Permanent Fish Barriers

Has anybody come across a permanent fish barrier that can be used in a body of water to prevent fish migrating into a certain area of a reservoir?

I have so far looked at hydroelectric powerstations where measures are taken to prevent fish from entering turbines. I've come across Electroscreens and Bio Acoustic Fish Fences (BAFF) but need more information on these. For less permanent fish containment, British Waterways appear to use stop nets. I don't know whether these can be used permanently however. Has anyone got any experience of any projects including fish barriers?

BAFF wouldn't work as a permenant screen, as it is a behavioural screen. An electric barrier could, depending on the water depth, but the cost could be high depending on the length of screen, and there are always concerns over H&S of other water users.

Best solution sounds like a physical screen or stop net.

Would need more info. to be certain.

Afternoon Stuart,

There's a gravel embankment seperating two bits of reservoir and its proposed to move ALL the fish from one side to the other.

The problem lies in that in there is a 6m2 Culvert in the causeway that the fish will swim back through unless stopped, hence the barrier. The problem is that this is a working reservoir and the Culvert needs to stay open and clear of any detritus/rags/branches or other matter that may block it and the flows to the main body of the reservoir.

Any suggestions?

Incidentally, How do you mean the BAFF is beahvioural? Can the fish learn to ignore it and thus make that form of barrier ineffectual?.

Cheers.

Hi Mart,
have a look at the best practice guide for fish screening that we wrote a few years ago: www.dti.gov.uk/renewables/publications/pdfs/rep52.pdf
It is mainly about fish screening in rivers, but there are details on BAFF's and other behavioural screens.

We have since written another best practice guide for all intakes, but this is not yet in the public domain (EA document).

"Can the fish learn to ignore it and thus make that form of barrier ineffectual?."

Sort of. Behavioural barriers are rarely 100% efficient, because if the fish are determined enough they will eventually get through.
Fish can habituate to acoustic repellent devices if they are continually or repeatedly exposed to them. A physical barrier would be best.

Do you need to stop fish of all sizes getting through? Self cleaning physical screen may be an option or a GFFB (Graduated field fish barrier) - electric screen.