These amazing pictures are from the Yucatan Peninsula off the Gulf of Mexico, where golden rays flock before undergo a biannual mass migration. See more of the stunning pictures of these near threatened rays (upto 2m in size) here.
A changing global climate may have profound effects on the Florida Keys coral reef, an Australian researcher says, but at least people are paying attention.
“People are concerned about tourism and the reef, of course,” economist Hans Hoegh-Guldberg said after his first Keys workshop Friday in Islamorada.
“But one positive thing about the environment is that people here see is an increasing environmental consciousness on both the corporate and personal level,” Hoegh-Guldberg said. “People are taking more and more notice.”
Hoegh-Guldberg will spend this week in the Keys to conduct four more workshops with residents as part of a scenario-planning process commissioned by the National Marine Sanctuaries Program of the National Oceanic and Atmospheric Administration.
“That means developing a set of alternative possible future worlds from ‘best case’ to ‘worst case,’ all equally credible and equally likely to occur,” said Hoegh-Guldberg. “We must plan to avert the worst and encourage the best.”
Jamaica Gleaner, May 2nd 2008
Coral reef degradation could result in annual losses of US$100 million to $300 million to the Caribbean tourism industry by 2015, marine scientists are predicting.
Rick MacPherson, director of conservation programmes with Coral Reef Alliance (CORAL), said at a Turks and Caicos conference this week that almost two thirds of the region’s reefs were under threat. Coastal development, he said, threatens 33 per cent of the reefs, while land-based sources of pollution have harmed 35 per cent, and over-fishing more than 60 per cent.
“Caribbean reefs have suffered an 80 per cent decline in cover during the past three decades, while 80 to 90 per cent of elkhorn and staghorn coral is gone,” MacPherson said in his presentation at the 10th annual Sustainable Tourism Conference (STC-10).
Senior research associate from Oxford University’s Centre for the Environment, Dr Murray Simpson, another conference speaker, said this new reality includes a potential geographic and seasonal shift in tourism demand which will swing business away from the region. Research in 2004 showed that 70 per cent of coral reefs were at risk of collapse because of human pressures, up from 58 per cent in 2002. Underscoring that only a very tiny portion of the sea bottom is covered by coral reefs, 0.09 per cent, with a total area about the size of Arizona or the United Kingdom, the experts say they are home or nursery ground for 25 per cent of all known marine species.
MacPherson said the dive tourism industry in the Caribbean would be the hardest hit, should the quality of the dive experience be diminished. He further warned that the effects of such a loss would be felt not only by tourism but sectors such as medicine.
“Fifty per cent of current cancer medication research focuses on marine organisms found on coral reefs,” he said. “The drug AZT, which has prolonged the lives of thousands suffering from AIDS, comes through sponge species from coral reefs.”
The world’s coral reefs, he said, yield economic value of more than US$100 billion per year from food alone.
“They are the primary source of protein for over one billion people,” said the conservationist. “Coastal tourism generates 85 per cent of all tourism – a US$385 billion dollar industry.”
However, there is, he says, an economic disconnect in the annual inverstment in research, monitoring and management, which is less than US$100 million.
A new study has revealed that hurricanes and storms limit the ability of corals to “recruit” new corals into their community.
The study, supported by Earthwatch Institute in the US, was carried out in Belize, a Central American country, by Earthwatch scientist Dr. James Crabbe in 2006 and 2007 with Edwin Martinez, Earthwatch Field Director in Belize, as well as with the help of young local scientists.
Coral Reefs, which can grow to be thousands of years old, form and grow when free-swimming coral larvae in the ocean attach to rocks or other hard surfaces and begin to develop.
But, the new study has determined that intense storms can wipe out this “recruitment” process.
“Increasing evidence now shows that storms are becoming more intense due to climate change,” said Crabbe. “Storms threaten the survival of the entire reef itself,” he added.
According to Crabbe, who is doing a lecture tour related to this work throughout 2008, “If the storms don’t destroy corals outright, they render them more susceptible to disease, and that is certainly apparent on the Belize reefs.”
A team from Earthwatch measured the size of more than 520 non-branching corals in two major coral reef areas in southern Belize: the Sapodilla Cayes Marine Reserve, a world heritage site in the second largest barrier reef in the world, and the Port Honduras Marine Reserve.
In addition to providing habitat for an array of marine life, non-branching massive corals robust and shaped like mounds, and sometimes called ‘brain corals’ buffer coastal zones from erosive wave energy.
Crabbe’s team determined the surface area covered by the corals and entered the growth rates of the corals into a computer model to determine when in history the coral colonies first settled.
They compared numbers of corals that started life in each year with hurricane and storm data, and as suggested by data from fringing reefs of Jamaica, the coral recruitment was much lower during storm years.
According to Crabbe, the study holds implications for marine park managers.
“They may need to assist coral recruitment and settlement by establishing coral nurseries and then placing the baby corals (larvae) in the reef at discrete locations, or by setting up artificial reef blocks to help the corals survive,” he said.
Several hundred years ago, the coral reefs of the Caribbean had up to six times more fish than they have today, according to a study published Wednesday.
The estimate is made by US scientists poring over the fate of the Caribbean monk seal, a fish-loving mammal driven to extinction in 1952.
Historical records from the 17th and 18th century show there were huge numbers of monk seals, distributed among 13 colonies across the Caribbean.
They were so plentiful that some ships’ maps of the West Indies even noted particularly dense locations of seals.
Alas for Monachus tropicalis, colonisation of the West Indies unleashed unbridled hunting, the bounty being seal oil that was used to grease machinery in sugar plantations.
Towards the end of the 19th century, the seals were reduced to a final redoubt of a few atolls — and their worst enemy became natural history museums and private collectors keen for monk seal skeletons.
In one disastrous episode, a 1911 expedition to Mexico by natural-history enthusiasts killed 200 seals, leaving just a handful alive, and driving the depleted population further towards extinction.
Two dominant coral species have built a good chunk of the Caribbean reef, and their ability to grow quickly may help the region’s coral reefs keep pace with rising sea levels caused by global warming, researchers say.
The endangered staghorn and elkhorn corals grow about 10 times faster than any other in the Caribbean and reproduce in part by breaking into bits for easy ocean spread.
Ken Johnson, who led the study published in the journal Science, said researchers had found that the staghorn and elkhorn coral were not that important until about 1 million years ago, when half the Caribbean coral species went extinct. Today about 60 coral species remain.
Johnson said one reason they quickly became dominant was they may have been able to keep up with rapid sea level rise by growing quickly, Johnson said. And if sea levels rise as predicted in the coming centuries, they may have to reprise this role.
“These are the species that are going to help coral reefs keep up with sea level change,” Johnson, a paleontologist at the Natural History Museum in London, said in a telephone interview.
Coral reefs, delicate undersea structures resembling rocky gardens that are made by animals called coral polyps, are important nurseries and shelters for fish and other sea life. They are also considered valuable protection for coastlines from high seas, a critical source of food, important for tourism and a potential storehouse of medicines for cancer and other diseases.
But researchers say overfishing, climate change and human development are threatening reefs worldwide. Even the dominant staghorn and elkhorn species are considered threatened under the U.S. Endangered Species Act. In the Caribbean, an added concern is that the reefs are especially sensitive because they are dominated by just two species, Johnson said.
“If these two species die out and become extinct, the Caribbean is in trouble,” he said.
The researchers produced their conclusions by using fossils to compare changes in coral diversity and reef development in the Caribbean over the past 28 million years. They showed that the characteristics of a dominant species were more important than the simple number of species, a finding that can better direct conservation efforts, Johnson said.
The “Status of Caribbean coral reefs after bleaching and hurricanes in 2005” is an excellent account of the impact of mass bleaching and hurricanes that hit the Caribbean in 2005. As you will remember, sea temperatures rose sharply in this region in May 2005, intensifying until October by which time hotspots covered most countries in the eastern Caribbean. This occurred during the hottest year on record for the northern hemisphere at that time, and resulted in a massive die off of corals.
As pointed out by the editors, Clive Wilkinson and David Souter, the 2005 event provided an important opportunity to study the impact of extreme thermal stress on coral reefs. Via network of hundreds of scientists that were linked by the Internet and backed up by sophisticated monitoring tools, key information and insights would gained into the relationship between thermal stress, bleaching and coral mortality.
Overall, coral reefs in eastern Caribbean were severely damaged by anyone’s estimate in 2005. What is perhaps most alarming is that the mortality ranged up to 50% in places like the US Virgin Islands and the Greater and Lesser Antilles. This came on top off a rapid deterioration of reefs that has been occurring over the past few decades. The coral cover of most (if not all) coral reefs in this region have been sliding rapidly downwards.
This is a useful collection of papers which I recommend that you read (link). My good friend Billy Causey, who has a long and proud history of fighting for the protection of Florida’s coral reefs, provides a very useful account of the history of bleaching in his region. There is also some useful information as well on the hurricane story, including on what drives their intensity and how they impacted reefs in 2005.
“A healthy reef ecosystem literally buzzes with sounds, activity and colors and is populated by incredibly dense aggregations of fish and invertebrates. In this respect, tropical reefs are more reminiscent of the African Serengeti than of the tropical rainforest they are often compared to, where the resident birds and mammals can be secretive and difficult to see. A coral reef can contain tens of thousands of species and some of the world’s most dense and diverse communities of vertebrate animals. Unfortunately, very few remaining coral reefs resemble this pristine condition; on most, corals and fishes are much less abundant than they were only a few decades ago”
John’s expert write-up and summary of threats to coral reefs related to climate change (coral bleaching, disease, ocean acidification) provides an excellent background of the literature and current threats, and is a worthy read for scientists, managers and the general public alike.
|Healthy Great Barrier Reef reefscape||A recovering Jamaican coral reef||Bleached corals off Puerto Rico in 2005|
Following close on the heels of IUCN report …
PARIS (AFP, Jan 28 2008) — The Caribbean’s fragile coral reefs were devastated in 2005 by a doubly whammy of record-high temperatures and 13 full-on hurricanes, according to a UN-sponsored report released Monday.During the last 50 years many Caribbean reefs have lost up to 80 percent of their coral cover, damaging or destroying the main source of livelihood for hundreds of thousands of people, said the report, prepared by a team of scientists and experts at the Global Coral Reef Monitoring Network.
The study was jointly sponsored by UNESCO and the Intergovernmental Oceanographic Commission.
Coral-based ecosystems are extremely sensitive to temperature increases, which have led over the last 50 years to massive bleaching — affecting up to 95 percent of the reefs around some islands, including the Cayman Islands, Jamaica, Cuba, and the French West Indies.
2005 was the warmest year since records were first kept in 1880, and global warming is likely to increase in years to come, climate scientists have warned.
National Oceanic and Atmospheric Administration,
January 24th 2008
A NOAA-sponsored expedition is investigating shallow and deep coral ecosystems off the Caribbean island of Bonaire, part of the Netherland Antilles. Multiple underwater robots and divers are surveying arguably the most pristine coral reefs in the Caribbean to learn why they remain relatively healthy while many in the Caribbean and around the world are threatened. The mission is one of the first in the International Year of the Reef 2008.
“The International Year of the Reef is a year-long, worldwide campaign to highlight the importance of coral reef ecosystems, and to motivate people to protect them,” said Vice Admiral Conrad C. Lautenbacher, Jr., under secretary of commerce for oceans and atmosphere and NOAA administrator. “NOAA supports this campaign with leadership and coordination, and by sponsoring scientific study of reef systems such as those off Bonaire.”
The expedition runs through January 30 and is chronicled online.
In shallower waters, the team is measuring changes from limited surveys in the 80’s and 90’s. In deeper waters, three robots called Autonomous Underwater Vehicles, will survey the “Twilight Zone,” 65 to 150 meters deep, where sunlight is scarce and little is known about reef systems.
“We believe this is the first science expedition using multiple AUVs to chart Bonaire’s reefs and likely the first to do so on coral reefs anywhere,” said expedition leader Dr. Mark Patterson of the Virginia Institute of Marine Science, College of William & Mary. “This is important because of scale, AUVs obtain wide-area data, allowing scientists to pinpoint further investigation.”