Tag Archives: marine organisms

Polar night

Arctic excursion explores how sea life copes with continuous winter darkness

When the North Pole tilts away from the sun during the winter, the Arctic region plunges into weeks of continuous darkness. The sun never peeks above the horizon, casting only a twinge of blue twilight at midday, and the moon dimly illuminates the landscape at night if conditions are clear. 

People living in this “polar night” have adapted to the darkness using artificial light, but how ocean inhabitants cope remains to be seen.   (more…)

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New Study Finds Extreme Longevity in White Sharks

Great white sharks—top predators throughout the world’s ocean—grow much slower and live significantly longer than previously thought, according to a new study led by the Woods Hole Oceanographic Institution (WHOI).

In the first successful radiocarbon age validation study for adult white sharks, researchers analyzed vertebrae from four females and four males from the northwestern Atlantic Ocean. Age estimates were up to 73 years old for the largest male and 40 years old for the largest female. (more…)

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Liquid calcium carbonate

Geologist Adam Wallace reports in ‘Science’ that calcium carbonate has a dense liquid phase

Computer simulations could help scientists make sense of a recently observed and puzzling wrinkle in one of nature’s most important chemical processes. It turns out that calcium carbonate — the ubiquitous compound that is a major component of seashells, limestone, concrete, antacids and other naturally and industrially produced substances — may momentarily exist in liquid form as it crystallizes from solution.

“Our simulations suggest the existence of a dense liquid form of calcium carbonate,” said co-corresponding author Adam Wallace, an assistant professor of geological sciences in UD’s College of Earth, Ocean, and Environment who conducted the research while a postdoctoral researcher at the Lawrence Berkeley National Laboratory. “This is important because it is an as-yet unappreciated component of the carbon cycle.” (more…)

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New Approach to Measuring Coral Growth Offers Valuable Tool for Reef Managers

Finds surprising growth patterns in the Florida Keys

ST. PETERSBURG, Fla. — A new more sensitive weight-based approach for monitoring coral growth in the wild has been developed by U.S. Geological Survey researchers leading to more definitive answers about the status of coral reefs.

Corals and other marine organisms build their skeletons and shells through calcification, the biological process of secreting calcium carbonate obtained from ocean water. This new approach to measuring corals can provide finer-scale resolution than traditional linear measurements of coral growth.  (more…)

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Explosive Evolution Need Not Follow Mass Extinctions

In the wake of a mass extinction like the one that occurred 445 million years ago, a common assumption is that surviving species tend to proliferate quickly into new forms, having outlived many of their competitors.

But new research shows that tiny marine organisms called graptoloids did not begin to rapidly develop new physical traits until about 2 million years after competing species became extinct. (more…)

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Sea Cucumbers: Dissolving Coral Reefs?

Washington, D.C. — Coral reefs are extremely diverse ecosystems that support enormous biodiversity. But they are at risk. Carbon dioxide emissions are acidifying the ocean, threatening reefs and other marine organisms. New research led by Carnegie’s Kenneth Schneider analyzed the role of sea cucumbers in portions of the Great Barrier Reef and determined that their  dietary process of dissolving calcium carbonate (CaCO3) from the surrounding reef accounts for about half of at the total nighttime dissolution for the reef. The work is published December 23 by the Journal of Geophysical Research.

Reefs are formed through the biological deposition of calcium carbonate (CaCO3). Many of the marine organisms living on and around a reef contribute to either its destruction or construction. Therefore it is crucial that the amount of calcium carbonate remain in balance. When this delicate balance is disrupted, the reef ceases to grow and its foundations can be weakened. (more…)

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HIMB Scientists Develop Website to Aid with Climate Change Research

A team of researchers from UH Mānoa’s Hawai‘i Institute of Marine Biology (HIMB) has developed an interactive global map of corals and zooxanthellae, commonly known as flagellate protozoa, as part of a hybrid web application titled GeoSymbio. This application provides global-scale biological and ecosystem information on symbiotic zooxanthellae called Symbiodinium, which are uni-cellular, photosynthetic dinoflagellates that live inside the cells of other marine organisms like anemones, jellyfish and corals.

The GeoSymbio application provides the genetic identification and taxonomic description of over 400 distinct Symbiodinium subclades or genetic lineages in invertebrate hosts that have been sampled from a variety of marine habitats, thereby providing a wealth of information for symbiosis researchers in a single online location. By utilizing Google Apps, the team was able to develop this web-based tool to discover, explore, visualize and share data in a rapid, cost-effective and engaging manner. (more…)

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