The tiger sharks arrive like clockwork every June, drawn to the Okaloosa Island Pier by an unusual event that happens in the Gulf.

• For the past four years, Okaloosa’s Natural Resources Chief Alex Fogg and his team have been there waiting for them, ready with heavy tackle, steel leaders and satellite tags to unlock the mysteries of why this impressive apex predator seeks out the Pier.

Last week marked another successful chapter in their ongoing research, with 12 more tiger sharks tagged during two intense days on the water. The effort brings their total to just under 40 animals since the project began in 2022.

“These are not small animals,” Fogg said. “This year our smallest was nine feet, our biggest was 12 feet. These are adults and sub-adults.”

The research began when Fogg’s team noticed an uptick in large tiger sharks around the pier in 2021. What started as curiosity about why they are here has evolved into a comprehensive study involving Louisiana State University, Mississippi State University and the United States Geological Survey.

• The satellite tags were purchased by the Okaloosa Island Pier and Destin-Fort Walton Beach, to supplement tags historically provided by LSU and MSU. Local charter boat Finatical Charters joined in on the research and provided a second platform for tagging activities.

The sharks’ annual pilgrimage centers around a peculiar natural phenomenon. Each summer, massive schools of small baitfish called herring aggregate around the pier. By mid-June, these schools begin dying off in what researchers suspect may be oxygen depletion caused by their own density.

• “Once they die and start covering the bottom, the sharks show up like clockwork,” Fogg explained. “Literally, the day after these die-offs start, the tiger sharks show up in numbers. We’re seeing aggregations now of upwards of 20 or 30 animals.”

The tagging process requires precision teamwork. After hooking a shark with heavy tackle, the team works for 30 to 45 minutes to tire it out before bringing it alongside their boat. A crew of six researchers then springs into action, each with a specific role from securing the animal to taking measurements and applying the different tags.

The satellite tag application to the dorsal fin takes about five minutes. The surgical implantation of an acoustic tag in the shark’s belly requires just one to two minutes. Sometimes, depending on the animal’s condition, the team draws blood or takes a small fin clip for genetic analysis before releasing the animal.

“All the animals that we have tagged over the years, we’ve heard from every single one of them for at least a period of time, well beyond the tagging process,” Fogg said. “So we know that all the animals have survived.”

• The team has already heard from all of the satellite-tagged tiger sharks from last week’s effort, confirming the animals are healthy and moving.

The acoustic tags, about the size of a battery, can last up to eight years and have revealed remarkable migration patterns. The tagged sharks have been detected throughout the region, down into South Florida and across the western Gulf.

“These sharks are moving quite a ways, but the cool part is many of them come back to the Okaloosa Island pier each year,” Fogg said. “Once June hits, they start to meander their way back over to northwest Florida.”

What makes the Okaloosa Island Pier unique remains a mystery. Despite numerous piers to the east and west, none experience similar tiger shark aggregations.

• “We don’t really know why or what is so special about the Okaloosa Island Pier,” Fogg admitted, but noted it’s a focus of the research.

The research has attracted serious academic attention. A Louisiana State University researcher has made the project part of his dissertation work, analyzing everything from the sharks’ specific hangout spots around the pier to differences in behavior between males and females, large and small animals.

For visitors hoping to catch a glimpse of these impressive predators, Fogg recommends walking out on the pier during their summer stay. He says the sharks are focused mainly on their baitfish buffet and couldn’t be bothered by those fishing the pier.

• “You can go to the pier and see these animals and they’re just lazily swimming along, scooping up all the dead fish that are on the bottom,” he said. “There’s no other place on the planet to be honest. “

The team has also installed an underwater camera to provide real-time viewing opportunities for those who can’t visit in person. Fogg says his team is finalizing getting it online for the public.

As this year’s tagging season concludes, the research continues to yield surprises. Despite four years of tagging, the team has yet to recapture any previously tagged animals, suggesting the local population may be larger and more diverse than initially thought.

“That goes to show you that these are a lot of unique animals,” Fogg said.

The sharks typically remain around the pier for about six weeks before departing, often coinciding with the first strong Gulf storms that disperse their food source. Then begins their long journey across the Gulf, until the clockwork cycle brings them home again next June.

All tagging activities are conducted under proper research permits. While the public can observe the sharks from the pier, shark fishing is not permitted at the pier or county parks, and diving by the public is not allowed at the pier.