Tag: oceans

Sea level rise overwhelming some coral reefs

A sea turtle swims lazily along a coral reef in Hawaii, trailed by tropical fish. (Photo by Kosta Stamoulis, courtesy Oregon State University via Flickr.)

Seafloor erosion outpacing expectations

Staff Report

Coral reefs aren’t just threatened by pollution, ocean acidification and over-heated ocean temperatures. In some places they are being undermined by erosion of the seafloor, U.S. Geological Survey scientists said in a new study that looked at reefs in Florida, the Caribbean and Hawaii.

In the five study sites, the reefs can’t keep pace with sea level rise. As a result, coastal communities protected by the reefs are facing increased risks from storms, waves and erosion.

The degradation of reefs and the subsiding seafloor go hand-in-hand, as sand and other sea floor materials have eroded over the past few decades. In the waters around Maui, the sea floor losses amounted to 81 million cubic meters of sand, rock and other material – about what it would take to fill up the Empire State Building 81 times, the researchers calculated.  Continue reading “Sea level rise overwhelming some coral reefs”

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Mega-waves swept Caribbean corals far inland

brain coral boulder eight feet in diameter stands 750 feet inland in the British Virgin Islands. Geologists say that the coral was brought ashore, probably alive, by an unusual tsunami or storm between the years 1200 and 1480.(Credit: Brian F. Atwater, U.S. Geological Survey.

New research will help islands prepare for future coastal hazards

Staff Report

Sometime before Columbus sailed into the Caribbean, a massive ocean upheaval tossed giant coral boulders far inland on tiny island — a sign that there may have a tsunami, or perhaps an extra-powerful hurricane in the region.

The new findings, published in the journal Geosphere, will help coastal planners prepare for unexpected hazards, according to researchers with the U.S. Geological Survey. The boulders were found in the British Virgin Islands at Anegada—a low-lying island named by Columbus in 1493 and located behind a coral reef that faces the Puerto Rico Trench. Continue reading “Mega-waves swept Caribbean corals far inland”

Deep oceans at risk from climate change

Close-up of a tripod fish at 1960 meters depth in the Northeast Providence Channel near Eleuthera Island. Photo courtesy NOAA.

‘It is the equivalent of having summer for the first time in thousands to millions of years’

Staff Report

Deep sea ecosystems that have barely been explored are at risk from global warming, as low-oxygen zones spread and ocean acidification increaseses. By 2100, organisms deep on the  ocean floor may face starvation and sweeping ecological changes, according to scientists from 20 of the world’s leading oceanographic research warned last week.

“Biodiversity in many of these areas is defined by the meager amount of food reaching the seafloor and over the next 80-plus years – in certain parts of the world – that amount of food will be cut in half,” said Andrew Thurber, an Oregon State University marine ecologist and co-author of the study, published in the journal Elementa. Continue reading “Deep oceans at risk from climate change”

Can ‘supersites’ anchor coral reef protection efforts?

Yellow tangs swim in a coral reef ecoystems.
Yellow tangs swim in a coral reef ecoystems. Photo courtesy NOAA.

Study says 90 percent of all predatory fish species have been lost from Caribbean coral reefs

Staff Report

Not all Caribbean reefs are created equal, say researchers with the  University of North Carolina at Chapel Hill, who recently identified reef areas they are calling “supersites”that could help restore populations of predatory fish needed maintain an ecological balance.

That’s the good news. The bad news is their study also shows that up to 90 percent of predatory fish are gone from Caribbean coral reefs. The research suggests that these supersites should be prioritized for protection and could serve as regional models showcasing the value of biodiversity for tourism and other uses. Continue reading “Can ‘supersites’ anchor coral reef protection efforts?”

Pollution from China disrupts ocean ecosystems

Shifting nutrient balance shapes plankton blooms

A plankton bloom in the Arctic waters of the Barents Sea. Photo courtesy NASA.
A plankton bloom in the Arctic waters of the Barents Sea. Photo courtesy NASA.

Staff Report

Pollution from Chinese factories is changing the nutrient balance in the ocean, say scientists who studied depositions of chemicals and plankton blooms in the East China Sea. These waters are increasingly threatened by harmful algal blooms that choke off vital fish populations, according to the new study, led by researchers at the University of California, Irvine.

“There has been massive growth in emissions from China’s factories and cars over the past few decades, and what comes out of the smokestacks and tailpipes tends to be richer in nitrogen than phosphorus,” said Katherine Mackey, assistant professor of Earth system science at UCI and lead author of the study, published recently in Frontiers in Marine Science. Continue reading “Pollution from China disrupts ocean ecosystems”

Non-native species invade Mediterranean through newly enlarged Suez Canal

Scientists warn of ecosystem, health impacts

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Port Cros National Park, France. A new study says native marine ecosystems in the Mediterranean are at risk from non-native species invading via the Suez Canal. @bberwyn photo.

Staff Report

Scientists say the 2015 expansion of the Suez Canal has enabled non-native species to swarm into the Mediterranean, potentially impacting fisheries and human health.

“The Mediterranean Sea is the most invaded marine basin in the world. The number of non-indigenous species greatly increased between 1970 and 2015. 750 multicellular non-indigenous species were recorded in the Mediterranean Sea, far more than in other European seas, because of the ever-increasing number of Red Sea species introduced through the Suez Canal,” said Bella Galil of the Israel National Center for Biodiversity Studies. “This raises concerns about the increasing introductions of additional NIS and associated degradation and loss of native populations, habitats and ecosystem services.” Continue reading “Non-native species invade Mediterranean through newly enlarged Suez Canal”

New surveys confirm Great Barrier Reef damage

Heat-driven coral bleaching continues to take a toll

Staff Report

A new survey of the Great Barrier Reef shows that an ocean heat wave that peaked last March killed up to 95 percent of corals in some parts of the northern reef.  And in the aftermath of the worst coral-bleaching event on record, predatory snails are now taking on toll on the remaining corals.

According to the ARC Centre of Excellence for Coral Reef Studies, researchers recently returned to 83 reefs they surveyed at the height of the bleaching event.

“Millions of corals in the north of the Great Barrier Reef died quickly from heat stress in March and since then, many more have died more slowly,” said Dr. Greg Torda whose team recently returned from re-surveying reefs near Lizard Island. Continue reading “New surveys confirm Great Barrier Reef damage”