Why do yabbies do so well in muddy dams?
Crayfish have a great instinctive fear of bird predators (e.g., shags or cormorants). During daylight hours crayfish in clear water are very vulnerable to shags and are inactive in hiding places. However, the muddy water in most dams provides 24 hour nighttime light conditions on the bed of a dam, so shags can’t see to hunt there and crayfish are active during the daytime. Crayfish don’t need to see to feed; they can do it by touch, smell and taste. Underwater darkness in muddy dams is the reason why yabbies can be harvested so readily with baited traps during the daytime.
