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Spotting Fish from Space

Satellites 850 kilometres out in space are being used to spot likely fishing grounds, in a research project that is already making New Zealand's commercial fishing more efficient and more profitable.

"Basically, we're trying to take a lot of the guesswork out of the problem of finding fish," NIWA scientist Dr Michael Uddstrom says.

Satellites can pick up data on sea surface temperature, plant plankton and currents, "which, when considered together, provide important information on where fish are likely to be caught," Uddstrom says.

That enables researchers and fishers to spot where water temperature is best for a particular target species and to identify productive fronts where fish are likely to gather. By matching that information and data from other sources, NIWA is working out the best times and places for the fishing boats.

"We will be able to target fishing vessel effort, thereby reducing search times, increasing fishing times, and hence improve catch efficiency," he says.

Satellites can sense these ocean fronts, where different water masses meet. "Fronts often have plenty of plant plankton, which is the basis of the entire food chain." Where the plankton is, the fish are likely to be, too.

Uddstrom says that his PGSF-funded project probably has another three years to run. The institute uses satellites owned by US, Japanese, and European agencies.

He says some fishing companies will collaborate in the project by allowing researchers to direct fishing effort, and thus test theories.

Preliminary data has already been sold to the fishing industry.

"Some companies and fishers have reported that the sea surface temperature reports are critical to their operations and have already led to better catches," he says.

In time, this data might show the best fishing grounds anywhere in the economic exclusion zone and adjacent high seas areas.

"This step will provide fisheries guidance that will be second to none in the world and extend the lead already given to the New Zealand industry through current services resulting from this research," Uddstrom says.

The results of the research are also helping to develop fisheries in Fiji and Tonga.