What do the yabbies do?
We know that marron in these dams are forced into shallower water during summer. Although yabbies are more tolerant of low oxygen, they probably favour the warmer, well oxygenated, shallow water, too. The bad effects of this crowding onto a smaller area of the dam bed are reduced survival and growth, since these production factors are very much influenced by density (crowding) of crayfish.
