Following on from the keepnet thread...

[peter crabtree]

I believe in certain situations releasing your first bream or roach can cause a shoal to move on. I imagine it similar to a blackbird spooking from the garden
doing it's alarm call, where most of the other garden birds equate the shrill warning to danger.
In winter silverfish tend to shoal up and a caught and released shoal member could give warning, either by it's body language or by emitting a pheromone or both, thus alerting other shoal members to disperse??

[barbelboi]

Do you find that on still waters Simon, I've only noticed it to any extent on the smaller rivers.
Jerry

[cg74]

Originally Posted by barbelboi

Do you find that on still waters Simon, I've only noticed it to any extent on the smaller rivers.
Jerry

I've found it more problematic on smaller waters, both rivers and still.

The species most effected IMO/experience are chub and bream, followed closely by roach.

[S-Kippy]

The only time I ever use a net [if rules permit] is when I'm roach fishing and for the same reasons Simon gives.Roach spook easily at the best of times and returning them in my experience does spook the shoal.

TBH if you're not a match angler the waters you could use a net on even if you wanted to are few & far between. I can think of one stillwater plus the Thames where I might use a net when pleasure fishing. I only have them really for the odd friendly match.