Archive for the 'News' Category

From ScienceDaily

Scientists have found that only about ten percent of the fall-run Chinook salmon spawning in California’s Mokelumne River are naturally produced wild salmon. A massive influx of hatchery-raised fish that return to spawn in the wild is masking the fact that too few wild fish are returning to sustain a natural population in the river.

The study, published in the online journal PLoS ONE, highlights the danger of relying on census techniques to evaluate the health of wild salmon populations and their habitats. Most hatchery fish in California are unmarked and therefore undetectable in population surveys. For this study, the researchers were able to identify hatchery fish by using a novel technique to detect traces of a hatchery diet preserved in the ear bones of adult fish.

“We expected to find hatchery fish, but the sheer number of hatchery fish returning to spawn in the wild is surprising,” said first author Rachel Johnson, a fishery biologist affiliated with the Institute of Marine Sciences at UC Santa Cruz and with the Bay-Delta Office of the U.S. Bureau of Reclamation.

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Photo from UBC Botanical Garden and Center for Plant Research

From ScienceDaily

A natural substance obtained from seeds of the “miracle tree” could purify and clarify water inexpensively and sustainably in the developing world, where more than 1 billion people lack access to clean drinking water, scientists report. Research on the potential of a sustainable water-treatment process requiring only tree seeds and sand appears in ACS’ journal Langmuir.

Stephanie B. Velegol and colleagues explain that removing the disease-causing microbes and sediment from drinking water requires technology not always available in rural areas of developing countries. For an alternative approach, Velegol looked to Moringa oleifera, also called the “miracle tree,” a plant grown in equatorial regions for food, traditional medicine and biofuel. Past research showed that a protein in Moringa seeds can clean water, but using the approach was too expensive and complicated. So Velegol’s team sought to develop a simpler and less expensive way to utilize the seeds’ power.

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Empty cans of pesticide in a ditch at a farm in Arusha, Tanzania. Photo by Norwegian School of Veterinary Science

From ScienceDaily

An increase in human activity is posing a threat to natural aquatic ecosystems in Tanzania and contributing to environmental damage and ecological changes.

Doctoral research carried out by Hezron Emmanuel Nonga shows that agriculture and livestock farming leads to eutrophication in lakes and the proliferation of cyanobacteria which produce microcystins. New information about microcystins and other mycotoxins in Tanzanian lakes is useful for appraising the risk linked to drinking water and edible fish, which in turn affects the health of both humans and animals.

In Tanzania, there are many and varied wetland areas and aquatic ecosystems which are productive but also vulnerable. Hezron Emmanual Nonga’s doctoral research project has studied how human activities affect ecosystems in wetlands and has also examined the incidence of cyanobacteria, the production of microcystins and the possible effects of these toxins on wild species.

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By Elisabeth Rosenthal from The New York Times

Clamshell containers on supermarket shelves in the United States may depict verdant fields, tangles of vines and ruby red tomatoes. But at this time of year, the tomatoes, peppers and basil certified as organic by the Agriculture Department often hail from the Mexican desert, and are nurtured with intensive irrigation.

Growers here on the Baja Peninsula, the epicenter of Mexico’s thriving new organic export sector, describe their toil amid the cactuses as “planting the beach.”

Del Cabo Cooperative, a supplier here for Trader Joe’s and Fairway, is sending more than seven and a half tons of tomatoes and basil every day to the United States by truck and plane to sate the American demand for organic produce year-round.

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From ScienceDaily

Fuel made from wood could become a competitive commercial alternative to fuel made from corn by 2020 if the wood biofuel industry is supported, according to a new University of British Columbia study.

Corn ethanol is currently blended with gasoline to satisfy government-mandated targets to include renewable content in transportation fuel. Compared to corn, wood-based biofuel is considered more sustainable but is not currently produced in large commercial quantities in Canada and the United States because the costs are too great.

The study, published in the most recent issue of the journal Biofuels Bioproducts & Biorefining, identifies several opportunities for reducing these costs. Researchers in UBC’s Faculty of Forestry found that large-scale commercial production of wood-based ethanol, also known as cellulosic ethanol, will reduce capital and operation costs and assist in achieving the improvements necessary for wood-based ethanol to compete, without government support.

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