Saturday, May 27, 2006

Study: Overfishing Puts Southern California Kelp Forest Ecosystems at Risk; 'So Sensitive'


Santa Barbara, California (May 25, 2006 22:19 EST) Overfishing presents a much greater risk to the kelp forest ecosystems that span the West Coast -- from Alaska to Mexico's Baja Peninsula -- than the effects of run-off from fertilizers or sewage from the shore, say scientists at the University of California, Santa Barbara. The findings have important implications for the design of California's Marine Protected Areas.

In an article published in the May 26 issue of Science, researchers describe the first study to compare the top-down versus bottom-up human influences on the food chain of the kelp forest ecosystems.

BASICALLY, only nutrient inpuits at extreme levels from run-off are very detrimental to the nutrient rich kelp forest ecosystems. However, removing top predators creates an abundance of prey, many herbivores, which devestate the kelp forests... read more here.

Rare Kniejaw found off Maui



This is a spotted knifejaw, a fish that usually lives in deeper waters around the Northwestern Hawaiian islands, extremely rare around the main islands. Read the article here.

Divers carry pathogens in their wetsuits

Scuba divers could inadvertently be carrying coral disease from one reef to another, say scientists who have shown that bugs stick to wetsuits like glue. But a quick rinse in disinfectant can stop the spread.

Around 60% of the world's corals are thought to be under threat from warming seas, overfishing, pollution and coral diseases. Researchers have wondered whether ocean-hopping divers are playing a part by shipping disease-causing bacteria from an infected spot to a pristine one.

Diver and microbiologist Kay Marano-Briggs of George Mason University in Fairfax, Virginia, decided to investigate.

Thursday, May 25, 2006

UConn scientists probe sea squirt invasion


GROTON, Conn. - A blob-like creature is invading Long Island Sound and posing a threat to its lobsters and other shellfish, University of Connecticut scientists say.

The researchers say they have found colonies of invasive sea squirts, blob-shaped animals that reproduce easily, on the floor of the sound.

They believe this variety of sea squirt, known as didemnum, arrived on the hulls of ships from Asia. They have no known predators.

"This thing has the potential for causing significant economic impact when it attaches to the floor of the Sound, where it blankets and suffocates shellfish and lobsters," said Ivar Babb, director of UConn's Undersea Research Center at Avery Point in Groton.

The animals range in color from a creamy translucent pearl to olive or tan. In Japan, there are some red species.

"This thing is ugly," Babb said. "It has no socially redeeming virtues."

The UConn researchers, who want to document how much of the Sound's floor the sea squirt blankets, went out Tuesday on UConn's 72-foot coastal research vessel.

Using a remote-controlled robot, they began mapping a region of about 1 square mile near Fisher's Island, taking pictures and video.

"We are seeing some large colonies of these sea squirts," said Robert Whitlach, a professor of marine sciences at UConn at Avery Point, who was on board the boat Tuesday afternoon. "Sometimes they are a few inches in diameter; other times they are a mat 4 to 5 square feet."

They cannot break the colonies apart, Babb said. Like sea stars that become damaged, they can grow replacement parts. Splitting one sea squirt in half doesn't kill it; it only creates two of the plankton-eating creatures.

If the scientists don't find bigger quantities of the blob-like creature, they might use chlorine or vinegar to kill it. First, however, they plan to study the effect those substances might have on other marine life native to the Sound.

Florida turtle eggs may have been buried

NEW SMYRNA BEACH, FL, United States (UPI) -- Construction crews may have accidentally buried a protected sea-turtle nest at Florida`s New Smyrna Beach because biologists might not have marked it.

However, a Volusia County, Fla., environmental consultant on sea turtles, Bob Ernest, told the Orlando (Fla.) Sentinel a nest might not have been there in the first place.

'This was our fault,' Ernest told the newspaper. 'We didn`t have the proper procedures in place.'

The incident is said to be the first reported problem involving the federally protected sea turtles and a $14 million, 5-mile-long dune restoration project.

Although turtle nesting officially started May 1, dune restoration was allowed to continue and Ernest`s Ecological Associates Inc. of Jensen Beach was assigned to monitor the nesting and move nests at risk from the construction work.

WHAT??? NOT HAVE THE PROPER PROCEDURES IN PLACE??? Aren't you a consulting and monitoring firm? Shouldn't you know what the hell you are doing? The problem with these private consulting firms is that they are private, not regulated by the government and therefore usually find or go along with whoever is paying them. Turtle nest monitoring should be done by state officials, not some guy getting paid by the big companyies doing the beach construction.

Video shows volcano erupting 555 metres underwater; 'It was a riveting sight'


Newport, Oregon (May 24, 2006 22:37 EST) An international team of scientists has presented its findings from the first observations of the eruption of a submarine volcano that in 2004 and 2005 spewed out plumes of sulfur-rich fluid and pulses of volcanic ash 550 meters below the ocean's surface near the Mariana Islands northwest of Guam. Check out the article.

Experts warn of New England hurricane


Amid a flurry of new data showing a dramatic increase in the water temperatures in the north Atlantic ocean, forecasters Monday said something of a perfect storm is developing, and raised the specter that a major hurricane will threaten New England this summer.

"The chances of a hurricane hitting the East Coast are exceptionally high," said Ken Reeves, the director of forecast operations at AccuWeather in State College, Pa.

Conditions are prime for a major tropical system to race up the Eastern Seaboard, maintaining its strength when it encounters the warm waters off the Middle Atlantic coast, he said. A buoy 200 miles off the New Jersey coast recorded a water temperature of 70 degrees in mid-April. It's typically 42 degrees at that time.

"It's only a matter of time before a major landfall happens in New England," Reeves said. "It could be this year."

Though Hurricane Gloria was the last storm to directly hit the region when it struck Connecticut as a robust Category 2 storm in September 1985, "The Long Island Express" storm in 1938 devastated Danbury with flooding and wind damage.

A group of longtime residents discussed memories of the great storm Monday at the Danbury Senior Center.

Granville Varian, 90, was working at Mallory's hat shop on Rose Street when the storm hit. He drove his Oldsmobile to Main Street to pick up his wife.

"I had to drive up on the sidewalk to get her," Varian said. "The roads were all dirt and they all washed out."

It took the couple an hour and half to make the trip to their house on Middle River Road, where he still lives. The trip usually takes 15 minutes.

The factory where Varian worked flooded and closed for a week.

C. Rodney Dow was working with his brother picking apples at a farm in Milford, Mass., when the great storm struck.

"Chickens were flying through the air," said Dow, 86, of Danbury. The squawking foul were not the only objects floating through the sky. Buildings also were uplifted by fierce winds, he said.

The Northeast ranks behind only the Carolinas as the region that it is most likely to be hit this year, forecasters said.

The heightened risk for Connecticut begins with the peak of the season in mid-August and will last until early October, Reeves said.

The outlook for Connecticut came as the National Weather Service predicted there would be fewer named tropical systems this year than last.

An above-normal tropical storm season could produce between four and six major hurricanes in the Atlantic Ocean and Gulf of Mexico this year, but conditions don't appear ripe for a repeat of 2005's record activity, the National Hurricane Center predicted Monday.

There will be up to 16 named storms, the center predicted, which would be significantly less than last year's record 28. Still, people in coastal regions should prepare for the possibility of major storms, said Max Mayfield, director of the National Hurricane Center.

"One hurricane hitting where you live is enough to make it a bad season," Mayfield said.

Should a storm hit Danbury, residents can expect to contend with rain and high winds. The storm surge would impact residents along the coast.

Emergency operations officials plan to conduct a drill next month in Hartford, where they will simulate the response to a category 3 storm.

Connecticut emergency management officials said they recently updated the state's storm evacuation plan.

AccuWeather's prediction that a major storm would likely hit New England this year drew criticism Monday from experts who said that it is difficult, if not impossible, to predict where a hurricane will strike.

"Will this year be the one? No one really knows," said Bill Jacquemin, a meteorologist at the Connecticut Weather Center in Danbury.

Reeves defended his forecast, saying critics "over-rely on computer models." He and his team look at patterns that indicate where a storm might hit, and they correctly predicted that the Gulf Coast would be a focus of activity last year, he said.

"There is no mystery about them."

Wednesday, May 24, 2006

French Scientists Find 'Living Fossil'



French scientists who explored the Coral Sea said Friday they discovered a new species of crustacean that was thought to have become extinct 60 million years ago.

The "living fossil," a female baptized Neoglyphea Neocaledonica, was discovered 1,312 feet under water during an expedition in the Chesterfield Islands, northwest of New Caledonia, the National Museum of Natural History and the Research Institute for Development said in a statement.

Another so-called living fossil from the Neoglyphea group was discovered in 1908 in the Philippines by the U.S. Albatross, a research vessel. It remained unidentified until 1975 when two French scientists from the natural history museum identified and named it: Neoglyphea Inopinata. More of the creatures were then found in expeditions to the Philippines between 1976 and 1984.

In October, marine biologist Philippe Bouchet and Bertrand Richer De Forges found the new species of the same living fossil group while trolling an undersea plateau in a remote area between Australia and New Caledonia.

Bouchet, in a telephone interview with The Associated Press, described the nearly 5-inch creature as "halfway between a shrimp and a mud lobster." Its huge eyes, reddish spots and thickset body distinguished it from the 1908 crustacean.

The huge eyes suggest that light plays a role in the behavior of the creature, which could actively hunt prey, Bouchet said.

With the Coral Sea discovery, "the group is less completely extinct than was thought," he said.

Beyond the intrinsic value of the discovery, the marine biologist said he had been working in the region for two decades before coming across the elusive creature, underscoring that "there are places on this planet incredibly remote and little explored."

The discovery "conveys a message that, in the first years of the 21st century, the exploration of planet Earth is not over," Bouchet said.

Navy Ship ‘Reefing’ May Have Down Side, Environmentalists Say



May 23 – The intentional sinking of a retired World War II-era aircraft carrier by the US Navy is being hailed as an economic boon for a Florida panhandle town still in recovery from successive hurricanes. But the safety of the "artificial reefing" program, designed to attract divers from around the world, is untested, and now hundreds of pounds of toxins have been dropped to the ocean floor.

Since the USS Oriskany was decommissioned in the 1970s, the Navy has been trying to dispose of the 888-foot warship, along with an increasing number of other retired ships, most of which contain the banned carcinogen Polychlorinated biphenyl (PCB).

On May 17, after a pre-planned explosion, the Oriskany sank in 37 minutes. It now sits 22.5 nautical miles Southeast of Pensacola, Florida.

"There’s a lot of questions here," said Kurt Davies, research director for Greenpeace, which has filed requests under the Freedom of Information Act to find out more about the Environmental Protection Agency’s process for approving the "reefing." "What we’re very concerned about is the dialogue between the Navy and the EPA about PCB waste that’s on board the Oriskany."

Davies said his group seeks information about why the EPA changed its own rules and then made an extra exception to those rules in order to allow the Navy to sink the ship.

In 1989, during the scrapping of a submarine on the West Coast, the Navy discovered that PCBs were contained in the vessel.

Subsequent testing found PCBs in the wiring, insulation, paint, gaskets, caulking, plastic and other non-metallic materials in almost all of the Navy’s ships built prior to 1976. That year, Congress banned the manufacture, processing and distribution of commercial PCBs. Research has shown that exposure to the toxin can disrupt the hormone systems of animals, and, over time, cause cancer in humans.

The discovery forced the Navy to put its plans to sink several ships on hold. Although hundreds of ships had been intentionally sunk, the EPA took a position that deliberately sinking vessels containing PCBs would violate the Clean Water Act.

According to a 2004 report by the Artificial Reef Subcommittees of the Atlantic and Gulf States Marine Fisheries Commissions, the EPA ban on the use of PCBs created a situation in which "no vessel could be cost-effectively prepared for sinking."

Efforts to have the Oriskany turned into a museum or sold off for scrap material both failed, and the Navy had decided that dismantling and recycling the ship was a "cost-prohibitive option," with a price tag of at least $12 million.

Then, in 2001, with the Navy seeing an increasing number of warships in need of disposal, the EPA’s Office of Pollution, Prevention, Pesticides and Toxics program changed the definition of reefing from "continued use" to "disposal." The language tweaking raised the acceptable level of PCBs from 2 parts per million to 50 parts per million, and allowed for the reefing of the Spiegel Grove off of Key Largo, Florida.

Even still, the Oriskany had solid concentrations of PCB’s that exceeded the legal limit, and the Navy said it couldn’t remove the remaining 700 pounds of PCBs without completely dismantling the ship.

In its 2004 environmental assessment of the proposed sinking of the Oriskany, the Navy wrote, "The purpose of the proposed action is to reduce the inactive ship inventory. The need for the action is to reduce expenses associated with maintaining ships that are pending disposal."

The EPA granted a one-time permit to allow for sinking of the Oriskany.

Aside from the risk that fish near the site will become contaminated, five threatened or endangered species of sea turtles are also found near the Oriskany’s new home. Davies pointed out the irony that Florida’s citizens and legislators fight one form of pollution, but some welcome a second with open arms.

"In Florida, you’ve been defending [the environment] against oil rigs – this very part of the Gulf of Mexico – for fear of pollution on your beaches in Florida," Davies said. "This is another case of a pollution source being introduced into the system."

Greenpeace says it is concerned that economics may have trumped health and safety in the approval process. Florida’s application to become the Oriskany’s new home had to compete with proposals from Mississippi and Texas, as well as a joint bid by Georgia and South Carolina.

The sinking of the Oriskany is expected to bring in millions of dollars every year to Escambia County, and the effects are already being seen. Speaking to The NewStandard two days after the Oriskany sank, Jim Phillips, at the Pensacola dive shop MBT Divers, said his business has been getting non-stop calls from people seeking to make reservations to dive the site.

"We never really made it on the map as far as being a dive destination," Phillips said. But he predicted that would change, as one of only three sunken aircraft carriers in the world now sits on the ocean floor only an hour’s boat ride from shore. "Now that the Oriskany's here, that will put us probably close to the top."

Phillips told TNS that the diving community was heavily involved in helping bring the Oriskany to the Pensacola area.

"We were very active," Phillips said. "Personally, it consumed pretty much every day for the last almost three years."

In their 2003-04 annual report, the Pensacola Bay Area Chamber of Commerce credits the area’s Convention and Visitors Bureau for playing an instrumental role in seeing Pensacola chosen as the sinking site. Phillips said those involved in the roughly 30 dive shops and dive boat operations served as information sources for the EPA and other government agencies.

"If environmental people had questions, if we had the opportunity to help resolve some of the issues, we did," Phillips said. "We did lots of communicating with legislators and the different politicians at the different levels involved."

For its part, the EPA denies interference by locals, politicians or the Navy in its decision-making process. "There is a feisty competition any time there is one offered for reefing," acknowledged Mark Fite, chief of the EPA's Children’s Health, Lead and Asbestos Management Section of Region 4.

But Fite insisted the approval process was thorough. "We weren’t pushed into any decision," he told TNS. "This was a decision that EPA has the sole authority to make, and we’ve done that."

Fite said the State of Florida is developing a program to test PCB levels in fish caught in the vicinity of the ship, and that the monitoring plan "will go on for a number of years."

Laura Niles, spokesperson at the EPA’s Region 4 office, added that any fish caught with PCB levels of more than two parts per million will trigger further assessment. Niles also said the standards used for the Oriskany will not apply to future reefings and that the EPA is in the process of developing a national reefing approval process.

While Greenpeace is not against all artificial reefing projects per se, Davies said, the group is concerned that the Navy has more sinkings planned. "We feel like they’re greasing the path for a really quick fix on the problem of ship disposal that [carries] uncertain risks."

Lad Akins, the executive director of the Reef Environmental Education Foundation (REEF), a Key Largo-based group that collects data and educates the public on marine life, said there is "considerable debate" among those in his field about the merits of sinking giant ships. "I have concerns, and I think that anybody who says they don’t, should have," he said.

Despite his belief that the pollution from the Oriskanys’ innards will not be an immediate problem, Akins says there are questions that remain unanswered. "What happens when you get a severe hurricane?" he asked. "What’s it going to do to that structure, and what’s it going to look like in 50 or 100 years?"

In a 2004 environmental assessment of the Oriskany, the Navy quoted a 1997 Gulf States Marine Fisheries Commission document, which says vessels have life spans as artificial reefs that may exceed 50 years. But Akins points out that "almost anything you put in the ocean is gonna break down if you give it enough time, and certainly that ship will break down someday."

Jellyfish that can get under your skin


Imagine a farm in the ocean, where cowboys corral sea life instead of livestock.
While there is not yet talk of a jellyfish stampede, a team of Israeli scientists have taken a natural mechanism in sea animals used for 700 million years and have turned it into a medical advance that could make injections pain-free.

Researchers at NanoCyte startup have discovered a way to take the miniscule stingers found in sea creatures and fill them with important pharmaceuticals that can be delivered painlessly through the skin of a patient. A person simply rubs on a cream loaded with sea-life stingers and embedded with a drug such as insulin onto the skin, activating the stingers which inject the drug.

In the near future, this may mean no more daily injections for diabetics, no more injections at the dentist office and no more injections before surgery.

Anyone who has been stung by a jellyfish knows how fast the pain can travel. Based on this mechanism, NanoCyte investigated non-toxic versions of similar animals, the sea anemone, and discovered a way to put its sting to good use. Sea anenomes may look like flowers, but they are a boneless animal which prey on other sea life. They live in the sea usually attached to the sea bed or rock, but can move around slowly.

Read the rest here.

Monday, May 22, 2006

OK...

So I know I haven't been updating in a while. For the last three weeks I have been kind of homeless. I moved out of my place at the end of April, and for the first two weeks of May I was living in Key Largo at NURC for work. We had the internet there, but I didn't get on very often. Anyway, I have some pictures I attempted to take in the mangroves on my last day working. I apologize for their poor quality but it was my first time trying to use a close-up lens (not a macro) and also the water was shallow and stirred up easily.

This was my attempt at one of those cool pictures you see in National Geographic that are half under and half out of the water. As you can see, I am not good at it, but I think it has as much to do with the equipment I was using ( a point and shoot 35mm).

Mangrove snappers, there's also a couple grunts in the bottom lefthand corner, again this is blurry mostly bc of me but the fish were pretty active.

A blue crab, pretty big guy too.

This is a lookdown in the mangroves...

And just in case, on my journey back to the North, I stopped at 3 aquariums.
First, I stopped in Atlanta at the Georgia Aquarium, which is very impressive. They have numerous huge tanks that you get to see from all sorts of angles, including underneath! The large barrier reef tank was awesome, I sat there for about 20 minutes. They fed the fish while I was there and all the fish came out from the reef. And of course, the whale shark tank, probably the coolest thing I have ever seen. There are so many fish in that tank its amazing. The plexiglass is like 2 feet thick, and it has a movie theater sized viewing window which is awesome. You could sit there for hours if there weren't so many people. They have some coldwater exhibits, with otters and seals and sea lions, and beluga whales. They also have a freshwater section, which was cool. When you first walk in there is a nice big African cichlid tank. The coolest freshwater exhibit though was this huge tank of river fish with gars and sturgeon and the like that pretty much goes all around you, up over your head, on both sides, incredible.They also have a Georgia native section, which I think is lacking.Plus they have more touch tanks than I have ever seen. I do however have a few knocks: way too much empty space (yes they have the biggest tanks in the world, fine, but so much more could be done); they have an upstairs with nothing (no displays); their native Georgia section, in my opinion, sucks (no salt marshes? ); also some of the fish in the displays weren't in the best condition (the yellowtail snapper in the whale shark tank all looked sickly and in the fw section the discus and angels looked in pretty rough shape as well) It is definitely worth the trip
I next visited the North Carolina Aquarium at Fort Fisher ( there are 3 small aquariums in North Carolina). It was just remodeled and despite its small size, it was very impressive. So much attention to detail was paid, it was incredible. The best thing about it is it deals primarily with natives, and it has outdoor nature walk through a botanical garden and pond. You cant expect too much when you go to these small aquariums, but they are definitely worth the time. They are usually not crowded, so you can see everything.
Finally, I stopped into the National Aquarium at Baltimore. Now this, this was incredible. It's hard to explain it here but I will try. It's built up, not out, but it has 3 buildings. Anyway, you start on the 1st floor (which is actually the second floor) and you are at the surface of their huge ray tank. Basically this place is six stories high and you walk along this path viewing all the tanks along the outside loop of the aquarium. They have more educational stuff, the first "section" you get to is all about adaptation, so you see fish in different environments, with different techniques for feeding and survival. There are small and large tanks here so you can really see everything. Then you go up to native Maryland fish, from upstream freshwater, down to marshes, seagrass beds in coastal lagoons and the ocean. This was cool. (I always like a good marsh display) Then you journey to the Pacific, you see coldwater kelp forest with this awesome california sheephead, which you need to check out that picture. Then reef tanks. Next you go to the Amazon River Basin (this tank is awesome), a display with trees and water up about halfway. They have caiman, tons of turtles, big pacus, other various characins, uarus, severums, festivums, geophagus, schools of bleeding hearts, cardinals, rummynose. It's absolutley an amazing tank. Huge catfish. I can't even list it all. Then you go around the corner to see an awesome discus tank. Next you go to the top level which is a greenhouse with all live trees and also serves as an aviary, the upland rainforest. Not only are the birds flying all around and then they have little water displays one with angel fish and one with pirhanas. They also have a sloth and monkeys (although apparently the monkeys were misbehaving so they were put away when I was there). But then you walk down and you are walking down these spiraling ramps on the inside of an Atlantic reef tank, with schools of lookdown and bar jacks, grunts, snappers, surgeonfish swimming around you. And then under that tank is the shark tank with sand tigers, sandbar and nurse sharks. That's just building one!!! They have an awesome frog display in the Dolphin building (I hear the dolphin show is supposed to be good but I don't go see those). And in the third building they have this awesome Australia exhibit again where you walk through this aviary with huge tanks, waterfalls, birds flying around. It's too much to describe. No wasted space here. As cool as the whale sharks are at Georgia, this aquarium in Baltimore is better in my opinion.

Just in case anyone is wondering, that is now my 14 aquariums visited. Including the three I described above, I have been to the Miami Seaquarium, the Clearwater Aquarium, Florida Aquarium and Seaworld in Florida, the North Carolina Aquarium at Pine Knolls Shores, Jenkinsons Aquarium at the Jesrey Shore, the New York Aquarium in Coney Island ( I actually worked there for a summer), Atlantis Aquarium in Riverhead, Mystic Aquarium in Connecticut and the New England Aquarium in Boston. Oh and I have also been to the Curacao Seaquarium in Curacao. I want to go see the Shedd in Chi-town and Monterrey.

Tuesday, May 02, 2006

Samana


Check out this site, Samana.org...
Samana is a beautiful place in the Dominican Republic. I stopped there on my seamester trip. Of course I did not do the whale watching which they are famous for, they were big into promoting their eco tourism. We did a hike through the forest to an amazing waterfall and also went to a "playa rincon" which was a pristine beach wheree you can take canoes up into a mangrove lined river. Samana is an amazing place, the people are all friendly, and the Presidente is ice cold!

Marine Current Turbines


Marine Current Turbines Ltd (MCT) is developing radically new technology, backed by the UK government, for exploiting tidal currents for large-scale power generation. We do not have any commercially available products at present, but we aim to achieve this by 2007-8.

SEE THE MCT WEBSITE!

This thing is pretty cool...


The replacement tongue

This is so awesomely disgustingly great I had to post it. There’s a louse that consumes a fish’s tongue and replaces it with itself. Cymothoa exigua was discovered inside the mouth of a red snapper bought from a London market. The louse had grabbed ahold of the tongue and slowly eaten it away until only a stub was left. It then latched onto the stub and became the fish’s tongue — getting a free meal after having fed on the tongue artery while it ate away.

Naturally, some crazy scientists are excited by the find, while the rest of the world remains disgusted. I’m intrigued: it’s certainly a novel idea, and quite frankly, I’m surprised something like this hasn’t been discovered before. The fish most likely came from California, but there is some confusion. Cymothoa was known to exist in the Gulf of California, but since it showed up in London, they’re not sure whether the fish was imported or the louse is simply expanding its territory. Cymothoa poses no danger to humans since it only attaches to fish tongues. Found attached to Lutjanus guttatus (a red or rose-spotted snapper, depending who you read), the parasite poses no danger to humans, but is pretty disgusting.

It enters through the fish’s gills and uses claws to attach itself to the base of the snapper’s tongue and survives by drinking blood from an artery. Once the tongue has been gotten rid of, it attaches itself as a new tongue, and manipulate’s the fish’s food and consumes the free food particles as the fish eats. Again, there is some confusion on what exactly happens: whether the louse eats the tongue, or simply causes it to atrophy due to blood loss, but the net effect is the same: the louse becomes the new tongue.

Imagine dicing up a fish for dinner and seeing one of these little monstrosities, eh? (Another larger image)

From Practical Fishkeeping, Discovery, and CBBC News.
(thanks polyscience.org)

Monday, May 01, 2006

Does a South American electric fish hold the key for humans learning to regrow lost limbs?


Humans can regrow skin, muscle and even livers, but regenerating an entire arm or leg is beyond our biological skills.

That's an ability we lost through evolution. But it's something lower animals - such as electric fish - still do.

Nobody's sure why we lost that ability. Studying animals that can regrow body parts could help us, through science, find ways to regain that skill, said Graciela Unguez, an assistant professor of biology at New Mexico State University.

Unguez is studying an electric fish from South America that can regrow its entire tail. The science is in its infancy, but her goal is to figure out how the fish regrows types of new specialized cells to replace the ones it lost.

"The fish, when you cut its tail, it will regrow a stump of immature cells," Unguez said. "Then it will start making muscle cells."

The immature cells change and specialize to replace the fish's skin, spine and electric organs, which it uses for defense and navigation, she said.

In her studies, she can cut a fish's tail off over and over again and watch it repeatedly grow back.

If scientists can figure out the chemistry that makes those immature cells change and grow a new tail, they might be able to create drugs that can be injected into a human amputees' limb to regrow it, Unguez said.

Higher animals have a far more complex range of cell types than the fish, and it might be we lost the ability to regenerate because of that complexity, Unguez added.

"Regeneration is a huge problem to solve," Unguez said. "If we lose a hand, it's a question of you have to regenerate the right size (of hand), the exact number of cell types that were there before."

Specialized cells - like blood, bone, nerve and skin - might also be much harder for the body to revert back to an earlier stage of development so, like the fish's stump of immature cells, they can rebuild an organ, said Harold Zakon, a professor of neurobiology at the University of Texas-Austin, who is working with Unguez.

"Perhaps by focusing on specialization, becoming something and staying that thing, the job (of a cell) could be done more efficiently," Zakon said. "Having lots of specialists may be a way of having an organism that works very well, but those specialists may not be able to go back and do somebody else's (a different cell's) job."

Unguez has been studying the fish for the past few years. On May 31, she starts a new $130,000-a-year grant from the National Institutes of Health that should greatly help her research.

That grant will last for three years.

Unguez and Zakon also plan to work this summer on an $18,000 research project at the Woods Hole Marine Biological Laboratory in Massachusetts that will investigate the evolutionary history of regeneration, Zakon said.

There are two predominant ideas about how animals like the electric fish can reproduce limbs:

One idea is that some animals can revert mature cells to an earlier stage of development and then regrow them to specialize in a different aspect - such as a skin cell reverting and regrowing as a bone cell.

The other idea is that animals depend mostly on stem cells to regenerate tissue.

"That idea would then suggest that our inability to regrow a new hand is that we just don't have enough stem cells or they don't go through enough cycles to promote growth," Unguez said.

The truth might be that animals use a combination of reverting cells and stem cells in the process.

If it is that combination, that could be better news for amputees. It would create more options for companies to create different drugs that could trigger some cells to revert and regrow, while adding stem cells to speed the process along, Unguez said.

New drugs for amputees are probably several years away. But understanding how the cells regrow will certainly speed the process along, Zakon said.

"Things move so fast these days, but I'd still say we're probably decades away from anything realizable," Zakon said. "I hope it's sooner."

Israel launches world's first underwater museum


It was the largest, most impressive port in the Roman Empire when it was inaugurated in 10 BCE. And some 2,016 years later, the ancient port of Caesarea - along the Mediterranean coast of Israel - was inaugurated again last week, this time as the world's first underwater museum.

Divers can now don their wet suits and tour the sign-posted remains of the magnificent harbor built by King Herod to honor his Roman patron, Caesar Augustus. The site has been excavated over the last three decades by a team led by the late Prof. Avner Raban of the University of Haifa's Recanati Institute for Maritime Studies.

It's not your ordinary museum tour. Visitors float from one 'exhibit' to the next, marveling in silence at the untouched remains of a once-glorious harbor: a Roman shipwreck, a ruined lighthouse, an ancient breakwater, the port's original foundations, anchors, pedestals.

"It's a truly unique site," said Sarah Arenson, a University of Haifa maritime historian and participant in the project. "This port was built as the state-of-the-art port of the Roman Empire, and made the other ports of the time, including those of Rome, Alexandria and Piraeus, look small and out-of-date by comparison."

Arenson notes that the port is also unique today: "There are no other ancient ports in the world that are accessible to ordinary divers," she told ISRAEL21c. Some such ports are restricted to authorized scientists. Others may be open to any diver, but would be meaningless to such visitors "because," explains Arenson ,"all you would see is a bunch of stones."

At Caesarea, divers view some 36 different sign-posted sites along four marked trails in the sunken harbor covering an area of 87,000 sq. yards They are given a water-proof map which describes in detail each of the numbered sites along the way (currently maps are in English and Hebrew; within a few months they will be available in six additional languages.) One trail is also accessible to snorkelers. The others, ranging from 7 to 29 feet below the surface, close to the beach, are appropriate for any beginner diver.

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Scientists study hundreds of dead dolphins


ZANZIBAR, Tanzania - Scientists tried to discover Saturday why hundreds of dolphins washed up dead on a beach popular with tourists on the northern coast of Zanzibar.

Among other possibilities, marine biologists were examining whether U.S. Navy sonar threw the animals off course.

Villagers and fishermen were burying the remains of the roughly 400 bottlenose dolphins, which normally live in deep offshore waters but washed up Friday along a 2 1/2-mile stretch of coast in Tanzania's Indian Ocean archipelago.

The animals may have been disturbed by some unknown factor, or poisoned, before they became stranded in shallow waters and died, said Narriman Jiddawi, a marine biologist at the Institute of Marine Science of the University of Dar es Salaam.

Experts planned to examine the dolphins' heads to assess whether they had been affected by military sonar.

Some scientists surmise that loud bursts of sonar, which can be heard for miles in the water, may disorient or scare marine mammals, causing them to surface too quickly and suffer the equivalent of what divers call the bends - when sudden decompression forms nitrogen bubbles in tissue.

A U.S. Navy task force patrols the coast of East Africa as part of counterterrorism operations. A Navy official was not immediately available for comment, but the service rarely speaks about the location of submarines at sea.

A preliminary examination of their dolphins' stomach contents failed to show the presence of squid beaks or other remains of animals hunted by dolphins.

That was an indication that the dolphins either had not eaten for a long time or had vomited, Jiddawi said.

Their general condition, however, appeared to show that they had eaten recently, since their ribs were not clearly visible under the skin, she said.

Although Jiddawi said Friday that poisoning had been ruled out, experts were preparing to further examine the dolphins' stomachs for traces of poisonous substances such as toxic "red tides" of algae.

Zanzibar's resorts attract many visitors who come to watch and swim with wild humpback dolphins, which generally swim closer to shore than the Indo-Pacific bottlenose.

The humpbacks, bottlenose, and spinner dolphins are the most common species in Zanzibar's coastal waters.

The most conclusive link between the use of military sonar and injury to marine mammals was observed from the stranding of whales in 2000 in the Bahamas. The U.S. Navy later acknowledged that sonar likely contributed to the stranding of the extremely shy species.

"These animals must have been disoriented and ended up in shallow waters, where they died," Abdallah Haji, a 43-year-old fisherman, said Saturday as he helped bury the dolphins near the bloodied beach.

Residents had cut open the animals' bellies to take their livers, which they use to make waterproofing material for boats.

"We have never seen this type of dolphin in our area," said Haji, who said he has fished in Zanzibar's waters for more than two decades.