Strange that this breamy subject should come up now..
My eldest son is presently employed as a commercial diver, he is working in Germany on a contract to replace a concrete bed on a large Commercial lock between the River Havel and a large lake , the lock has been blocked , a lot of steelwork is being upgraded and the slab is being removed on the river side, it is a big job, about the size of probably ten tennis courts , the present concrete slab is about 3 feet thick, and the job is to totally remove it and replace with a thicker bigger slab. The slab is being drilled to reduce the slab into bits about the size of a pool table and then the “bits” hoisted out .
You can imagine the industrial noise being made, core drills, coffer dams beig constructed , power drivers , hydraulics, you name it, it is there...
Now I come to the bream, out of interest my son one day took a dive a hundred yards or so further down the river during his break, and swam into a huge shoal of bream, he did not find out how big it was but he said they were everywhere from the bottom to mid water, he had not seen them in the working area at all,he thought no more about it , but told me via watsap.
A week or so later he turned up, and started his days work, he was first in the water , and was amazed to see the bream shoal was now swimming around above the concrete slab amongst the steelwork, chains, drills etc, not only were the bream there, they were crowding in and the ones on the bed were actually laying on the bottom sideways , with the others swimming above them, the fish were actually in the way of the work and they seemed oblivious to the noise and disruption.
When working, my son always has a go pro type camera on his helmet so the job can be viewed by the other Divers to see where they are at, he took a 2 min clip of the bream shoal and watsapped it me .. it is amazing, I cant load up the video in here but will attach a still or two later.
When my son had finished his dive he was wondering why the bream shoal suddenly appeared, looking downriver he saw that there was a flock of about 100 Cormorants that had appeared , he went and dived under the birds, where the bream had been, the river was barren of fish. It seems that the bream were more frightened of the birds than the industry.
the below picture is above the bream shoal whwr some of the steelwork is being upgraded/removed.
A couple of days later, after being “harrassed “ by Bream, he turned up for work and the shoal had vanished, you guessed it, the Cormorants had flown away, he had a swim dowwnstream and the bream were back again, leaving the work area abandoned . The video is a couple of minutes long, and shows in detain the sheer numbers of fish involved, the above couple of snapshots dont really do it justice.
David.