Where do you conduct your research?

We work in Andros, The Bahamas, in Jupiter Florida, USA and the Florida Keys, USA.

How do you catch the sharks? 

Different sharks require different capture techniques. This can be anything from a shallow water gillnet (light weight fishing line meshing with weights on bottom floats on surface) to target newborn lemon sharks, or block rigs (concrete block with, leader wire / monofilament and float) to capture reef sharks, nurse or tigers sharks, to polyball fishing (large buoy with line and hook drifted over area to target particular species) deployed for great hammerhead or silky sharks. Our capture techniques are all designed to reduce the time the sharks are restrained for to ensure quick processing and release.

How do you identify individual sharks? 

We place Passive Integrated Transponders (PIT; Biomark – www.biomark.com) in all the sharks we capture. These are the size of a grain of rice and have an alphanumeric number that is unique to each shark. They are placed in the muscle next to the dorsal fin (via hypodermic needle) and can last ten years or more. PIT tags are great for identifying individuals across long time periods and have excellent retention as sharks can’t rub them off, like external marker tags.

What tags do you use to track sharks? 

We use a combination of satellite and acoustic electronic devices. Satellite tags (SPOT or PSAT, Wildlife Computers, Microwave Telemetry, Lotek Wireless) are typically used to monitor migration patterns both horizontally and vertically as they can provide locations of the sharks during tracks (e.g. 30 days to 2 years) and depth / temperature information at 5-minute intervals throughout their deployment. Acoustic tracking tags are usually deployed to examine habitat use at finer scales, determining the role of various biological factors (e.g. biotic / abiotic) on how sharks use particular areas. 

Do the tags harm the sharks? 

Our team are very careful with how we handle and place tags on sharks. Most satellite devices are placed next to or through the dorsal fin. There are no nerve endings in the fins and although we are unable to ask a shark if it feels us making a hole to place a tag, they do not react. The tags are temporary with materials that breakdown over time, so eventually there are no tag remnants on the shark. Acoustic tags are typically implanted in the body cavity and can last up to 10-years, many recent studies that our scientific team have been involved with have tracked some individuals up to 6-years with tags implanted showing no adverse effects.

Why do you tag sharks?

In order to conserve and manage sharks, researchers use tags to track them in their natural habitat and study their movement patterns and behavior. This tagging allows researchers to better understand the species’ life history, social behavior, reproduction and much more, including how often the animals may interact with fisheries. These fields are all very important for advancing the conservation and management of sharks. For example, Saving the Blue recently tagged a great hammerhead in Andros. Within the Bahamas, this shark was protected as part of the national Shark Sanctuary. When the shark left the Bahamas and swam to the United States, however, it was subject to fishing pressure as regulations permit limited harvest in federal waters. By revealing where sharks move and the routes they travel, scientists can understand how best to influence management and ultimately, protect them. This protection is only possible with the use of tags, which reveal the secrets of these fascinating creatures!

What information do you take from each shark?

This depends on the research projects we have ongoing, but a typical ‘work-up’ will involve taking length measurements, fin clip (for genetic analyses – stock structure, gene flow, mating characteristics; stable isotope analysis – diet, trophic position), blood and muscle (stable isotope analysis – short term diet, trophic position). We will determine sex via presence of claspers and measure those as well as check to see if they are flexible (hard = mature). 

For more information on any of the above, please contact our science committee.