Which Ocean Species Will Outlast the Rising Acidity of Seawater?

Many of the projected effects of climate change on the world’s oceans are already visible, such as melting polar ice caps and rising sea levels. But invisible changes may be the most threatening to human food sources, beginning with the tiny species like plankton that inhabit the bottom of the oceans’ food chain.

Strength in numbers: A satellite’s view
of billions of E. huxleyi, blankets of tiny
plankton floating off the east coast of
southern England. Credit: NASA

As emissions from human activities increase atmospheric carbon dioxide, they, in turn, are modifying the chemical structure of global waters, making them more acidic.

Many researchers have speculated that most aquatic species won’t be able to adapt in time to survive the acidification that has already begun, but there are some who are more optimistic. One of them is Jennifer Sunday, a postdoctoral ecologist and evolutionary biologist at Canada’s Simon Fraser University.

“You hear people say species aren’t going to adapt in time,” she explained in an interview, “but I just knew that we don’t really know that. This really motivated me to start thinking about a study to test this. We can and did put some science and data to this question.”

Sunday and her team published a review earlier this year in Trends in Ecology and Evolution, aiming to help researchers improve their chances of finding potential survivors. It suggests that more studies should focus on identifying species with enough genetic variety to produce a mutant that can adapt.

Sunday feels that the better researchers get at searching for adapters, the more will be found.

The process that creates this risk is swift and globe-spanning. Oceans absorb roughly a quarter of the rising CO2 emissions from the atmosphere, so as that concentration increases, the oceans absorb more of the gas. In the past 150 years, human-induced climate change has changed the ocean acidity from roughly pH 8.3 to pH 8. (In the pH scale, 1 is most acidic, 7 is neutral and 14 is basic, or least acidic).

“It’s anywhere from 10 to 100 times faster than anything we’ve seen over the last million years,” said Richard Feely, a chemical oceanographer and senior researcher with the National Oceanic and Atmospheric Administration. “That’s just according to our good records.” And acidity is only expected to rise.

“By the end of this century,” Feely said, “projections are an increase by another 100 to 130 percent.”

Which tiny sea creatures can win the lottery?Changes in pH levels can have massive effects on marine life, a fact that has led many scientists to believe that most species can’t withstand large increases in acidification. When CO2 mixes with ocean waters, it binds calcium molecules that are usually free for marine creatures to build shells. The more acidic waters can also corrode existing shells.

Sunday isn’t the first to try and isolate survivor species. Several teams worldwide have already been exploring the potential of marine life species to adapt to predicted climate changes.

In 2009, a European team published their research on the tiny circular plankton Emiliania huxleyi, made up of light-reflecting mineralized calcium ovals. These tiny plankton sometimes float in populations so large, they’ve been spotted from outer space.

Looking at strains of the plankton under varying CO2 levels, researchers found that while some plankton had difficulties forming their shells when the water was more acidic, others did not, causing researchers to speculate that the plankton might be able to use another form of calcium to substitute in shell making. Other studies have shown that certain species thought incapable of evolving quickly can, in fact, rapidly adapt.

Evolution is like a lottery. The faster a species reproduces, the greater the number of unique ticket combinations it creates in the genes of its offspring. For species that produce the right genetic mutation, their number is drawn and the prize is survival.

“This is particularly important when you want to look at a species’ ability to cope with change,” said Jennifer Pistevos, a master of research student at the Marine Biological Association, who studied clone populations of Celleporella hyalina, a tiny organism she found to have an amazing ability to reproduce in both more acidic and warmer water conditions.

“Faster reproduction rates give us a chance to see how vulnerable a species is,” Pistevos said.

In 2012, Sunday and colleagues spanning three continents reviewed past studies, and based on this work, propose future research dedicated to efforts to locate adapters by incorporating more experimental evolution into the studies.

Experimental evolution identifies members of a species born with the winning genetic ticket instead of those who can come up with the correct number during their lifetime. Being born with the winning ticket means these individuals may be able to ride the acidifying tides in the kind of time frame needed—which is immediately.

Questions that can’t be answered in the labSunday and her team also suggest more work should consider a species’ response to multiple environmental changes, such as increased temperature and oxidation levels, as well as multiple stages of life. Currently, many studies only follow a species at a specific point in its members’ lives, such as infancy. Without tracking an organism over its life span and in a complicated and changing environment, it’s hard to say whether observed changes will translate into overall survival.

Although Sunday sees her work as laying the groundwork for less pessimistic predictions of the future fate of marine life, not everyone agrees that the approach is realistic. Aran Mooney, a biologist at the Woods Hole Oceanographic Institute who studies the effects of ocean acidification on Atlantic long-fin squid larvae, said some methods Sunday recommends are not practical for studying all species.

“Overall, the review is very good for us,” he said. “The authors point out some great goals and the limitations we face.” But for species like squid, Mooney said, Sunday’s suggestions are unlikely to be used.

“Measuring squid evolution in the lab might be doable to some extent,” Mooney said, “but it isn’t really possible to raise multiple generations or even young to adult—[they] don’t do all that well in captivity.”

Though Sunday agreed that predicting exactly how oceans will look in the future remains hard, researchers are starting to look in the right places. “The question just seemed too difficult before,” she said. “We wanted to put our advice out there so people could see it’s not impossible for species to adapt in time.”

“I do predict some species will adapt,” concluded Sunday, “but not all. Ultimately, it’s pretty shocking to think we’ll be losing species and it will be because of us.” More

The third in a series. To see the first two parts, click here and here.

 

© 2014

The California Drought Is Far From Over, And The Entire State Is Suffering

For a few days last month, it rained in San Francisco. Residents across the city cheered a welcomed respite from a drought that has crippled California for more than two years -- but the celebration turned out to be premature.

On Thursday, for the first time this century, the U.S. Drought Monitor declared that all of California is in a “severe” drought, with many areas of the state in an even worse condition, from "extreme" to "exceptional," the poorest possible rating.

“This is a once-in-a-generation conversation,” Mark Svoboda, a climatologist at the National Drought Mitigation Center, told The Huffington Post. He added that the last time California experienced comparable conditions was in the mid-1970s.

“The state has doubled its population between then and now,” Svoboda said. “You’ve got a lot more people using a relatively finite amount of water.”

The map below, courtesy of the U.S. Drought Monitor, shows the varying levels of drought throughout California. The orange represents “severe,” the red is “extreme,” and the maroon is “exceptional” -- the agency’s highest level (Story continues below):

No area of the state is feeling the effects of the drought more harshly than San Diego, where wildfires have ripped through more than 10,000 acres of land and tens of thousands of residents have been forced to evacuate. “In a drought, the biggest threat to health and human safety is wildfire,” Doug Carlson, an information officer at the California Department of Water Resources, told HuffPost.

And there doesn’t appear to be an end in sight. “The drought has set the stage for a very busy, very long, potentially very dangerous fire season,” Daniel Berlant, a spokesperson for CAL FIRE, said to HuffPost. “As we move into the more traditional summer months, the days are only going to get longer, and the temperatures are only going to get higher.”

California’s wildfire season usually peaks during summer and fall months and then tapers during the typically rainy winter. But the drought has turned wildfires into a year-round issue. “With that lack of rain, the grass, brush and trees really have been tinder-dry all year long,” Berlant explained, noting such conditions help flames flourish.

Svoboda added that the state’s hot, dry surface leads to a hot, dry, atmosphere, which creates a prime environment for wildfires to spread. “You also typically see windier conditions,” he added. “These are all things that fires feed on.”

The damage in Southern California has ravaged hills, homes and businesses. Beloved craft brewery Stone Brewing Company evacuated its premises on Thursday. On Wednesday, KTLA senior producer Marcus Smith tweeted a widely-recirculated photo of a “firenado,” a dangerous phenomenon caused by strong winds whipping spirals of fire into the air. More

 

© 2014

Threat to food security

Warming sea temperatures and ocean acidification put the millions around the world who rely on the sea, at risk.

He sat shirtless on his thin bamboo floor in a home built on posts rising out of the Banda Sea. Tadi had just returned in his dugout canoe from scanning crevices in a nearby reef for octopus. He and his neighbours spend every day this way – scouring the ocean for something to eat or sell. Fishing, here, is about survival.

Their stilt village on Hoga Island, Indonesia, has no industry, no land, no running water. They dive without oxygen, wearing hand-carved wooden goggles, and carry spearguns hacked from logs with their machetes. They eat what they catch and sell the rest, using the money to buy everything else they need: boat fuel, root vegetables, rice and wood.

Without fishing, “how would I feed my family?” asked Tadi, who like many Indonesians has only one name.

Now Tadi’s community, like countless others across the globe, is on a collision course with the industrialised world’s fossil fuel emissions. Hundreds of millions of people around the world rely on marine life susceptible to warming temperatures and ocean acidification, the souring of seas from carbon dioxide emitted by burning coal, oil and natural gas. That includes US Pacific Northwest oyster growers and crabbers in the frigid Bering Sea, who now face great uncertainty from shifts in marine chemistry.

But from Africa to Alaska, many coastal communities face a substantially greater risk. These cultures are so thoroughly dependent on marine life threatened by carbon dioxide that a growing body of research suggests their children or grandchildren could struggle to find enough food. The science of deciphering precisely who might see seafood shortages remains embryonic, but with many of the most at-risk coastal communities already facing poverty, marine pollution, over-fishing and rising seas, the potential for calamity is high.

“I can’t tell you how many people will be affected,” said Sarah Cooley, at Woods Hole Oceanographic Institution in Massachusetts, who studies links between acidification and food security. “But it’s going to be a very big number.”

Said Andreas Andersson, an acidification and coral reef expert with the Scripps Institution of Oceanography in San Diego: “These people are literally going to be fighting for their lives.” More

 

The world is closer to a food crisis than most people realise

Unless we move quickly to adopt new population, energy, and water policies, the goal of eradicating hunger will remain just that.

Food riots in Algeria in 2008. Photograph: Fayez Nureldine/AFP/Getty Images

In the early spring this year, US farmers were on their way to planting some 96m acres in corn, the most in 75 years. A warm early spring got the crop off to a great start. Analysts were predicting the largest corn harvest on record.

The United States is the leading producer and exporter of corn, the world's feedgrain. At home, corn accounts for four-fifths of the US grain harvest. Internationally, the US corn crop exceeds China's rice and wheat harvests combined. Among the big three grains – corn, wheat, and rice – corn is now the leader, with production well above that of wheat and nearly double that of rice.

The corn plant is as sensitive as it is productive. Thirsty and fast-growing, it is vulnerable to both extreme heat and drought. At elevated temperatures, the corn plant, which is normally so productive, goes into thermal shock.

Time is running out. The world may be much closer to an unmanageable food shortage – replete with soaring food prices, spreading food unrest, and ultimately political instability– than most people realise.

As spring turned into summer, the thermometer began to rise across the corn belt. In St Louis, Missouri, in the southern corn belt, the temperature in late June and early July climbed to 100F or higher 10 days in a row. For the past several weeks, the corn belt has been blanketed with dehydrating heat.

Weekly drought maps published by the University of Nebraska show the drought-stricken area spreading across more and more of the country until, by mid-July, it engulfed virtually the entire corn belt. Soil moisture readings in the corn belt are now among the lowest ever recorded.

While temperature, rainfall, and drought serve as indirect indicators of crop growing conditions, each week the US Department of Agriculture releases a report on the actual state of the corn crop. This year the early reports were promising. On 21 May, 77% of the US corn crop was rated as good to excellent. The following week the share of the crop in this category dropped to 72%. Over the next eight weeks, it dropped to 26%, one of the lowest ratings on record. The other 74% is rated very poor to fair. And the crop is still deteriorating.

Over a span of weeks, we have seen how the more extreme weather events that come with climate change can affect food security. Since the beginning of June, corn prices have increased by nearly one half, reaching an all-time high on 19 July. More