Date Time Crayfish key to waterways health Just like the canary in the coalmine, the presence or absence of freshwater crayfish can tell us a lot about creek health in the Blue Mountains. Recent research conducted by Blue Mountains City Council show that while pesticides remain a common threat in many local waterways, crayfish populations at Jamison Creek (Wentworth Falls) have made a remarkable recovery after a serious incident of pesticide contamination at the site in 2012 led to the deaths of over 1000 crayfish. These results are among several just released in Council’s 2021 Waterways Health Snapshot. This annual report on the ecological health of our waterways is compiled from data gathered at over 50 monitoring sites, which are located throughout the Blue Mountains from Lapstone through to Mount Wilson.