Western Dry Rocks – Tagging and Telemetry In the Florida Keys, our Finfish Research Team is using underwater listening devices across the ocean floor to monitor how fish populations change over time in response to the Western Dry Rocks Spatial Closure. How do they work? Throughout the spatial closure, we’ve been surgically implanting special acoustic tags in the bellies of fish. Once the tagged fish are released, our listening devices begin to pick up their signals as they swim by our equipment,