It is the high quality of the chalk water and the careful management of weed beds that make chalk streams ideal for brown trout. In most cases the fishing is managed primarily by riparian owners and clubs, some of whom have resident river keepers. Occasionally the fishing is supplemented by regular introduction of reared brown trout and very occassionally rainbow trout.
These rivers support an abundance of insect life on which fish feed.
In the late 1880s Frederick Halford and George Marryat studied the fly life on the River Test, and Halford then wrote the angling classic of Floating Flies and How to Dress Them, followed by Dry Fly Fishing Theory and Practices. In effect his work and writings changed the whole method of fishing on chalk steams and they continue to the present day. In later years G E M Skues developed upstream nymph fishing for fish feeding subsurface on the River Itchen, and although frowned upon by the purist dry fly fishermen at that time, it is now an acceptable practice on most chalk streams.
Fishing on these gin clear waters means that the angler is in fish stalking country and anglers only cast their flies, whether floating imitations or nymphs, upstream to rising or feeding trout.
Anglers should also note that fishing can be suspended on many rivers during certain periods in the summer when fisheries cut and manage weed.
Trout fishing on chalk streams calls for a subtle approach due the gin-clear nature of the water. Lighter rods around 9ft and throwing a 4 or 5 line are best suited to most of the trout fishing on the larger rivers, and rods of 7 1/2 - 8ft rated for a 3 weight line are better balanced for the smaller streams and bournes. There is no need for anything other than a full floating line with a long fine tippet 2-3lb BS, though not so light as to offer the larger fish too easy an opportunity to break it!
In the spring dry flies such as Greenwells and Medium and Dark Olives Kites in sizes 14 & 16 and GRHE and PT nymphs in sizes 14 and smaller are used. In addition to these, as the temperature rises and we move into late spring and summer, dry flies could also be CDC's Klinkhammers, iron Blue Dun, Tups indespensible Grey Wulff, Houghton Ruby etc, again in sizes 14-16. Now we can also add Mayfly imitations into the mix, with Grey Wulff, Spent Mayfly, French Partridge in sizes 10-12, but increase the tippet strength to around 5lb when using these.
As the season progresses through mid & late summer, dry files should decrease in size, down to size 18, Black Ants, Gnats, Spiders etc on 2lb tippet, and the usual nymphs even smaller - down to size 20s! As we enter the autumn, the same selection of flies can be used, but still keep them small 16-18 for dries and 14-16 for nymphs.