27 Jun 2012:
BP Oil Spill Accelerated
Erosion of Louisiana Marshlands
The 2010 BP oil spill hastened the loss of Louisiana’s already fragile salt marshlands
, a new study says. In a comparison of erosion rates at three healthy marsh sites and three areas affected by the oil spill, University of Florida scientists found
that oil from the spill coated thick grasses on the outer edge of some wetlands, killing off salt marsh plants 15 to 30 feet from the shoreline. When those grasses died, the deep roots that held the soil sediment died as well, causing the rate of erosion on shore banks to more than double. In Louisiana’s Barataria Bay, for instance, oiled marshes have receded nearly 10 feet per year after the spill — about twice the normal rate of erosion in a region already losing huge areas of marshland as a result of channelization of the Mississippi River and rising sea levels. “We already knew that erosion leads to permanent marsh loss, and now we know that oil can exacerbate it,” said Brian Silliman, a University of Florida biologist and lead author of the study, published in the Proceedings of the National Academy of Sciences
25 Jun 2012:
U.S. Atlantic Coast Already
‘Hotspot’ of Sea Level Rise, Study Says
A 600-mile stretch of the U.S. East Coast is experiencing rates of sea level rise that are three to four times greater than the global average
, according a new study. In a new analysis, scientists at the U.S. Geological Survey (USGS) found that sea levels from Boston, Mass. to Cape Hatteras, N.C. have risen 2 to 3.7 millimeters per year since 1990, compared with a global average of 0.6 to 1 millimeters per year. According to the study, published in the journal Nature Climate Change
, sea levels appear to be rising in this mid-Atlantic region because a major Atlantic current that carries tropical water to the north is slowing down; that warmth expands seawater, which can lead to higher sea levels. “Many people mistakenly think that the rate of sea level rise is the same everywhere as glaciers and ice caps melt… [but] as demonstrated in this study, regional oceanographic contributions must be taken into account
in planning for what happens to coastal property,” said Marcia McNutt, director of the USGS.
14 Jun 2012:
Australia to Create
World’s Largest Marine Reserve
Australia has announced that it will create the world’s largest marine reserve,
a network of protected areas that will cover 1.2 million square miles, more than one-third of the country’s waters. Environment Minister Tony Burke, making the announcement in advance of the Rio+20 sustainability summit, said the action will expand the number of Australia’s marine reserves from 27 to 60 and will protect waters of the Coral Sea and other key ocean habitats. “It’ time for the world to turn a corner on protection of our oceans, and Australia today is leading that next step,” said Burke. “What we’ve done is effectively create a national parks estate in the ocean.” Limited fishing and oil drilling will be allowed in some areas, and the fishing industry will receive hundreds of millions of dollars in compensation for reducing or eliminating commercial fishing in numerous tracts of ocean.
13 Jun 2012:
Ban on Fish Discards
Is Approved by the European Union
The European Union has decided to end the controversial practice of allowing fishermen to select high-value species from their nets and then discard the remainder of dead fish, a practice that leads to the destruction of an estimated 1 million tons of edible fish a year
in EU waters. The EU Council announced its intention to implement a discard ban, but did not set a firm date, saying discard bans for some species could be phased in as late as 2020. Although some environmental groups praised the ban, others said that allowing the practice of fish discards to continue for another eight years could be too late to save some severely overfished species, such as plaice and sole. EU officials hailed the long-sought ban, with the president of Denmark calling it “a very important step in the direction of a radical new fisheries policy — a sustainable fisheries policy.” Conservationists say the policy of allowing fishermen to meet their quotas by selecting only certain species and tossing away the rest is one of the main reasons for the precipitous decline in European fish stocks.
08 Jun 2012:
Major NASA Discovery Finds
Phytoplankton Blooms Under Arctic Ice
For the first time, scientists have discovered extensive blooms of phytoplankton under Arctic Ocean ice,
contradicting the widely held conviction that such blooms could not occur under sea ice that blocked the sun's rays from triggering the blooms. Scientists on a NASA-sponsored expedition to the Arctic Ocean say the blooms are likely related to the rapid thinning of Arctic sea ice, which allows sunlight to penetrate the ice and trigger blooms. Working on a U.S. Coast Guard icebreaker last summer in the Beaufort and Chukchi seas off Alaska, the scientists discovered massive blooms that extended from the sea-ice edge to 72 miles inside the pack ice. The blooms did not occur under thick ice, but rather under melt ponds and nearly translucent melting ice. “This is like finding the Amazon rainforest in the middle of the Mojave Desert,” said Paula Bontempi, NASA’s ocean biology and biogeochemistry program manager. The research, published in Science
, sheds new light on how the Arctic Ocean ecosystem may be reacting to a rapidly warming climate,
affecting marine life from phytoplankton at the base of the food chain to gray whales at the top.
07 Jun 2012:
Environmental Tipping Point
Is Nearing, International Study Says
The rapid warming of the planet, a soaring human population, the steady loss of biodiversity, over-exploitation of energy resources, and the degradation of the world’s oceans are driving the world toward an ecological tipping point,
according to a new study in Nature
. Twenty-two scientists from five nations compared the major changes taking place today with previous ecological shifts — such as the end of the last Ice Age 14,000 to 18,000 years ago — that triggered mass extinctions of some species, expansions of others, and the creation of new global ecosystems. The paper said that while there is still considerable uncertainty as to whether the world is now approaching such a “state shift,” many signs point to a future of ecological upheaval. “Given all the pressures we are putting on the world, if we do nothing different, I believe we are looking at a time scale of a century or even a few decades for a tipping point to arrive,” lead author Anthony Barnosky
, a biologist at the University of California, Berkeley, said in an interview.
25 May 2012:
Marine Reserves Replenish
Commercial Fisheries, DNA Tests Show
DNA testing has shown that the creation of marine reserves where no fishing is allowed helps to replenish fish stocks outside the reserve boundaries
. In a study conducted at Australia’s Great Barrier Reef, researchers collected tissue samples from two species of commercially popular fish — including 466 samples of adult coral trout and 1,154 samples from stripey snapper — located within three reserve areas. After collecting juveniles of both species in protected and unprotected areas over the next 15 months, the researchers found that about half of the juveniles were offspring of fish found in the reserve areas, even though the reserves accounted for just 28 percent of the study area. In other words, fish found in the reserves “punch above their weight in replenishing fishery stocks
,” said Garry Russ, a researcher from James Cook University and one of the authors of the study, published online in the journal Current Biology
22 May 2012:
Seagrasses Hold More Carbon
Per Square Kilometer Than Forests
The planet’s seagrass meadows store more than twice as much carbon per square kilometer as forests
, demonstrating that coastal vegetation can play an important role in mitigating climate change, a new study says. Writing in the journal Nature Geoscience
, a team of scientists calculated that coastal seagrass beds can store up to 83,000 metric tons of carbon per square kilometer, compared with 30,000 metric tons of carbon per square kilometer in typical forests. While seagrasses occupy less than 0.2 percent of the world's oceans, they account for more than 10 percent of all the carbon trapped in the sea.Seagrasses have a unique ability to store carbon in their roots and soil in coastal areas, the study showed. In some regions, they found, seagrass beds have stored carbon for thousands of years. “Seagrasses only take up a small percentage of global coastal area, but this assessment shows that they’re a dynamic ecosystem for carbon transformation,” said James Fourqurean, a scientist at Florida International University and lead author of the study.
22 May 2012:
Rivers are Largest Source
Of Mercury in Arctic Ocean, Study Says
A new study suggests that rivers may be funneling far more toxic mercury into the Arctic Ocean than previously believed, a finding that may portend even greater mercury concentrations in the future as the effects of climate change accelerate the region’s hydrological cycle. Despite the Arctic's remoteness, scientists have long known that mercury levels in Arctic mammals are among the highest on the planet, a factor largely attributed to mercury being deposited in the Arctic Ocean from the air. But according to Harvard scientists
, circumpolar rivers — particularly three Siberian rivers, the Lena, Ob, and Yenisei — may be contributing twice as much mercury as the atmosphere. According to the scientists, mercury levels in the Arctic tend to increase sharply during the spring and summer. Using a sophisticated model of atmospheric and ocean conditions, they concluded the only factor that could explain this spike was increased flow of these rivers as they melt. According to the researchers, more mercury may be entering the river systems as melting permafrost increasingly releases mercury locked in the soil. In addition, mercury is likely coming from runoff from gold, silver, and mercury mines in Siberia. The study is published in Nature Geoscience
18 May 2012:
EU Fisheries Observers
Are Intimidated, Bribed by Crews
Observers placed on European Union fishing boats to reduce the amount of illegal and unreported catches are often subject to threats, intimidation, and bribes
when they try to do their jobs, according to a report in the Guardian
. After interviewing more than 20 former and current fisheries observers and examining EU records, the newspaper said that the threats and harassment are common on Spanish and Portuguese fishing boats, which are notorious for egregious overfishing. The observers told the Guardian
that crew members would steal their records of fishing violations, threaten them with an “accident” at sea, kick their cabin doors to keep them awake at night, and take elaborate steps — including making illegal hauls while observers were eating — to conceal the extent of overfishing. Independent observers are placed aboard every vessel operating in the Northwest Atlantic Fishery Organization. But because of fishing industry pressure, observers who spot violations are only allowed to summon an inspector on board, but cannot provide the inspector with any details or records of infractions.
16 May 2012:
Wildlife in Tropical Regions
Has Declined 60 Percent Since 1970
Wildlife populations in the world’s tropical regions have fallen by more than 60 percent during the last four decades
, according to the latest version of the Living Planet Index. The Index — which tracks populations of 2,688 vertebrate species in tropical and temperate regions worldwide — found that species abundance in the tropics declined by about 44 percent on land, 62 percent in the oceans, and 70 percent in freshwater ecosystems from 1970 to 2008. Cumulatively, species abundance declined by about 1.25 percent annually every year compared with a 1970 baseline, according to the report, which is published by the World Wide Fund for Nature (WWF) and the Zoological Society of London. Wildlife populations declined by 38 percent in Africa during that period; about 50 percent in Central and South America; and 64 percent in Indo-Pacific regions. Overall, the global index dropped almost 30 percent during the same period. These steep population declines are the result of many factors related to human activities, including deforestation, habitat loss, pollution, overfishing, and climate change.
15 May 2012:
Record Number of Fish Stocks
‘Rebuilt’ in 2011, NOAA Study Says
U.S. officials say a record number of fish stocks recovered to healthy population numbers
in 2011 while a declining number of species were subject to overfishing. In a report
to Congress, the U.S. National Oceanic and Atmospheric
Administration (NOAA) declared that six species have been “rebuilt,” including the Bering Sea snow crab, the summer flounder found on the mid-Atlantic coast, the haddock in the Gulf of Maine, the Chinook salmon on the northern California coast, the Coho salmon on the Washington coast, and the Widow rockfish on the Pacific coast. Meanwhile, the number of stocks subject to overfishing decreased by four, and overfished stocks declined by three compared with the 2010 report. Samuel D. Rauch III, a NOAA deputy assistant administrator, said the findings underscore the fact that fisheries management — including sometimes unpopular catch limits — has been effective.
11 May 2012:
Eel Breeding Innovation
Sought to Conserve Wild Populations
Japanese biologists are racing to develop a type of food that would enable fish farmers to breed eels on a commercial scale
using for the first time larvae produced in captivity, a step that could reduce pressures on collapsing eel populations worldwide. While farmers have long bred captive eels — a popular delicacy in many countries — until now they have only been able to do so on a commercial scale using baby eels trapped in the wild, a step that has exacerbated the catastrophic decline in wild eel populations from the Far East to North America. The reason, scientists say, is that it has been difficult and expensive to produce the foodstuff critical to the development of eel larvae: a mixture of marine detritus known as “marine snow.” Scientists so far have considered a wide range of possible ingredients, including the yolk from shark’s eggs. “Whoever gets there first has made a tremendous discovery; you’re recovering a cultural tradition,” David Righton, a scientist with the UK-based Cefas marine laboratory, told the Guardian
. “Whoever does this is culturally important as well as becoming very rich.”
09 May 2012:
Warming Waters Attract
New Fish Species to British Waters
Warming ocean temperatures have changed the distribution of many critical marine species
off the British coast, as warm water fish are increasingly expanding into northern waters and cold-water species are swimming to colder depths, according to a new report. The report of the Marine Climate Change Impacts Partnership
, published by the UK and Scottish governments, found that warm water species such as the bluefin tuna and thresher sharks are more frequently appearing in the waters off southwest England and squid have become increasingly abundant in the North Sea. One southern species, the bib, has moved north by 212 miles (342 kilometers) in the last two decades, while common North Sea species such as cod and lemon sole are swimming at an average of 5.5 meters deeper per decade. The report, based on an analysis of scientific studies, warns these changes pose potential threats for native species and the commercial fishing industry as changing water temperatures could introduce invasive species and new diseases.
09 May 2012:
Groundwater Pumping Emerges
As a Factor in Sea Level Rise, Study Says
The vast amounts of water pumped out of the ground for irrigation, drinking water, and industrial uses will increasingly contribute to global sea level rise
in the coming decades, according to a new study. According to researchers at Utrecht University, humans pumped about 204 cubic kilometers (49 cubic miles) of groundwater in 2000, much of which evaporated into the atmosphere before ultimately entering rivers, canals and, eventually, the world’s oceans. While in earlier decades the rise in sea level caused by groundwater removal was canceled out by the construction of dams, that changed by the 1990s as humans pumped more groundwater and built fewer dams. By 2000, groundwater extraction resulted in a sea level rise of about 0.57 millimeters annually — compared with about 0.035 millimeters in 1990. According to the study, published in Geophysical Research Letters
, by 2050 the pumping of groundwater worldwide could cause sea levels to rise about 0.8 millimeters annually.
07 May 2012:
Japanese Tsunami Debris
Is Increasingly Washing Ashore in Alaska
Debris from last year’s tsunami in Japan, including some potentially toxic materials, is increasingly being discovered along the Alaska coastline
. Since January, millions of pieces of debris have washed ashore along the Alaska coast, from soccer balls and buoys to motorcycles and large drums containing unknown materials, according to the Marine Conservation Alliance Foundation (MCAF), a Juneau-based group monitoring the debris. In some areas, the group has observed mysterious sludge that apparently had leaked from the containers. “So we’re looking at a potential large-scale environmental problem, and what we’re dealing with now is just the start of it,” Merrick Burden, director of the MCAF, told the Juneau Daily News
. Much of the debris that has reached Alaska so far was likely pushed by west-to-east winds, and larger materials, driven by ocean currents, will start to reach the coast next year, officials say. To help state officials better understand the future threats, MCAF is urging mariners, fishing boats, and beachcombers to take photos when they spot debris and report it to their project
and the federal government.
04 May 2012:
Greenland Glaciers Moving
More Slowly Than Previous Estimates
A new U.S. study says that Greenland’s glaciers are sliding into the sea more slowly than previously estimated
, a finding that may indicate future sea level rise will not be as high as some projected worst-case scenarios. Using satellite data to track changes to 200 outlet glaciers from 2000 to 2011, a team of scientists calculated that Greenland’s glaciers accelerated by an average of 30 percent during the decade — a significant amount but not as rapidly as feared. In an earlier study, scientists calculated that glacial flow would increase by 100 percent between 2000 and 2010, and then stabilize at the higher speed, contributing as much as 19 inches to global sea level rise by the end of the century. According to the new study, published in the journal Science
, the glaciers are expected to continue gaining speed in the coming decades, possibly contributing four inches to sea level rise by 2100. The researchers cautioned, however, that a 10-year study is too short to make any conclusions on long-term behavior.
02 May 2012:
Polar Bears Taking Long Swims
In Absence of Summer Sea Ice, Study Says
A six-year study has found that polar bears are capable of swimming great distances
when foraging for food, an increasingly critical skill as Arctic sea ice declines in summer. Using GPS collars attached to 52 adult females in the southern Beaufort and Chukchi seas from 2004 to 2009, scientists from the U.S. Geological Survey (USGS) found that about a third of the bears — including some with cubs — completed swims greater than 30 miles. Writing in the Canadian Journal of Zoology
, the scientists found that in the case of 50 long-distance swims, the bears traveled an average of 96 miles, swimming from one to 10 days; one bear swam 220 miles. While such stamina will become increasingly important for polar bears as a warming climate makes resting on summer sea ice a less available option, the researchers expressed concern that traveling such great distances takes a greater energy toll on the animals. The study sample was too small to draw conclusions about the fate of entire populations, and it is unclear whether such long swims are a new behavior.
01 May 2012:
Oil and Gas Companies See
Offshore Wind Potential in North Sea
An increasing number of oil service companies are working with renewable energy companies
to develop offshore wind projects in the North Sea as the region’s fossil fuel resources dwindle and demand for clean energy rises. According to a report by Bloomberg News, companies such as Technip and Subsea 7 are seizing on the similarities between developing deepsea oil installations and building offshore wind platforms. For wind energy developers, as much as 25 percent of capital spending includes services that can be performed by oil and gas companies, said Jayesh Parmar, a UK-based consultant at Baringa Partners LLP. “The synergies available between offshore wind and oil and gas are most apparent in the North Sea,” Parmar said. “It makes sense here to be operating in both areas.” With numerous offshore wind projects planned, the European Wind Energy Association predicts that more than 446,000 people will work in the North Sea’s offshore wind sector by the end of the decade, twice the current workforce.
27 Apr 2012:
Warming Climate Has Caused
Water Cycle to Intensify, Study Says
A new study published in the journal Science
suggests that the cycle of evaporation and rainfall over the world’s oceans has accelerated 4 percent in the last half-century as a result of global warming, a development that could portend more extreme weather in the decades to come
. In an analysis of salinity in oceans from 1950 to 2000, scientists from Lawrence Livermore National Laboratory in California found that the salty areas of the ocean have gotten saltier and fresher areas have gotten fresher, a phenomenon they attribute to stronger patterns of evaporation and precipitation over the ocean. The researchers suggest a 1-degree F increase in global temperatures during that period was enough to trigger the 4 percent intensification of the water cycle. If that trend continues, they say, projected increases in temperatures by 2100 could cause the water cycle to intensify by as much as 20 percent, which means regions already receiving a lot of rainfall will receive even more and areas prone to drought will be even drier.
27 Apr 2012:
Pacific Shark Survey Shows
90 Percent Decline Near Human Populatons
A comprehensive census of Pacific reef shark populations has found that shark abundance has plummeted by roughly 90 percent
in waters located near islands inhabited by humans. Using underwater surveys
Gray reef sharks at Hawaii’s Kure Atoll
conducted by divers across 46 U.S. Pacific islands and atolls, researchers found that shark numbers near human populations were consistently depressed, regardless of location or ocean conditions, compared with pristine reef areas located farther away from humans. In fact, the researchers estimated that shark populations are less than 10 percent of historically peak numbers in these areas, said Marc Nadon, a University of Hawaii scientist and lead author of the study, published in Conservation Biology
. “In short, people and sharks don’t mix,” he said. Researchers say the data helps quantify how human activities, including overfishing and the controversial practice of shark-finning, are decimating shark numbers.
26 Apr 2012:
Warm Ocean Currents Play
Key Role in Melting Antarctic Ice Shelves
Warm ocean currents are melting many of Antarctica’s floating ice shelves from beneath
, which in turn is speeding up the flow of land-based glaciers into the ocean and increasing global sea levels, according to a new study. An international team of scientists, led by researchers from the British Antarctic Survey (BAS), used 4.5 million measurements from a satellite-based laser altimeter that precisely measures the changing thickness of ice shelves. Using those readings and other data, the researchers determined that 20 of 54 ice shelves that flow off the Antarctic continent and float on the Southern Ocean are melting and thinning from below. Most of the 20 ice shelves are in West Antarctica, where air and ocean temperatures have been steadily rising in recent years. Along the western Antarctic Peninsula, eight ice shelves have fully or partially collapsed in the past several decades, allowing inland glaciers to surge into the sea. But the study, published in Nature
, found that even the thinning of ice shelves, without total collapse, speeds up the flow of inland glaciers, increasing global sea levels.
24 Apr 2012:
European Satellite Provides
Precise Data On Arctic Sea Ice Thickness
The European Space Agency’s (ESA) CryoSat satellite is now providing highly accurate data on the thickness and volume of Arctic Ocean ice
. Using a high-resolution
synthetic aperture radar that sends down pulses of microwave energy, the satellite can measure the difference between the top of the ice and water in the cracks, or leads, that separate the floes. By measuring the height of the ice above water, which usually represents only one-eighth of total ice thickness, the satellite can provide data on ice thickness to within 10 to 20 centimeters, or 4 to 8 inches. The CryoSat satellite was launched in 2010, and since then scientists have been validating the measurements against other data from plane-based instruments and direct, on-ice measurements. "We now have a very powerful tool to monitor the changes taking place at the poles,” said Volker Liebig, the ESA’s director of Earth Observation.
23 Apr 2012:
Floating Wind Farm Research
Receives Boost from U.S., UK Leaders
U.S. and UK officials have announced plans to work together in developing floating wind turbine technology, an innovation that could open new areas of the world’s oceans to wind energy generation. In a collaboration announced in London, U.S. Energy Secretary Steven Chu and UK Energy Secretary Edward Davey said they would help fund research into floating platforms
that would support turbines in waters as deep as 500 feet, where wind speeds are consistently higher than near-shore wind farm sites. Officials hope floating turbine technology will reduce the costs of offshore wind
, avoiding expenses associated with building on seabed foundations and allowing turbine repairs to occur in port rather than on the water. “Floating wind turbines will allow us to exploit more of our wind resource, potentially more cheaply,” Davey said.
19 Apr 2012:
151 Planned Dams Threatens
Balance of Andean Amazon, Study Says
A new study warns that 151 hydroelectric dams planned along six major rivers in the Amazon basin over the next two decades, including dozens of so-called mega-dams, could significantly disrupt the region’s ecological connectivity
. Writing in the online journal PLoS ONE
, researchers say 60 percent of the dams currently being planned would cause the first major break in river connectivity between the Andean headwaters and the lowland Amazon, possibly threatening the free flow of several Andean-Amazon rivers. The Andes provide most of the sediment, nutrients, and organic matter to the vast, species-rich Amazonian floodplain. The study also found the majority of the projects would increase forest loss because of new roads and transmission lines. “There appears to be no strategic planning regarding possible consequences to the disruption of an ecological connection that has existed for millions of years,” said Matt Finer of the Center for International Environmental Law and the study's lead author.
12 Apr 2012:
Drilling of Arctic Could Pose
Ecological Risks, Lloyd’s Report Warns
A new report by Lloyd’s of London, the world’s largest specialist insurance market, warns that rapid development of Arctic oil resources threatens to cause huge ecological damage without strict oversight
and appropriate risk management. The report, Arctic Opening: Opportunity and Risk in the High North
, projects that as much as $100 billion ((£63 billion) will be invested in the Arctic region over the next decade as the melting of sea ice opens up vast areas to oil and gas exploration and creates new shipping routes. And while this phenomenon will create significant business opportunities, the report says it is “highly likely” that it will also further disturb ecosystems already stressed by climate change and create risks associated with oil spills, particularly in ice-covered areas. “The resilience of the Arctic’s ecosystems in terms of withstanding risk events is weak, and political sensitivity to a disaster is high,” a summary of the report
on the Lloyd’s Web site says. “As a result, companies operating in the Arctic face significant reputational risk.”
05 Apr 2012:
New iPad App Will Help
Mariners Avert Right Whale Collisions
A coalition of conservation groups has created an iPad/iPhone app capable of warning mariners when they are approaching areas of high risk for collision with endangered North Atlantic right whales. The so-called Whale Alert app, which is available for free
download, sends the latest information on right whale detections and relevant management advisories to the mariners’ devices. One feature links near real-time acoustic buoys that listen for right whale calls
to the mobile devices. Theoretically, mariners will be able to slow down or alter course when whales are detected. Developers of the technology hope the system will prevent fatal collisions between vessels and right whales
, which are vulnerable to being struck by ships because they live near shore, feed near the surface, and are slow swimmers. Scientists say populations of the species have dropped to between 350 and 550.
04 Apr 2012:
Model Shows Debris Field
In Pacific From Japanese Tsunami
A new animation developed by researchers at the University of Hawaii’s International Pacific Research Center illustrates the likely path of the spreading field of debris caused by retreating waves
from last year’s gigantic tsunami in Japan. The model —
based on satellite data and a network of scientific buoys showing sea surface height, ocean surface winds, and ocean currents — shows that debris swept into the Pacific by the event now likely stretches across an area covering 5,000 kilometers by 2,000 kilometers. Much of the debris was initially pulled by the strong Kuroshio Current, which travels past eastern Japan before shifting east and then into the North Pacific Current. The Japanese government estimates about 5 million tons of debris was pulled into the ocean; about 70 percent sank to the seafloor, with about 1.5 million tons still floating.
02 Apr 2012:
Some Corals More Resilient
To Increased Acidification, Study Shows
Some coral species may be better able to cope with the increasingly acidic condition of the world’s oceans
than previously believed, a new study says. Writing in the journal Nature Climate Change
, an international team of scientists describes an internal mechanism by which many coral species are able to buffer against the rising pH levels and still form healthy skeletons. According to the scientists, coral species with skeletons made of aragonite — including the well-known Porites
corals — contain molecular “pumps” that enable them to regulate internal acid balance. Corals that form calcite skeletons, however, do not have this mechanism. Also, the researchers found that coralline algae — which they describe as the “glue” that holds coral reefs together — remain vulnerable to ocean acidification. In another study, scientists at the Scripps Institution of Oceanography have documented how temperatures in the upper regions of the world’s oceans have increased by an average of .59 degrees F
(.33 degrees C) over the last 140 years, with the greatest temperature increases occurring at surface levels, where temperatures rose by an average of 1.1 degrees F.
30 Mar 2012:
Scientists Unlock Mystery
Of Where CO2 Was Hidden During Ice Ages
The question of why atmospheric concentrations of CO2 fall during ice ages
, and where that CO2 is stored, seems to have been answered by Swiss and German scientists. Using a new method of measuring isotopes in CO2 trapped in Antarctic ice cores, the scientists determined that in periods of global cooling, the oceans absorb more CO2 and store it deep underwater. As the Earth warms because the tilt of its axis enables it to absorb more energy from the sun, changes in ocean circulation transport CO2 from the deep sea to the surface, where it is released into the atmosphere. The Swiss and German scientists were able to determine through an isotopic “CO2 fingerprint” that the released carbon dioxide came from the deep ocean. The research, published in Science
, holds important lessons for climate science today, since atmospheric concentrations of CO2 — now close to 400 parts-per-million — are higher than they have been in 800,000 years and are warming the planet. Since warmer oceans absorb less CO2 than colder oceans, the mechanism of deep-sea storage of CO2 could be disrupted, further increasing carbon dioxide concentrations in the atmosphere.