A possible cause is global warming, researchers say. Warmer surface water makes it harder for plankton to get vital nutrients. "It's concerning because phytoplankton is the basic currency for everything going on in the ocean," said Boris Worm, a study co-author and Dalhousie University biology professor.

While satellite data only dates back to 1978, the researchers were able to access observations from the pioneering days of oceanography.  The Vatican did ask the Italian priest Pietro Angelo Secchi around 1865 to measure the clarity of the Mediterranean Sea. He simply lowered a white disk into the water and noted the depth when the object started to move out of sight.

The tiny organisms that make up plankton provide a crucial food source for larger marine life such as fish. Phytoplankton also plays an important role in the global carbon cycle. Through photosynthesis, Phytoplankton produces about half of the oxygen in Earth's atmosphere. It absorbs carbon dioxide and transforms it into organic matter, which sinks to the ocean or seafloor when the plankton dies. The amount of plankton in the water varies widely horizontally, vertically and seasonally, based on the availability of light and nutrients.

Researchers say that lower visibility is usually caused by higher amounts of plankton in the water. Combining data from the 19th century with observations made by satellites points to a long-term decline in plankton growth. "They're creating a climate record out of something that really wasn't designed to do this, using sophisticated techniques," said David Siegel, a marine scientist with the University of California who co-wrote a commentary on the paper. "It fills in a piece of our history, so we're able to tell the story of what has been happening in the last 100 years."

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"Regulating wastewater discharge from the land will help coral reefs resist climate change," said van Woesik according to a press release. "In the face of climate change and ocean warming, this study gives managers hope that maintaining high water quality can spare corals."

Corals are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, and are formed by polyps that live together in groups. The polyps secrete a hard carbonate exoskeleton which provides support and protection for the body of each polyp. Reefs grow best in warm, shallow, clear, sunny and agitated waters. High nutrient levels such as those found in runoff from agricultural areas can harm reefs by encouraging excess algae growth.

Coral reefs are fragile ecosystems, partly because they are very sensitive to water temperature. They deliver ecosystem services to tourism, fisheries and shoreline protection. The annual global economic value of coral reefs has been estimated at $30 billion.

The Nick Hobgood photo shows Tube Sponges surrounded by golden sweepers, wrasses and cardinal fish.

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Researchers from the BAS, Lamont-Doherty Earth Observatory (LDEO) and the National Oceanography Centre used an autonomous underwater vehicle called Autosub to dive beneath the Glacier's floating ice shelf and map the ocean floor. The measurements revealed a submarine ridge rising 900 feet (300 meters) above the sea floor. Scientists say that the Pine Island Glacier was once scraped across this underwater ridge, which slowed its flow.

However, in recent decades it has thinned and disconnected from the ridge, allowing the glacier to move ice more rapidly from the land into the sea. This also permitted relatively warm seawater to flow over the ridge and into a widening inner cavity, more than doubling the ice shelf area exposed to the corrosive ocean. As the melting increases the glacier's flow accelerates, drawing down the inland ice and moving its vulnerable grounding line (where the ice begins to float) deeper into the interior of the West Antarctic Ice Sheet.

"The discovery of the ridge has raised new questions about whether the current loss of ice from Pine Island Glacier is caused by recent climate change or is a continuation of a longer-term process that began when the glacier disconnected from the ridge," said lead author Adrian Jenkins, British Antarctic Survey, in a press release. “We do not know what kick-started the initial retreat from the ridge, but we do know that it started some time prior to 1970. Since detailed observations of Pine Island Glacier only began in the 1990s, we now need to use other techniques such as ice core analysis and computer modeling to look much further into the glacier’s history in order to understand if what we see now is part of a long term trend of ice sheet contraction. This work is vital for evaluating the risk of potential wide-spread collapse of West Antarctic glaciers."

Scientists say that the West Arctic Peninsula is currently contributing about 10 percent of the previously frozen fresh water that causes global sea levels to rise. To put this in perspective, all the fresh water stored in the Arctic ice cap would only cause the oceans to rise 1 millimeter.

"Since our first measurements in the Amundsen Sea, estimates of Antarctica's recent contributions to sea level rise have changed from near-zero to significant and increasing," says co-author Stan Jacobs. "Now finding that the PIG's grounding line has recently retreated more than 30 kilometers from a shallow ridge into deeper water, where it is pursued by a warming ocean, only adds to our concern that this region is indeed the 'weak underbelly' of the West Antarctic Ice Sheet. Increased melting of continental ice also appears to be the primary cause of persistent ocean freshening and other impacts, both locally and downstream in the Ross Sea."

Scientists take measurements at the glaciology-field-camp on the Pine Island Glacier. Photo: British Antarctic Survey

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"Our oceans are filled with plastic waste. Yet on land, there is a shortage of recycled plastic," says Electrolux President and CEO Hans Stråberg in a statement. "The supply of sustainable raw material, such as recycled plastic, is crucial for making sustainable appliances, and assisting consumers in making their homes greener. I therefore hope you will join us in raising awareness about the threat plastic poses to marine habitats, and the urgent need for taking better care of the plastic that already exists."

The Swedish company says that the concept of using recycled plastic to manufacture vacuum cleaners is not new.  Electrolux has already produced vacuum cleaners using 55 percent recycled plastic during their Ergospace Green project.

One of the largest garbage patches circulates within the North Pacific gyre, one of the five major oceanic gyres. The exact size of the garbage patch is unknown, with estimates ranging from an area the size of the state of Texas to one larger than the continental United States. The existence of the Great Pacific Garbage Patch was first predicted in a 1988 paper published by the National Oceanic and Atmospheric Administration (NOAA).

Like other areas of concentrated marine debris in the world's oceans, it is thought that the Great Pacific Garbage Patch formed gradually as a result of marine pollution gathered by oceanic currents. Most debris consists of small plastic particles suspended at or just below the surface, making it impossible to detect by aircraft or satellite.

While the new initiative called "Vac from the sea" can certainly raise attention about the garbage patches floating in the Oceans, it sounds also a bit like a public relations stunt. Electrolux did not give any time frame nor did the company say how much litter they plan to collect or how many units they plan to manufacture. The company says that it will work with experts and volunteers to dive, fish, and scavenge several hotspots in the world's oceans. Electrolux states that it has created Twitter and Facebook accounts to attract volunteers.

A promotional video describes the planned initiative "Vac from the sea."

The graphic shows the approximate location of the Great Pacific Garbage Patch north of the Hawaii Archipelago. Illustration: NOAA/Public Domain

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"If you consider how much ocean crust there is on Earth, and how much of that is hydrologically active, then this environment could be one of the most massive habitats for microbial life on Earth," Orcutt said. "There may be new species of life and new types of metabolism that we haven't discovered yet."

The reservoir was discovered by using a technique known as scientific drilling. It allows researchers to obtain samples of liquids that were trapped in sedimentary rocks and or subsurface aquifers, mostly microbial life, preserved in drilled samples. While every part of the planet, from the polar ice caps to the Equator, supports life of some kind, only recent advances have demonstrated that microbes can thrive deep beneath the Earth's terrestrial surface. Some scientists believe that the total biomass in so-called "uninhabitable zones" exceeds all animal and plant life found on the surface.

"The subsurface under deep oceans is an extreme environment for any life to exist. Such environments may be present on other planets so life might exist there in the form of microbial organisms," Orcutt said. Because the microscopic organisms exist in an extreme environment that receives no light, the microbiologist believes her research also can yield a new understanding of the potential for life on other planets.

Scientists have already extracted microbes that can be cultured from cores drilled more than 3 miles (4.83 kilometers) into the Earth's crust. Since temperatures increase rapidly in the sub-seafloor, it is likely that the limit of life in the "deep biosphere" is defined by temperature rather than absolute depth.

Photo: Global Adventures, LLC

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