Gray's Reef National Marine Sanctuary
Gray's Reef National Marine Sanctuary
Data Buoy Science

Acoustic Tagging Project


Project Overview


Purpose

To better manage marine resources, we need to understand the biology of fishes and what factors impact their behavior. The acoustic tagging project will help managers understand how much time red snapper, black sea bass and two grouper species (gag and scamp) spend in particular areas of Gray's Reef National Marine Sanctuary. Also, this project will allow us to track their daily, seasonal, and annual movements to better understand the behavior of these fish. The movement patterns may vary between individual species being studied or between individual age groups.

There are several questions we hope to answer, such as:

  • Do resident times differ between species?
  • How does temperature or weather affect the amount of time the fish spends in the sanctuary?
  • Does the time of day or period in the lunar cycle have an effect on the amount of time the fish spends in the sanctuary?

Twenty-two acoustic receivers are placed around Gray's Reef National Marine Sanctuary to listen for tagged fish. If you happen to accidentally pull up one of the receiver arrays please keep the array and call us at 912-598-2345. We will retrieve the unit and return it to the water in the appropriate location so that we can continue tracking fish in Gray's Reef National Marine Sanctuary.


Tags and Receivers

Fifty-four (54) fish are currently tagged with transmitters: six (6) red snapper (Lutjanus campechanus), thirteen (13) scamp (Mycteroperca phenax), six (6) black sea bass (Centropristis striata) and twenty-nine (29) gag (Mycteroperca microlepis). From 2008 to 2010, fish were caught using hook and line and vented using an empty hypodermic needle. In 2012, fish were caught in a baited trap and the surgery was completed underwater to reduce the amount of stress experienced by the fish.

Scientists aboard the NOAA Ship Nancy Foster prepare to tag a red snapper

Scientists aboard the NOAA Ship R/V Nancy Foster prepare to tag a red grouper. Photo: GRNMS

The tags were then surgically implanted into the fish's abdominal cavity. These tags emit a unique "ping" every 120 seconds at a frequency, which the acoustic receivers can detect up to about 200 meters.

Twenty-two acoustic receivers arrays are deployed in the sanctuary. An acoustic receiver array consists of the receiver attached to a buoy line that is suspended vertically in the water column using two subsurface floats and a steel bar as an anchor. The receiver is attached about 1.5 meters from the bottom. Divers retrieve the receivers once every three months, download the data, and then return the receiver to the mooring. For more information on the tagging procedure see frequently asked questions or contact us by phone at (912) 598-2345.


Area

Densely colonized habitat within Gray's Reef NMS

Densely colonized habitat within Gray's Reef NMS
Photo: Greg McFall, GRNMS

Gray's Reef consists of four habitat types: flat sand, rippled sand, sparsely colonized live bottom and densely colonizedlive bottom. Receiver arrays were positioned on flat or rippled sand, adjacent to areas of densely colonized live bottom. Snapper and grouper species are commonly associated with densely colonized live bottom. Researchers believe that placing receivers near these areas will increase the chance of fish being detected by the receivers.


NOAA Logo

leaving site Indicates a link leaves the web site; Please view our Link Disclaimer for more information | Privacy Policy | Contact Us
Revised by Gray's Reef National Marine Sanctuary Webmaster | User Survey
National Marine Sanctuaries | National Ocean Service | National Oceanic & Atmospheric Administration | U S Dept of Commerce
Web Site Owner: National Ocean Service