Staffan suggested last time that optimal foraging theory may not
adequately explain modern man's desire to go fishing.   I am in complete
agreement with this - last Saturday, I took my two boys out for 4 hours
of lazy fishing and didnt even get a bite.
        In support of my experience, Hawkes in her classic study of Ache
optimal foraging behavior (Hawkes K et al.  Why hunters gather: optimal
foraging and the Ache of eastern Paraguay.  Am Ethnologist
1982;9:379-398) showed that the caloric return (calories derived from
the food per handling hour) from fishing ranked 9th out the top 12 foods
regularly acquired by the Ache.   Hawkes notes, "why dont Ache fish more
often?. . . . .five women spent 2.25 hr each fishing a small lagoon and
stream.  Their returns were neglible: less than 2 kg of fish.   This
seemed to be viewed more as play than foraging. . . . .  38 adults spent
5 hr each fishing the lagoon and took about 25 kg fish.    The addition
of these two incidents to the figures results in a total of 288
forager-hours for 216 kg of fish, which is 1.3 hr/kg or about 733 Cal
per forager hour.   These figures suggest that the Ache fish
infrequently because they do better hunting."
        So, it seems that in living hunter gatherers in inland tropical
situations, they have the same problems as my sons and I had - fishing
generally has a low caloric return rate.   Clearly, there are exceptions
to this - witness the salmon runs utilized by Inuit and other indigenous
populations living at northern latitudes and the shellfish mounds in
coastal areas - however these resources only tended to be exploited
towards the end of the pleistocene, and as previously stated, there is
little evidence of regular exploitation of the aquatic environment for
most of the time hominids have existed.

                                        Best wishes,

                                        Loren