Tag Archives: coral

Coral and ocean acidification

UD professor’s sensor enables first carbonate ion concentration measurements inside coral

An interdisciplinary team of researchers led by University of Delaware professors Wei-Jun Cai and Mark Warner has successfully measured both pH and carbonate ion concentration directly inside the calcifying fluid found in coral, an important development in the study of how ocean acidification will affect marine calcifying organisms such as corals and shellfish. (more…)

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Corals and climate

For corals adjusting to climate change, it’s survival of fattest and most flexible

The future health of the world’s coral reefs and the animals that depend on them relies in part on the ability of one tiny symbiotic sea creature to get fat — and to be flexible about the type of algae with which it cooperates. (more…)

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New Study Reveals How Sensitive U.S. East Coast Regions May Be to Ocean Acidification

A continental-scale chemical survey in the waters of the eastern U.S. and Gulf of Mexico is helping researchers determine how distinct bodies of water will resist changes in acidity. The study, which measures varying levels of carbon dioxide (CO2) and other forms of carbon in the ocean, was conducted by scientists from 11 institutions across the U.S. and was published in the journal Limnology and Oceanography.

“Before now, we haven’t had a very clear picture of acidification status on the east coast of the U.S.,” says Zhaohui ‘Aleck’ Wang, the study’s lead author and a chemical oceanographer at Woods Hole Oceanographic Institution (WHOI). “It’s important that we start to understand it, because increase in ocean acidity could deeply affect marine life along the coast and has important implications for people who rely on aquaculture and fisheries both commercially and recreationally.” (more…)

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Genetic Patterns of Deep-Sea Coral Provide Insights into Evolution of Marine Life

Patterns Also Shed Light on How Environmental Disturbances Affect Aquatic Organisms

The ability of deep-sea corals to harbor a broad array of marine life, including commercially important fish species, make these habitat-forming organisms of immediate interest to conservationists, managers, and scientists. Understanding and protecting corals requires knowledge of the historical processes that have shaped their biodiversity and biogeography.

While little is known about these processes, new research described in the journal Molecular Ecology helps elucidate the historical patterns of deep-sea coral migration and gene flow, coincident with oceanic circulation patterns and events. The investigators propose a scenario that could explain the observed evolutionary and present-day patterns in certain coral species. The findings can help scientists determine how climate change and other global processes have affected ocean habitats in the past and how they might do so in the future. (more…)

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Global Warming Refuge Discovered Near At-Risk Pacific Island Nation of Kiribati

Ocean currents may mitigate warming near handful of equatorial islands

Scientists predict ocean temperatures will rise in the equatorial Pacific by the end of the century, wreaking havoc on coral reef ecosystems.

But a new study shows that climate change could cause ocean currents to operate in a way that mitigates warming near a handful of islands right on the equator.

Those islands include some of the 33 coral atolls that form the nation of Kiribati. This low-lying country is at risk from sea-level rise caused by global warming. (more…)

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Researchers Find Unprecedented, Man-Made Trends in Oceans Acidity

Nearly one-third of CO2 emissions due to human activities enters the world’s oceans. By reacting with seawater, CO2 increases the water’s acidity, which may significantly reduce the calcification rate of such marine organisms as corals and mollusks, resulting in the potential loss of ecosystems. The extent to which human activities have raised the surface level of acidity, however, has been difficult to detect on regional scales because it varies naturally from one season and one year to the next, and between regions, and direct observations go back only 30 years.

By combining computer modeling with observations, an international team of scientists concluded that anthropogenic CO2 emissions, resulting from the influence of human beings, over the last 100 to 200 years have already raised ocean acidity far beyond the range of natural variations. The study is published in the January 22, 2012 online issue of Nature Climate Change. (more…)

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USGS Undertakes Additional Studies of Reef Damage in Gulf of Mexico to Assess Cause

Gainesville, Fla.— A team of U.S. Geological Survey (USGS) and academic scientists are analyzing samples of coral and surrounding sediments from an area damaged near the Deepwater Horizon site in the Gulf of Mexico.

These samples, collected in December, are being used to investigate how and why the corals on these reefs died. (more…)

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Coral Algae Discovered in Black Corals at Never Before Seen Depths

Hawaiian Black Coral. Image credit: Daniel Wagner, HIMB

Researchers at the Hawai‘i Institute of Marine Biology (HIMB), an organized research unit in the University of Hawai‘i at Mānoa’s School of Ocean and Earth Science and Technology have made a remarkable new discovery.

When most people envision coral, they typically think of shallow-water reef-building corals found along beaches and tropical nearshore habitats. These “typical” corals are dependent upon photosynthetic algae (also known as Symbiodinium or zooxanthellae) found in their tissues to obtain nutrients to live off of.

In deeper less known waters, closely related black corals were considered to be void of these algae because of the light shortage to support photosynthesis. In fact, all black corals were considered to lack Symbiodinium (algae), because they are typically found at great depths where light levels are very low. (more…)

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