Finally, they tested tissue samples from a 12-foot mako and compared the samples with DNA that was extracted from Potter’s shark. They found that the sharks were related, but it was unclear just how closely related they were.
Today’s makos are likely bigger due to the availability of food for the sharks off the West Coast. The Marine Mammal Protection Act of 1972 prohibited the killing of seals and sea lions. As a result, the sharks were left with a feast.
“Basically, what we learned is that this characteristic of getting absolutely massive is a characteristic of the general population along the California coastline,” O’Connell said. “To me, that’s an exciting thing. It means that there’s a lot of very big makos out there… and they have the ability to control the entire ecosystem.”
Currently, the species are at a healthy population, but an assessment of shortfin mako sharks in 2017 revealed that overfishing is a risk to them.
Anglers are allowed to catch two makos per day, which is a rule that could reduce their numbers significantly.
The NOAA is managing the species and is continuing efforts to end overfishing.
