Using a kayak drone the Norwegian Institue of Research found more sprat than the traditional method of employing an echo sounder on a boat. Photo HI
The report from the sprat cruise shows that the kayak drone found more fish close to the surface than the usual measurements, especially at night
The kayak drone was developed by the Institute of Marine Research and equipped with an environmentally friendly electric motor and modern sonar. This is the first time that marine scientists have experimented with drone technology during the sprat voyage.
During the voyage in August, the drone was present to supplement the usual measurements made with the research vessel “Kristine Bonnevie” in Årdalsfjorden, the fjord arm inst in Sognefjorden
Echo sounder cannot measure all the fish
“We have had a suspicion that we are not able to cover the sprat well enough on our voyage in the Sognefjord, says population manager for coastal sprat at HI,” says Cecilie Kvamme.
“The suspicion is related to the fact that a good part of the sprat goes close to land and close to the water surface, so that “Kristine Bonnevie” cannot register it on the echo sounder. That’s why I became a researcher.”
Espen Johnsen and senior engineer Atle Totland are invited to experiment with the light and agile kayak drone during this year’s cruise.
“We know that sprat goes up to the surface, especially at night, and naturally you do not get to measure what is above the keel of the boat. It is a fairly large source of error with traditional research vessels,” says Johnsen.
They did experiments over two days: in the evening on Saturday 15 and in the day on Sunday 16 August. The drone followed a course between predefined points in the fjord.