Globally, sharks are top predators. This doesn't mean we need to be scared of them. It means they're vitally important for maintaining the balance of marine food webs. 

Shark stocks have been decimated, and this is largely a result of shark finning. This horrific and inhumane process involves sharks being caught (mainly on long-lines, like tuna), hauled on board (generally still alive), finned (where their dorsal, pectoral and caudal fins are hacked off), before being thrown back in the ocean still alive. Bleeding, and with no way of swimming, they torpedo straight to the sea floor where they're either attacked by other animals or drown because they can't swim. 

If anything this cruel happened on land, or anywhere people could see it, I've no doubt it would be outlawed. In fact, in many countries it is. The problem is, when there's such a high demand, and so many people willing to pay so much for a bowl of shark fin soup, there is a very good incentive to risk the low chance of being caught, and go finning anyway. After all, you are but a speck in the ocean. What are the chances?

Why fin? The rest of the shark is worth much less - it's just like every other white fleshy fish. If you think about it, the fins are only a small portion of the weight and size of the shark. With limited space below decks to store their catch, it is hardly worth filling the hold with the entire (useless) body of the shark. With just fins, their catch is worth many, many times more than it would be if the entire shark was kept. 

The theory behind this is the basis of eating sustainably. My Scottish ancestors would always use the entire animal they killed, for if they lose one of their flock, they must make use every last part of it. This is where traditions such as Haggis came from. And today, any good butcher will tell you he's trained to make use of as much of the animal as possible. 

Though over generations, this has become less important. If we do kill an animal, or in fact harvest fruit and veggies, so much of it is just scrapped. This is all well and good if we have the capacity to farm animals and plants to ensure there is enough for all, but wild stocks are a very different story, and sharks even moreso. 

With up to 90% of our sharks gone, there is a further problem. As these top predators have evolved over millions of years (since before dinosaurs), they have developed evolutionary traits which make sure they can't breed themselves into starvation. Most sharks, particularly the medium to large species, have very slow reproduction rates. It's common sense really. If you're a top predator, you have no threat from other animals; no natural way to keep numbers down. And if numbers get too high, it's the tragedy of the commons - you'll all end up with no food. So those clever sharks decided to sacrifice having too many babies for the sake of the species. They are slow to reach sexual maturity, they can usually only have 1 or 2 pups at a time, and it's a long time before they can have more. 

The rate of reproduction is one of the factors in determining which seafoods are sustainable and which are not. And it turns out, sharks are among the slowest group of animals to reproduce. So really, we should avoid catching them at all. Yet in order to meet the desires of some Asian countries, we are allowing these vitally important animals to be pushed to extinction for less than 10% of their body mass. 

However, we can all help curb this disastrous trend. Surprisingly, shark fins are on the menu in many Asian restaurants in Australia. At the very least, we can help persuade restaurant owners here that Australians do not support shark finning. Though boycotting something is no use unless they know you're boycotting. It doesn't have to be a screaming match or a spectacle. Just politely let it be known that you will be eating at a restaurant that doesn't have shark fin on the menu. If enough people come to you saying they'll support your competitor while shark fin is on your menu, surely it's a sacrifice you'll eventually make.

And it really is a small sacrifice when you consider the impacts of not making it. Not only the impacts on marine environments worldwide, but also the impacts on all other fisheries stocks. The danger is not sharks. The danger is no sharks.