Earlier this week, a group of Fort Pierce spearfishermen stumbled upon a rare occurrence – a white shark (the true common name actually omits the ‘great’ part) patrolling the warm waters of Florida.
White sharks have perhaps the widest global range (the habitat they can persist in) of any shark species, largely because this species is more or less “warm-blooded.” The white shark is in the Family Lamnidae, a group of speedy and robust predatory sharks that includes the makos, threshers, and porbeagles. These species are superb swimmers, and have a relatively higher metabolism due to their warmer internal temperature. For this reason, they are generally always on the move and hunting speedy prey.
While a few white sharks are spotted off Florida and the Keys each year, seeing them in the summer is quite a rare event, mainly because the warmer water temperatures can actually be energetically costly for warm-blooded species (where they would need to keep raising their metabolic rate).
Furthermore, white sharks don’t exclusively feed on marine mammals like seals. They actually have a wide range of food items that includes bony fishes like tuna and jacks, they can switch prey with seasonal changes, and recent research suggests that may even utilize stalking and scavenging (on whales) as a feeding strategy. There aren’t many large marine mammals off Florida in the summer, so it’s possible this species was passing through while stalking spawning schools of game fishes.
White sharks are among the most publicized and well-studied species of shark in the world. And while they are certainly a very “sexy” species, they are truly magnificent predators. The most intriguing thing about them is that they are still keeping us guessing – still surprising the greater research community as new insights on their biology and ecology develop. And while the discussion of “danger” surrounding this species is a common thing, I think ocean conservation in general can benefit from avoiding the mention of its falsified mythology. Therefore, my main question is this: will a news story or the journalism community ever be able to resist mentioning the movie Jaws when a shark is sighted?
One thing is for certain – I would have loved to be on that boat. And while our research team has actually encountered and tagged mako sharks (a close relative of the white shark) in Florida waters, I speak for all of us when I say that we are still holding out for an encounter like this.
-Austin Gallagher
PhD Student, Research Assistant
RJ Dunlap Marine Conservation Program
Abess Center for Ecosystem Science and Policy
www.austingallagher.com