Are there extreme types of dams where yabbies do very poorly?
One extreme type of dam is the highly organically polluted dam on the valley floor, which is quite saline and, therefore, clear of clay turbidity (exposed to shag predation) in autumn and spring and has a toxic blue green algal bloom in summer. The other extreme type of dam is the very muddy, low salinity (and low calcium) dam well up a valley hill slope, with a small catchment, perhaps roaded, and little organic input.
