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In Other Ocean News

 

Project attempts to smother invasive clams

South Lake Tahoe, CA - Scuba divers are unrolling large rubber mats in Lake Tahoe with the idea of killing Asian clams by suffocating them.

Efforts are under way to rid Emerald Bay — perhaps Lake Tahoe's most iconic place — of an unwelcome visitor.

Asian clams, which have overrun the southeast portion of the lake, might still be eliminated successfully from the landmark bay on lake's west shore, scientists say.

Scuba divers are unrolling large rubber mats on five acres of the lakebed near the mouth of Emerald Bay, where Asian clams are found, with the idea of killing the invaders by suffocating them.

Blankets of rubber lie on the floor of Lake Tahoe at the entrance to Emerald Bay. More than 5 acres of the lake bottom are being covered with the rubber in an effort to smother many of the Asian clams now found near the bay.

Asian Clam have also been found in Donner Lake, another large Sierra Nevada lake, and may have migrated down the Truckee River to Reno, Nev., and potentially to its mouth at Pyramid Lake about 40 miles northeast of Reno.

"Eradication isn't a word that's used. It's controlling it," Schladow said. "If we can identify satellite populations, let's hit those first, and go back to the mother lode."

In 2009, scientists first used rubber barrier mats to kill clams at Marla Bay and South Lake Tahoe, Calif. The method proved highly effective at killing clams by robbing clam beds of oxygen.

Subsequent tests conducted at the Emerald Bay infestation were less effective, "an unpleasant surprise" scientists eventually linked to soil conditions and temperature variations, Schladow said.

The problem is now being overcome at Emerald Bay by putting down a layer of shredded aspens beneath the rubber mats. The decomposing material helps eat up oxygen and kill clams.

"They're not easy to suffocate. Clams are very good at clamming up," said Brant Allen, a UC Davis researcher who was diving at the Emerald Bay kill zone Tuesday. At the depth of about 15 feet, Allen and his colleagues are in the process of laying down more than 200 mats, each 100 feet long and 10 feet wide.

Unfortunately for seafood lovers, Asian clams grow to about 1.5 inches at most and are tasteless. So any idea of creating a culinary sensation from the invaders like tilapia, lionfish, snakeheads or black tiger shrimp isn't on the table.

"If there was a commercial incentive to aid in their removal, that would be fantastic," Schladow said.

 

Air-Powered Motorcycle Runs on Scuba Tank, Rotary Engine

The O2 Pursuit, a project from an engineering school graduate in Australia, runs off compressed air stored in an on-board tank. Dean Benstead’s project began with a rotary air compression engine, around which he built a dirt bike. He started with a Yamaha WR250R frame, and added a scuba-diving tank and a 25-pound engine to power the rear wheel. Squeeze the throttle and air is released to accelerate the bike. And its stats are impressive. The O2 Pursuit gets 62 miles of travel on a full tank, and can hit a top speed of 87 mph.

Air beats electric both for convenience and environmental kindness. There’s no battery to dispose of when the cells eventually break down, filling up with air takes two minutes rather than hours required for charging, and it can be stored in an inert state forever. And while the air-powered car is little more than a four-wheeled scam we’ve been hearing about for decades, the low weight of a bike is perfectly suited for the application.

“When the air comes out, it’s in the same state as when you compressed it,” Benstead said. “You haven’t technically used anything.”

 

Casio Develops Pocket-Sized Transcever for Scuba Diving Use

YAMAGATA, JAPAN, November 13, 2012 — Yamagata Casio Co., Ltd., a manufacturing subsidiary of Casio Computer Co., Ltd., announced today that it has applied technologies accumulated through the production of Casio products to develop an underwater transceiver that lets users enjoy spoken conversation when scuba diving. Casio will display a prototype of the new Logosease dive transceiver at the Diving Equipment and Marketing Association Show 2012 in Las Vegas, U.S.A., from November 14.

 

 

The Logosease is a transceiver that allows users to have spoken conversations underwater, revolutionizing the diving experience by solving the problem of communication limited to written signs and basic hand signals. With the Logosease, which is small enough to fit into a pocket and attach to the strap of a diving mask, divers can converse normally with the scuba regulator in their mouths. Since a full face mask or any other type of special equipment is unnecessary, the Logosease lets leisure divers converse with ease.

 

Vietnam dives into underwater heritage


A joint project by Australian and Vietnamese researchers is aiming to uncover and preserve the underwater heritage of Vietnam.
The project, a collaboration between the Bach Dang Battlefield Research Group and the Vietnamese Institute of Archaeology, is aiming to uncover material such as ships, underwater cities and aircraft.

"Unfortunately for about 20 years the Vietnamese were entering into agreements with treasure hunters, the treasure hunters would come in, raise a lot of material and it would all be sold. "They would lose access to their own cultural heritage. As a result they brought in legislation, regulation which stops that kind of thing happening any more, at least in principle."


Professor Staniforth says his particular research is focused on the site of the defeat of Kublai Khan's fleet by the Vietnamese in 1288.


The site is now covered by rice paddies, Professor Staniforth says, so tools such as magnetometers, metal detectors and ground-penetrating radar must be used.

"It's a medium to long term strategy so that the Vietnamese have their own capacity to do the kind of work that we can do in Australia."

Sea Shepherd's New Vessel -Former Japanese Research Vessel (the irony of taking on whalers with a ship they themselves built)

Los Angeles-based philanthropist and co-creator of TV’s “The Simpsons,” Sam Simon, had donated funds for the purchase of a ship, Sea Shepherd's new Antarctic patrol ship, the SSS Sam Simon.

The vessel, retired from service by the Japanese Government in 2010, has since been laid up in Shimonoseki, Japan, alongside the very ships Sea Shepherd will confront this season.

Originally built as Seifu Maru in 1993 by IHI shipyard in Tokyo, to a high standard with no expense spared by the Japanese Government, the ice-strengthened steel vessel was operated by the Maizuru Meteorogical Observatory, a department of the Japan Meteorological Agency, out of Kyoto Prefecture.

While Sea Shepherd and most of the world agrees that the word “research” has no place in the Institute of Cetacean Research’s (ICR's) whaling program, Seifu Maru was indeed responsible for a considerable amount of real ocean current data contributing to Japan's western North Pacific Whaling Program (JARPN).

 

Diving sickness rises after naval ship sinks

Australia - Medical experts expect the number of scuba divers suffering the bends to reach a record high in New South Wales this year, because of a new diving site on the state's central coast.

Former HMAS Adelaide was scuttled in April last yearand quickly became a diving draw card.

The wreck lies about 32 metres below the surface, which is around the depth limit for many recreational divers.

Figures from the hyperbaric medicine unit at Sydney's Prince of Wales Hospital show 27 patients were treated for the bends up until August this year.

In comparison there were 19 cases in total in 2011 and 28 in 2010.

Glen Hawkins from the University of New South Wales, who is also the medical director of private firm Hyperbaric Health, says the dive season has only just begun.

"By August this year, we've already reached the annual normal number and haven't hit the main diving season yet," Dr Hawkins said. "I would expect there's actually going to be a few more cases and we'll actually get a record number of divers being treated this year."

He says there are several contributing factors to the condition, including the depth of the wreck, the time between dives and relative diver inexperience.

Dr Hawkins says local diving operators need to ensure measures are in place to help address the problem. "It's important that they get feedback that there is a problem," he said.

"The reality is they may not actually be aware that something like this is happening because the people come in, do their dive, then disappear.

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