Oddities of the deep Gulf move closer to us
It seems that a lot of uncommon critters are being spotted in the Gulf of Mexico of late.
Anna Maria Island anglers in less than 150 feet of water are catching sailfish, usually a deepwater denizen.
Dolphin, mind you, the fish, are being caught relatively close to shore, a species usually found only in the deep.
Ted Dorenkamp had a whale shark visit, nudge and bump his boat off Bean Point in the Gulf last week.
It is thought that our old friend the Loop Current is to blame.
There is a huge mass of water in the form of a current that enters the Gulf between the Yucatan Peninsula of Mexico and the western edge of Cuba. The Loop Current flows toward Louisiana, then branches toward Florida to the east and Texas to the west.
The Loop Current does a series of, well, loops through the Gulf before ending up in the Florida Straits between the Florida Keys and Cuba. It then forms the Gulf Stream and heads north across the Atlantic Ocean to Ireland.
In the spring and summer, it seems the loops in the Loop Current migrate a bit more eastward toward Southwest Florida. Deepwater fish that hang out in the current move with it, and we see critters like sailfish and dolphin-the-fish move closer to shore.
Whale sharks, too.
About those big fish
Whale sharks are the largest fish found in the waters on Earth at upwards of 50 feet in length. The big fish are in almost all the world’s warm-water oceans. They take their name from the first people who spotted one and described it as being as big as a whale and shaped like a shark.
Unlike sharks, though, these critters are filter-feeders. Lunch is plankton, small fish or maybe an occasional mackerel that gets scooped up in their big maw. The only harm they can cause humans is to roll on one, or gum you to death – both unlikely occurrences.
They do seem to be curious about swimmers and boats, though, and don’t mind being approached or approaching a diver to see what that other-world thing is doing in its environment. Dorenkamp can attest to that fact after his encounter last week with a whale shark 18 miles off Bean Point.
Whale sharks also are sort of a psychedelic-colored fish. Their skin is marked with a yellow spots, stripes and checkerboard patterns over a gray background. The marks are distinct on each shark, making identification easier.
They’re mostly deepwater critters, and can dive to depths of a mile. Most of the time, though, they’re found near the surface slurping up plankton. They’re also solitary, although whale sharks have been seen clumped up where the food supply is good in a gam, herd, school, pod, shiver or collage, whichever is your choice of description for the grouping.
Jack Morris is a senior biologist doing shark research at Mote Marine Laboratory. He’s been part of a team that is tagging whale sharks, mostly off Cancun, Mexico, to study their travels.
Morris said they’ve tagged between 600 and 700 of the animals. There seems to be a large aggregation of whale sharks off the Yucatan Peninsula, making tagging easier.
They’ve also installed some satellite tags on a few of the fish to track both movement and water conditions. One “star” that was tagged logged 4,500 miles, from Yucatan through the Florida Straits to the Caribbean, and when the tag came off she was in the southern hemisphere in the Atlantic.
It is plausible that the whale shark Dorenkamp saw last week could be in the Indian Ocean next year, Morris said.
The path of the creatures means that there are no sub-species of whale sharks, Morris said. They travel, they mate with new friends, they move on throughout the warmer waters of the world.
The collection of the fish near Mexico seems to be a result of an upwelling of ocean currents, which draws other fish and lots of plankton for whale shark lunches.
A whale shark was spotted off Pinellas County last February. Dorenkamp saw one off Anna Maria last week. There have also been reports of a whale shark off Lido Key and Venice of late. Same fish? Who knows?
Are there more around than usual? Again, no one knows, although Morris suggested that the increase in sightings could be due to more people being out on the water than in past years, or the lack of red tide, or the drought and the resulting absence or reduction of pollutants entering the water through stormwater runoff.
There is a “very cool” thing about whale sharks and how they eat. Morris said there is a hair-like rim in front of the animal’s gills that serves as a collector of plankton. The animals gulp in water through their mouth and pump it toward their gills. The filters collect the plankton, which the whale shark then slurps off with its big tongue, like a kid licking a Popsicle, or shakes its head before taking a big swallow.
“It’s very unusual, and very cool,” he said.
Females whale sharks bear live young, up to 200 at a time, all about 2 feet long at birth. The fish reach sexual maturity at age 30 or so, and can live up to 100 years.
Flying fish, too
Morris pointed out another oddity in the Gulf of late. Flying fish, normally a deepwater species, have been spotted on the M-1 and M-2 reefs about 8 miles out. He has no idea why they’re so close to shore.
Flying fish, according to National Geographic, “can be seen jumping out of warm ocean waters worldwide. Their streamlined torpedo shape helps them gather enough underwater speed to break the surface, and their large, wing-like pectoral fins get them airborne.
“Flying fish are thought to have evolved this remarkable gliding ability to escape predators, of which they have many. Their pursuers include mackerel, tuna, swordfish, marlin and other larger fish.
“The process of taking flight, or gliding, begins by gaining great velocity underwater, about 37 miles per hour. Angling upward, the four-winged flying fish breaks the surface and begins to taxi by rapidly beating its tail while it is still beneath the surface. It then takes to the air, sometimes reaching heights over 4 feet and gliding long distances, up to 655 feet.
“Once it nears the surface again, it can flap its tail and taxi without fully returning to the water. Capable of continuing its flight in such a manner, flying fish have been recorded stretching out their flights with consecutive glides spanning distances up to more than 1,300 feet.”
The Florida Museum of Natural History has a grim forecast for the fate of whale sharks.
Whale sharks have fins. Fins are prized in east Asia for soup, priced at upwards of $100 a serving. The museum’s assessment of whale sharks, both for its meat and its fins, states:
“At present, commercial fisheries for whale sharks are limited, but may expand from an increased demand for food products. In Taiwan, approximately 100 whale sharks are taken annually. The whale shark meat fetches a high price in this country, and this fact has stimulated larger harvests over the last years. Fishing for this shark also occurs in the Philippines … providing food for the local fishing communities.”
Here’s a fish that can grow to 50 feet in length and can live for upwards of 100 years, and people are killing it to make soup?