Underwater Robot Collects Data To Help Sand Tiger Sharks
Sand tiger sharks, also known as gray nurse sharks or Carcharias taurus, have a large body that can go from 6.5 to 10.5 feet (around 2 to 3.2 meters). They are distributed throughout the world's subtropical or temperate waters and can be found right above the ocean floor, near the shore. They are a docile species as they show no aggression, as long as they're not bothered first.
Since their reproduction is extremely low and their habitats predictable, sand tiger sharks are being dragged to extinction due to overfishing. Its population decreased by over 75% during the '80s and '90s, and today they are classified as a vulnerable species by the International Union for Conservation of Nature.
To understand more about this species behavior and help its conservation, scientists from NOAA, the Coastal Studies Institute Duke University, Sand Shark Consortium, and North Carolina Aquariums are using underwater robots.
The researcher Avery B. Paxton is leading this research that started last July. She says that there's still a lot to understand about this type of shark, and we can get some answers by using this method underwater.
“It gets us our eyes underwater without having to physically touch the sharks or bring them up to the surface...”, “We thought that was a really big benefit to this method. It gives us a great picture of what’s going on underwater.” - Paxton says.
This marine robot includes several cameras, sensors, water temperature and salinity trackers. It is also capable of capturing signals from acoustic tags that were previously placed on the sharks. To measure the animal, there are two lasers coming from the robot that point to the animal's skin and give that information.
All the underwater procedures are done with the least disturbance possible to the shark community and since sand tiger sharks are such docile creatures, the marine robot can easily get close to their space.
The study area takes place in the waters of North Carolina, where scientists place the robot in the water and control it from the boat using a joystick. The data is being collected from a community of sharks living around eight shipwrecks from the World Wars I and II.
Although this shark species population is declining, the research team says that North Carolina "is a huge puzzle for us" as it's continuously replete with sand tiger sharks. The shipwrecks may have the answer and that's something this team will find out.
This research aims to discover new ways that better protect all shark species.
As Paxton said, “Sand tiger sharks, along with other sharks, are important for the health of coastal oceans”, “These sharks often function as some of the top predators in the system, which really maintains the overall health of the ecosystem.”
Keywords: Underwater robot, sand tiger shark, Carcharias taurus, decline,