At the Greater Cleveland Aquarium, one of our key exhibits is a 250,000-gallon shark exhibit. It is nothing short of breathtaking to see these perfectly adapted hunters glide effortlessly inches about your head. From active predators to those that cruise along the bottom, our range of sharks showcases four very unique evolutionary tracks.
Growing up to ten feet long, the most intimidating shark you’ll see is the sand tiger. If you don’t recognize the name, it’s probably because this one species goes by so many: grey nurse, spotted ragged-tooth, blue-nurse sand tiger, etc. No matter what the preferred name, this is one seriously impressive animal. Usually found off the coasts of Japan, Australia, South Africa, the Mediterranean and the Eastern coasts of North and South America, this shark has an international following.
Unlike larger sharks, the sand tiger prefers to stay in relatively shallow waters, usually less than 65-feet. This behavior is largely due to its diet: fish, smaller sharks and skates. The shark prefers to hunt at night, using stealth to silently approach and attack prey on the ocean floor. Unlike virtually any other shark, the sand tiger can inhale large quantities of air, which it then uses as ballast. This means the shark can remain at a given depth with little to no effort. It also gives the shark a considerable advantage when hunting.
Although it may look extremely threatening (usually swimming with mouth open and rows of teeth on display), the sand tiger is a particularly calm, non-aggressive shark. There are no recorded cases of fatal human attacks and unprovoked attacks usually involve the shark defending itself. Curiously enough, this shark is actually a cousin of the famous great white. Ironically, it has no relation to the tiger shark.
In fact, the docility of the shark is one of the main reasons it is a favorite of aquariums. Unfortunately, even its rather pleasant temperament has not been enough to protect the shark against man. The U.S. Government’s National Oceanic and Atmospheric Administration does have concern about the vulnerability of the shark, but not yet enough evidence to put it on the endangered species list. It has been made illegal to harm, kill or harvest any part of the sand tiger along the Atlantic coast of the United States.
The major threats to the shark include beach nets, food shortages, finning and low birth rates.
To protect swimmers during busy seasons, it is relatively common practice to install nets around popular beaches. The theory is that the nets keep vacationers in and threats, such as sharks, out. Problems arise when sand tigers, which prefer shallow waters to begin with, get caught in such nets. Though in most areas of the world this issue has begun to raise alarm, it is still a problem.
The more predominant threats come in the way of large fishing nets and finning. Though it is largely illegal in most parts of the world, in Japan, sand tiger fins are an increasingly popular item. The practice of getting these fins involves catching the shark, cutting off the fins and usually then returning the shark to the water. This leads to a particularly horrifying death for the sand tiger. Those that are caught accidentally in large fishing nets around the world have extremely low survival rates.
These problems are compounded by the fact that the sand tiger reproduces at a slow rate. When one shark is lost, it can take a significant amount of time for that loss to be made up. The bleak reality is that these sharks simply cannot keep up with the pace they are being destroyed.
It is estimated that in the last ten years the worldwide population of sand tigers has decreased by a sobering 20 percent.
Yet, there certainly still is time to reverse this trend. By learning about fishing methods that don’t involve accidental capture, we can allow such incredible animals to begin to recover. By creating new, non-threating barriers at popular beaches we can ensure far higher survival rates. By increasing pressure on countries that engage in the mutilation and destruction of such vulnerable creatures, we can help stop the sand tiger from moving higher up on the threatened list.
For many generations, sharks like the sand tiger have fascinated us. Let’s turn that fascination into a drive for conservation. It may seem strange, but these amazing hunters desperately need our help.