Metas delivers New Sensor Platform

A cooperation project between Institute of Marine Research and Metas AS, and funded by Statoil.
15. April 2015

Metas has developed two different sensor platforms: Tow-Fish, -a towed vehicle, and the Fish-Buoy, -a stationary platform. The challenge was to be able to design sensor platforms with the needed signal to noise performance to be able to distinguish eggs from other elements on a 333 kHz acoustic system.

TwoFish with Stereo Camera
TwoFish with Stereo Camera

Deployment
Fish Buoy was deployed in Lofoten area for collecting acoustic data from cod eggs and larvae. A rope is connected to the unit with an anchor in the other end. The anchor is bringing the unit down to the monitoring depth given by the length of the rope.

Deployment of Fish Buoy in Lofoten area
Deployment of Fish Buoy in Lofoten area

Detection
The overarching aim for this project was to prove that cod eggs can be detected acoustically and thus build the basis for designing acoustic egg surveys in the future. The challenge was to be able to design sensor platforms with the needed signal to noise performance to be able to distinguish eggs from other elements on a 333 kHz acoustic system. The first units was successfully used on the egg and larvae cruise in Lofoten in March this year. Small cod larvae was clearly detected at ranges up to 25 meters.

Echogram showing track of 2 mm Cod larvae.
Echogram showing track of 2 mm Cod larvae.