Those with an interest in exploring a bit about fish in the ancient human
diet may wish to see the following URL, which has a bit of information and
lots of contact information for researchers working in that field:

http://atlas.otago.ac.nz:800/~foss/ICAZ/icaz.htm


Also there is a short article by Mike Richards on the use of meat in
ancient British Isles diets. The suggestion is that the Brits were
depending primarily on meat for their nutritition up to around 2000 b.c.
There's not a lot of detail but it's interesting anyway:

http://britac3.britac.ac.uk:80/cba/ba/ba12/ba12feat.html#richards