Rights: The University of Waikato Published 27 November 2007 Download

Dr Vicky Webb from NIWA explains in a video conference with Cobden School students, why scientists are trying to develop a marine paint that stops sea-life attaching themselves to the bottom of boats.


Dr Vicky Webb (NIWA) So there's lots of reasons why we do not want to see lots of growth on the bottom of these ships. Have any of you got any ideas what some of those reasons might be?

Cobden School Is it that you could be transferring them to other places?

Dr Vicky Webb (NIWA) Excellent, that’s one of the main reasons in fact that we don’t like to see these things covering the bottoms of boats. In fact several of our most invasive marine species have come in as hitch hikers on the bottom of big supertankers. There’s also another reason why fisherman don’t like them on the bottom of their boats. Any other clues? Think about dragging your tyres along on the ground when you’re riding your bike. Yes?

Cobden School It makes you go slower?

Dr Vicky Webb (NIWA) Yes, that’s called drag, it makes the boats go slower. So in order to go 10 knots, you need lots more petrol, lots more diesel and it costs a lot of money. They say that the big supertankers of the world with the amount of fouling, the amount of these organisms growing on the hull, that you can barely see, costs around 5 million dollars extra in diesel per year for each supertanker. So the cleaner they are, the slicker they go through the water.