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Environmental Monitoring

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March 2017 Issue

OSIL Buoy Network
Off Abu Dhabi

Ocean Scientific International Ltd. (OSIL) has installed a network of eight monitoring buoys off the coast of Abu Dhabi, United Arab Emirates (UAE). The rugged 1.2-m coastal buoys are equipped with multiparameter sondes for water quality monitoring and GPRS telemetry equipment. The buoys are in water depths ranging from 6 to 16 m in locations along the UAE coastline amid extensive coral formations and seagrass beds.


Ocean Circulation Slows,
Promotes Acidification

With the ocean absorbing more carbon dioxide over the past decade, less of the greenhouse gas is reaching the Earth’s atmosphere. But this promotes ocean acidification, which breaks down the calcium carbonate shells of marine organisms. New research from UC Santa Barbara geographer Timothy DeVries and colleagues demonstrates that a slowdown of the ocean’s overturning circulation is the likely catalyst. It’s unknown whether the slowdown is related to natural climate variability or to climate change caused by human activity.

DeVries and researchers Mark Holzer of the University of New South Wales in Sydney and François Primeau of UC Irvine compiled existing oceanographic tracer data into three decade-long time periods: the 1980s, the 1990s and the 2000s. Computer analysis enabled characterization of the ocean circulation per period. As the circulation changed from decade to decade, their model predicted a big dip in oceanic carbon dioxide uptake during the 1990s, then a large increase in uptake during the 2000s. These swings were attributed directly to the changes in ocean circulation.

Prevailing scientific wisdom asserts that the deceleration of circulation diminishes the ocean’s ability to absorb anthropogenic carbon dioxide from the atmosphere as surface waters warm and become saturated with carbon dioxide. But the weaker overturning circulation brings less naturally carbon dioxide-rich deep waters to the surface, which limits how much of that gas in the deep ocean escapes to the atmosphere. That causes the ocean to absorb more carbon dioxide from the atmosphere.


Release of Methane
Into Atmosphere Unlikely

The breakdown of methane hydrates due to warming climate is unlikely to lead to massive amounts of methane being released to the atmosphere, according to an interpretive review of scientific literature performed by the U.S. Geological Survey and the University of Rochester.

Methane, or gas, hydrate is a naturally occurring, ice-like form of methane and water that is stable in a narrow range of pressure and temperature conditions mostly found in undersea sediments at water depths greater than 1,000 to 1,650 ft. and in and beneath permafrost at high latitudes. Methane hydrates are not currently exploited for energy production.

Gas hydrate deposits store enormous amounts of methane at relatively shallow depths, making them particularly susceptible to the changes in temperature that accompany climate change. Methane is also a potent greenhouse gas, and some researchers have suggested that methane released by the breakdown of gas hydrate during past climate events may have exacerbated global warming.

The new review concludes that current warming of ocean waters is likely causing gas hydrate deposits to break down at some locations, but most of the methane released remains in undersea sediments, dissolves in the ocean or is converted to carbon dioxide by microbes.


Wärtsilä Joins Seabin
To Tackle Ocean Litter

Wärtsilä has joined the Seabin Project’s global pilot program tackling ocean littering via education, research and technology. Wärtsilä will work in cooperation with the Seabin Project for the next three years and has sponsored both the city and port of Helsinki’s involvement with the program.

The Seabin is a floating rubbish bin for marinas, docks, yacht clubs and commercial ports that collects floating rubbish. Water is sucked in from the surface and passes through the catch bag filter.

Seabin’s global pilot program will be launched April 2017 with the installation of the latest prototype around the globe, including Helsinki.


Arctic Ocean Litter
Increases 20-Fold

In just 10 years, the concentration of marine litter at a deep-sea station in the Arctic Ocean has risen 20-fold, according to a study by researchers at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI).

Since 2002, AWI researchers have been documenting the amount of litter at two stations of the AWI’s Hausgarten, a deep-sea observatory network in the Fram Strait. The scientists observed the ocean floor at 2,500-m depth using a towed camera system.

They found mostly plastic and glass litter. The study indicates a positive relationship between litter density and the summertime expansion of sea ice; sea ice could entrain floating litter during ice formation, then during warmer periods, the ice breaks up and is transported south to the Fram Strait with the Transpolar Drift, releasing entrained litter when it melts.


Algae Weed Threatens
Great Barrier Reef

New research shows how weed-like algae will kill vital coral in the Great Barrier Reef because of increased carbon dioxide concentrations in the atmosphere. The Griffith University study, conducted in collaboration with other experts in reef and chemical ecology, showed that if current-level global carbon dioxide emissions continue, corals will suffer significantly by 2050 and die off by 2100.

Carbon dioxide promotes algae growth, and algae will compete for space with corals in the reef and eventually take over. The researchers discovered that some algae produce more potent chemicals that suppress or kill corals in a matter of weeks. The research, undertaken at Heron Island, has global impact because one of the most noxious seaweeds is a common brown algae species found in reefs worldwide.


2017:  JAN | FEB | MARCH | APRIL | MAY | JUNE | JULY | AUG | SEPT
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Sea Technology is read worldwide in more than 110 countries by management, engineers, scientists and technical personnel working in industry, government and educational research institutions. Readers are involved with oceanographic research, fisheries management, offshore oil and gas exploration and production, undersea defense including antisubmarine warfare, ocean mining and commercial diving.