There is evidence that some microbial life had migrated from the Earth’s oceans to land by 2.75 billion years ago, though many scientists believe such land-based life was limited because the ozone layer that shields against ultraviolet radiation did not form until hundreds of millions years later.
But new research from the University of Washington suggests that early microbes might have been widespread on land, producing oxygen and weathering pyrite, an iron sulfide mineral, which released sulfur and molybdenum into the oceans. (more…)
Michelle Bayefsky hopes that London’s future will be filled with elm trees.
The Yale junior spent part of her summer in that city helping to ensure that will be the case.
An International Bulldogs Internship allowed Bayefsky the opportunity to work for an environmental charity called The Conservation Foundation, which among other initiatives is engaged in a project to re-establish elm tree populations in the United Kingdom (U.K.). For Bayefsky, the experience was not only an introduction to environmental work, but also confirmed that small actions can sometimes have a big impact. (more…)
Scientists have found the answer to why female killer whales have the longest menopause of any non-human species – to care for their adult sons.
Led by the Universities of Exeter and York and published in the journal Science the research shows that, for a male over 30, the death of his mother means an almost 14-fold-increase in the likelihood of his death within the following year.
The reason for the menopause remains one of nature’s great mysteries and very few species have a prolonged period of their lifespan when they no longer reproduce, as in humans. However, female killer whales stop reproducing in their 30s-40s, but can survive into their 90s. While different theories have been put forward for the evolution of menopause in humans, including the well-established ‘grandmother’ hypothesis, there has been no definitive answer to why females of a small number of other species, including killer whales, also stop reproducing part-way through their lives. (more…)
A NASA-sponsored expedition is set to sail to the North Atlantic’s saltiest spot to get a detailed, 3-D picture of how salt content fluctuates in the ocean’s upper layers and how these variations are related to shifts in rainfall patterns around the planet.
The research voyage is part of a multi-year mission, dubbed the Salinity Processes in the Upper Ocean Regional Study (SPURS), which will deploy multiple instruments in different regions of the ocean. The new data also will help calibrate the salinity measurements NASA’s Aquarius instrument has been collecting from space since August 2011. (more…)
Ear-bone ‘tree rings’ provide evidence of connectivity
Ocean scientists have long known that juvenile coral reef fishes use coastal seagrass and mangrove habitats as nurseries, later moving as adults onto coral reefs. But the fishes’ movements, and the connections between different tropical habitats, are much more complex than previously realized, according to a study published September 3 in Proceedings of the National Academy of Sciences. The findings have important implications for management and protection of coral reefs and other marine environments.
A number of studies have demonstrated a strong relationship between the presence of coastal wetlands and offshore fish abundance and fisheries yield, but it has proved difficult to develop quantitative assessment of habitat use by fish or their movement among different habitats. “The rationale for this study,”says Simon Thorrold, a biologist at Woods Hole Oceanographic Institution (WHOI), “was to determine the relative importance of different nursery habitats to reef fishes that spend their adult lives on coral reefs but may spend at least part of their juvenile residency elsewhere.” (more…)
Sustainable management of a huge, complex and valuable resource such as the ocean requires a comprehensive metric that did not exist until now. In the Aug. 16 edition of Nature a broad group of scientists including Heather Leslie, the Sharpe Assistant Professor of Environmental Studies, describes the Ocean Health Index. The index rates coastal places, from regions to nations, on 10 goals: artisanal fishing opportunity, biodiversity, carbon storage, clean waters, coastal livelihoods and economies, coastal protection, food provision, natural products, sense of place, and tourism and recreation. Leslie recently answered questions posed by David Orenstein.
How does the Ocean Health Index’s focus on integrating human factors make it different and valuable?
Recognizing people’s integral roles in ocean ecosystems, this index evaluates how well the ocean provides 10 key benefits to people and how well we are protecting its ability to do so in the future. (more…)
Changes in the speed that ice travels in more than 200 outlet glaciers indicates that Greenland’s contribution to rising sea level in the 21st century might be significantly less than the upper limits some scientists thought possible, a new study shows.
“So far, on average we’re seeing about a 30 percent speedup in 10 years,” said Twila Moon, a University of Washington doctoral student in Earth and space sciences and lead author of a paper documenting the observations published May 4 in Science. (more…)
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…)
