energieeffizientes angeln - ganz ohne angel und stress, nur bissel mit der lampe rumfuchteln, damit de insekten
anlockst, die wiederrum die springefischleins anlocken ... geniale idee 

As you see, there's nothing cruel about it. The boat is moving and as they're getting deep in the river, the
amount of fish grows and they get more wild. Nothing to do with the light.
At the end of the video he excuses himself for the bad movie quality for they only could reach the river at night.
Implicit that in the morning the fishes do the same jumping thing.

I've actually seen this happen, it's not as rare as you'd think. When there is a sudden change in barometric
pressure it also affects the fish and makes them go nuts. It usually happens right before a lightning storm.