Honestly, the answer is: OK… for now. The pressure on our open ocean shark populations is not as heavy as it is in other parts of the world but it is growing all the time. Increasing pressure from foreign vessels just outside our ocean – borders (it is 200 naughtical miles from any point along our coast, and is called our exclusive economic zone) together with our own vessels is going to have a detrimental effect at some point, but where is that point or more importantly, when!
My two trips onboard the tuna longline vessel was an experience I will never forget from both an interaction and fishing point of view. But from a shark point of you I found that, in general, they didn’t want to catch the sharks. This could have been purely because I was on board but it seemed as if they genuinely didn’t want to because they saw them as a pest rather than as a source of income. The only species they did keep was the shortfin mako because its meat as well as fins is valuable, whereas for most other shark species it is only the fins that fetch a decent price (R500 for 2 fins). The most common species caught on the longline was the blue shark (Prionace glauca) which was alive when caught (most of the time) and cut loose next to the boat. So after my two trips on board the tuna boats, I felt that there was a far greater threat to sharks out there than our tuna longline boats as the number of sharks caught and subsequently released was not excessive. The shark longliner was a very different story.
My most recent trip, as I mentioned earlier, was on board a shark longliner for a total of 20 days at sea. In this time, we caught over 50 tonnes of sharks which consisted mainly of shortfin mako and blue shark: 41 tonnes of mako and 15 tonnes of blue shark. But what struck me most about the operation was just a basic lack of knowledge. You see to these fishermen sharks are just another fish in the ocean, a fish which is seemingly as plentiful as other types of fish but makes them more money. They have no concept of the sharks’ life history strategy (how they live and reproduce) or how their fishing is affecting the species. It was my mission to at least impart some knowledge to the skipper and crew of the vessel whilst I was on board without aggravating anyone.
The first few days were an absolute hurricane in my life because within 24 hours of being on board we had caught over 4 tonnes of shark. Hmm wait, let me quickly explain how a longline works before I carry on.
The steel trace used with glow-in-the-dark covering
A longline vessel uses just that, a long line… a very long line. The long line is called the main line and the length ranges from 60 – 100km in length. Along the line at 20m intervals there are shorter lines called droppers which are between 20 and 30m long. Each of these droppers has a hook and bait attached to it. The line is put out at night and collected first thing in the morning. This is called the shooting and the hauling of the line. The shoot takes about 4-5 hours and the haul, depending on the weather, amount of fish, and any entangled line, will take between 7 and 12 hours. This happens every day and night weather permitting. Along the line there are buoys to keep the line afloat as well as radio buoys to make sure the skipper can find the line the next morning as it drifts. There are 10 radio buoys in total and this means that if the line is cut at any point (by another ship or strong current) then he can sail to the nearest radio buoy and pick up the line from there.
Ok, are we on the same page now… good J
I'll let that all sink in for now so please tune in again for the last episode…
Till then, keep on keepin' on ;)
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