By Jonathan Fildes, Science and technology reporter, BBC News, San Francisco
The delicate interplay between the oceans and atmosphere is changing with catastrophic consequences.
That is the conclusion of researchers investigating 'dead zones' off the coast of the US, where populations of marine life were suddenly wiped out.
These vast graveyards occur where there are disturbances to currents driven by coastal winds, they say.
Dead zones have been recorded off the coast of California and Oregon every year for the last five years.
The most intense event, which left the ocean floor littered with the carcasses of crabs, happened in 2006.
'It was unlike anything that we've measured along the Oregon coast in the past five decades,' said Dr Francis Chan of Oregon State University (OSU).
Dead zones have also been seen in the waters off Chile, Namibia and South Africa."
Read more at BBC News...
http://news.bbc.co.uk/1/hi/sci/tech/6370905.stm
25 May 2007
Wind shifts devastate ocean life
9 May 2007
Tags follow 'Nemo' fish to home
The remarkable homing instincts of some coral reef fish have been revealed.
A team tagged two species of reef fish larvae to see where the juveniles were going after spending weeks and even months maturing in open sea.
It found most of the orange clownfish - made famous by the Finding Nemo movie - and vagabond butterflyfish returned to the reef where they had first hatched.
Writing in the journal Science, the team said the discovery could have implications for marine protection.
"Marine fish lay very small eggs, and when they do, they are released into the water column," explained co-author Professor Geoff Jones from James Cook University in Queensland, Australia.
"They develop into a really tiny little larvae that we think drift around in the water currents, sometimes for months.
"The missing link in our understanding of coral reef fish has always been: where do the larvae go?"
Help from Mum
But until now, finding this out has been extremely tricky - attaching tags to miniscule larvae is not an easy task.
So the international team of researchers tackled the problem by getting the mother to help.
They did this by collecting female coral reef fish from a small 0.3 sq km reef in Kimbe Bay, Papua New Guinea, and injecting them with a rare, stable barium isotope. 
The females pass this isotope to their developing offspring where it accumulates in their bones, giving the baby fish unique chemical signatures.
A few weeks later, the team returned to the reef and collected young fish to test them to see if they carried the "tag".
"We found that 60% - well over half - were coming back to the small island reserve, which was an unexpected result," Professor Jones told the BBC.
Navigational feat
The scientists are uncertain how the vividly coloured orange clownfish and vagabond butterflyfish perform this feat but hope to find out with further research.
"Perhaps they are somehow remaining in sensory contact with their home island and are able to maintain their position and not end up drifting too far away," said Professor Jones. 
"Or maybe they are getting carried away, but they have a homing mechanism to swim back to their home reef."
Although the study was carried out on two species, Professor Jones believes the finding may apply to other coral reef fish too, and if this is the case, it could have consequences for marine conservation.
It shows that small no-take marine reserves are a good way to protect over-fished species, he said, because there should be enough juveniles returning to the area to sustain numbers over time.Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/6623981.stm
Published: 2007/05/04 15:14:23 GMT
© BBC MMVII
8 May 2007
BBC NEWS | Science/Nature | Wind shifts devastate ocean life
BBC NEWS | Science/Nature | Wind shifts devastate ocean life: "Wind shifts devastate ocean life
By Jonathan Fildes
Science and technology reporter, BBC News, San Francisco
The Oregon researchers watched crab populations crash
Enlarge Image
The delicate interplay between the oceans and atmosphere is changing with catastrophic consequences.
That is the conclusion of researchers investigating 'dead zones' off the coast of the US, where populations of marine life were suddenly wiped out.
These vast graveyards occur where there are disturbances to currents driven by coastal winds, they say.
Dead zones have been recorded off the coast of California and Oregon every year for the last five years.
The most intense event, which left the ocean floor littered with the carcasses of crabs, happened in 2006.
'It was unlike anything that we've measured along the Oregon coast in the past five decades,' said Dr Francis Chan of Oregon State University (OSU).
Dead zones have also been seen in the waters off Chile, Namibia and South Africa."
23 Apr 2007
Vitamins benefit divers' health
Vitamin doses can reduce ill-effects of scuba diving on divers' circulation, a study suggests.
The scientists from Croatia and Norway gave vitamins C and E, which work as antioxidants, to divers, the Journal of Physiology reported.
The vitamins stopped ill-effects of the dive on the cells lining blood vessels, which can lead to high blood pressure and other associated diving problems.
But diving experts said the vitamins would have a limited impact.
"The intervention showed a positive effect" said Ante Obad, lead researcher
The researchers, from the University of Split School of Medicine in Croatia and the Norwegian University of Science and Technology carried out the study on seven professional divers before a 30-minute, 30-metre dive.
They performed two dives 24 hours apart, with doses of vitamins C and E administered two hours before the second one.
Six of the divers took part in a second trial eight months later, in which some were given antioxidants while others received a dummy pill.
The team found that antioxidant treatment prevented endothelial dysfunction, which stops the cells lining blood vessels working properly, causing high blood pressure.
High blood pressure is relatively common in divers and can lead "
More at BBC...
http://news.bbc.co.uk/1/hi/health/6314901.stm
30 Oct 2006
Scuba Diving Fiji: Scientists go hi-tech to save coral
Scuba Diving Fiji: Scientists go hi-tech to save coral:
 At cold depths, the rate of growth is very slow |
It is only in the past few decades that technology allowing humans to peer into the previously uncharted depths has become available to scientists.
Remote Operated Vehicles (ROVs) and manned submersible craft have opened up to exploration a whole new world of deep marine ecosystems.
One of the most startling discoveries has been the number of coral reefs living hundreds of metres beneath the surface, in temperatures ranging from 4-13C (39-55F).
The existence of cold-water corals has been known since the 18th Century, but the vast number of reefs found in the deeper reaches of the world's waters has amazed researchers.
Yet just as scientists are beginning to understand the significance of the coral to the surrounding environment, they are also witnessing destruction.
'Glacial' growth
Environmentalists point the finger of blame at the fishing industry and the practice of bottom-trawling with drag nets.
This method of fishing involves scouring the sea bed with huge nets that are some 60m-wide; they are held apart by two huge metal plates weighing up to five tonnes.
"It's heavy gear, and the reefs and the coral colonies are very fragile and easily damaged," Jan Helge Fossa, chief scientist at the Norwegian Institute of Marine Research, tells TVE's Earth Report programme for BBC World.
"So it was quite obvious that this was an activity that couldn't go on," he adds.
Cold corals are very slow growing. Some individuals are estimated to be up to 1,800 years old, and many reefs began forming at the end of the last Ice Age.
Damage inflicted by bottom-trawling can result in catastrophic consequences for the species living amid the reefs.
Onboard the institute's research vessel, Dr Helge Fossa is leading a survey for cold corals off the northern coast of Norway.
Robot eyes
The Institute provides advice on the marine environment to the Norwegian government, which is one of the few nations that have introduced laws to protect cold-water corals.
After performing a multibeam sonar sweep that provides a real-time map of the search area, the team launches a ROV through the side of the ship.
Once the vehicle reaches the site 200m below the surface, its four powerful lights allow the onboard camera to beam pictures back to the scientists on the surface. 
Norwegian marine scientist
"What we see here is only coral rubble, and it's trawled out to small pieces," Dr Helge Fossa observes. "We have so far seen no live coral."
It is not long before the prime suspect is located: discarded trawling equipment. Closer inspection reveals that the nets and gear are likely to be about 20 years old.
Norway's Coral Act 1999 protects all coral reefs in the nation's waters from intentional damage, and bottom-trawling has been completely banned in areas surrounding five specific reefs.
However, the country has the longest coastline in Europe, making monitoring and policing the region a tough task.
Video campaign
To date, there have been no prosecutions from data gathered by the space-borne Vessel Monitoring System (VMS), but Dr Helge Fossa's team hopes images obtained by its high-definition submersible-camera system will help change that.
"We know that it is important to get our results out, not only to the government but also to the public," he says. "That's why we use a lot of videos, it tells more than a thousand words." 
He said it made people understand why the complex ecosystems needed protecting: "I have never heard a person in Norway, after looking at the videos, who objects to protection."
Some scientists believe that other nations should adopt similar protection measures as Norway, otherwise many more deep cold-water reefs will resemble a lunar surface.
The Television Trust for the Environment's (TVE) Earth Report - Cold Corals Deep will be broadcast on BBC World on 21 and 23 October 2006. Please check schedules for further details
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/6067806.stm
Published: 2006/10/20 12:17:05 GMT
© BBC MMVII
