Since most shark species are endangered, it is important to protect the ‘spawning’ areas where females give birth and produce their young. A new satellite-connected device, known as BAT, will allow scientists to know the location of these regions.
Its name is an acronym for “Birth Warning Tag,” and BAT is being developed by a team led by Professor James Sulikowski of Arizona State University and Professor Neil Hammerschlag of the University of Miami. The egg-shaped device is 6 cm long, 2.5 cm (2.4 x 1 in) wide and weighs 42 g (1.5 oz) when out of the water.
Here’s how it works…
Conservationists first capture female sharks at sea, bring them by boats, and roll them to a lethargic state. A portable ultrasound device is then used to scan the uterus to see if any embryos are present. If there is, insert her BAT into the uterus through the cloaca using a special applicator.
The shark is then released and the BAT remains harmlessly trapped inside the embryo. When those embryos develop into offspring and those offspring are born, BAT is expelled from the uterus with them.
It floats on the surface of the water and the dryness sensor attached to the top switches from standby to transmission mode. Utilizing a flexible antenna, BAT will begin transmitting signals to the orbiting Advanced Research and Earth Observation Satellite (ARGOS). These signals are sent at 15 second intervals for approximately 2 weeks until the battery runs out.
By accessing ARGOS data remotely from the lab, scientists can identify where sharks gave birth and where there are still growing sharks.
James Slikowski
The technique was successfully tested on a female tiger shark caught in the Bahamas that gave birth off the coast of Georgia after 157 days, and a scalloped hammerhead shark caught near North Carolina that gave birth off the coast of South Carolina. 46 days later.
“We’ve been trying to do this since we started working with sharks. This is our holy grail. We’ve really advanced shark science 20, 30, 40 years.” Sulikowski said. “This new satellite-based technology is of particular value for the protection of endangered shark species, where protecting shark spawning and nursery grounds is a conservation priority.”
In case you were wondering, BAT isn’t recovered from the ocean after every use, but those tested so far are typically washed up on shore and returned to scientists. He says he is.
A paper on this study was recently published in the journal scientific progress.
Source: Arizona State University
