Research in Pacific shows ocean trouble
Acidity rises, oxygen drops, scientists find
By LISA STIFFLER
Seattle Post-Intelligencer
March 31, 2006
Research fresh off a boat that docked Thursday in Alaska reveals some frightening changes taking place in the Pacific Ocean.
As humans are pumping out more carbon dioxide that is helping to warm the planet, the ocean has been doing yeoman's work to lessen the effects -- but it's taking a toll.
Christopher Sabine, NOAA
Scientists lower 36 bottles used for water sampling from the deck of the Thomas G.
Thompson while doing research near the equator. Over time, the changes could have an
impact that ripples through the food chain, from microscopic plants that can't grow right to
salmon and whales unable to find enough to eat.
The Pacific is getting warmer and more acidic, while the amount of oxygen and the building blocks for coral and some kinds of plankton are decreasing, according to initial results from scientists with National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory, the University of Washington and elsewhere.
"There are big changes," said Christopher Sabine, chief scientist for one leg of the research trip, which ultimately traveled from Antarctica to Alaska.
Many of the most interesting results are tied to the ocean becoming increasingly acidic because of its absorption of carbon dioxide.
"You don't have to believe in climate change to believe that this is happening," said Joanie Kleypas, an oceanographer with the University Corporation for Atmospheric Research, a non-profit organization based in Boulder, Colo. "It's pretty much simple thermodynamics."
And it's alarming.
"Acidification is more frightening than a lot of the climate change issues," Kleypas said. That's in part because the process is hard to alter.
"It's a slow-moving ship, and we're all trying to row with toothpicks," she said.
Carbon dioxide is a byproduct of burning fossil fuels such as oil and gas. Over the past 200 years, the ocean has absorbed about half of what's been released into the atmosphere.
Sabine and the other researchers found that in the past 15 years, there's been a detectable decline in the ocean's pH, which is a measure of acidity ranging from zero to 14, with zero being most acidic (water is neutral, or pH 7, while seawater is about pH 8).
The pH of the saltwater has dropped 0.025 units since the early 1990s. The number seems unremarkable, but the pH scale is exponential, so a one-unit drop is a 10-fold decrease. The new measurement also puts the ocean on track for a dramatic decline by the end of the century.
Plankton -- tiny plants and animals that live in the ocean -- are among the creatures that could be harmed by the change. In addition to the water becoming more acidic, the extra carbon dioxide reduces the amount of chemical compounds used to construct coral and the shells of plankton.
"That's a major issue," said John Guinotte, a marine scientist with the Bellevue-based Marine Conservation Biology Institute who studies deep sea corals.
"You're likely looking at serious effects through out the marine food web across the board," he said.
The pole-spanning trip that ended Thursday is part of the Repeat Hydrography project. The most recent trip was aboard the Thomas G. Thompson, a UW-operated vessel, and lasted about three months. Thirty-five scientists from about a dozen universities and government labs participated.
The plan is to survey 19 routes crisscrossing all the world's oceans, then repeat those trips every 10 years to detect trends in ocean conditions. Ocean measurements were taken every 60 miles from the surface to the bottom of the sea.
Researchers from California State University-San Marcos and the University of South Florida towed nets behind the vessel to catch plankton, which they then subjected to acidic conditions on par with what might be experienced in the future.
"They're seeing that the shells of these organisms start to dissolve even while the organism is still living," said Sabine, an oceanographer with NOAA's Seattle lab.
Some of the creatures tested are little snails that are "a major food source for salmon and whales and these larger things and they make a shell that is very susceptible to a decrease in pH," he said.
Other experiments show that microscopic plants at the base of the food chain that build protective plates out of calcium carbonate don't grow properly in the acidic water.
"We don't expect to go out and find living organisms with dissolving shells," Sabine said. "We expect to find perhaps a change in where these organisms are thriving or perhaps fewer of them over time."
The ocean scientists expressed an urgency over reducing carbon dioxide emissions as soon as possible.
"Anything we can do to slow that rate of change will slow the rate of response in the oceans as well," said Kleypas. "It buys us some time."
TO LEARN MORE
The national project: ushydro.ucsd.edu
Local participants: www.pmel.noaa.gov/co2/co2-home.html
P-I reporter Lisa Stiffler can be reached at 206-448-8042 or lisastiffler@seattlepi.com.
Caribbean coral suffers record death
By SETH BORENSTEIN
AP SCIENCE WRITER
Seattle Post-Intelligencer
March 30, 2006
WASHINGTON -- A one-two punch of bleaching from record hot water followed by disease has killed ancient and delicate coral in the biggest loss of reefs scientists have ever seen in Caribbean waters.
Researchers from around the globe are scrambling to figure out the extent of the loss. Early conservative estimates from Puerto Rico and the U.S. Virgin Islands find that about one-third of the coral in official monitoring sites has recently died.
"It's an unprecedented die-off," said National Park Service fisheries biologist Jeff Miller, who last week checked 40 stations in the Virgin Islands. "The mortality that we're seeing now is of the extremely slow-growing reef-building corals. These are corals that are the foundation of the reef ... We're talking colonies that were here when Columbus came by have died in the past three to four months."
Some of the devastated coral can never be replaced because it only grows the width of one dime a year, Miller said.
Coral reefs are the basis for a multibillion-dollar tourism and commercial fishing economy in the Caribbean. Key fish species use coral as habitat and feeding grounds. Reefs limit the damage from hurricanes and tsunamis. More recently they are being touted as possible sources for new medicines.
If coral reefs die "you lose the goose with golden eggs" that are key parts of small island economies, said Edwin Hernandez-Delgado, a University of Puerto Rico biology researcher.
On Sunday, Hernandez-Delgado found a colony of 800-year-old star coral - more than 13 feet high - that had just died in the waters off Puerto Rico.
"We did lose entire colonies," he said. "This is something we have never seen before."
On Wednesday, Tyler Smith, coordinator of the U.S. Virgin Islands Coral Reef Monitoring program, dived at a popular spot for tourists in St. Thomas and saw an old chunk of brain coral, about 3 feet in diameter, that was at least 90 percent dead from the disease called "white plague."
"We haven't seen an event of this magnitude in the Caribbean before," said Mark Eakin, coordinator of the National Oceanic and Atmospheric Administration's Coral Reef Watch.
The Caribbean is actually better off than areas of the Indian and Pacific ocean where mortality rates - mostly from warming waters - have been in the 90 percent range in past years, said Tom Goreau of the Global Coral Reef Alliance. Goreau called what's happening worldwide "an underwater holocaust."
And with global warming, scientists are pessimistic about the future of coral reefs.
"The prognosis is not good," said biochemistry professor M. James Crabbe of the University of Luton near London. In early April, he will investigate coral reef mortality in Jamaica. "If you want to see a coral reef, go now, because they just won't survive in their current state."
For the Caribbean, it all started with hot sea temperatures, first in Panama in the spring and early summer, and it got worse from there.
New NOAA sea surface temperature figures show the sustained heating in the Caribbean last summer and fall was by far the worst in 21 years of satellite monitoring, Eakin said.
"The 2005 event is bigger than all the previous 20 years combined," he said.
What happened in the Caribbean would be the equivalent of every city in the United States recording a record high temperature at the same time, Eakin said. And it remained hot for weeks, even months, stressing the coral.
The heat causes the symbiotic algae that provides food for the coral to die and turn white. That puts the coral in critical condition. If coral remains bleached for more than a week, the chance of death soars, according to NOAA scientists.
In the past, only some coral species would bleach during hot water spells and the problem would occur only at certain depths. But in 2005, bleaching struck far more of the region at all depths and in most species.
A February NOAA report calculates 96 percent of lettuce coral, 93 percent of the star coral and nearly 61 percent of the iconic brain coral in St. Croix had bleached. Much of the coral had started to recover from the bleaching last fall, but then the weakened colonies were struck by disease, finishing them off.
Eakin, who oversees the temperature study of the warmer water, said it's hard to point to global warming for just one season's high temperatures, but other scientists are convinced.
"This is probably a harbinger of things to come," said John Rollino, the chief scientist for the Bahamian Reef Survey. "The coral bleaching is probably more a symptom of disease - the widespread global environmental degradation - that's going on."
Crabbe said evidence of global warming is overwhelming.
"The big problem for coral is the question of whether they can adapt sufficiently quickly to cope with climate change," Crabbe said. "I think the evidence we have at the moment is: No, they can't.
"It'll not be the same ecosystem," he said. "The fish will go away. The smaller predators will go away. The invertebrates will go away."
By LISA STIFFLER
P-I REPORTER
Seattle Post-Intelligencer
April 3, 2006
Study finds reefs could turn brittle from global warming
Even the coldest, darkest depths of the world's oceans can't escape the harmful effects of global warming -- and that includes deep-sea corals, local researchers have found.
The scientists are connecting the ocean's increasing absorption of carbon dioxide -- a greenhouse gas produced by burning fossil fuels -- with changes in the chemistry of seawater. More carbon dioxide leads to a reduced supply of calcium compounds used by corals and other marine creatures to build their shells.
That could result in osteoporosislike conditions that cause stony coral reefs to become brittle. It could slow their growth and even limit the areas where the corals can grow.
Corals play an important role in the marine web of life, providing food and shelter for fish and invertebrates. Researchers have found sea sponges that contain anti-cancer agents among the corals as well.
"A lot of these corals will be in conditions that will be detrimental," said John Guinotte, lead author of the research paper published today in the peer-reviewed journal Frontiers in Ecology and the Environment.
Guinotte, a marine scientist at the Bellevue-based Marine Conservation Biology Institute, found that the majority of deep, rocky corals are found in areas "supersaturated" with calcium-carbonate compounds used to build their shells.
By the end of this century, as more carbon dioxide is released and the oceans become more acidic, only 30 percent of those waters are expected to still be supersaturated.
"Corals have been around for millions of years ... but corals as we know them today, the reefs we know today, have no experience with these conditions," Guinotte said in an interview.
The study pulled together earlier research on the location of the corals and current and future ocean conditions.
It was written by six researchers from the United States, Australia, Germany and France.
Many of the deep-sea coral reefs were undiscovered until the past 15 to 25 years. They are mostly in the North Atlantic, though smaller clumps form in the Pacific Ocean, including the Washington coast.
Other changes associated with global warming -- increased ocean temperatures and changes in water circulation patterns and saltiness -- could also harm the remote corals.
"The ocean is this frontier; they just discovered these things not long ago," said Joanie Kleypas, an oceanographer with the National Center for Atmospheric Research in Boulder, Colo. "This stuff is kind of scary."
Scientists last week reported that record hot water and disease have triggered the largest loss of Caribbean corals ever seen.
About one-third of the tropical corals officially being monitored have recently died, according to preliminary estimates from Puerto Rico and the Virgin Islands -- some of them centuries old.
A research team including scientists from the National Oceanic and Atmospheric Administration and the University of Washington returned Thursday from a trip stretching from Antarctica to Alaska documenting changing ocean conditions.
According to the team's preliminary results, the ocean has became noticeably acidic over the past 15 years, threatening the health of tiny snails and plants at the base of the food chain.
"Oceans are changing dramatically with climate change," said Philip Mote of the UW's Climate Impacts Group. "Effectively, we're just finding more and more ways to interfere with the climate system."
This report contains information from The Associated Press. P-I reporter Lisa Stiffler can be reached at 206-448-8042 or lisastiffler@seattlepi.com.
Posted by Arthur Caldicott on 05 Apr 2006