Scientists seeking an oceanic counterpart to the tree rings that document past weather patterns on land have found one in the subtropical waters of Dry Tortugas National Park near the Florida Keys, where long-lived boulder corals contain the chemical signals of past water temperatures. By analyzing coral samples, USGS researchers and their colleagues have found evidence that an important 60- to 85-year-long cycle of ocean warming and cooling has been taking place in the region as far back as the 1730s.

The cycle called the Atlantic Multidecadal Oscillation, or AMO, is linked to rainfall over most of the US, Midwestern droughts, hurricane intensification and landfalls, and the transfer of ocean heat from the tropical Caribbean Sea to the North Atlantic Ocean by way of the Gulf Stream. It interacts with ongoing climate change in poorly understood ways, and it is very hard to spot in pre-20th century records.

An important new research paper, titled “Response of Sediment Bacterial Communities to Sudden Vegetation Dieback in a Coastal Wetland,” examines the consequences of plant disappearance and changes in salt marsh soil communities following Sudden Vegetation Dieback (SVD).

The paper, published in Phytobiomes, an open-access journal of The American Phytopathological Society, is written by Wade Elmer, Peter Thiel, and Blaire Steven, scientists at the Connecticut Agricultural Experiment Station in New Haven. The setting for this study was the marshes of Connecticut’s Hammonasset Beach State Park.

Phytoplankton are the foundation of ocean life, providing the energy that supports nearly all marine species. Levels of phytoplankton in an ocean area may seem like a good predictor for the amount of fish that can be caught there, but a new study by Nereus Program researchers finds that this relationship is not so straightforward.

“Using measurements of phytoplankton growth at the base of the food web to estimate the potential fish catch for different parts of the ocean has long been a dream of oceanographers,” says author Ryan Rykaczewski, Assistant Professor at University of South Carolina and Nereus Program Alumnus. “We know that these two quantities must be related, but there are several steps in the food chain that complicate the conversion of phytoplankton growth to fish growth.”

An analysis of fossilized parrotfish teeth and sea urchin spines by researchers at Scripps Institution of Oceanography at the University of California San Diego showed that when there are more algae-eating fish on a reef, it grows faster.

In the new study, published in the Jan. 23 issue of the journal Nature Communication, Scripps researchers Katie Cramer and Richard Norris developed a 3,000-year record of the abundance of parrotfish and urchins on reefs from the Caribbean side of Panama to help unravel the cause of the alarming modern-day shift from coral- to algae-dominated reefs occurring across the Caribbean.

“Our reconstruction of past and present reefs from fossils demonstrates that when overfishing wipes out parrotfish, reef health declines,” said Cramer, a postdoctoral researcher at Scripps and lead author of the study.

If coastal salt marshes are like savings accounts, with sediment as the principal, all eight Atlantic and Pacific coast salt marshes studied are "in the red," researchers found.

Scientists working on a rapid assessment technique for determining which US coastal salt marshes are most imperiled by erosion were surprised to find that all eight of the Atlantic and Pacific Coast marshes where they field-tested their method are losing ground, and half of them will be gone in 350 years’ time if they don’t recapture some lost terrain.

Trees may be easy to spot on the plains of Africa but they are often overlooked as a source of income for farmers. A University of Illinois study shows trees on farms may help reduce rural poverty and maintain biodiversity.

Scientists are calling for the urgent protection of ecologically valuable roadless areas, writes Tim Radford, as a new global map shows that roads lead to loss of biodiversity and damage to ecosystems by fragmenting habitat and providing access to exploiters.

New evidence involving the ancient poop of some of the huge and astonishing creatures that once roamed Australia indicates the primary cause of their extinction around 45,000 years ago was likely a result of humans, not climate change. 

One of Alaska’s most abundant freshwater fish species is altering its breeding patterns in response to climate change. This could impact the ecology of northern lakes, which already acutely feel the effects of a changing climate.

That’s the main finding of a recent University of Washington study published in Global Change Biology that analyzed reproductive patterns of three-spine stickleback fish over half a century in Alaska’s Bristol Bay region. The data show that stickleback breed earlier and more often each season in response to earlier spring ice breakup and longer ice-free summers.

Pioneering new research has provided a fascinating new insight in the quest to determine whether temperature or water availability is the most influential factor in determining the success of global, land-based carbon sinks.

The research, carried out by an international team of climate scientists including Professors Pierre Friedlingstein and Stephen Sitch from the University of Exeter, has revealed new clues on how land carbon sinks are regulated on both local and global scales.