Even in Deepwater Canyons, America’s Corals At Risk

August 18, 2014 by  
Filed under Secrets of the Ocean

At the beach this summer, gazing out over the waves from the shoreline, it’s hard to imagine the underwater world that lies just below the blue expanse: Partly because it’s so other-worldy, and partly because we just don’t know very much about it.

coral.png

A squat lobster makes its home among various deep-sea corals in Norfolk Canyon, offshore Virginia. (Image courtesy of Deepwater Canyons 2013 - Pathways to the Abyss, NOAA-OER/BOEM/USGS.)

Scientific exploration into the ocean’s depths reveals new discoveries every day, and researchers at the U.S. National Oceanic and Atmospheric Administration (NOAA) are at the forefront on this work. Take a look at the incredible images from some of their recent dives off the Atlantic Coast:

These amazing gardens of deep-sea coral communities, in Dr. Seuss-like shapes and colors, are a sanctuary for marine life. They serve as a nursery for young fish and crustaceans, and shelter a range of sea life seeking a safe haven from threats that lie in the open waters of the deep sea.

However, the Atlantic’s deep-sea coral communities are at risk. They are highly vulnerable to harm from fishing gear, such as trawlers that pull their fishing nets along the bottom of the ocean. Most deep-sea corals are very slow-growing, so once they’re cut down, that habitat remains destroyed for a very long time. In fact, one pass of trawl gear can destroy corals that have been growing for hundreds, even thousands, of years.

The public now has an opportunity to help protect these ocean oases. Last Monday, the Mid-Atlantic Fishery Management Council, made up of federal officials and state representatives from New York, New Jersey, Delaware, Pennsylvania, Maryland, Virginia and North Carolina, took an historic step forward to adopt protections for the region’s unique, ecologically important and highly vulnerable deep-sea coral communities. The Council released a full array of options for deep-sea coral protections and will soon ask the public to weigh in on the best ways to preserve these ecosystems.

This is the moment to act on the issue. Because of their depth and rugged topography, the deep-sea coral communities off the Atlantic coast have been largely sheltered from harmful bottom trawling. But as traditional fish species become overfished or markets change, fishing will continue to move into deeper waters and more difficult terrain.

We have a unique window to protect the deep-sea corals and the ecosystems they help support before irreversible damage is done. The Council should protect against the use of damaging fishing gear in both discrete coral protection zones, which would safeguard particularly high-value coral habitat like submarine canyons, and broad coral protection zones, which would provide a level of protection for deeper areas in the region until it is determined that coral communities are not present in these areas.

NRDC is working to ensure that these incredible resources are protected for the future. Public hearings to discuss the Council’s proposed protections will be held this fall — it is important that every voice is heard.

A version of this article was originally published on Live Science Expert Voices.

Article source: http://switchboard.nrdc.org/blogs/achase/even_in_deepwater_canyons_amer.html

Improving water quality can help save coral reefs

August 20, 2012 by  
Filed under Water Quality

Corals are made up of many polyps that jointly form a layer of living tissue covering the calcareous skeletons. They depend on single-celled algae called , which live within the coral polyps.

The coral animal and the associated zooxanthellae depend on each other for survival in a , where the coral supplies the algae with nutrients and a place to live. In turn, the algae offer the coral some products of their , providing them with an important energy source.

High can block photosynthetic reactions in the causing a build-up of toxic , which threaten the coral and can result in a loss of the zooxanthellae.

a nutrient-stressed staghorn coral

Light and temperature trigger the loss of symbiotic algae (bleaching) in a nutrient-stressed staghorn coral. Credit: University of Southampton

Without the algae, corals appear white, a state which is often referred to as ‘bleached’. Bleaching often leads to coral death and mass coral bleaching has had already devastating effects on coral reef ecosystems.

The study of University of Southampton, published in the latest issue of the journal Nature Climate Change, has found that of the water can increase the probability of corals to suffer from heat-induced bleaching.

Within the coral, the growth of zooxanthellae is restricted by the limited supply of nutrients. This allows the algae to transfer a substantial amount of their photosynthetically fixed carbon to the coral, which is crucial for the symbiotic relationship.

Algal growth becomes unbalanced when the availability of a specific nutrient decreases compared to the cellular demand, a condition called nutrient starvation.

Researchers from the University of Southampton based at the Coral Reef Laboratory in the National Oceanography Centre, Southampton, found that an increased supply of dissolved nitrogen compounds in combination with a restricted availability of phosphate results in phosphate starvation of the algae. This condition is associated with a reduction in photosynthetic efficiency and increases the susceptibility of corals to temperature and light-induced bleaching.

Dr Jörg Wiedenmann, Senior Lecturer of Biological Oceanography at the University of Southampton and Head of the Coral Reef Laboratory, who led the study, says: “Our findings suggest that the most severe impact on coral health might actually not arise from the over-enrichment with one group of nutrients, for example, nitrogen, but from the resulting relative depletion of other types such as phosphate that is caused by the increased demand of the growing zooxanthellae populations.”

Dr Wiedenmann adds: “Our results have strong implications for coastal management. The findings suggest that a balanced reduction of the nutrient input in coastal waters could help to mitigate the effects of increasing seawater temperatures on . However, such measures will be effective only for a short period of time, so it is important to stop the warming of the oceans, which will otherwise destroy most of the reefs in their present form in the near future.

“Finally, our results should help the design of functioning marine reserves.”

Journal reference:

Nature Climate Change
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Article source: http://phys.org/news/2012-08-quality-coral-reefs-video.html

Warmer oceans taking toll on world’s coral reefs

February 28, 2011 by  
Filed under Protecting Habitats


Global warming took a toll on coral reefs in 2010, endangering one of the world’s key ecosystems that benefit people in countless ways.

Coral reefs are habitat for almost 100,000 known marine species, including about 40 percent of all fish species. They feed millions of people, protect coasts by absorbing wave energy, and shelter creatures that could become sources of medicine for treating cancer, HIV/AIDS and other diseases.

National Oceanic and Atmospheric Administration satellite data show that 2010, the warmest on record, was hard on corals. Warmer than normal temperatures stressed tropical corals, causing them to bleach – expelling the algae that live in their tissue, giving them color and nourishment.

Some 75 percent of the world’s reefs are threatened by climate change, overfishing and pollution, according to a new assessment from the World Resources Institute and other conservation organizations. The number increased dramatically from the group’s last assessment in 1998.

“It will take a Herculean effort to reverse the current trajectory and leave healthy ocean ecosystems to our children and grandchildren,” said Jane Lubchenco, the marine scientist who heads NOAA. “How the world rises to this challenge is a reflection of our commitment to one another and to the natural world that gives us sustenance, wisdom and a reflection of our souls.”

Coral reefs cover less than a tenth of 1 percent of the oceans’ acreage, but that’s still about 100,000 square miles. Scientists who dive to study reefs can’t cover them all, so they’re turning increasingly for help from satellites.

NOAA’s satellite data on ocean heat showed that bleaching is occurring in all regions and becoming more frequent. Extreme bleaching kills corals because they can’t survive without the nourishment the algae provide. Less intense bleaching can weaken corals, reduce their growth and reproductive ability, and make them more vulnerable to disease.

Mark Eakin, a University of Miami-trained oceanographer who coordinates NOAA’s Coral Reef Watch satellite program, said that 2010 was only the second time on record that bleaching occurred globally.

The first global bleaching, from 1997 to 1999, came when an exceedingly strong El Nino – a periodic warming of ocean surface temperatures in the tropical Pacific – was followed by an especially strong version of its opposite counterpart, La Nina. About 15 percent of the world’s corals died then.

“Fast forward to 2010,” Eakin said. This time, El Nino and the La Nina that followed weren’t nearly as strong.

“The problem that we’re seeing is, as the oceans keep warming on a year-to-year basis, it doesn’t take as big or as unusual conditions to result in this sort of event.”

The bleaching from last year in many places was the worst since 1998. In the warmest months, bleaching hit the Pacific, the Indian Ocean, Southeast Asia and the southern Caribbean.

The Florida Keys and the northern part of the Caribbean, where unprecedented bleaching occurred in 2005, were spared last year because tropical storms cooled the waters.

Coral reefs are more diverse in life forms than even rain forests. The most abundant life is in the Coral Triangle, from the Philippines down to Indonesia and across to Papua New Guinea.

“I’ve been diving in some places there where I see more species on any given reef than we have in all of the Caribbean,” Eakin said.

Article source: http://www.miamiherald.com/2011/03/01/2091297/warmer-oceans-taking-toll-on-worlds.html

Coral spreading northward in Japan as ocean temperatures rise

January 22, 2011 by  
Filed under Global Warming

Corals that inhabit warm ocean areas are spreading northward in Japan’s coastal waters, apparently due to global warming, researchers have announced.

According to a research team from the National Institute for Environmental Studies in Ibaraki Prefecture and the Kushimoto Marine Park Center in Wakayama Prefecture, the northern limits of the habitats of several species of coral lying mostly near the Nansei Islands south of Kyushu have been moving northward at a “unprecedented speed” of up to 14 kilometers per year.

The unusual phenomenon is thought to have been caused by rising sea temperatures associated with global warming. As corals serve as the home for various marine plants and animals, researchers fear a possible change in the regional ecosystem.

In the sea around Japan, average water temperatures in winter have risen by 1.1 to 1.6 degrees Celsius over the past century. Out of nine species of corals that the research team analyzed, four that live in tropical waters have so far spread northward. One of the four species was observed inhabiting the area near Kagoshima Prefecture’s Tanegashima island in 1988, but was found to have spread 280 kilometers northward to Nagasaki Prefecture’s Goto Islands 20 years later.

Article source: http://mdn.mainichi.jp/mdnnews/news/20110122p2a00m0na019000c.html