Wind pushes plastics deeper into oceans, driving trash estimates up
Decades of research into how much plastic litters the sea may have only skimmed the surface. A new study reveals that wind drives confetti-sized pieces of plastic debris deeper underwater than previously believed, more than doubling earlier estimates of the pollutant’s presence in oceans.
“In windy conditions the traditional approach to measuring plastic marine debris captures only a small fraction of plastic pieces,” said Tobias Kukulka, assistant professor of physical ocean science and engineering in the University of Delaware’s College of Earth, Ocean, and Environment. “Our study helps to better understand how much plastic there is and where, as well as the complexity of the ocean dynamics at work.” (more…)
Almost all the sediment-associated chemical concentrations found in 131 of the nation’s rivers that drain to the Atlantic, Pacific and Gulf Coasts are lower than worldwide averages, according to a new study by the USGS. These coastal rivers are a significant pathway for the delivery of sediment-associated chemicals to the world’s coastal zones and oceans.
“I hope that the results of this new study will remind everyone that it is not only river water that can transport chemicals and pollutants, but also the associated sediment load,” said USGS Director Marcia McNutt. “Our citizens expect high environmental quality as compared with worldwide averages, but clean water alone will not suffice if river sediments are host to toxic heavy metals and concentrated organics that can produce dead zones.” (more…)
A new study led by the University of Massachusetts Amherst and involving the University of Colorado Boulder proposes a simple new mechanism to explain the source of carbon that fed a series of extreme warming events on Earth about 50 million years ago called the Paleocene-Eocene Thermal Maximum, or PETM, as well as a sequence of similar, smaller warming events afterward.
“The standard hypothesis has been that the source of carbon was in the ocean in the form of frozen methane gas in ocean-floor sediments,” said lead study author Rob DeConto of the University of Massachusetts Amherst. “We are instead ascribing the carbon source to the continents in polar latitudes where permafrost can store massive amounts of carbon that can be released as CO2 when the permafrost thaws.” (more…)
An international research team is reporting the results of a research cruise they organized to study the amount, spread, and impacts of radiation released into the ocean from the tsunami-crippled reactors in Fukushima, Japan. The group of 17 researchers and technicians from eight institutions spent 15 days at sea in June 2011 studying ocean currents, and sampling water and marine organisms up to the edge of the exclusion zone around the reactors.
Led by Ken Buesseler, a senior scientist and marine chemist at the Woods Hole Oceanographic Institution (WHOI), the team found that the concentration of several key radioactive substances, or radionuclides, were elevated but varied widely across the study area, reflecting the complex nature of the marine environment. In addition, although levels of radioactivity in marine life sampled during the cruise were well below levels of concern for humans and the organisms themselves, the researchers leave open the question of whether radioactive materials are accumulating on the seafloor sediments and, if so, whether these might pose a long-term threat to the marine ecosystem.The results appear in the April 2 online edition of the journal Proceedings of the National Academy of Sciences (PNAS). (more…)
*Damaged deep-sea corals discovered months after Deepwater Horizon spill*
Scientists are reporting new evidence that the Deepwater Horizon oil spill has affected marine life in the Gulf of Mexico, this time species that live in dark ocean depths–deepwater corals.
The research used a range of underwater vehicles, including the submarine Alvin, to investigate the corals. The findings are published this week in the journal Proceedings of the National Academy of Sciences (PNAS). (more…)
A University of Delaware oceanographer has stumbled upon an unusual aid for studying local waterways: radioactive iodine. Trace amounts of the contaminant, which is used in medical treatments, are entering waterways via wastewater treatment systems and providing a new way to track where and how substances travel through rivers to the ocean.
UD study assesses ocean use off Delaware, Maryland and New Jersey coasts
The Center for Carbon-Free Power Integration (CCPI) at the University of Delaware has issued a new report about ocean use off the coast of Delaware and parts of Maryland and New Jersey. The study addresses viable places to locate offshore wind farms, taking into account biological, ecological and other considerations. The report includes feedback from interested groups who attended a November 2011 workshop, as well as input from experts.
“This report demonstrates that the ocean is already active with ecological and human activity,” lead-author Alison Bates said. “It shows what government regulators ought to consider in planning for offshore wind development and the beginning of a way forward for offshore wind developers and existing users to accommodate one another.” (more…)
A fundamental shift in the Indian monsoon has occurred over the last few millennia, from a steady humid monsoon that favored lush vegetation to extended periods of drought, reports a new study led by researchers at the Woods Hole Oceanographic Institution (WHOI). The study has implications for our understanding of the monsoon’s response to climate change.
The Indian peninsula sustains over a billion people, yet it lies at the same latitude as the Sahara Desert. Without a monsoon, most of India would be dry and uninhabitable. The ability to predict the timing and amount of the next year’s monsoon is vital, yet even our knowledge of the monsoon’s past variability remains incomplete. (more…)
