Showing posts with label oceans. Show all posts
Showing posts with label oceans. Show all posts

Wednesday, December 16, 2009

A Fish Oil Story

A Fish Oil Story
By PAUL GREENBERG
Published: December 15, 2009


If you are someone who catches and eats a lot of fish, as I am, you get adept at answering questions about which fish are safe, which are sustainable and which should be avoided altogether. But when this fish oil question arrived in my inbox recently, I was stumped. I knew that concerns about overfishing had prompted many consumers to choose supplements as a guilt-free way of getting their omega-3 fatty acids, which studies show lower triglycerides and the risk of heart attack. But I had never looked into the fish behind the oil and whether it was fit, morally or environmentally speaking, to be consumed.

The deal with fish oil, I found out, is that a considerable portion of it comes from a creature upon which the entire Atlantic coastal ecosystem relies, a big-headed, smelly, foot-long member of the herring family called menhaden, which a recent book identifies in its title as “The Most Important Fish in the Sea.”

The book’s author, H. Bruce Franklin, compares menhaden to the passenger pigeon and related to me recently how his research uncovered that populations were once so large that “the vanguard of the fish’s annual migration would reach Cape Cod while the rearguard was still in Maine.” Menhaden filter-feed nearly exclusively on algae, the most abundant forage in the world, and are prolifically good at converting that algae into omega-3 fatty acids and other important proteins and oils. They also form the basis of the Atlantic Coast’s marine food chain.

Nearly every fish a fish eater likes to eat eats menhaden. Bluefin tuna, striped bass, redfish and bluefish are just a few of the diners at the menhaden buffet. All of these fish are high in omega-3 fatty acids but are unable themselves to synthesize them. The omega-3s they have come from menhaden.

But menhaden are entering the final losing phases of a century-and-a-half fight for survival that began when humans started turning huge schools into fertilizer and lamp oil. Once petroleum-based oils replaced menhaden oil in lamps, trillions of menhaden were ground into feed for hogs, chickens and pets. Today, hundreds of billions of pounds of them are converted into lipstick, salmon feed, paint, “buttery spread,” salad dressing and, yes, some of those omega-3 supplements you have been forcing on your children. All of these products can be made with more environmentally benign substitutes, but menhaden are still used in great (though declining) numbers because they can be caught and processed cheaply.

For the last decade, one company, Omega Protein of Houston, has been catching 90 percent of the nation’s menhaden. The perniciousness of menhaden removals has been widely enough recognized that 13 of the 15 Atlantic states have banned Omega Protein’s boats from their waters. But the company’s toehold in North Carolina and Virginia (where it has its largest processing plant), and its continued right to fish in federal waters, means a half-billion menhaden are still taken from the ecosystem every year.

For fish guys like me, this egregious privatization of what is essentially a public resource is shocking. But even if you are not interested in fish, there is an important reason for concern about menhaden’s decline.

Quite simply, menhaden keep the water clean. The muddy brown color of the Long Island Sound and the growing dead zones in the Chesapeake Bay are the direct result of inadequate water filtration — a job that was once carried out by menhaden. An adult menhaden can rid four to six gallons of water of algae in a minute. Imagine then the water-cleaning capacity of the half-billion menhaden we “reduce” into oil every year.

So what is the seeker of omega-3 supplements to do? Bruce Franklin points out that there are 75 commercial products — including fish-oil pills made from fish discards — that don’t contribute directly to the depletion of a fishery. Flax oil also fits the bill and uses no fish at all.

But I’ve come to realize that, as with many issues surrounding fish, more powerful fulcrums than consumer choice need to be put in motion to fix things. President Obama and the Congressional leadership have repeatedly stressed their commitment to wresting the wealth of the nation from the hands of a few. A demonstration of this commitment would be to ban the fishing of menhaden in federal waters. The Virginia Legislature could enact a similar moratorium in the Chesapeake Bay (the largest menhaden nursery in the world).

The menhaden is a small fish that in its multitudes plays such a big role in our economy and environment that its fate shouldn’t be effectively controlled by a single company and its bottles of fish oil supplements. If our government is serious about standing up for the little guy, it should start by giving a little, but crucial, fish a fair deal.

Paul Greenberg is the author of the forthcoming “Four Fish: The Future of the Last Wild Food.”


http://www.nytimes.com/2009/12/16/opinion/16greenberg.html?em

Sunday, June 21, 2009

CO2 currently at highest level in 2.1 million years

Atmospheric carbon dioxide levels are higher than any point in the last 2.1 million years, report researchers writing in the journal Science.

Analyzing the shells of single-celled plankton buried under the Atlantic Ocean off the coast of Africa, Bärbel Hönisch, a geochemist at Columbia University's Lamont-Doherty Earth Observatory, and her colleagues dtermined that peak CO2 levels over the last 2.1 million years averaged only 280 parts per million. By comparison current CO2 levels stand at 385 parts per million, or 38% higher than the long-term peak.


Annual mean atmospheric CO2 concentrations (ppm), 1850-2008 [top]; Monthly atmospheric CO2 records from sites in the SIO air sampling network 2005-June 2009 [bottom].

The findings provide new insight on the role of CO2 in global cycles of cooling and warming, suggesting that a shift towards longer glacial cycles — producing a major ice age about every 100,000 years instead of every 40,000 — some 1.2 million to 500,000 years ago was the result not of declining CO2 levels, but another factor, perhaps Earth's orbit and tilt, which determines how much sunlight falls on each hemisphere, or changes in how previous ice ages affected subsequent ice ages.

"Previous studies indicated that CO2 did not change much over the past 20 million years, but the resolution wasn't high enough to be definitive," said Hönisch. "This study tells us that CO2 was not the main trigger, though our data continues to suggest that greenhouse gases and global climate are intimately linked."

B. Hönisch et al. Atmospheric Carbon Dioxide Concentration Across the Mid-Pleistocene Transition. SCIENCE VOL 324 19 JUNE 2009

http://news.mongabay.com/2009/0618-co2.html

Sunday, May 31, 2009

Climate change turning seas acid: scientists

This is a really serious issue.

BONN, Germany (Reuters) - Climate change is turning the oceans more acid in a trend that could endanger everything from clams to coral and be irreversible for thousands of years, national science academies said on Monday.

Seventy academies from around the world urged governments meeting in Bonn for climate talks from June 1-12 to take more account of risks to the oceans in a new U.N. treaty for fighting global warming due to be agreed in Copenhagen in December.

"To avoid substantial damage to ocean ecosystems, deep and rapid reductions of carbon dioxide emissions of at least 50 percent (below 1990 levels) by 2050, and much more thereafter, are needed," the academies said in a joint statement.

The academies said rising amounts of carbon dioxide, the main greenhouse gas emitted mainly by human use of fossil fuels, were being absorbed by the oceans and making it harder for creatures to build protective body parts.

The shift disrupts ocean chemistry and attacks the "building blocks needed by many marine organisms, such as corals and shellfish, to produce their skeletons, shells and other hard structures," it said.

On some projections, levels of acidification in 80 percent of Arctic seas would be corrosive to clams that are vital to the food web by 2060, it said.

And "coral reefs may be dissolving globally," it said, if atmospheric levels of carbon dioxide were to rise to 550 parts per million (ppm) from a current 387 ppm. Corals are home to many species of fish.

"These changes in ocean chemistry are irreversible for many thousands of years, and the biological consequences could last much longer," it said.

The warning was issued by the Inter-Academy Panel, representing science academies of countries from Albania to Zimbabwe and including those of Australia, Britain, France, Japan and the United States.

UNDERWATER CATASTROPHE

Martin Rees, president of the Royal Society, the British science academy, said there may be an "underwater catastrophe."

"The effects will be seen worldwide, threatening food security, reducing coastal protection and damaging the local economies that may be least able to tolerate it," he said.

The academies' statement said that, if current rates of carbon emissions continue until 2050, computer models indicate that "the oceans will be more acidic than they have been for tens of millions of years."

It also urged actions to reduce other pressures on the oceans, such as pollution and over-fishing.