Southern corals unlock climate clues

While great attention is being given to the threat of global warming to corals of the Great Barrier Reef, the corals off southern Australia are giving scientists information about climate change.

As divers and fishermen in southern waters know well, corals are not restricted to tropical waters.

The most obvious of the southern versions occur in large boulder-like formations known in South Australia as bommies.

They are now throwing new light on the history of Australia's southern oceans, revealing details of past climates and the human impact on the sea.

Sam Burgess of the Australian National University and the ARC Centre of Excellence for Coral Reef Studies, is completing a PhD on these little-known South Australian corals, proving their importance to issues of climate change and ocean health.

"Most people are surprised to learn that there are large corals in these colder waters," Ms Burgess said.

"They think corals only occur in the warmer waters of the tropics."story continued

Appetite for fish is stripping reefs

By Michael Casey
Associated Press
KOTA KINABALU, Malaysia -- Diners' appetite for live reef fish -- a status symbol for many newly rich Chinese -- has caused the populations of these predators to plummet around Asia as fishermen increasingly resort to cyanide and dynamite to bring in the valuable catch.
Entire reef ecosystems, already endangered by pollution and global warming, are at risk.
A study released this past week about the trade in Malaysia found that catches of some grouper species and the endangered Napoleon wrasse fell by as much as 99 percent from 1995 to 2003, a period coinciding with soaring economic growth in countries where the exotic fish are a delicacy.
"The removal of these large, predatory fish might upset the delicate balance of the coral reef ecosystem," said Helen Scales, who co-authored the study for the Swiss-based World Conservation Union. The study appeared in the online edition of Proceedings of The Royal Societies.
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Baby Fish "Smell Their Way Home"

Remarkable in itself, the discovery by a team including Professor Mike Kingsford of the ARC Centre of Excellence for Coral Reef Studies and James Cook University and colleagues from Woods Hole, USA, also shines a new light on how the breathtaking diversity of fish on coral reefs has arisen. This has major implications for how reefs are managed.

(PressZoom) - Marine scientists working on Australia’s Great Barrier Reef have uncovered evidence that baby fish, only millimetres long, manage to find their way to their home coral reef across miles of open sea by using their sense of smell.

Remarkable in itself, the discovery by a team including Professor Mike Kingsford of the ARC Centre of Excellence for Coral Reef Studies and James Cook University and colleagues from Woods Hole, USA, also shines a new light on how the breathtaking diversity of fish on coral reefs has arisen. This has major implications for how reefs are managed.

“The babies of many coral fish species are swept off their home reef by ocean currents within days of hatching. Ordinarily you’d expect them to be thoroughly mixed up and this would mean the population of one reef would be pretty much the same, genetically, as another,” he says.more on this story

Belize serves unspoiled Caribbean beauty

BY VICKI SMITH
THE ASSOCIATED PRESS

Needle-nosed ballyhoo fish leap from the water, lured by the wake as Capt. Bobby Halliday motors off Ambergris Caye. The turquoise waters here are so clear you can see blades of sea grass and lobster traps more than 20 feet below the surface.

Halliday has been guiding fishing trips through these waters for years, making some customers so happy that they gave him the two 60 horsepower engines that power his boat, the Blanca Lilly. He slows to troll and, suddenly, even more is visible below: parrot fish, angel fish and a 5-foot bull shark, silent as a shadow.

He rigs up our fishing poles in more than 30 feet of water, and we quickly land a pile of Spanish mackerel, yellowtail snapper and a fighting barracuda. Halliday pries a mackerel from a hook, spilling blood on the deck.

When I step back, he laughs.

"That's when Bobby's having a good day, when there's blood in the boat," he says. Then, he nods to my husband. "That's a good catch, man."

Destructive fishing practices

All fishing methods/practices have an impact on the target resource and may affect also non-target species. Many of them also have an impact on the wider aquatic environment. The "normal" effect of exploitation should not be confused with "destruction"

Destructive fishing refers to any type of fishing technique that destroys fish habitat. These include Dynamite fishing or 'blast' fishing or the use of explosives, spear fishing beach seining, trap/pot fishing and poisoning.

There are many negative effects that result from these practices. Dynamite and other explosive fishing methods destroy habitats and breeding sites for decades. Larger fish are stunned and removed by fishers, but many smaller or less desirable fish die and are left amongst the broken coral. Explosives can also have very serious consequences for the users themselves.

more on this story

Survival of the mangroves

We continue our look this week at mangroves, which are among the planet's most threatened tropical ecosystems. We examine, exclusively, some of those threats below. Have questions, comments? Email Petre Williams at williamsp@jamaicaobserver.com.
THERE are a range of threats to mangrove forests in Jamaica and, by extension, the Caribbean and the world. They include over-harvesting, river changes, clearing, over-fishing, pollution, coral reef loss and climate change.Over-harvestingMangrove trees the world over are used for firewood charcoal production as well as for construction wood and wood chips. While harvesting is a practice that has been ongoing for hundreds of years, it has got out of hand in recent times. In some instances, faced with limited alternatives, if any, people in certain poor communities, such as St Thomas here in Jamaica, increasingly rely on mangroves for charcoal production, for example. The result is over-harvesting, which threatens the survivability of mangrove forests.www.jamaicaobserver.com

Fish's homing instinct a clue to coral reef diversity

James Randerson, science correspondent
Tuesday January 9, 2007
The Guardian


Scientists have discovered that a fish species on the Australian Great Barrier Reef can sniff its way back to the patch of reef where it hatched.
If the cardinal fish's remarkable odour-assisted homing abilities are common, the researchers suggest it might help to explain the diversity of marine life on coral reefs. "Coral reefs are famous like tropical rainforests for their diversity of species," said Jelle Atema at the Marine Biological Laboratory at Woods Hole in Massachusetts. But that amazing biodiversity looks puzzling when you consider that many marine species reproduce by releasing their eggs into the water to be carried at the whim of the current, he said. That would mean species are dispersed widely, preventing the genetic isolation in local areas needed for new species to evolve.

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Hero fish may save reef

SCIENTISTS have discovered a masked superhero protecting the Great Barrier Reef: batfish.

The mild-mannered dusky batfish has emerged as the saviour of coral in distress from a weed infestation.
Research has led scientists to warn we still know dangerously little about the complex ecosystem that keeps the World Heritage-protected reef functioning.

Scientists at the Centre of Excellence for Coral Reef Studies in Townsville were doing experiments to simulate over-fishing on a coral reef when underwater cameras recorded batfish -- not known as a weed feeder -- decimating a choking overgrowth of sargassum weed.

Batfish are not a protected species and coastal mangrove areas where they spend their juvenile period are in decline.
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