Kohala Coast Getaway, Part 3: Manta Rays
I squeezed into my full-length—and wet—wetsuit, slithered into another called a "shorty" and pulled a neoprene "hoodie" on my head, securing it with a chin strap. The ocean water temperature in Hawaii varies from about 76 in winter to 81 degrees in summer, a mere five degrees difference. On our earlier scuba dive at dusk here off Hawaii (Big) Island, my dive computer put the evening's water temperature at 77 degrees.
In addition to liking uninterrupted sleep, I like to be warm—or, as my husband would say, I run cold. And, after living in Hawaii for over a decade, my blood is thin, I get cold easily, and a few degrees can tip the scales from warm to cold. (I know. I know. I can hear some of you now. "You're complaining about 77 degree water temperature?" you ask. "Wimp," you declare. Wimp, indeed.)
But some things in life are worth doing a second time. They are not to be checked off your bucket list and forgotten. Some things warrant doing again and again. Even if you have to brave certain fears and weather the elements.
I mean, would you drink just a glass of wine and say, "I've tasted one, I've tasted them all?" No. There are hundreds of different wines to taste. Hundreds of different California wines to taste. And, in California, hundreds of different cabernet sauvignon wines to taste. Even, new harvests from the same vineyard to taste each new season. Not to mention occasions—Valentine's Day—and people to celebrate.
There are more than 170 identified manta rays that live in the Kona coastal waters of Hawaii (Big) Island. There's Sugar Ray, Knight Ray and Keiki Ray. Rachel Ray, Randall Ray and Ray Charles. Plus, Lefty, Hook and Captain Kirk. And mother of all manta rays, Big Bertha, with a 16-foot wingspan. Until this past weekend, I'd met four some two years ago. That leaves 166 more for me to meet.
This past Saturday night, I met eight more.
Of course, four may have been repeats. If I pulled out my underwater dive photographs from my first dive with manta rays and compared the belly markings, I'd know.
That brings up some interesting facts about manta rays:
-Manta rays belly markings are like fingerprints; no two are alike.
-Manta rays can grow to 20 feet, wingtip to wingtip. Their pectoral fins have evolved into wide triangular wings, which helps explain why they belong to a group of animals called batoids, which includes rays and skates.
-Manta rays are closely related to sting rays, but they do not have stingers.
-Like other members of the shark and ray family, the skeleton of manta rays is made entirely of cartilage.
-One of the largest animals in the ocean, manta rays eat some of the smallest. Manta rays feed on plankton (microscopic organisms, such as copepods, miniscule shrimp-like creatures and the larvae of fish, lobster and octopus that floats in open water). They use their cephalic fins to funnel water—and, hence, food—into their mouths and are known as filter feeders. (They do possess very small teeth—more like sandpaper, really—that forms along the lower jaw.)
-The word "manta" comes from the Spanish word for cloak, thanks to their broad, blanket-like body.
-Manta rays weight approximately 100 pounds for every foot of their wingspan.
-Manta rays can sail several feet out of the water.
-Manta rays' skin is covered with dermal denticals, small tooth-like structure, much like their shark cousins. Their skin has a mucous coating to defend against disease.
-Mantas reproduce via aplacental (without a placenta) viviparity (give live birth). A pup hatches from its thin-shelled egg inside the mother. After hatching the pups are fed by uterine milk until they are ready to be expelled. At birth, pups are about 3-4 feet wide and weigh approximately twenty pounds. The pectoral fins are curled around the pup in an S-shape, and when the pups are expelled, they unfold their wings and start to swim.
After tugging on my second and third skins, called wetsuits, I splashed into the dark water, the sun having firmly set. Jupiter may even have been out, but, perhaps not, because the vog from Kilauea Volcano had been thick lately. Cool water seeped inside my wetsuit at the ankles, wrists and neck.
I cinched tight, alternately, the underwater light strapped to my left wrist and the underwater camera around my right. I clamped my regulator in my mouth and dipped my face in the water to test the seal on my mask. And came face to face with the giant maw of a manta ray. It was like the behemoth had come knocking on our door to see if we wanted to play. More likely, it was hungry and wanted us to shine our lights, which attracts the plankton in the water that the manta rays like to eat.
Research shows that the manta ray brain case is encircled by a net of blood vessels. Some researchers hypothesize that this keeps the brain warm during deeper dives. Organisms with warm brain cases are thought to be more intelligent than those without. Hence, Big Bertha's knocking on our door.
Divemasters are notorious comedians. In our pre-dive briefing, our divemaster, Shannon, with Big Island Diver, said the number one rule about diving with manta rays was not to touch them. "Treat them like the dancers in Vegas," she said. "It's fine for them to touch you, but you cannot touch them."
There were a few other rules:
-Sit on the ocean floor and stay out of the water column where the manta rays feed.
-Hold your flashlight above your head.
-Remove all snorkels from masks, because manta rays are good at maneuvering between and among themselves but not good at detecting plastic and metal.
I released the air in my BCD to descend 30 feet to rest on the bottom of the ocean with the five other members of my dive group and an assortment of other divers.
The manta rays had beat us to dinner.
In some places, though, manta rays are dinner. Some manta ray populations around the world have been fished to extinction, according to Manta Pacific Research Foundation. Some people use the skin of manta rays for leather to make boots and wallets. Others dry their gills and grind them into a powder for aphrodisiacs and power enhancing medicines. And, according to Shannon, manta ray meat is turning up in imitation crab and lobster. If we are to enjoy the creatures of the ocean, we want to make sure there are still creatures to enjoy, she said, and encouraged our dive boat of 12 divers to check with the Monterey Bay Aquarium's Seafood WATCH to make sustainable choices when it comes to eating seafood.
In Hawaii, manta rays are protected. That doesn’t mean they have it easy. It's not unusual for one to show up trailing fishing line. Another of our divemasters dove with a knife strapped to his calf. "To cut fishing line off coral," Smiling Mike said. But I'll bet he'd use it to free a manta ray's cephalic fin from fishing line, as well, and such stories exist if you ask. Kona's first identified manta ray—dubbed Lefty—lost the use of her left cephalic fin, supposedly to marine entanglement.
Eight manta rays knitted the water above our heads like an intricate cable stitch, their giant mouths wide open. I could see down their gullets and through their radiator-like gill arches. Finger-like projections, called gill rakers, strained and captured the food while the excess water slipped out through the gill slits. Scientist call this ram-jet feeding.
I leaned on my left side, using my elbow in the sand as a pillar to support my body. I pointed my light up with my left hand and took pictures with my right, instinctively ducking just a bit as one manta ray swam over my body, unfurling its long wings to propel itself through the water. Many call this an underwater ballet, and I can't argue with that.
As the manta rays passed overhead, I struggled to sit still, as the mantas' wake surged the water in a super-slow motion boil.
Everywhere I looked, which admittedly wasn't very far in the dark sea, I saw graceful shapes moving through the water. Manta rays swooped by in layers. Criss-crossing. Undulating. Performing backward somersaults.
It was the most civilized feeding frenzy I'd ever witnessed, and, according to Shannon, we have the cooler water temperature to thank for it. Freshwater springs seep into the sea along the coastline and create the perfect temperature for plankton to grow. The shape of the bay, known as Garden Eel Cove in the daytime and Manta Ray Heaven after sunset, and the way the ocean’s waves roll in, create swirling eddies of cool water. The perfect feeding grounds for manta rays.
On my second opportunity to dive with manta rays, I finally outsmarted the cold-water-loving plankton, and, thanks to my neoprene hoodie, I sat on the ocean floor, breathing and warm.