SediMeters Can Save Corals from Dredging Spill

The ongoing dredging of Miami Harbor has caused siltation (the accumulation of sediments) on the coral reefs outside the harbor. In a settlement of a recent lawsuit, the contractor, U.S. Army Corps of Engineers (USACE), has agreed to pay $400,000 for moving corals out of the way. They are not using any instrument for measuring the sediment accumulation, even though such an instrument exists, is being manufactured right in Miami, and costs less than $2,000 per instrument.

The Lindorm SediMeter was designed explicitly for this application: Real-time monitoring of dredging spill accumulation, so that works could be halted when the siltation was putting the environment at risk. The sediment plume is transported by currents, so the risk to the bottoms can vary from hour to hour. The idea with the real-time monitoring is to pause works temporarily in critical situations, and then resume them as soon as conditions change, thus saving money and the environment.

The inventor of the SediMeter, Dr. Ulf Erlingsson, was the Swedish government’s expert in supervising the sediment spill monitoring from the dredging for the bridge-tunnel between Sweden and Denmark. It was the most ambitious spill-monitoring program ever undertaken, and quite costly. Based on his experience as government expert in that project, he set out to create a more cost-effective method using the SediMeter. The method is based on science, statistics, and legal auditing requirements so as to be as enforceable and objective as possible. The SediMeter can of course also be used separately from the proposed regulatory framework, and for other things such as science, for which the instrument was originally developed almost 30 years ago.