Features

May 14, 2014

Tracking Currents with Drifters and Dye

Gray's Reef National Marine Sanctuary Drifters deployed May 12, 2014; locations as of May 14, 2014. Photo:Google

On Monday May 12, 2014, researchers and staff from Georgia Southern University and Gray's Reef National Marine Sanctuary released 50 gallons of a non-toxic red dye (rhodamine WT) into the Altamaha River. The plume of dye that resulted was monitored visually, with support by volunteers from the GA chapter of the Coastal Conservation Association (CCA), and with instrumentation as the dye flowed from the release point along the Georgia coast and offshore. Tracking the path of the dye will provide estimates of the extent to which the Altamaha River delivers dissolved con-taminants, nutrients and freshwater along the Georgia coast and to hard-bottom reefs, such as Gray's Reef, found approximately 20 miles offshore.

Georgia Southern Universtiy professor Dr. Risa Cohen prepares to deploy surface drifter in released dye, (see red dye background water). Photo: Jody Patterson

In addition to the dye release, the investigators deployed two GPS satellite-enabled current drifters that will provide information on how larger materials, such as dead stalks of marsh grass, may disperse after being transported from the Altamaha River estuary. You can follow the drifter's tracks on a Google map and find out where they go! Data obtained from the drifter paths are available to educators for use in the classroom. These student-drifters were constructed from basic materials found in local hardware stores and the GPS satellite transmitter tracking and mapping was coordinated through NOAA's NE Fisheries Science Center.

Gray's Reef education staff will conduct drifter building work-shops for educators to develop current studies into classroom lesson plans and then participate in their drifters' deployment during future releases. To receive Gray's Reef education program announcements, including workshop opportunities, subscribe to our listserv.

Plume of dye travels out to sea with currents. Photo: Jody Patterson