Charleston Gyre

Daily At-Sea Log January 28th

  January 28, 2003

“Exploration of the Charleston Gyre and its contribution to the production on the southeast United States continental shelf”
By Rachel McEvers, Project Oceanica

The title of our,
National Ocean Service Center for Coastal Fisheries and Habitat Research, mission is “Exploration of the Charleston Gyre and its contribution to the production on the southeast United States continental shelf”. This is the fourth cruise of the mission. On this particular cruise we will examine the fate of zooplankton (very small floating animals) and ichthyoplankton (very small fish larvae) in the region of the meso-scale eddy formation known as the Charleston Gyre.

Preliminary work indicates the swirling motion of the eddies that form off the Gulf Stream, brings nutrient-rich water from deep and off the shelf edge to near surface and results in enhanced primary production. Therefore, this may be an ideal place for juvenile fishes to feed as they grow. The reason for this cruise is to assess production of the Charleston Gyre, its contribution to production of the entire southeastern Atlantic Bight, and its potential as pelagic spawning and nursery habitat for fishes.

Right now we are making CTD casts every 5 miles. The CTD tells us the temperature, salinity and depth of the water. By measuring the temperature and salinity, we are able to determine when we are within the Charleston Gyre. Once the center of the eddy (gyre) is reached, drifters will be released. Five are satellite-tracked and one is GPS-tracked from the ship. The GPS-tracked drifter will be followed. Three MOCNESS (plankton net) tows will be made in the vicinity of the drifter each night and one will be made during the day. CTD casts will be made throughout the cruise to make sure we are still in the eddy. Once the mission is over, the GPS-tracked drifter will be retrieved. The satellite-tracked drifters will continue to send information via satellite even after the cruise is completed.

Career of the Day:
Robin Cheshire, Biological Science Technician for NOAA National Ocean Service

Robin works in the Beaufort, NC NOAA lab. He has a Bachelor’s degree in fisheries and wildlife science from North Carolina State University and a Master’s degree in zoology also from NC State. Robin says he decided to become a marine scientist when he moved to Wilmington, NC and fell in love with the sea. Robin’s duties include fieldwork in the Florida and Chesapeake Bays monitoring fishes regarding sea grass habitats and marsh restoration. In the lab he weighs, measures and records information about the fish he has caught. He then analyzes and records his findings. He is very interested in larval fish growth rates related to the warm water eddies that spin off the Gulf Stream.

The thing Robin likes best about his job is being by the water. The only thing he doesn’t really like is that the fieldwork sometimes keeps him away from his family for long periods of time. When asked what kind of sea creature he would like to be he said a seahorse. His reason was “they’re cool”.


Ph. 843-953-7263
Project Oceanica
Dept. of Geology & Environmental Geosciences
College of Charleston
Charleston, SC 29424
Fax 843-953-7850