Dealing with Dead Zones: Hypoxia in the Ocean
When water runs off of farmland and urban centers and flows into our streams and rivers, it is often chock-full of fertilizers and other nutrients. These massive loads of nutrients eventually end up in our coastal ocean, fueling a chain of events that can lead to hypoxic "dead zones" — areas along the sea floor where oxygen is so low it can no longer sustain marine life. In this episode, we're joined by NOAA scientist Alan Lewitus to explore why dead zones form, how the problem of hypoxia is growing worse, and what we're doing about it.
Source: National Oceanic and Atmospheric Administration (NOAA)
Author: Troy Kitch
Read the full article here.
Earth’s Oceans Suffocate as Climate Change and Nutrient Loading Create “Dead Zones”
"A new research study from a Global Ocean Oxygen Network (GO2NE) team of scientists reveals that the number of low- and zero oxygen sites in the world’s oceans have increased dramatically in the past 50 years. The Intergovernmental Oceanographic Commission of the United Nations created the GO2NE working group to provide a multidisciplinary, global view of deoxygenation, with the end goal of advising policymakers on preserving marine resources by countering low oxygen. [...]"
Source: environmental monitor
Author: Karla Lant
New measurement technology helps to determine NO concentrations in the ocean
"Nitrogen monoxide (NO) belongs to the group of nitrogen oxides which are infamous as toxic emissions in urban agglomerations. But NO is also produced in nature and plays a role in the nitrogen cycle. However, from earth's largest ecosystem, the ocean, we have hardly any NO measurements."
Source: Science Daily
Oceans suffocating as huge dead zones quadruple since 1950, scientists warn
Areas starved of oxygen in open ocean and by coasts have soared in recent decades, risking dire consequences for marine life and humanity
"Ocean dead zones with zero oxygen have quadrupled in size since 1950, scientists have warned, while the number of very low oxygen sites near coasts have multiplied tenfold. Most sea creatures cannot survive in these zones and current trends would lead to mass extinction in the long run, risking dire consequences for the hundreds of millions of people who depend on the sea. [...]"
Source: The Guardian
Chinese firm makes breakthrough in ocean technology
"A Chinese company is pioneering the nation's first deep-sea thermal-power technology to drive drifting underwater vehicles for an international ocean observation program, reports said Thursday.
Involving 30 countries and regions, the Argo program is a global array of 3,800 free-drifting automated vehicles dubbed "floats" that measure the temperature and salinity of the upper 2,000 meters of the ocean, according to the program website.
The new thermal-technology powered float, manufactured by the 710 Institute affiliated to the China Shipbuilding Industry Corporation and the School of Meteorologic Oceanography of National University of Defense Technology, offers a kind of perpetual motion to ocean observations, Science and Technology Daily reported on Thursday. [...]"
Source: Asia Pacific Daily
Gulf of Mexico Battles Expanding Dead Zone in Louisiana
The Gulf of Mexico meets the shorelines of Alabama, Louisiana, Mississippi, Texas and western Florida and is home to a large fishing industry. Several rivers from the Midwestern watershed flow south into the Gulf, carrying with them sediment, nutrient loads, and pollution from fossil fuel burning and wastewater systems.
The problem isn’t new, but it is expanding. "
Author: Mindy Cooper
Source: Environmental Monitor
Mysterious ‘shadow zone’ traps 2000-year-old water
"A MYSTERIOUS abyss in the ocean known as the “shadow zone” traps ancient water dating back to 400AD. We now know why it’s there.
IT’S called the “shadow zone” and it lies around two kilometres below the surface in an ocean abyss where trapped water dates back to the fourth century.
This ancient water, which is between 1000 and 2000 years old, dates back to when the ancient Germanic tribe the Goths instigated the end of the Western Roman Empire and the rise of Medieval Europe. [...]"
50-years of data from a 'living oxygen minimum' lab could help predict the oceans' future
The mass of data, collected in two new Nature family papers, could help scientists better predict the impact of human activities and ocean deoxygenation on marine environments. Currently, oxygen minimum zones (OMZs) constitute up to 7 percent of global ocean volume. Continued expansion of OMZs in the northeastern subarctic Pacific has the potential to transport oxygen-depleted waters into coastal regions, adversely affecting nutrient cycles and fisheries productivity. [...]"
Source: University of British Columbia (media contact: Chris Balma)
Ocean acidification could doom key Arctic fish species: study
Ocean acidification combined with warming of the world oceans and loss of oxygen is having a severe impact on key Arctic marine species such as polar cod in the Barents Sea, according to a new study conducted by German scientists.
"The eight-year interdisciplinary study, which began in 2009 and involved more than 250 scientist in the German research network on ocean acidification BIOACID (Biological Impacts of Ocean Acidification), investigated how different marine species respond to ocean acidification – a change in the ocean chemistry that occurs when carbon dioxide (CO2) from the atmosphere dissolves in seawater.
In addition to ocean acidification, the study, Exploring Ocean Change: Biological Impacts of Ocean Acidification, also examined the cascading effect of other stressors such as ocean warming, deoxygenation, overfishing and eutrophication – the increased concentration of nutrients in estuaries and coastal waters that causes harmful algal blooms, ocean dead zones and fish kills. [...]"
Source: The Independent Barents Observer
A strong case for limiting climate change
"As a gigantic carbon sink, the ocean has taken up about a third of the carbon dioxide (CO2) released into the atmosphere by human activities. But when absorbed by seawater, the greenhouse gas triggers chemical reactions, causing the ocean to acidify. Ocean acidification affects ecosystems and important services the ocean provides to humankind. This includes the regulation of the Earth's climate, food provision, recreation as well as biodiversity as a condition for intact and functioning ecosystems. [...]"