How well do yabbies cope with low oxygen levels?
Yabbies can survive for much longer times at lower oxygen levels than many other crayfish, such as marron. At zero oxygen they can change their metabolism to a form which doesn’t need oxygen, although this can’t go on indefinitely and they must be inactive. They can survive and prosper relatively well in richer dams where the winter clay turbidity is replaced by algal blooms at the start of summer; marron will die off in these very rich dams. One observation by farmers, which fits our current Yabby dam theory but needs to be confirmed by actual research, is that the, usually overabundant, spring-summer spawning in dams with year round clay turbidity is less successful in algal bloom dams because the eggs and hatched young attached under females’ tails are less tolerant of low oxygen. Fewer less crowded juveniles will grow through to marketable weights more quickly. However, it needs to be remembered that while yabbies can survive at extremely low, if not zero, oxygen levels, they can’t
