Shark migration season has begun in southeast Florida. In the largest migration in U.S. coastal waters, blacktip sharks are headed south in the thousands for their annual migration off Florida's southeast coast.
- Shark migration begins in southeast Florida
- Thousands of blacktip sharks migrating south
- Research shows decline in number of sharks migrating south
Stephen Kajiura, Ph.D., an internationally renowned shark researcher at Florida Atlantic University, has been observing and tracking the sharks for eight consecutive years.
Using a boat, plane, acoustic monitoring devices, and drones, he can report their whereabouts in real-time.
Odds are that anyone in the water will be within a 60-foot radius of one of the sharks.
However, monitoring the migration patterns of blacktip sharks is not just about public safety, it's also about ocean health.
Kajiura said the sharks sweep through the waters and "spring clean" as they weed out weak and sick fish species helping to preserve coral reefs and sea grasses.
The sharks migrate down south during the coldest months of the year--when water temperatures drop below 71 degrees--and head north when is starts to warm up. Kajiuar said they swim as far south as southern Broward County or northern Dade County and as far north as North Carolina.
In prior years, researchers have reported as many as 15,000 sharks on any given day--but that's not the case this year.
Aerial video taken on Feb. 27, 2018 off MacArthur Park in Singer Island shows dramatically fewer blacktip sharks during migration season as compared to video footage from previous years.
“Last year, we saw a dramatic decline in the number of blacktip sharks that migrated south. In fact, it was so low that we estimated the population to be about one-third of what we have seen in previous years,” said Kajiura. “We want to make sure that these snowbirds come back to South Florida, because if they don’t, it will have a huge ecological impact in this region.”
Since water temperatures affect the migration of these sharks, studying the correlation of water temperatures and their migration patterns provides Kajiura with a powerful predictive tool.
Kajiura and his team use several different tools to capture date, photos, and video of the sharks. Kajiura said South Florida's crystal clear waters make it easy to distinguish the sharks.
He and his team can cover and record a field of view that's approximately 650 feet wide and less than 15 feet deep. They will then take those images back to the lab and manually count the sharks on a computer screen.
“My research assistant has personally counted more than 100,000 sharks on the computer screen, which actually look like little black dots,” said Kajiura.
Kajiura said the different ocean-observing tools they use provide different visual perspectives of these sharks to enhance his team’s ability to keep an eye on the oceans and census populations, and monitor animal responses to climate change.
Information from the Florida Atlantic University.