Sunday, August 1, 2004
A circle of scuba divers silently kneel 40 feet below on the ocean's rubbly bottom. Dense clouds of zooplankton swarm around their bodies as they shine their lights toward the surface. Engulfed in darkness, the divers wait for wings beneath the waves.
Twenty minutes later, a large female manta ray named "Andrea" flaps in slow-motion above their heads. With an open cavernous mouth, she glides, pivots and somersaults into the clouds, feasting on the drifting microscopic creatures. Wide-eyed divers struggle to spotlight her. The beams of their lights follow Andrea's every twist and turn, trying to catch another glimpse of her before she eats and runs.
Since the mid-1980s, dive boat operators on the Kona Coast have taken divers like these underwater to witness this nightly feeding ritual. In 2002, Big Island dive operators might have made over $2.5 million in combined revenues from the yearly 11,000 visitors viewing Hawaii's mantas, according to the state's Department of Business, Economic Development and Tourism. Although the dives' popularity and revenues increased over the years, the protection of Hawaii's mantas remained the same -- nonexistent.
Not for long, said Tim Clark, scientific director of Manta Pacific Research Foundation, a Kona nonprofit organization dedicated to the study and conservation of mantas. The foundation is preparing to ask the Hawaii Legislature next year to enact a "No Kill, No Extraction" law, making it illegal to kill, capture or intentionally injure mantas in Hawaiian waters.
There is no immediate fishing threat in Hawaii.
"To make a law, there needs to be some kind of biological basis," said Walter Ikehara, Aquatic Resources Division program manager for the Department of Land and Natural Resources. "When it comes to pre-emptive measures, I hesitate to speculate what would become of it, especially since there are other things of high priority. Still, we would consider it and would very much like to see their research."
Manta Meat Market
Slaughter. This is the word Clark uses to describe what's happening in Mexico, Indonesia and the Philippines. He said fisheries are slowly annihilating entire manta populations. They catch enormous amounts of mantas in order to meet the growing demand for fresh or dried manta meat.
Mexico banned manta fishing in 2000. Still, fishing continues at small camps because the ban isn't enforced. Clark estimated 500 mantas are caught there yearly for consumption.
A market for dried gill rakers has developed in China. The rakers are ground into a powder and used to make traditional medicines. Indonesian fisheries supply this market as well as catch more than 1,500 mantas annually. There, a single manta sells for about $160. Gill plates costs $143 while manta skin is $5, Clark said.
The increased market led to a rising fishing effort and a decline in manta populations in those areas. Fisheries fishing farther away proves their catches are dwindling, Clark said. "The level of fishing mantas can sustain is small," he said. "Our research shows they're poor species to fish. If mantas are continually exploited by these fisheries, they will be driven to extinction."
The Philippines have felt the effects of manta fishing. In March 1998, fishing was banned but still practiced in the southern part of the country. The manta populations are now considered threatened. Fishermen changed occupations. They're eco-tourism guides searching for the remains of a once thriving population, Clark said. "These beautiful, majestic, gentle giants are being threaten by hunting," Clark said. "It's time we protect this species before it's too late. A live manta is worth more than a dead one."
Uncloaking Kona's Population
Since 2001, Clark has investigated the habitat use and feeding ecology of Hawaii's mantas. The research is not only for the foundation, but also for his University of Hawaii doctorate work. Monthly, he and other foundation members give public lectures called "Reef Talks" to local schools and community organizations.
Clark has surveyed plankton and performed year-long tracking studies of Kona's manta population. He's "responsible for many 'firsts' in the current manta ray research field," such as proving there's "only one manta birostis species," according to http://www.mantapacific.org. In Spanish, manta means cloak, a well-chosen name for this underwater creature which is a member of the elasmobranch family of cartilaginous fish. This family includes sharks, according to http://www.divernet.com.
Like basking sharks, mantas are filter feeders. Their teeth resemble sand paper. They consume about 12 percent of their weight (180 to 300 pounds) in plankton daily, Clark said.
The largest manta was discovered in the Bahamas. It weighed more than 3,000 pounds and had a 22-foot wingspan. Hawaii's mantas, on the other hand, have a wingspan of 8-14 feet. When mantas are between the ages of 10-15, they reproduce. One female manta reportedly had three pups in seven years. So far, Clark hasn't found any data showing mantas have more than one pup every three years.
His tracking data indicates Kona's manta population is a closed population, meaning no migration in or out of the Kona Coast.
With the help of 12 volunteer UH interns, Clark tags mantas with an index finger size dart. They then follow the mantas in a 33-foot research vessel for five days. Clark also uses passive tags which last two years and are connected to 15 receivers on the Big Island. These receivers record location and depth.
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He said there's 80 to 100 individual mantas using the coastline and going down to 300 feet daily. Some mantas stay 3-5 miles off Keahole Point, near the "garden eels dive site."
Due to the low reproductive rate and limited dispersal, Clark is "pretty upset and worried" about mantas being fished. "Mantas cannot reproduce fast enough to replace the ones that are being fished out," he said. "Usually, when you're trying to sustain a fishery, you want something with a high turnover like shrimp, which reproduces 1,000 (offspring) per year. Mantas cannot sustain fisheries. Those, who chose not to believe this, are decimating entire populations of mantas."
Manta Pacific Research Foundation co-founder Keller Laros, left, leads divers on an afternoon dive as manta ray "Cousteau" swims past.
Manta Man
Keller Laros is "Manta Man" -- at least, that's his nickname at Jack's Diving Locker. For 13 years, Laros, the foundation's co-founder, has taken photo IDs of Kona's mantas while leading weekly afternoon and night dives. He's done 5,405 dives and recorded about 85 mantas. His data suggests about 40 of those mantas are re-sighted yearly, proving the population is small.
Laros began photographing and cataloging mantas because of "Lefty," a female manta with a broken left cephalic fin. Hanging unfurled and limp, the fin blocks half her mouth, which makes eating a challenge. Lefty was the first manta divers really got to know because she hung around them to feast, Laros said. Their underwater lights supplied her with an abundance of food.
While on dives, Laros said he would constantly keep an eye out for her. He noticed the spots on mantas' chests varied. Shortly after, Laros began assigning names to the mantas to distinguish and keep track of them. Big Bertha, Sugar Ray, Baby Huey, Taz, and Cousteau are some of the mantas' names. Usually, the first diver to spot and capture the manta on film selects the name.
"I've been diving for so long. Many of the mantas appeared as babies and I watched them grow up," Laros said. "I feel connected with them. They're unique individuals, not just another school of fish. Oftentimes, I'm like a worried parent. I'm with them for an hour and, the other 23, I hope they're not getting in trouble."
Over the years, Laros and other local professional scuba divers have spotted "big, nasty fishing hooks" in mantas. While most hooks rust and eventually fall out, stainless steel hooks must be removed. It took a year and the combined effort of local divers to remove with pliers a hook from the face of a manta named "Vicky." She still has a scar, Laros said.
Other mantas aren't so lucky, he added. Baby manta "Koey" had her cephalic fin cut off by a hook and fishing line.
"It's an absolute shame and it breaks my heart," Laros said. "She was an immaculate beauty. But because of someone's carelessness, her fin hangs there, dead. It could have been prevented."
Protection Plea
Wounds like these are exactly what Manta Pacific wants to stop. Laros doesn't think people in Hawaii try to intentionally harm the mantas.
"They just don't realize the potential harm they may be causing," he said. "People commonly think they're at a petting zoo when viewing the mantas. But touching them wipes off their protective mucus layer and causes red streaks to appear on their chests."
In 1993, Kona's dive operators drafted six guidelines for people to follow while on manta dives. It was then certified by The Ocean Recreation Council of Hawaii and PADI's Project AWARE. The guidelines can be found at http://www.mantapacific.org.
Recently, Clark helped mantas appear on the 2005 Red List, a list of species considered vulnerable or threatened by the scientific community. The list advises nations on which species they should consider protecting. "We felt it was time to start protecting the manta rays and the Red List is one step in that direction," he said. "The list affords them greater protection than they have at this time."
In May, the foundation started a petition to show and gather support for a "No Kill, No Extraction" law. Until the end of the year, it will collect signatures at http://www.mantapacific.org and local dive shops.
Before coming to the Big Island, Charles Galloway got his scuba certification in Austin, Texas. He heard diving with mantas was one of the top 100 things to do here. Before going on two dives July 16, he signed the foundation's petition. "The island is growing and it's time it plans ahead before it's too late," he said. Galloway watched four mantas hover overhead that night. One manta ray barrel-rolled in front of him with an open mouth, guiding plankton in with its unfurled mouth. "Until now, I had never seen a manta," he said after the dives. "They're pretty amazing. I'd like to see them protected; so, I can come back and see another one with my children."
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