Tag Archives: upwelling

Acid Seas Threaten Creatures that Supply Half the World’s Oxygen

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Ocean acidification is turning phytoplankton toxic. Bad news for the many species – us, included – that rely on them as a principal source of food and oxygen.

June 16th, 2014 By Martha Baskin and Mary Bruno, crosscut.com

What happens when phytoplankton, the (mostly) single-celled organisms that constitute the very foundation of the marine food web, turn toxic?

phytoplankton pseudonitzschia_Their toxins often concentrate in the shellfish and many other marine species (from zooplankton to baleen whales) that feed on phytoplankton. Recent trailblazing research by a team of scientists aboard the RV Melville shows that ocean acidification will dangerously alter these microscopic plants, which nourish a menagerie of sea creatures and produce up to 60 percent of the earth’s oxygen.

The researchers worked in carbon saturated waters off the West Coast, a living laboratory to study the effects of chemical changes in the ocean brought on by increased atmospheric carbon dioxide. A team of scientists from NOAA’s Fisheries Science Center and Pacific Marine Environmental Lab, along with teams from universities in Maine, Hawaii and Canada focused on the unique “upwelled” zones of California, Oregon and Washington. In these zones, strong winds encourage mixing, which pushes deep, centuries-old CO2 to the ocean surface. Their findings could reveal what oceans of the future will look like. The picture is not rosy.

Scientists already know that ocean acidification, the term used to describe seas soured by high concentrations of carbon, causes problems for organisms that make shells. “What we don’t know is the exact effects ocean acidification will have on marine phytoplankton communities,” says Dr. Bill Cochlan, the biological oceanographer from San Francisco State University oceanographer who was the project’s lead investigator. “Our hypothesis is that ocean acidification will affect the quantity and quality of certain metabolities within the phytoplankton, specifically lipids and essential fatty acids.”

Acidic waters appear to make it harder for phytoplankton to absorb nutrients. Without nutrients they’re more likely to succumb to disease and toxins. Those toxins then concentrate in the zooplankton, shellfish and other marine species that graze on phytoplankton.

Consider the dangerous diatom Pseudo-nitzschia (below). When ingested by humans, toxins from blooms of this single-celled algae can cause permanent short-term memory loss and in some cases death, according to Dr. Vera Trainer, an oceanographer with NOAA’s Fisheries Marine Biotoxins Program. Laboratory studies show that when acidity (or pH) is lowered, Pseudo-nitzschia cells produce more toxin. When RV Melville researchers happened on a large bloom of Pseudo-nitzschia off the coast of Point Sur in California, where pH levels are already low, they were presented with a rare opportunity, explains Trainer, to see if their theory “holds true in the wild.”

Multiple phytoplankton populations became the subjects of deck-board experiments throughout the Melville’s 26-day cruise, which began in mid-May and finished last week.

Another worrisome substance is domoic acid, a neuro-toxin produced by a species of phytoplankton. Washington has a long history of domoic acid outbreaks. The toxin accumulates in mussels and can wind up in humans. “Changes in the future ocean could stimulate the levels of domoic acid in the natural population,” says Professor Charles Trick, a biologist with Western University in Ontario, and one of the RV Melville researchers. Which means that the acidified oceans of tomorrow could nurture larger and more vigorous outbreaks of killer phytoplankton, which could spell death to many marine species.

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How to Battle Ocean Acidification

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June 16th, By John Upton, Pacific Standard (psmag.com)

It’s a fearsome problem. But we’re not just watching helplessly.

Shellfish are dying by the boatload, their tiny homes burned from their flesh by acid. Billions of farmed specimens have already succumbed to the problem, which is caused when carbon dioxide dissolves and reacts with water, producing carbonic acid.

When ocean life starts to resemble battery gizzards, how can humans possibly respond?

Immediately curbing the global fossil fuel appetite and allowing carbon dioxide-drinking forests to regrow would be obvious steps. But they wouldn’t be enough. Oceanic pH levels are already 0.1 lower on average than before the Industrial Revolution, and they will continue to decline as our carbon dioxide pollution lingers—and balloons.

In a recent BioScience paper, researchers from coastal American states summarized what we know about ocean acidification, and described some possible remedies.

Chart: Bioscience

Chart: Bioscience

As John Kerry kicks off two days of ocean acidification workshops, here’s our summary of the scientists’ overview:

WHAT WE KNOW

  • Acid rain can affect ocean pH, but only fleetingly, especially when compared with the effects of carbon dioxide pollution.
  • Studies of naturally acidified waters, like those near CO2 vents, suggest that acidification will depress species diversity; algae will continue to take over.
  • Farm runoff and fossil fuel pollution can worsen the problem in coastal areas. The nitrogen-rich pollution fertilizes algae. That initially reduces CO2 levels, but the plankton is eaten after it dies by CO2-exhaling bacteria. This type of pollution appears to be worsening the acidification of the Gulf of Mexico.
  • Strong upwelling, in which winds churn over the ocean and bring nutrients and dissolved carbon dioxide up from the depths, exacerbate local acidity levels in some regions. In the upwell-affected Pacific Northwest, climate change appears to be leading to stronger upwelling.
  • Shellfish are “highly vulnerable” to ocean acidification. Some marine plants may benefit. Fish could suffer from neurological changes that affect their behavior. Coral reefs are also being damaged.
  • Declining mollusk farm production could cost the world more than $100 billion by 2100.
  • Marine plants can help buffer rising acidity. Floridian seagrass meadows appear to be protecting nearby coral.

WHAT’S BEING DONE

  • The National Oceanic and Atmospheric Administration created an ocean acidification program in 2012. It’s monitoring impacts, coordinating education programs, and developing adaptation strategies.
  • American experts are talking less these days about ocean acidification as a universal problem, and becoming more focused on local and regional solutions.
  • Alaska, Maine, Washington, California, and Oregon have initiated studies and working groups.

WHAT MORE COULD BE DONE

  • The EPA could enforce the Clean Water Act to protect waterways from pollution that causes acidification.
  • Other coastal states could model new working groups on the Washington State Blue Ribbon Panel, which helped form the West Coast Ocean Acidification and Hypoxia Science Panel.
  • Incorporate ocean acidification threats into states’ coastal zone management plans.
  • Expand the network of monitors that measure acidity levels, providing researchers and shellfish farmers with real-time and long-term pH data.
  • Expand marine protections to reduce overfishing and improve biodiversity, which can allow wildlife to evolve natural defenses.

Source: http://www.psmag.com/navigation/nature-and-technology/how-battle-ocean-acidification-83489/

Acid Oceans Can Be Fought at Home

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Coastal communities can help combat ocean acidification by cutting back on water pollution
Jun 5, 2014, By Elspeth Dehnert and ClimateWire

For coastal communities in the United States, the path to confronting souring seas can likely be found close to home in their very own backyards.

The National Oceanic and Atmospheric Administration's Ocean Acidification Program has established a successful monitoring program at the regional scale. A bit over one month ago, it made a startling discovery off the country's West Coast—proof that ocean acidity is indeed having a negative impact on marine species Credit: Jeff Gunn via Flickr

The National Oceanic and Atmospheric Administration’s Ocean Acidification Program has established a successful monitoring program at the regional scale. A bit over one month ago, it made a startling discovery off the country’s West Coast—proof that ocean acidity is indeed having a negative impact on marine species
Credit: Jeff Gunn via Flickr

In fact, according to a recent study co-authored by several current and former Stanford researchers, there are several local and regional actions—many of which are not too costly—that can be taken to accelerate the adaptation to ocean acidification.

“We think of ocean acidification as being controlled by carbon dioxide, and it is, but there are a lot of different things humans do that affect the chemical equilibrium of the carbonate system in the coastal zone,” said Aaron Strong, lead author of the study and a graduate student in the Emmett Interdisciplinary Program in Environment and Resources.

He pointed to river discharge, local-scale upwelling, and nutrient and stormwater pollution as some of the major factors behind ocean water’s increasingly unbalanced acidity levels.

“Ocean acidification should become a part of the conversation among quality managers, stormwater managers, agricultural managers … and it tends not to be in that space,” Strong added.

To fill in the gaps, the study outlines current local and regional ocean-acidification management efforts and recommends nine other “opportunities for action” that state agencies, nongovernmental organizations, universities and industry can implement for about $1 million a pop.

“An international agreement on climate change to reduce CO2 is not the only solution,” he said.

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Gulf of Maine Uniquely Susceptible to Ocean Acidification

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The Working Waterfont, May 21, 2014. By Heather Deese and Susie Arnold

A recent study led by Aleck Wang, a chemical oceanographer from Woods Hole Oceanographic Institution, has identified the Gulf of Maine as outstanding in an unfortunate way—more susceptible to pressures of ocean acidification than any other region along the eastern seaboard and Gulf of Mexico.

oysters, maine.Ocean acidification may not be a familiar term for many, but it is a critically important aspect of ocean chemistry for all of us to understand.

Ocean acidification is the changing chemistry of seawater caused by the ocean’s absorption of carbon dioxide (CO2). As CO2 is absorbed into seawater, the resulting reactions decrease the availability of carbonate ions, which are critical building blocks for forming the shells and skeletons of many marine organisms. The process also increases the number of hydrogen ions, which leads to lower pH and greater acidity. Toxic chemicals from storm water, industrial pollution and other runoff that flows into the ocean also can contribute to acidification of coastal waters.

Wang and his colleagues think the Gulf of Maine’s susceptibility may be due to a few different factors. Fresh and cold water holds more CO2, and the Gulf of Maine has a lot of colder and fresher water coming in from the Labrador Current, in addition to a large proportion of fresh water from rivers. Also, the semi-enclosed shape of the Gulf tends to hold this more acidic water.

Around the same time this study came out, researchers in Alaska published disturbing results on the impacts of ocean acidification on Red King Crab and Tanner crabs. Their laboratory studies showed decreased survival and growth in low pH water in both species and 100 percent mortality of Red King Crab larvae after 95 days in acidification scenarios predicted for the end of this century.

A few months later, a scallop aquaculture operation in British Colombia appeared to become the latest commercial victim of ocean acidification with a massive die-off.

Oyster aquaculturists on the West Coast have been responding to die-offs for nearly ten years and within the last several years their onsite pH monitoring has confirmed the link to acidification. Upwelling conditions in the Pacific Northwest, which bring cold water to the surface, tend to have lower pH than surface water. The pH of this water has decreased further in recent decades due to increasing atmospheric CO2 and pollutants that run from the land into the ocean.

Rep. Mick Devin, D-Newcastle, who also is a marine biologist at the University of Maine’s Darling Marine Center, has been concerned about the vulnerability of Maine’s marine ecosystems and fisheries-dependent communities to this unfolding threat. Last fall, he proposed LD 1602, which would establish a commission to study the effects of coastal and ocean acidification on species that are commercially harvested and grown along the Maine coast.

Thanks to support from diverse interest groups, including fishing and aquaculture industries, coastal community members, environmental groups, state agencies and others, the bill became law April 30.

Scientists still don’t know exactly how changing chemistry will impact the various life stages of most marine organisms, particularly a lot of commercially important species. For example, there is still very little known about the possible impacts on lobsters.

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Ocean acidification is most urgent threat to marine conservation

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By Bill Dewey

November 6th, 2011

THE Taylor family has farmed shellfish in Puget Sound for over a century. The business now faces a challenge to its very existence that we didn’t even know about until five years ago: ocean acidification.

Seawater upwelling on Washington’s coast at times is so corrosive that the shells of oyster larvae dissolve faster than they can form. Recent research shows that the shifting chemistry of seawater impacts far more than oysters. Increasing acidity can deform, stunt, disorient and even kill a number of species throughout the marine food web, from tiny plankton to scallops, crabs and fish. Understanding how these corrosive waters impact the ocean’s ability to produce food is a pressing global security issue.

If we don’t begin addressing ocean acidification promptly, the future of shellfish farming and the entire seafood industry is at stake. On our current path, we are consigning our heirs to a world of increasing scarcity and conflict over ocean resources.

Are we up to it? The tools we need already exist. We can prevent many of acidification’s worst consequences by embracing proven and often profitable strategies to increase energy efficiency, manage fossil-fuel emissions and limit nutrient runoff. We can reduce harm to seafood supplies through scientific monitoring and research. These are all things we can do locally and make a difference.

In the open ocean, acidification results from emissions of carbon dioxide (CO2) that mix into seawater. The oceans absorb about a quarter of the 70 million tons of CO2 we emit every day. This forms carbonic acid. The acid thins the ocean’s naturally rich soup of carbonate, the basic construction material used by many marine organisms to build shells, skeletons and reefs. Along our coasts, human activities amplify these changes by increasing runoff of soil, fertilizer and animal wastes, triggering hypoxia and acidification in many bays and estuaries where we grow shellfish.

For Taylor, acidification is not a future threat estimated by modeling or projections. It’s here now. During 2007-2009, our oyster larvae production declined up to 80 percent. Other West Coast operations were also decimated. At the Whiskey Creek Hatchery in Netarts Bay, Ore., oyster larvae dissolved in their tanks.

By monitoring water chemistry we’ve learned to avoid and buffer corrosive waters — restoring a good portion of our production, for now. We’re fortunate that we have the ability to control the seawater chemistry for our baby oysters in our hatcheries. The picture is not so rosy for critters that must survive in the increasingly acidic ocean.

At Taylor, we feel like the proverbial canary in the coal mine, with a twist: After getting knocked down, we lived to sing. Having seen the impact of high-CO2 waters we feel some responsibility to speak out and make others aware of the serious and only recently understood consequences of continued high carbon emissions on the ocean.

We are fortunate that Seattle is a hub of work on ocean acidification. An international seafood industry study group run by the Sustainable Fisheries Partnership is based here. NOAA’s principal scientist on the issue, Dr. Richard Feely, is at Sand Point. The University of Washington’s Terrie Klinger leads studies on how acidification’s effects might be mitigated. Former 3rd District Congressman Brian Baird was the most knowledgeable representative in Congress on this issue and continues his interest.

All our efforts at marine conservation and resource management will prove inadequate if we don’t tackle the most basic problem of all — ocean acidification.

Bill Dewey is communications and policy director for Taylor Shellfish Farms, based in Shelton, Wash., the largest producer of farmed shellfish in the U.S.