- I mean would hens be able to find or catch a
> fish? Even if they did would they eat
> it?


I am living on the coast of Bc in an island and we feed chickens with left
over from the fish store ( bones , salmon heads , crab shells etc ... it
raise their omega 3 content . not necessary if they have pleinty access to
insects worms and greens ( all omega 3 rich ). the chickens like to eat the
left over fishes but they have a stop on them easelly .they are opportunist
omnivores and will gladly eat dead animals meats when given opportunity .
i also read an accompt old of 3 centuries of a french visiting scandinavia
and being surprised to see cows eating small fishes caught in a tide pool .
some even herbivorous animals need some animal source of foods at time .(
insects )

the main thing with raising animals on their natural diet is to allow them
to have the choice and let them regulate their intake by instinct .
to raise omega 3 content in eggs and chickens they used flax in the context
of mass production ( grass and insect will not be accessible) there is
problem  because of antinutrients in falx who stop them to assimilate
properlly their food .
if left with choice flax will not be favored .Chia seed . old Mayan 3rd crop
in importance ( after corn and beans ) is omega 3 rich and dont have the
antinutrients in flax seems to be promising to raise chickens .( don't give
the fishy taste like flax do )

jean-claude