BY RENEE CHO

When runoff from fertilizedlawns, agricultural fields andsewage treatment plantsreaches our rivers and coasts,it causes a water pollutionproblem known as eutrophi-

cation. In other words, unhealthy levelsof nitrogen and phosphorus. Theseexcess nutrients stimulate algal blooms.And these blooms, in turn, starve thewater of oxygen, creating a dead zonewhere no creatures can survive. Someblooms are even toxic to humans.

One way to “bioextract” these nutri-ents that shows promise involves the useof shellish and seaweeds. Charles Yarish,Ph.D., professor of ecology and evolu-tionary biology at the University of Con-necticut, is one of the researchersinvolved in a $2.4 million project to helpclean up the Bronx River in New YorkCity using mussels and seaweeds, fund-ed by the Long Island Sound FuturesFund (longislandsoundstudy.net).

Nitrogen and phosphorus exist inorganic (plant and animal residue) andinorganic (mineralized) forms. As shell-fish filter water, they remove organicnutrients, while seaweeds take up inor-ganic nutrients. This project will use thenative red seaweed Gracilaria in summerand fall, and kelp, which thrives in win-ter. Because no large source of youngseaweeds exists, Yarish and his col-

leagues are initially cultivating a seed-stock of the seaweeds in their labs.

This summer and fall, a 20' by 20' raftof ribbed mussels and four seaweed lineswill be placed at the mouth of the BronxRiver in coordination with the NationalOceanic and Atmospheric Administra-tion (NOAA). Yarish estimates that themussels will filter organic nutrients fromup to 5.07 million liters of water daily;

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The Seaweed and Shellfish SolutionUsing Nature’s Filters to Help Curb Pollution and Fish Farm Waste

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An integrated multi-trophicaquaculture site in the Bay ofFundy, Canada, with salmoncages (back left) and musseland seaweed rafts.

Charles Yarishwith his Gracilaria(red seaweed)seedstock.

with seaweeds filtering the inorganicnutrients. Research suggests that the twospecies might also increase oxygen,improving water quality and fish habi-tats. Once the mussels and seaweedshave done their work they will beremoved periodically to extract excessnutrients, and undergo extensive test-ing. “We want to find out what’s beingtaken up by the shellfish and the sea-weed, and what impact the system hason the local environment,” says Yarish. Ifsuccessful, the strategy could be used inother nutrient hot spots around the U.S.

Yarish will also be conducting a paral-lel Gracilaria-only project at an openwater research site on Long IslandSound belonging to the BridgeportRegional Aquaculture Science & Tech-nology Education Center in Connecti-cut, a high school for marine scienceand aquaculture technology.

Both projects must yield environ-mental and economic benefits to beviable. Because the Bronx River site isnear a wastewater treatment plant, noedible species can be cultivated there;

however the ribbed mussels and sea-weeds (and the Connecticut Gracilaria)will be evaluated for their economicpotential for use as biofuels, agar (acomponent of red algae used in labs),biochemicals, animal feed, and nutrientextraction. The Connecticut Gracilariawill also be assessed as a possible foodproduct by some of the Bridgeport stu-

dents who run a seafood market at theAquaculture school.

Combining species from differentfood web levels to perform ecosystemservices is also the basis of integratedmulti-trophic aquaculture (IMTA), anancient practice that is being revived tomake aquaculture more sustainable.Farmed aquatic organisms represent thefastest growing source of animal protein,responsible for over half of globalseafood consumption. But the expand-ing sector of industrialized aquaculture,comprised mostly of fishmeal-fedmonocultures of finfish and shrimp,fouls waterways with uneaten feed andfish waste containing nitrogen andphosphorus, resulting in pollution ofthe sea bottom and eutrophication.

Yarish’s colleague Thierry Chopin,Ph.D., professor of marine biology at theUniversity of New Brunswick, is work-ing on IMTA with Cooke Aquaculture(cookeaqua.com) which produces andsells millions of pounds of salmon andtrout in New Brunswick, Canada. Bluemussels placed downstream from the

Thierry Chopin at an aquaculture site inCanada.

E MAGAZINE SEPTEMBER/OCTOBER 2011

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“[Blooms] starve the water of oxygen, creating a dead zone where no creatures can survive.”

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salmon pens consume midsize organicparticles, while kelp downstream fromthe mussels take up inorganic nutrients.Sea urchins and sea cucumbers have beenadded to the mix to consume larger par-ticles on the ocean floor, and Chopinenvisions eventually adding more speciesto the managed ecosystem according totheir ability to consume different sizedparticles or when they flourish.

IMTA increases aquaculture’s sustain-ability and profitability. Recently, Loblaw,Canada’s largest food retailer, began sell-ing Cooke’s IMTA salmon in Ontario andQuebec as WiseSource™Salmon. Cooke’smussels are sold for food, and its sea-weeds are used in restaurants and cos-metics manufacturing. Cooke is also test-ing seaweeds as a partial protein substi-tute in salmon feed, which could poten-tially generate more income.

IMTA can be done in marine or freshwater, temperate or tropical regions, andin tanks. “It’s a theme and has varia-tions…like music,” says Chopin. “IMTAis the theme, and the variations are the

many regions and species.” Chile, Turkey,South Africa, Israel, Norway, Ireland,Scotland and China also practice IMTA,each region selecting its species accordingto economic potential, habitat and cul-tural context.

Establishing the true value of IMTAwould require calculating the economicvalue of nutrient removal, savings in feedthat would otherwise be wasted, enhancedproductivity of a healthier ecosystem, cropdiversification and sustainably producedfood crops. Chopin won’t declare IMTAthe silver bullet for aquaculture’s environ-mental problems yet, but its prospectshold promise. E

RENEE CHO is a freelance environmentalwriter in New York City and a regular con-tributor to The Earth Institute's State of thePlanet blog.

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Tank-grown Gracilaria.

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BY LINDSEY BLOMBERG

Every day, America wastes enoughfood to fill California’s 90,000-seatRose Bowl Stadium, according toJonathan Bloom, author of American

Wasteland: How America Throws AwayNearly Half of Its Food (and What We CanDo About It) (Da Capo). This past May,the Food and Agriculture Organization ofthe United Nations (FAO) reported thatroughly one-third of the food producedin the world for human consumptionevery year, some 1.3 billion tons, gets lostor wasted. People in America and otherwealthy nations topped the food-wastinglist because they “can afford to wastefood,” the FAO report noted.

U.S. homes and businesses threw outmore than 34 million tons of food in2009, the U.S. Environmental ProtectionAgency (EPA) reports, which amounts tomore than 14% of the nation’s totalmunicipal solid waste stream. Paper is theonly material category where Americansgenerate more waste, but while 60% ofpaper is recycled every year, only 3% offood scraps are turned to compost. Theremaining 97% is sent to landfills where itrots and produces harmful, potent, heat-trapping methane gas. According to theEPA, composting would eliminate landfillmethane emissions as well as “regeneratepoor soils, suppress plant diseases andpests, reduce or eliminate the need forchemical fertilizers, and promote higheryields of agricultural crops,” but only ahandful of cities like Seattle, Washington,

E MAGAZINE SEPTEMBER/OCTOBER 2011

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Author Jonathan Bloom Digs through the Problem of Billions of Tons of Food Waste

Wasted

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San Francisco, California, and Boulder, Col-orado, offer residential curbside compost-ing pick-ups.

Composting remains rare in developednations in part because food is cheap, read-ily available and easily accessible. Most don’tthink twice before tossing out vegetablesthat have rotted in the fridge or stop to con-sider the environmental toll of fertilizers,chemicals, oil and water used to grow, trans-port and store that food.

“There’s just such a tremen-dous disconnect, with peoplenot understanding thehighly dangerous situa-tion we are in,” saysMarianne Bänziger,deputy chief of theInternational Maizeand Wheat Improve-ment Center.

And all those over-stocked grocery stores,full to bursting with milk,bags of salad mix, fruit, veg-etables and other items with cos-metic blemishes or surpassed sell-by datesare discarded en masse when they haven’t—or can’t be—sold. Then there are the rotis-serie chickens and baked goods that aremade in-house on a daily basis; those itemsare usually kept out for only one day. Whatdoesn’t sell is thrown away that night.

And five billion eggs are thrown out eachyear because if one egg in a dozen cracks theU.S. Department of Agriculture cannotguarantee that carton’s freshness. So out thecarton goes. A former Safeway employee,John Wadginski, said in an article on the siteHunger in California that he’s haunted bymemories of the food he was required towaste as a former deli employee at SafewayInc. Wadginski said he threw out untouched10-pound hams, ribs and other “daily spe-cials” that totaled some 50 pounds of food anight.

Prepared foods served at supermarketsalad bars and buffets cannot be donated,despite their abundance, and many grocers,though legally protected from being heldliable for any donations made in good faith,are wary of donating anything but non-per-ishable food items to hunger-relief pro-grams. But some have made efforts. Wal-Mart, for instance, has partnered withhunger-relief charity Feeding America(feedingamerica.org), and as of the end of2010 had donated more than 127 millionpounds of food (about 100 million meals)to needy families.

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And a new grocerystore model scheduled toopen in Austin, Texas, thisfall could prove it’s possi-ble to eliminate much of thewaste seen in conventionalsupermarkets. The store, calledIn.gredients (in.gredients.com), plansto become “the first package-free and zerowaste grocery store in the United States.”Focused on the concept of “pre-cycling,”the store will encourage shoppers to bringand fill their own containers from home,purchasing only the amounts of food theyneed. A similar store, Unpackaged (beun-packaged.com), already exists in London.That store’s website encourages cus-tomers to “Reduce by only buying whatyou need, reuse by bringing your con-tainers for a refill, recycle what you can’treuse and if you can’t reuse or recycle it,

then don’t buy it!”Below, Bloom shares his thoughts on

our growing food waste crisis and thosezero-waste concept stores.E Magazine: What’s behind the moun-tains of waste at mainstream grocerystores?Jonathan Bloom: It’s the prepared food,produce, and, to a lesser extent, dairyand the butcher. [And] theamount of baked goods thatare available for donationor gets thrown out isastounding. I’ve visitedfood recovery organiza-tions and food banksthat just get inundatedwith donated breadsand baked goods and it’sso much that they oftencan’t find a use for all of it.I’ve seen food banks sendingbread to hog farms and even havingto throw it out. Supermarkets are leery todonate perishables like produce and freshproteins. Those kinds of foods that peopleneed are not donated at anywhere near thesame frequency. E: Do you see the situation gettingworse now that supermarkets offer alarge amount of pre-cooked meals andprepared food buffets?J.B.: From that standpoint, it’s definitelygetting worse. The buffets are the largestculprits. If it’s an open buffet like you seeat Whole Foods, they can’t donate thatfood at the end of the night for health andfood safety concerns. The prepared foodsthat are behind the glass counter can be

donated but unfortunate-ly [stores] often don’tbecause of liability fears.As we get busier and

busier, more are buyingthese prepared foods and con-

venience items at supermarketsin much greater numbers so stores are

upping their supply. And the moreoptions you have, the more that inevitablywill not be sold and they’ll have to throwout at the end of the night. E: Why do you think we have such anoverabundance of food stocked andmade in our grocery stores? It doesn’tseem like a cost-effective approach.J.B.: Well, it stems from a post-war atti-tude that advised farmers to produce asmuch as they can. Add in the crop scien-tists and agricultural engineers whose jobit is to “up” yields and we just have thisescalation of production. We’re producingabout twice the amount of calories that weneed per person per year without any realplan of how to put them to use or how todistribute that excess in a wise way. Atremendous amount gets wasted. It’s defi-nitely time to re-think how we grow foodand how much we produce because it hasthese impacts both in terms of the amount

of food that’s wasted and the taxingof the soil [as we] create this

abundance that we don’tneed. E: What can supermarketcustomers do to stopfood waste?J.B.: I think public pres-sure from people going totheir supermarkets and

asking them what they dowith their leftover bread and

what happens to the milk once itreaches the sell-by date will have an

impact. If we can communicate that desireto make food waste become part of the sus-tainability conversation, then I think storeswill act quite rapidly.E: Do you think new zero-waste super-markets like In.gredients could take off?J.B.: Asking people to bring their ownbags isn’t terribly inconvenient, we canhandle that. In.gredients asks people totake it a couple steps further, but I don’tthink it’s too much. I don’t think you’llever get a mass conversion if you’re askingpeople to go too far outside of their com-fort zone. E

LINDSEY BLOMBERG is a contributingwriter at E.

BY LINDSEY BLOMBERG

Scientists predict that a “dead zone”in the Gulf of Mexico could expandto between 8,500 and 9,421 squaremiles this year, roughly the size of

New Jersey and Delaware combined.Dead zones are oxygen-depleted, lifelessexpanses of water. The dead zone in theGulf, 60 miles off the coasts of Louisianaand Texas, is one of the largest in theworld and has more than doubled sincethe 1980s. In 2002, a staggering 8,400square miles of the Gulf was “hypoxic”or lacked sufficient oxygen for mostmarine life to live.

The Gulf ’s dead zone is largely causedby agricultural waste like nitrate- andphosphate-containing fertilizer from theMidwest Corn Belt, which is carried byrainwater into the Mississippi River andflushes into the Gulf. Other toxins in thedead zone’s runoff include sewage, ani-mal waste and car exhaust. “The Missis-sippi is a drainage for a third of thecountry and there are all kinds ofsewage-treatment plants and factoriesdischarging chemicals into the river,”Charles Jagoe, an environmental toxicol-ogist at Florida A&M University, said ina National Geographic News story.

Record flooding along the Mississippithis spring has caused twice the amount

of average runoff to drain into the Gulf,as this year’s high corn prices encouragedadditional planting that resulted in excessamounts of fertilizer. And the U.S. Geo-logical Survey (USGS) said the 164,000tons of nitrogen that reached the Gulfthis May was 35% higher than average.

“Stream flows were nearly double nor-mal during May, delivering massiveamounts of nutrients to the Gulf, and

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The low-oxygen or “dead zone”portions of the Gulf of Mexicostretch across thousands ofmiles. The lowest oxygen levelsappear in red.

Dead in the GulfA “Dead Zone” in the Gulf of Mexico May Reach Historical Proportions this Year

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Dead fish from the Gulf of Mexico.

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that's what drives the dead zone,” DonaldScavia, director of the University ofMichigan Graham Sustainability Insti-tute, told the school’s paper. The Univer-sity of Michigan contributed to a team ofNational Oceanic and Atmospheric Asso-ciation (NOAA)-supported scientists inpredicting this year’s dead zone expansionin the Gulf, as did the Louisiana Universi-ties Marine Consortium (LUMCON)and Louisiana State University.

The Mississippi’s warm freshwater,combined with the nitrogen and phos-phorous runoff, sits on top of cooler salt-water in the Gulf of Mexico preventingoxygen in the atmosphere from reachingthe deeper water. Strong sunlight duringthe warmer spring and summer months,meanwhile, promotes the growth ofalgae blooms and dead zones peak. Sincethe water is unable to support life, thealgae remains uneaten, sinks to the bot-tom and sucks up oxygen while itdecomposes.

The massive dead zone poses seriousthreats for the future of Gulf fisheriesand marine life populations already suf-fering from the ongoing effects of themassive Deepwater Horizon oil spill in2010. “There’s a huge area where you justcan’t catch anything for a long period oftime," Nancy Rabalais of LUMCON toldThe New York Times. A study conductedduring the summers of 2006 and 2007found that nearly a quarter of femaleAtlantic croaker fish caught in the Gulf ’sdead zone had devel oped deformed,testes-like organs instead of ovaries.Researchers weren’t sure how long thefish were living in the low-oxygen deadzone before they developed these sexualdefects, but lab experiments showed thatthe changes could happen in as little as10 weeks of exposure.

Female croakers caught during thisperiod were found to have a decreasedlevel of aromatase, the key chemicalneeded to produce estrogen and ovaries.Some of the female “testes” even con-tained sperm, but were not able to fertil-ize normal eggs. “If the oxygen levels godown, it affects the brain and the neuro-hormones and neuropeptides that itproduces,” says M.S. Rahman, a marinebiologist at the University of Texas inAustin’s Marine Science Institute. Malefish have also shown sexual defects fromlow oxygen levels. Those caught in thedead zone had smaller than averagetestes and lower sperm counts. Repro-duction rates that should average a 40-80% hatching rate were instead only

producing a 10% hatching rate. Croakers are a “pretty typical Gulf

fish,” says Prosanta Chakrabarty, a fishbiologist at Louisiana State University inBaton Rouge. “I wouldn’t be surprised ifthese findings could be generalized.”

Though the Gulf dead zone continuesto expand, future restoration and recov-ery is possible. Such a turnaround hasbeen seen in the Black Sea, which con-tained the largest dead zone in the worldduring the 1980s. Following the collapseof the Soviet Union, fertilizers becametoo costly to use. Phosphorus applica-tions were cut by 60% and nitrogen use

was halved. By 1996, the dead zone wasabsent for the first time in 23 years.

“The evidence suggests that if thespigot of nutrients can be turned off,coastal systems can recover,” NOAAAdministrator Dr. Jane Lubchenco toldThe San Francisco Chronicle. “Doing itcan be accomplished by using fertilizersmore efficiently, preventing human andanimal sewage from entering rivers, andreplanting vegetation [along riverbanks]to absorb excess nutrients.”E

LINDSEY BLOMBERG is a contribut-ing writer at E.

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