Tag Archives: Coral Reefs

Coral Reefs May Be Protected By Natural Ocean Thermostat

Posted on by
1

Science Daily, Feb 8th 2008

Natural processes may prevent oceans from warming beyond a certain point, helping protect some coral reefs from the impacts of climate change, new research finds. The study, by scientists at the National Center for Atmospheric Research (NCAR) and Australian Institute of Marine Science (AIMS), finds evidence that an ocean “thermostat” appears to be helping to regulate sea-surface temperatures in a biologically diverse region of the western Pacific.

The research team, led by NCAR scientist Joan Kleypas, looked at the Western Pacific Warm Pool, a region northeast of Australia where naturally warm sea-surface temperatures have risen little in recent decades. As a result, the reefs in that region appear to have suffered relatively few episodes of coral bleaching, a phenomenon that has damaged reefs in other areas where temperature increases have been more pronounced.

The study lends support to a much-debated theory that a natural ocean thermostat prevents sea-surface temperatures from exceeding about 88 degrees Fahrenheit (31 degrees Celsius) in open oceans. If so, this thermostat would protect reefs that have evolved in naturally warm waters that will not warm much further, as opposed to reefs that live in slightly cooler waters that face more significant warming.

“Global warming is damaging many corals, but it appears to be bypassing certain reefs that support some of the greatest diversity of life on the planet,” Kleypas says. “In essence, reefs that are already in hot water may be more protected from warming than reefs that are not. This is some rare hopeful news for these important ecosystems.”

Continue reading →

Floodwaters ‘threatening Great Barrier Reef’

Posted on by
2

Brisbane Times (29th Jan 2008)

Scientists from across Queensland are converging on the mouth of the Fitzroy River in Rockhampton over fears that sediment and toxic chemicals carried by floodwaters in central Queensland now reaching the ocean may damage the Great Barrier Reef.

Marine scientists from James Cook University, the Queensland Environmental Protection Agency and the Department of Natural Resources will be collecting water samples, measuring flow rates and diving on the reef to assess its condition first hand.

Dr David Haynes, acting director of water quality and the Coastal Developmental Unit of the Great Barrier Reef Marine Park Authority, said that sediment could pose a significant threat to the health of the reef.

“The main problem with sediment is one of the things it will do is settle on coral and physically smother them in high enough concentrations,” he said.

“It can also make the water highly turbid and reduce the amount of light that can penetrate through the water and corals are very dependent on light to obtain food; they use algae in their cells to manufacture food.

“If the corals are in dirty water then the coral’s food source is cut off for as long as the water is dirty.”

Continue reading →

Coral reefs and climate change

Posted on by
Reply

A colleague of mine, Dr John Bruno forwarded me an excellent article that he wrote for The Encyclopedia of the Earth, titled “Coral Reefs and Climate Change”

“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

 

Science Expedition to Coral Reefs in Caribbean Helps Launch International Year of the Reef

Posted on by
Reply

launch Fetch AUV.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.”

Continue reading →

Is there a case for the “bacterial bleaching hypothesis’? Oculina patagonica / Vibrio shiloi revisited

Posted on by
3

The idea that mass coal bleaching is caused by bacteria bleaching as opposed to temperature stress has been quite a contentious issue over the past decade. Despite the fact that massive amounts of evidence that have accumulated that support the idea that thermal stress has driven the mass episodes of coral bleaching (pigment loss associated with the dissociation of the symbiosis between coral and their dinoflagellates) over the past 30 years, some oxygen has been given to the alternative idea that mass coral bleaching is triggered by the presence of bacteria from the genus Vibrio.The idea that bacteria were involved in triggering coral bleaching originated from work done on the temperate coral Oculina patagonica from the Mediterranean sea (an invading species from the Atlantic coast of South America) seemed to suggest that the annual coral bleaching was due to a bacterial infection from a putative pathogen, Vibrio shiloi.

This discussion focuses on recent work done by my laboratory and which was published in the Nature journal ISME (download here) and which suggests that bacteria are not responsible for triggering mass coral bleaching (in O. patagonica or anything else). We are interested in your thoughts and hope that you will comment in the hope of resolving debate over this issue for once and for all.

The Bacterial Bleaching Hypothesis is based on a series of eloquent microbiological investigations conducted by Eugene Rosenberg and his group revealed the intra-cellular penetration, multiplication and subsequent cellular lysis of zooxanthellae by V.shiloi resulted in the annual bleaching of O.patagonica in temperatures above 28ºC. Since then, the bacterial bleaching hypothesis has been extrapolated as an explanation for global mass coral bleaching, and more recently, the coral ‘probiotic hypothesis’ (link). To some (including Eugene Rosenberg), the workplace emphasis onto bacteria rather than climate change as the cause for mass coral bleaching – the implications for the future of coral reefs would be highly significant if Rosenberg were correct.

Continue reading →

2008 is International Year of the Coral Reef

Posted on by
Reply

Marianas Variety, 21st Jan 2008

Different environmental groups and government agencies gathered on Friday at the SandCastle of the Hyatt Regency Hotel Saipan to declare 2008 as the International Year of the Coral Reef.

Gov. Benigno R. Fitial and Lt. Gov. Timothy P. Villagomez attended the event, with the chief executive urging the community to become more aware and action-oriented in the protection and conservation of the islands’ coral reefs.

Villagomez said the threat to coral reefs is not only a national or regional concern, but a global matter, especially in light of global warming.

Students, academicians, and other concerned individuals joined the event and got to hear Peter Houk, Division of Environmental Quality’s biologist, John Starmer, Coastal Resources Management biologist, and other invited speakers discuss the importance and possible solutions to the growing concerns regarding the coral reefs of the islands.

The symposium also recognized the medicinal value of reef organisms, and the different threats to coral reefs such as improper watershed development, sedimentation, marine debris, over-fishing, global warming, among other problems.

Global warming is the increase in the average temperature of the Earth’s near-surface air and oceans. One of the effects of global warming, according to experts, relates to the evaporation of water — the warming of the air will cause more water to evaporate into the atmosphere.

The participants in the symposium likewise acknowledged the need for an increased public awareness and for greater responsibility in protecting coral reefs for future generations.

The symposium was organized and sponsored by the Coastal Management Resources Office, the Division of Environmental Quality, the Division of Fish and Wildlife, the Coral Reef Initiative Program, the U.S. Environmental Protection Agency, the Marine Monitoring Program and the Mariana Islands Nature Alliance.

Isobel Bennett, Australian coral reef pioneer dies

Posted on by
Reply

It is with great sadness that I post that Isobel Bennett, a pioneer and founder of coral reef science in Australia and author of the book “The Great Barrier Reef” has passed away this week (see below for an obituary from The Age newspaper). Isobel was a truely unique person and one of Australia’s most distinguished marine sciences, and her death comes as a true loss to the scientific community. Click here for a link to an extensive interview conducted by the Australian Academy of Science detailing the life of one of “the last great naturalists”.

Seashore and reef expert dies at 98

The Age, January 14th 2008

A PIONEERING marine scientist who had a coral reef named after her has died at 98.

Isobel Bennett, who left school at 16 and went on to become a seashore expert, passed away at a nursing home in Mona Vale, in northern Sydney, yesterday.

Len Zell, a lecturer in marine and tropical biology at James Cook University, said Ms Bennett was schooled in the “university of life”, and had an insatiable curiosity. “She achieved high standing as an Australian marine scientist, not by education, but by sheer hard work, determination, attention to detail, and a never-ending curiosity that tired me out lifting boulders on many reef flats,” he said.

“The last time I was on Heron Island with her she was in her 80s, and we spent hours out on the reef flat turning boulders and photographing and discussing the critters there.”

Ms Bennett, who was awarded an honorary doctorate by NSW University, was born in Brisbane in 1909 and, as the eldest of four children, left school at 16 to enter the workforce.

Continue reading →

Humans Have Caused Profound Changes In Caribbean Coral Reefs

Posted on by
Reply

ScienceDaily, January 9th

Coral reefs in the Caribbean have suffered significant changes due to the proximal effects of a growing human population, reports a new study.

“It is well acknowledged that coral reefs are declining worldwide but the driving forces remain hotly debated,” said author Camilo Mora at Dalhousie University, Halifax, Canada. “In the Caribbean alone, these losses are endangering a large number of species, from corals to sharks, and jeopardizing over 4 billion dollars in services worth from fisheries, tourism and coastal protection,” he added.”The continuing degradation of coral reefs may be soon beyond repair, if threats are not identified and rapidly controlled,” Mora said. “This new study moves from the traditional localized study of threats to a region-wide scale, while simultaneously analyzing contrasting socioeconomic and environmental variables,” he added.

The study monitored coral reefs, including corals, fishes and macroalgae, in 322 sites across 13 countries throughout the Caribbean. The study was complemented with a comprehensive set of socioeconomic databases on human population density, coastal development, agricultural land use and environmental and ecological databases, which included temperature, hurricanes, productivity, coral diseases and richness of corals. The data were analyzed with robust statistical approaches to reveal the causes of coral reef degradation in that region.

The study showed clearly that the number of people living in close proximity to coral reefs is the main driver of the mortality of corals, loss of fish biomass and increases in macroalgae abundance. A comparative analysis of different human impacts revealed that coastal development, which increases the amount of sewage and fishing pressure (by facilitating the storage and export of fishing products) was mainly responsible for the mortality of corals and loss of fish biomass.

Additionally, the area of cultivated land (a likely surrogate for agrochemical discharges to coral reefs) was the main driver of increases in macroalgae. Coral mortality was further accelerated by warmer temperatures.

Continue reading →

‘Young guns’ of coral reef research head downunder

Posted on by
Reply

A worldwide network of the next generation of leading coral reef scientists and managers is set to meet for the first time at The University of Queensland (UQ) in Brisbane on December 10-14, 2007.

Sponsored by the Coral Reef Targeted Research and Capacity Building for Management Program (CRTR), the Leadership Forum will attract 55 postgraduate and postdoctoral students in coral reef studies from 20 countries.

The students will be joined by internationally-renowned coral reef scientists and managers and together they will build the students’ understanding of a wide range of issues surrounding coral reef ecosystems.

“These future leaders in coral reef science will hone their leadership skills and learn how to increase their influence among networks that manage and set policy for coral reefs worldwide,” said Professor Paul Greenfield, Senior Deputy Vice-Chancellor at UQ, a key partner in the CRTR Program.

“One of the major goals of the CRTR Program is to build the scientific capacity and knowledge necessary to give coastal managers and policy-makers the information they need to sustain the world’s coral reefs.”

The CRTR Program sponsors or associates with more than 55 students in coral reef studies worldwide. Students from Mexico, The Philippines, Cuba, Tanzania, Kenya, USA, Australia, United Kingdom, Colombia, Venezuela, Palau, Thailand, Canada, Costa Rica, Belize and Guatemala will attend the event.

The CRTR Program is a leading international coral reef research initiative that provides a coordinated approach to credible, factual and scientifically-proven knowledge for improved coral reef management. The CRTR Program is a partnership between the Global Environment Facility, the World Bank, UQ, the United States National Oceanic and Atmospheric Administration and about 40 research institutions and other third-parties around the world.