity to spend some time with the Marine Biologists at Ushaka Marine World in Durban, and I even got up close and personal with some of the sharks! WOW….what an incredible experience!
But the main reason for my visit was to find out why shark populations are in trouble and continue to rapidly decline. Recent estimates suggest that around 100 million sharks are removed from our oceans annually. Sharks have become endangered by decades of over-fishing and in more recent years by the international trafficking of their fins, destined to fulfill an unnecessary, wasteful market of shark fin soup which function is merely status related. My curiosity got the better of me and I went in search for this soup, and I got some! To be honest, it’s smells like fish, not that I expected anything else, chunks of vegetables and then jelly-like pieces of fin. So a key component of marine ecosystems is being destroyed to appease a dubious taste without any nutritional value to it, I guess much much like in the case of rhino horn.
Why should we care? What will that mean for the oceans and even for fisheries targeting species other than sharks? We know from studies on land that when large predators are removed, entire ecosystems can be destabilized. That can be bad for animals and people. So if similar things happen in the oceans, we not only need to think about halting declines of sharks, we will probably need to find ways to rebuild their numbers. I think the attention that the Discovery Channel’s Shark Week brings to these animals is great, but that attention needs to extend beyond the first week of August for these predators and the places they live to recover and eventually thrive.
I had the opportunity to get in the water with a couple of small hammerheads – a species that I’ve always been fascinated with because they are so prehistoric-looking. They are well known for their ability to make very sudden and sharp turns. Not only does the hammer act as an organ of balance, but its body seems to be specifically designed to twist and bend. Believe it or not, the hammerhead has the ability to sport a nice tan! They are one of very few animals who tan from the sun. This happens to the shark because hammerheads are often cruising in shallow water or near the surface for extended periods of time.
Great news though is that five shark species have been put on a protection list to prevent them from being wiped out due to high demand for their fins including 3 species of hammerhead sharks. The majority of the 178 governments that are members of the convention also voted to add the oceanic whitetip shark (Carcharhinus), porbeagle shark (Lamna nasus) to Appendix II of Cites.
I also spend some time with a tawny nurse shark, which is also known as the sleepy shark. Very shy and gentle and they prefer to sleep during the day and to be more active at night. Extremely tiny eyes compared to their huge body, and unlike other sharks, they have an amazingly small mouth, it’s far ahead of the eyes and before the snout (sub-terminal), an indication of the bottom-dwelling (benthic) nature of these sharks and unlike others they have thousands of replaceable teeth, and are capable of crushing shellfish in their mouths. They also have one of the most unique feeding methods of any shark as they suck their prey into their mouth using a vacuum action. This suction is so great it is said to be able to suck fish out of ledges and even clams out of their shells. They are also very determined feeders, known to lift heavy coral heads in order to obtain prey. Very quick and powerful!
But let’s get back to protecting the sharks. It’s only quite recently that we’ve began to comprehend what our actions on land have on the creatures and their home down there. Undoubtedly the CITES listing is a positive development as far as shark conservation is concerned. Although there is understandably speculation about the effect, if any, the listing will have on the plundering of sharks. If we take the rhino situation as an example, there are international trade bans, heavy sentences being given to traffickers and dealers and yet greed and avarice continue to be the driving force behind our plundering of wildlife resources.
As custodians of the planet we call home, surely it’s time for us to take responsibility for conserving our biodiversity on which we all depend.
Have you ever had a shark “experience”? What was it like?
Just to keep you in the loop – I will be bringing you many more episodes of Earth Matters in the future, but from now on my segment will only be broadcast every 2 weeks. However, please be sure to stay tuned for your quick fix of my wildlife experiences!
And remember, take care of the earth and she will take care of you!