Our lab satellite tags sharks to study their migration patterns, such as this large female tiger shark in the Bahamas. Note the tag on the dorsal fin
In recent weeks, some conservation activists have been promoting an idea that I would like to respond to as a member of the scientific community. They claim that scientists shouldn’t publish data about shark migrations, movement, or population dynamics because such data helps fishermen to find areas where there are lots of sharks and kill them. This misguided anti-science paranoia demonstrates a fundamental lack of understanding about how conservation policy works.
Fishermen are neither having trouble finding sharks nor relying on the scientific community to learn where they are. In fact, this is exactly why such studies are needed.
Shark migration and habitat usage data are critical to developing effective management plans. One of the ten guiding principles of the U.N. International Plan of Action for Sharks is to “determine and protect critical habitats.” As we can’t stop all shark fishing in the entire ocean*, the goal is to identify the most important habitats (i.e. nursery areas, mating aggregation locations, etc). and focus conservation efforts on those. We can’t effectively protect sharks if we don’t know where they are, when they are there, and (ideally) what they are doing there.
Detailed data on population dynamics are critical for developing science-based sustainable catch limits. If managers don’t know how many sharks are in a population, they can’t accurately determine how many can be sustainably fished (and in many cases, just saying “don’t fish for them at all” is a cop-out that ignores the reality of the situation*).
Finally, detailed population data is also necessary for determining which species are the most threatened. If we weren’t monitoring population sizes, we wouldn’t know that some species are in need of additional legal protections. Indeed, most strong legal protections (Endangered Species Act, CITES, certain RFMO rules including quota reductions, etc) can’t be implemented without detailed scientific data showing that the species is declining in population.
Without scientists studying and publishing data on shark migration patterns and population dynamics, conservation policy would be crippled, but commercial fishing would still be doing just fine.
*Yes, I am aware that some countries are Shark Sanctuaries where no commercial fishing for sharks is allowed. If fishing is prohibited in an area, it’s unclear what negative impacts the publication of tracking data could have. However, most countries are not Shark Sanctuaries, and many areas, including international waters, will never be. If your goal is “no one in the world ever fishing for sharks anywhere” rather than protecting particularly threatened species and opposing unsustainable overfishing, you’re going to be disappointed.
For more information on the applications of satellite tags to shark research, please see our lab’s review paper on the subject.
