Unplugged with ONC's Super Pump: A Reversing Pump that Mitigates CTD Data Loss Due to Sediment Blockage

Ocean Networks Canada, an initiative of the University of Victoria, operates cabled ocean observatories that allow for collection of near real-time, high-frequency water property observations via CTD (Conductivity, Temperature, Depth) and dissolved oxygen (DO) instruments. Continuous, long-term time series from these instruments are needed for establishing environmental baselines, studying physical ocean dynamics, and detecting regional change. In recent years, the CTD/DOs deployed in coastal, near-bottom, sediment and particle laden environments have been fraught with severe data quality issues caused by material load into the instruments' internal plumbing. Here we present a mechanical solution, the Super Pump, that capitalizes on ONC network's near unrestricted power to circulate a heavy flow of water through the CTD/DO plumbing, on-demand. Two successful deployments of the Super Pump at coastal observatories suggest the pump substantially reduces data loss.