13 Tiger Sharks, 2 days, 1 shark net

In all too familiar a fashion we hear via the grapevine that KwaZulu/Natal Sharksboard have killed a significant number of sharks in the past week at the netted installations of Park Rynie and Scottburgh.

Predictably silent until forced to comment the media machine of Sharksboard kicks in with a stark admission that 13 tiger sharks were caught in the netted installations of Park Rynie (1) and Scottburgh (12) between Thursday and Friday last week.  In this case they claim to have released nine of the sharks alive (a claim no less as there is absolutely no way to verify this statement and there is a significant amount of unrecorded “dumping” – the practice of discarding the animal at sea be they sharks, rays, turtles or dolphins).

Perspective by longtime shark activist and Shark Angel Mark Addison who has been witness to the damage shark nets cause personally, in South Africa, for the last several decades. He operates Blue Wilderness - an organization that relies upon healthy shark populations - for the amazing shark conservation and outreach work they do.

By this measure with four dead and nine released you may feel sad for the dead ones and relieved that at least some made it. Of course they were “tagged for science” according to the statement and then released. The reality is that, by their own admission (on their website www.shark.co.za), in the case of fishing for sharks: a struggle by a shark for over two hours would amount to a “very low chance of survival” on release. Tiger sharks have the musculature to pump water over their gills, unlike many other species, and of the 434 Tiger sharks tagged and released from the nets, 23 have been recaptured. This gives a mark/recapture figure of 5.3%, high by most species standards but relates to the fact that Tiger sharks are at least seasonally resident on our coast and continually catching animals from a specific population leaves a “punch hole” effect in that population. Of course there are no released statistics on whether the recaptured animals were dead or alive when recaptured but I suppose that only really matters if you value live sharks over dead ones. 

In sharks, the tremendous struggle, to free themselves from the nets causes the acids to build up in  the body which generally kills the animals if they don’t suffocate due to confinement in the net. So a released animal is not necessarily going to survive. In fact there is a huge body of evidence that says most don’t. In Marine Protected Areas (of which the Aliwal Shoal MPA incorporating Scottburgh and Park Rynie is one) the mark/recapture rate with some species is as high as 30%. Unless they die or move house it would seem that 5%, or thereabouts, indicates a very high mortality rate post release especially when you consider that they don’t have any natural predators in the MPA other than themselves and the odd bull shark or white shark - if they are that small.

Which brings one to another point about what size class would in fact be dangerous to water users if this is the reason for the nets in the first place!  Given that Sharksboard report that they caught and killed four Tiger sharks, tagged and released nine and offer no information on size class it seems a bit odd? Why is this important you may ask? Quite simply because small tiger sharks eat small food and big sharks have the option of bigger prey items such as turtles. The dentition of the little guys limits their food availability and essentially they are on baby foods such as rays, skates and bony fish. Sharksboard claim they don’t know why they caught so many animals – probably the nets would be a good guess – and yet offer nothing on size class leaving the puzzle incomplete. Depending on what size of animal they caught you would be able to determine what they were after. Generally, tigers get caught in the nets because they attempt to scavenge some hapless animal that is caught in the nets and then get trapped themselves. As they are not solitary and don’t mind sharing their food, others will get caught in the same way and a domino effect is created. Bigger Tiger sharks may in fact try to scavenge on others caught in the nets. Given that the average size class of Tiger sharks caught in the nets has declined significantly over the years it is hard to believe that any of these animals could have posed a risk to bathers and if so then it could only be because the nets had entangled something that they had come in to scavenge on.

In this case then, far from “protecting” bathers, the nets have acted as an aggregating device for sharks and drawn them to the area. This is as bad as the ill-conceived drum- lines plan that they have implemented in the far north and south of the province –baited beaches! Little wonder why tourist numbers are on the decline! Walking tours in a Lion Park at feeding time has a similar ring to it - funny how it hasn’t taken off as a tourist activity either!  

I have no doubt that the “Killing Fields of KZN” will continue to reap havoc on our coast by destroying the very animals we need to keep our coast healthy.

For years, the Shark Angels in South Africa have been working on their "Remove the Nets" campaign. Very soon, we'll be revealing the revised campaign on the Shark Angels site. And we have got big plans for the campaign in 2012. Watch this space!

More about the shark nets

Thanks Andy, for inspiring a new generation of conservationists and for being a part of our team! - Shark Angels