Fishing for blackbelly rosefish at 120 m

Thursday, July 6, 2017 / Trondheim fjord, Norway

Blueye was invited on a fishing trip with renowned sports fisherman Bjørn Florø-Larsen. The goal was to try to film and fish a specimen of the deep water species blackbelly rosefish. This species normally live between 150 and 600 m depths and is rarely filmed by anyone except scientists with access to a professional level ROV.

Bjørn Florø-Larsen is famous for many record catches in the Trondheim-fjord, like a 162 kg atlantic halibut or a 17.26 kg cusk, which also happens to be the world record. Bjørn doesn't only target large fish. He is a specimen angler who has caught a total of 122 different species of fish in Norwegian water.

162 kg halibut caught by Bjørn Florø-Larsen
162 kg atlantic halibut caught in the Trondheim-fjord in the summer of 2016 Photo: Sverre Magnus Selbach

Bjørn invited Blueye out on a fishing trip, with a specific goal of trying to film and observe the blackbelly rosefish. This species normally live between 150 and 600 m depth, but can occasionally be found shallower. He had a spot where he regularly catches them at about 120 to 140 m, a perfect depth to explore using the Blueye Pioneer underwater drone.

Leaving the harbour
Heading out to the fishing spot in Bjørn's boat, Black Pearl 2.0 Photo: Joachim Reiten Arntzen (Blueye Robotics)

The blackbelly rosefish is a typical sit-and-wait predator. It will stand on its pectoral fins, waiting patiently for prey to swim by. The fish does not have a swimming bladder, so when it stops swimming it will sink back to the bottom. The lack of swimming bladder also makes it possible to release the fish if you want to prefer to do catch and release fishing, as it will not get injured by expanding gas on the way to the surface.

Blackbelly rosefish
A blackbelly rosefish (helicolenus dactylopterus) resting on the seabed at 122 m depth in the Trondheim fjord. Photo: Blueye Pioneer

When we got out to the fishing spot we launched the drone and headed down to about 140 m depth. After searching for about 10 minutes we found what we were looking for; a blackbelly rosefish! We were able to observe the fish, and Bjørn was truly excited about being able to observe and learn about the fish and its environment and behavior.

We piloted the drone back up to the surface before Bjørn released his bait to make an attempt to catch a specimen. It didn't take long before the fish took the bait!

Bjørn posing with catch and drone
Bjørn posing with catch and drone. Photo: Joachim Reiten Arntzen (Blueye Robotics)

We have of course made a video from the fishing trip. Enjoy!