Whale sharks spotted off AMI

Whale shark
Whale sharks are easily identified by their massive size, up to about 45 feet, and their polka dot coloration. - Kim Bassos-Hull, Mote Marine Laboratory | Submitted

Five whale sharks – the largest fish on Earth – were spotted about 40 miles off Anna Maria Island this weekend, and Mote Marine Laboratory scientists are asking people to report new sightings immediately.

The reasons for their rare visit are unknown, but whale sharks are thought to occasionally filter feed on local blooms of plankton or fish eggs, according to Mote.

Eight years ago this month, 10 whale sharks were spotted off Sarasota, about two months after the three-month-long April 20, 2010 Deepwater Horizon oil spill began. The unusual occurrence allowed Mote divers four hours to satellite tag several of them. Dr. Bob Hueter, director of the Center for Shark Research at Mote, told The Sun that the spill could have been the culprit: “We don’t know that the spill is pushing large animals into our waters, but this unusual grouping of whale sharks suggests that we should consider that hypothesis.”

Mote asks that boaters report any whale shark sightings in the Gulf of Mexico immediately from your boat or just after disembarking, within 24 hours at most, to Dr. Bob Hueter at Mote’s Center for Shark Research at 941-302-0976. Please note the number of whale sharks spotted, the date, time, location and exact GPS coordinates if possible.

If more whale sharks are reported, Hueter wants to attach a satellite tag to one or more of the gentle giants to collect data on their location and the temperatures and depths they encounter over a six-month period.

The tag trails behind the shark’s first dorsal fin on a short tether, and whenever the shark is at the surface, the tag transmits a precise location data. Retrieving the tag will yield extensive data, but if it cannot be recovered, the scientists will still receive real-time GPS signals from the tag, revealing where the shark is traveling, along with summarized data on depth and temperature.

“It’s important to understand where these sharks migrate, feed and carry out other key parts of their life cycles, so that resource managers can successfully protect them,” Hueter said in a press release. “We have placed satellite-linked tracking tags on numerous whale sharks at a major feeding aggregation off Mexico’s Yucatan Peninsula in the past decade, but it’s rarer that we can find and tag these huge fish off Florida’s Gulf Coast.”