Shark and Sawfish: Surveys and Tagging
Shark and sawfish research conducted by the Southeast Fisheries Science Center.
Gulf of Mexico States Shark Pupping and Nursery Area
Conventional theory assumes that shark nursery areas are habitats where female sharks give birth to young or lay eggs, or where juvenile sharks spend their first weeks, months, or years of life. The Shark Population Assessment Group is currently testing a number of hypotheses regarding juvenile sharks and essential fish habitat that challenge this assumption. There are many bays and inlets along the Gulf of Mexico coastline which may serve as essential habitat for sharks. These habitats vary from near-oceanic conditions to shallow, enclosed estuarine areas.
Through the Gulf of Mexico States Shark Pupping and Nursery Area project, also known as GULFSPAN, our scientists are attempting to identify which shark species use which coastal ecosystems, gauge the relative importance of these areas, and determine migration and distribution patterns of neonate and juvenile sharks. Data collected through this project are used in NOAA Fisheries’ Stock Assessment and Fisheries Evaluation (SAFE) Report for Atlantic Ocean and Gulf of Mexico Highly Migratory Species.
The group is currently surveying four coastal bay systems in northwest Florida: St. Andrew Bay, Crooked Island Sound, St. Joseph Bay, and Apalachicola Bay including the Gulf side of St. Vincent Island.
Juvenile spinner shark, Carcharhinus brevipinna, measured and tagged with a dart tag during annual GULFSPAN surveys.
Recovery of Smalltooth Sawfish
In U.S. waters, smalltooth sawfish (Pristis pectinata) have declined by up to 95 percent since the beginning of the 1900s as a consequence of historical fishing mortality and habitat loss. Because of this population decline and range reduction, NOAA Fisheries listed the U.S. distinct population segment as endangered under the Endangered Species Act in 2003. NOAA supports and participates in a number of research projects regarding sawfish. These projects provide vital information on habitat needs, population abundance, and the response of sawfish to recovery actions. Data collected from these projects are used to monitor the status of the population and aid in management and recovery decisions.
A juvenile smalltooth sawfish, Pristis pectinata, captured in a gillnet.
Approximately every 4 to 6 weeks, scientists from the Shark Population Assessment Group conduct research on smalltooth sawfish in critical habitat areas, primarily Everglades National Park and Ten Thousand Islands National Wildlife Refuge. Data is collected on abundance, movement, and habitat use.
Shark Tagging
NOAA Fisheries’ Cooperative Shark Tagging Program is an ongoing tagging/recapture study for shark and ray species in the Gulf of Mexico and western Atlantic Ocean. Our Shark Population Assessment Group has played an important role in this study, tagging over 20,000 sharks since 1993. This study helps determine the movement patterns of elasmobranchs (sharks, rays, and skates) in order to better understand their abundance, when/where they use coastal habitats, what distances they migrate and where they migrate to, and overall, how they are distributed.
NOAA Fisheries’ shark tagging program use five basic types of tags:
- Dart tag - used on moderate to large sharks (approximately 10 centimeters or 3.9 inches long).
- Roto tag - used on moderate to large sharks (small and large versions; approximately 4.5 centimeters or 1.8 inches long).
- Spaghetti tag - used only on small sharks (approximately 7 centimeters or 2.8 inches long).
- M-tag - used only on large sharks (approximately 18 centimeters or 7.1 inches long).
- Cinch-loop tag - used only on batoids (rays).
If you encounter a shark or ray that has been tagged with one of our tags, please measure the fork length (or total length) of the animal, record the tag number or keep the tag and contact NOAA Fisheries’ Panama City facility at (850) 234-6541 immediately.
Be prepared to submit the following information:
Your name, phone number, and home address.
Date, time, and location of your encounter with the shark/ray (please be as specific as possible).
Species, length, and condition of the shark/ray.
Your activity at the time of the encounter (e.g., fishing hook and line using shrimp as bait).
Information on the tag (especially the 4, 5, or 6-digit tag number), scars, or distinguishing marks.
In return for your assistance, the Shark Population Assessment Group will send you an official cooperative shark tagging program t-shirt and a letter with information about the shark/ray that you encountered.
Previously tagged lemon shark recaptured during survey.
Telemetry
Passive Acoustic Tracking
Passive acoustic telemetry is an important tool that is used to remotely study spatial ecology and migration patterns of aquatic organisms. The use of stationary underwater receivers removes the bias of potentially "chasing" animals within the study site and has been shown to produce reliable long term location movement. In addition, direct estimates of survivorship can be calculated from telemetry data. This permits a direct comparison of the relative importance of two habitats in terms of survivorship of juvenile sharks. Currently, the Shark Population Assessment Group has an acoustic array in Everglades National Park to monitor the movement of juvenile smalltooth sawfish, Pristis pectinata. This research is in cooperation with Florida State University's Coastal and Marine Laboratory and follows permits EVER-2011-SCI-0010 and ESA-13330.
Satellite Tagging
Recent advances in electronic data technology make it possible to store detailed records involving both vertical and horizontal movements of marine animals.
Information on swimming depth, water temperature, and a daily record of geolocation can be stored and uploaded to ARGOS satellites from pop-up satellite archival transmitters known as PAT tags. PAT tags can collect and relay data for periods up to 12 months depending on data recording intervals.
SPOT Tags
Smart Position or Temperature (SPOT) tags are an excellent method to obtaining near real-time movement data of species that periodically break the surface of the water. Towed tags are attached via a long tether, are positively buoyant, and can float at the surface behind a slow moving animal that is near the water’s surface. These tags can provide data for up to six months, depending on the tag battery life and frequency of data transmission.
sPAT Tags
Survivorship pop-up archival transmitting (sPAT) tag s are used to assess short-term survivorship of tagged animals. The sPAT tag uses a suite of sensors and algorithms that monitor the status of a tagged animal for up to 30 days. Generated reports are sent to the tag owner identifying the survivorship status of the tagged animal providing valuable data on how species respond to the stress of capture, particularly on longline gear.
The Shark Population Assessment Group is currently involved in collaborative projects using satellite technology to better understand movement and activity patterns of smalltooth sawfish and dusky sharks.
Smalltooth sawfish with a towed pop-up satellite archival transmitter.