
Philip, it varies from region to region.
The season for Brown Trout starts as early as March 15, a little later in some areas. It ends sometime this month, the end I think, but I'm not sure.
There is no legally enforced closed season for Rainbows, as they generally don't breed in the wild. Individual fisheries may impose their own closed seasons though.
As for Salmon, varies widely, from river to river.
Best bet is to check directly with the water you intend to fish. Failing this, contact your local E.A. office.
Hope this helps.