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Hydrologists Find Mississippi River’s Buffering System for Nitrates is Overwhelmed

By Guest PostJune 9, 2014Environmentancient magnetic field, carbon fiber thailand, cfrp reinforced polymer, climate plan, crystalline filaments, dead zone, f1 cars, fiber reinforced plastics, formula 1 cars, fraction, geology, green america, gulf of mexico, john podesta, lars ellenrieder, mechanism, mississippi river, sam komplex, usgs, zellfluessigkeit

AUSTIN, Texas — A new method of measuring the interaction of surface water and groundwater along the length of the Mississippi River network adds fresh evidence that the network’s natural ability to chemically filter out nitrates is being overwhelmed.

The research by hydrogeologists at The University of Texas at Austin, which appears in the May 11 edition of the journal Nature Geoscience, shows for the first time that virtually every drop of water coursing through 311,000 miles (500,000 kilometers) of waterways in the Mississippi River network goes through a natural filtering process as it flows to the Gulf of Mexico. (more…)

Real-time Monitoring Pays Off for Tracking Nitrate Pulse in Mississippi River Basin to the Gulf of Mexico

By Guest PostAugust 26, 2013Environmentbaton rouge, brian pellerin, connecticut, dead zone, gulf of mexico, hypoxic zone, kevin richards, lori caramanian, mississippi drainage, mississippi river basin, nitrate data, nitrate pulse, nitrate removal systems, noaa, raccoon river, rainfall, real time monitoring, research hydrologist, seasons, usgs, van meter

Cutting edge optical sensor technology is being used in the Mississippi River basin to more accurately track the nitrate pulse from small streams, large tributaries and ultimately to the Gulf of Mexico.

Excessive springtime nitrate runoff from agricultural land and other sources in the Mississippi drainage eventually flows into the Mississippi River. Downstream, this excess nitrate contributes to the Gulf of Mexico hypoxic zone, an area with low oxygen known commonly as the “dead zone.” NOAA-supported researchers reported that the summer 2013 dead zone covered about 5,840 square miles, an area the size of Connecticut. (more…)

Global Extinction: Gradual Doom as Bad as Abrupt

By Guest PostFebruary 8, 2012Environment, Sciencebrooks ellwood, canadian arctic, carbon dioxide, charles henderson, coal deposit, dead zone, earth, ellesmere island, extinction, factor, fossil, geologic history, geology, global extinction, greenhouse, greenhouse gas, h richard lane, harry rowe, indian ocean, katherine freeman, marine life, mass extinction, national science foundation, ocean, permian period, permian triassic boundary, sedimentary rock, siberian traps, siberian volcanic activity, south china, steven bates, tethys, the great dying, thomas algeo, timothy lyons, united states, university of calgary, university of cincinnati, volcanic deposit, volcanic rock, volcanism in siberia, warming, west blind fiord

*In “The Great Dying” 250 million years ago, the end came slowly*

The deadliest mass extinction of all took a long time to kill 90 percent of Earth’s marine life–and it killed in stages–according to a newly published report.

It shows that mass extinctions need not be sudden events.

Thomas Algeo, a geologist at the University of Cincinnati, and 13 colleagues have produced a high-resolution look at the geology of a Permian-Triassic boundary section on Ellesmere Island in the Canadian Arctic. (more…)

Gulf of Mexico Dead Zone Severely Impairs Reproduction in Atlantic Croaker, Researchers Find

By Guest PostJune 16, 2011Environment, Scienceandrogens, aromatase, atlantic croaker, coast of louisiana, coastal regions, dead zone, enzyme, estrogens, female sex hormones, fish population, gulf of mexico, hypoxic area, hypoxic coastal zone, hypoxic dead zone, impairment of reproductive output, low oxygen waters, male sex hormones, marine animals, marine science, marine scientist, masculinized, neuroendocrine function, ovarian masculinization, oxygen levels, peter thomas, reproductive impairment, saydur rahman, second largest seasonal hypoxic zone, sperm and eggs, the university of texas at austin, thomas and rahman, world

AUSTIN, Texas — Atlantic croaker living in the large Gulf of Mexico “Dead Zone” exhibit severe reproductive impairment with potential long-term impacts on the fish’s population abundance, researchers from The University of Texas at Austin’s Marine Science Institute have found.

Males and females were found to produce dramatically fewer sperm and eggs. In addition, females in the hypoxic Dead Zone waters were masculinized — some 20 percent actually produced sperm in their ovaries. The sex ratio was also heavily skewed toward males in the hypoxic area. (more…)

Widespread Ancient Ocean “Dead Zones” Challenged Early Life

By Guest PostJanuary 8, 20111 commentEnvironmentanoxic, atmospheric oxygen, bacteria, benjamin gill, cambrian period, chesapeake bay, dead zone, diversification of life, earth, enriqueta barrera, fluctuations, gulf of mexico, iron, late ediacaran period, maryland, molybdenum, nitrogen, ocean, oceanic oxygen, oxygen level, oxygen rich, phosphorus, timothy lyons, ucr, virginia

*Persistent lack of oxygen in Earth’s oceans affected animal evolution*

The oceans became oxygen-rich as they are today about 600 million years ago, during Earth’s Late Ediacaran Period. Before that, most scientists believed until recently, the ancient oceans were relatively oxygen-poor for the preceding four billion years.

Now biogeochemists at the University of California-Riverside (UCR) have found evidence that the oceans went back to being “anoxic,” or oxygen-poor, around 499 million years ago, soon after the first appearance of animals on the planet. (more…)

Reseachers Predict Larger-than-average Gulf ‘Dead Zone’; Impact of Oil Spill Unclear

By Guest PostJuly 2, 2010Environment, Scienceaquatic, Atchafalaya, bacteria, center for sponsored coastal ocean, dead zone, deepwater horizon, donald scavia, ecologist, geological survey, graham sustainability institute, gulf hypoxic zone, gulf of mexico, hypoxia, hypoxia zone, hypoxia-fueling algae, lake Ontario, louisiana state university, louisiana universities marine consortium, matt Larsen, Mississippi, national oceanic and atmospheric administration, nitrogen, noaa, organic matter, oxygen-starved, river, school of natural resources and environment, university of michigan, US, usgs

ANN ARBOR, Mich.—University of Michigan aquatic ecologist Donald Scavia and his colleagues say this year’s Gulf of Mexico “dead zone” is expected to be larger than average, continuing a decades-long trend that threatens the health of a $659 million fishery.

(more…)

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