An additional camera installation in Jockfall Sweden
Our friends from Jockfall, Sweden recently installed an additional camera to their new Riverwatcher camera system in the river Kalixalven.
The new camera is mounted at the end of the camera tunnel and shows the fish entering into and swimming through the camera tunnel. The existing camera inside the tunnel records a side view video clip of the fish as which is used for identification and validation of the Riverwatcher counting and monitoring data.
It has been observed that when the water flow in the tunnel is too slow, some species may tend to dwell inside the unit, as the tunnel apparently offers a convenient and safe shelter.
Although this clearly indicates that fish are comfortable with the Riverwatcher and are happy to stay inside the unit. However this behaviour can produce unusual results with fish continuously going in and out of the tunnel increasing both the up and down counts from the Riverwatcher.This issue can be resolved by increasing the water flow in the tunnel.
The video sequence below recoded by the new additional camera clearly shows a salmon passing the through the Riverwatcher which, as well as the 2 cameras, also has custom made openings in the side walls of the tunnel to increase the water flow. The fish sense the current from the holes and pass through the camera tunnel fast and efficiently.
If you look closely you can see the Riverwatcher camera switching on when the lights hit the fish towards the end of this video, producing a good clear side view of the fish passing.