Splake are not sterile. I have seen lots of splake that produced viable eggs and sperm, but have never found anywhere in Maine where they actually reproduced. We had about 15 splake lakes in my region of eastern Maine which we trapnetted, gillnetted, and creel surveyed without finding any "wild" splake. We checked with several Canadian biologists who stocked splake and none had found any natural reproduction. Some told us that although the stocked splake produced viable sex products, their differing habits in the fall did not result in any spawning.