I've just returned from a two and a half week trip onboard shark longliner. The shark longline fleet in South Africa is pretty small, only 3-4 vessels, which mainly fish for mako sharks. The gear set up of the vessel is slightly different but the fishing techniques are very similar to the swordfish and tuna longliners (that is using long line with 1,000 - 1,300 baited hooks).
Jose, the skipper, welcomed me with a big smile and a promise that we wouldn't catch any birds on this trip. I've heard these kind of promises before. But, this time, Jose kept his promise and we returned back to shore with empty bags - which is always excellent.
We lost half a day due to bad weather, but still managed to collect some valuable data. We were experimenting for the first time the efficiency of circle hooks compared to J-hooks. We also studied the hooks' sinking rate which affects the seabird bycatch greatly (the faster the line sinks, the less time albatrosses and petrels have to steal it).
It was very interesting to see that despite large numbers of birds around the boat most of the trip no birds were caught on the line.
On the way to the fishing grounds and back we tested the bird-scaring lines (tori lines). Jose came up with some nice ideas and together we are going to design a slightly different version to fit his vessel and hopefully the rest of the fleet.
I want to thank Jose and the crew for an excellent trip. It is always exciting to work people who care for sea and its inhabitants with a great passion.