By Bill Barker
Anyone who swims in the ocean – and who is honest – would admit that every now and then they feel a twinge of apprehension about the possibility of being attacked by a shark.
But there is a growing awareness that, despite the occasional shark attack tragedy somewhere in the world, sharks are in fact quite timid animals, who have much more to fear from people than we have to fear from them. Members of the Nature Coast Marine Group attended a screening at the Narooma Kinema last week of the film ‘Sharkwater’, which brought home in graphic detail the horrific slaughter of sharks that is pushing them to the brink of extinction. I recommend it to anyone interested in the fate of the marine environment.
Sharks have been a very successful life form in evolutionary terms, but they are now in crisis worldwide. The United Nations estimates that millions of them are killed each year. Most are slaughtered just for their fins, which end up in soup in Chinese restaurants. ‘Sharkwater’ shows fishermen in other parts of the world slicing the fins off living sharks and throwing the animal back into the sea to perish.
Sharks are slow to reproduce and have only few young and so are very vulnerable to fishing. They cannot withstand this kind of fishing pressure, quite apart from the barbaric way in which it is carried out. Sharks are essential to the ecological balance of our environment as apex predators.
For divers, a shark sighting is usually a highlight and many people travel far to enjoy an adrenaline pumping shark encounter. I well remember my own first experience of diving with a big shark. Descending into fairly murky waters at the Tollgates off Batemans Bay, I saw the unmistakeable profile of a large shark coming towards me. Soon we had half a dozen Grey Nurse Sharks swimming back and forth right in front of us, some of them coming very close, some swimming above us and some seeming to sneak up on us from behind. This might seem a bit unnerving, but you quickly get used to it, and knowing that the Grey Nurse Sharks are harmless unless provoked, you soon feel disappointed if you see only a few sharks or if they don’t approach closely.
The Grey Nurses in our waters are classified as critically endangered. Once they were plentiful but years of hunting, netting and spearing reduced their numbers to a tiny fraction of what they were. They have been protected since 1984 but a survey in 1998 – 2000 found less than 300 of these animals were left. There is a real risk that in a few decades they will be extinct, which would be a sad fate for a magnificent animal, which occupies an important ecological position as an apex predator. It is important that protection measures are in place and effective.
We are privileged in our region to have two aggregation sites where these sharks can be readily observed: at Montague Island and the Tollgates Islands off Batemans Bay. The sharks are usually around from November to April. The Tollgates is in a Batemans Marine Park sanctuary zone, while the Montague Island aggregation site is a habitat protection zone where fishing at anchor or with bait is prohibited from November to April. There are also rules controlling diving with the sharks.
Another fairly big shark that is often seen in South Coast waters is the Wobbegong. This is rather different from most people’s idea of what a shark looks like and how it behaves. Its beautifully camouflaged body is flattened and it is usually found resting under rocks or ledges. It is so well camouflaged that a diver can have a bit of a shock suddenly to find that he or she is almost touching the shark. Sometimes divers take these sharks for granted because they lie motionless and do not readily react to the presence of divers. But they are an ambush predator and can move with lightning speed to attack prey or to defend themselves.
Unfortunately the Wobbegong is also under threat, many of them ending up in fish shops, marketed as ‘flake’. Total catches of Wobbegong in NSW waters halved from 1991 to 2001, indicating that their numbers are plummeting. They too need protection.
The other shark commonly seen in our waters is the Port Jackson Shark. This is a rather odd-looking character, with a pig-like snout and crests over its eyes. It grows to a bit over a metre long and is commonly found resting in groups of up to 15 or so, in holes and caves. While inoffensive, it should be approached with care as it has a venomous spine at the front of each dorsal fin. It produces a spiral-shaped egg case which is sometimes washed up on beaches.