Research platforms may affect accurate collection of data in low light
Light is an important cue for nearly all life on Earth. Plants use light for photosynthesis, animals use light to set sleep cycles, and marine organisms use light to find food, avoid predators and even hide in plain sight. (more…)
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…)
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…)
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…)
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…)
*Pikaia is most primitive vertebrate known*
Researchers from the University of Toronto, the Royal Ontario Museum (ROM) and the University of Cambridge have confirmed that a 505 million-year-old creature, found only in the Burgess Shale fossil beds in Canada’s Yoho National Park, is the most primitive known vertebrate and therefore the ancestor of all descendant vertebrates, including humans.
The research team’s analysis proves the extinct Pikaia gracilens is the most primitive member of the chordate family, the group of animals that today includes fish, amphibians, birds, reptiles and mammals. Their study is based on the analysis of 114 specimens and is published in the British scientific journal Biological Reviews. (more…)
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…)
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…)
