I think Joe's problem is that freshwater shrimp or ghost shrimp are not very common in northern ponds, thus it is hard to find a pond where one can just dip them. Southern Lake Erie is the northern range for this species. Winter temperatures and ice cover must be stressful for these guys. I have never seen them in a weedfree pond unless the fish were not present or only present in very low numbers. IN the north when the weed die back in the winter the fish might prey very heavily on these shrimp thus eliminating them from many waters. It is also possible that the breeding season is shorter in the north thus populations do not get as big or high thus less predation eliminates them quicker. Numerous habitat and climate differences to consider with this.
Last edited by Bill Cody; 08/06/08 09:00 PM.