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Sustainable Aquaculture and Fisheries for a Secure Future |
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| Researchers use bacteria to break down sex-changing steroid Researchers in Mexico have found that three common species of bacteria break down methyltestosterone, a potentially harmful steroid that fish farmers use to turn young tilapias into males. The discovery may eventually result in a safer environment for farm workers and nearby residents and wildlife. Produced By Tiffany Woods Video's Page |
| Researchers aim to bolster stocks of snooks
Researchers at a university in Mexico are trying to breed and raise snooks in captivity, but getting the newborn fish to eat has been a challenge. The university aims to sell young snooks to fishermen-turned-fish farmers as a way to relieve fishing pressure on wild stocks. It also hopes to sell them to the government to release into coastal lagoons and rivers. Produced By Tiffany Woods Video's Page |
| Tilapia research and public outreach improve Hondurans' diets and incomes
U.S.-funded tilapia research and public outreach in Honduras have improved local residents' diets and put money in their pockets. Produced By Tiffany Woods Video's Page |
| Researchers aim to boost production of two native fish species in Mexico
Researchers in Mexico are trying to develop a genetically superior broodstock of Mayan cichilds and bay snooks for use in fish farming. The challenge, however, is to produce fish that grow fast enough to compete economically with popular, quick-growing tilapia Produced By Tiffany Woods Video's Page |
| With U.S. help, Kenya aims to boost economy via fish farming
Aquaculture is helping jump-start Kenya's struggling economy, thanks in part to an international program led by Oregon State University. Press Release Page |
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The AquaFish CRSP Kenya Baitfish Project: Making the Connections Video Page |
| Small-scale changes could make long-term improvements in Asian aquaculture
Iloilo, Philippines - Shrimp monoculture in Southeast Asia has had a checkered reputation in the past, and has been blamed for the reduction of mangroves, diminished water quality, and the spread of shrimp diseases. Press Release Page |
| USAID research increases profits for small-scale fish farmers in southeast Asia
Nueva Ecija, Philippines - The Philippines made its debut at the world's largest seafood fair in Brussels, Belgium, this year, showcasing some of the products that have made the Philippines the 8th leading fish-producer in the world. Press Release Page |
 | Wilfrido Contreras Sanchez scoops young tilapias out of a tank where they're fed methyltestosterone (MT) to turn them into males. Located at the Autonomous Juarez University of Tabasco in Mexico, these tanks were used in a study that tested the ability of bacteria to remove the MT steroid from the water. Contreras, the director of the biological sciences division at the university, helped conduct the research. -Photo By Tiffany Woods |
 | These plastic drums hold filters that clean the water in the fish tanks below them. Researchers at the Autonomous Juarez University of Tabasco in Mexico added bacteria to the filters to see if the microorganisms could remove a steroid called methyltestosterone from the water. -Photo By Tiffany Woods |
 | Lucero Vazquez Cruz swirls a flask containing bacteria and a steroid called methyltestosterone. She is a graduate student at the Autonomous Juarez University of Tabasco in Mexico and was one of the researchers involved in studying how bacteria degrade the hormone. -Photo By Tiffany Woods |
The above photos can be downloaded. Left click the image to view full resolution, then right click on the photo and select "Save Image As." Please credit Tiffany Woods as the photographer.
Bacteria on steroids: A new way to make water at tilapia farms safer?
By Tiffany Woods, 541-737-2940, tiffany.woods@oregonstate.edu
Source: Wilfrido Contreras Sanchez, 011-52-993-358-1500 ext. 6400, contrerw@hotmail.com
VILLAHERMOSA, Mexico – It's no secret that baseball stars, bodybuilders and cyclists have used steroids. Now it turns out that even bacteria get juiced.
Researchers in Mexico have found that three common species of bacteria have voracious appetites for methyltestosterone (MT), a potentially harmful steroid that fish farmers use to change the sex of tilapia. The discovery may eventually result in a safer environment for farm workers and nearby residents and wildlife. It has global implications given that tilapia is raised in more than 100 countries, according to the U.N. Food and Agriculture Organization.
Tilapia producers add methyltestosterone to the powdered food they dish out to large tanks of tiny tilapias called fry every day for three to four weeks to turn them into males. They want males because they grow faster than females and because having only one gender prevents reproduction. (Breeding makes the farmers' operation less cost-efficient.) The young tilapias swallow the steroid but then excrete it back into the water through their feces and urine.
Fish biologist Wilfrido Contreras Sanchez worries that MT residue might endanger the health of workers who wade into the water to scoop up juvenile fish. Also, many tilapia producers discharge the hormone-laced water from the tanks into streams, rivers and lagoons where it might harm other fish and amphibians, said Contreras, who heads the biological sciences division at the Autonomous Juarez University of Tabasco where the bacterial research was conducted. Additionally, the health of local residents who swim in or wash clothes in these bodies of water might be at risk, he said.
Contreras said little is known about how the use of MT in aquaculture might affect humans or wildlife. MT is an androgen and is prescribed to stimulate puberty in slow-developing adolescent boys and to treat breast cancer. The U.S. Food and Drug Administration has said that prolonged use of high doses of androgens has been associated with the development of liver cancer and that androgens may increase elderly people's chances of developing prostate cancer. High doses in women can lead to deeper voices, facial hair, acne and irregular menstrual cycles, the FDA said.
Contreras hopes that the bacteria he studied will eliminate potential hazards if added in sufficient amounts to the water filters in the tanks where the tiny tilapias dine on MT. They're naturally present in all fish culture systems (particularly in the filters) but not in large enough quantities to degrade the hormone, he said.
In lab tests, he and fellow researchers found that Pseudomonas fluorescens, which spoils milk, and Bacillus ceresus, the culprit of food poisonings, each removed 99 percent of the hormone after 20 days in flasks. Another species, P. aeruginosa, which can cause rashes, pneumonia, bladder infections and swimmer's ear and can even break down crude oil, devoured 97 percent of the hormone after 16 days in flasks.
Because the single-celled P. aeruginosa had multiplied rapidly in the lab, researchers selected it for the next leg of the experiment. They added billions of the bacteria to filters that used gravel and special plastic balls to clean the water of three 8,000-liter concrete tanks. The filters were inside plastic drums that stood on the edge of the tanks. Each tank held 5,700 young tilapias that were fed MT daily (The fish ate the MT before it was pumped into the bacteria-smothered water filters on the other end of the tanks).
The trial showed a trend toward lower levels of MT over time in the tanks where bacteria had been added versus the control tanks without bacteria, Contreras said.
He and his team plan to conduct more experiments to fine tune how many bacteria to use, what species or combination of species to use and how long to let them feast, Contreras said. If the kinks are worked out, the university hopes to grow mass quantities of whatever bacteria are finally selected and then sell the microorganisms to tilapia producers in the form of a concentrate, he said.
MT aside, the researchers uncovered something unexpected in their experiment. The fish in the tanks with P. aeruginosa weighed more than those in tanks without the bacteria. Some species of bacteria in aquaculture systems enhance growth, and P. aeruginosa may be one of them, Contreras said. Also, lab tests found no diseases in the kidneys, livers or spleens of fish raised in tanks with the bacteria. Because the bacteria are already ubiquitous and may be eaten by tilapias, Contreras doubts that they would cause any health problems, like infections, in people or fish.
The research was funded by Oregon State University, the University of Arizona, the Autonomous Juarez University of Tabasco, and the U.S. Agency for International Development through its AquaFish Collaborative Research Support Program.
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About the AquaFish Collaborative Research Support Program: AquaFish CRSP supports aquaculture and fisheries research in 16 countries that aims to improve diets; generate income for small-scale fish farmers and fishers; promote sustainable environmental practices; and enhance trade opportunities. It is funded by the U.S. Agency for International Development. Oregon State University serves as the lead institution responsible for technical and programmatic leadership of the CRSP in the United States and abroad.
 | Ramon Dominguez Sanchez guides his boat to a spot where his crew will cast out a net in hopes of catching snooks. He is the president of a fishing cooperative in Jalapita, Mexico. -Photo By Tiffany Woods |
 | A fisherman casts out a net in hopes of catching snooks off the gulf coast near Jalapita, Mexico. -Photo By Tiffany Woods |
 | Fishermen cast a net in hopes of catching snooks off the gulf coast near Jalapita, Mexico. -Photo By Tiffany Woods |
 | Snooks are for sale at the market in Villahermosa, Mexico. -Photo By Tiffany Woods |
 | These snooks are about to be fried at a Mexican restaurant. -Photo By Tiffany Woods |
Photos are for download purposes, please give appropriate credit to Tiffany Woods as the photgrapher. To Download Photos, left click image to view full resolution, then right click on the photo, select "save image as..." you will then be prompted to save the image to your harddrive.
10/19/10
Hooking up snooks
Researchers are trying to bolster stocks of the lucrative snook, but getting the fish to 'do it' and then getting their kids to eat is no easy catch.
By Tiffany Woods, 541-737-2940, tiffany.woods@oregonstate.edu
Source: Kevin Fitzsimmons, 520-820-0643, kevfitz@ag.arizona.edu; Wilfrido Contreras Sanchez, 011-52-993-358-1500 ext. 6400, contrerw@hotmail.com; Reynaldo Patino, reynaldo.patino@ttu.edu, 806-742-2851 ext. 261
JALAPITA, Mexico – The facility is part fertility clinic, part singles bar. It's tucked away on the beach in the sleepy village of Jalapita on Mexico's gulf coast amid coconut trees that stretch for miles. Under a blue sky, swimming pools bubble like hot tubs as palm fronds rustle in the warm breeze and tropical birds chatter. In one pool, four glistening, slender bodies eye each other across the water, their libidos artificially primed to put them in the mood.
This is where snooks come to hook up.
The fish are part of an experiment that aims to boost their population. Scientists at the Autonomous Juarez University of Tabasco in Mexico are trying to use these wild fish as a broodstock to crank out juveniles in captivity. The university aims to sell young snooks to fishermen-turned-fish farmers as a way to relieve fishing pressure on wild stocks. It also hopes to sell them to the government to release into coastal lagoons and rivers.
"We need to increase the population in the wild. They're overfished. There has also been a lot of habitat degradation from cutting down mangroves and from oil refineries and wells," says Kevin Fitzsimmons, a professor at the University of Arizona and former president of the World Aquaculture Society.
He's one of the participants in the snook project, which also involves Texas Tech University. The work is partially funded by the U.S. Agency for International Development through its AquaFish Collaborative Research Support Program, which is headquartered at Oregon State University.
This funny-named fish, known as robalo in Spanish, is the most expensive fish sold in Mexico City, according to the country's National Commission on Aquaculture and Fishing. Fishermen in Mexico earned more than $25 million for landing about 8,000 metric tons of snooks in 2008, making it the country's eighth most important aquatic product in terms of value, the commission reported.
Various species of snooks inhabit coastal waters, estuaries and lagoons from Florida to Brazil. A widespread one is the aptly named common snook, a silvery, streamlined, snouted carnivore with a dark lateral pinstripe and a bulldoggish underbite. These acrobatic fighters, which can reach 4 feet and 50 pounds, are highly prized by sport anglers. Fishermen in Florida and Texas used to catch snooks until those states banned commercial captures in 1957 and 1987, respectively, to protect the population.
"In Texas there's anecdotal evidence that they're making a comeback. Sport fishermen are finding them more often and in places where they didn't find them before," says Reynaldo Patino, the leader of the Texas Cooperative Fish and Wildlife Research Unit at Texas Tech University and one of the researchers involved in the project.
Efforts to influence what snooks do when no one is looking is complicated by their sexual plasticity. They're protandric hermaphrodites, meaning they can change from males into females. So far, researchers have had some success in getting them to breed in captivity, but getting their kids to eat has been a real head-scratcher.
"It's a challenge," says Wilfrido Contreras Sanchez, the lead investigator and the director of biological sciences at the university in Tabasco that's conducting the research. "Not much is known about snooks. There are still many questions."
To help answer those questions, he began contracting fishermen in Jalapita in 2006 to catch two species of snooks: fat and common. Researchers later injected some and implanted others with different doses of a hormone to induce spawning. They wanted to know which treatment and which dosage produced the most mature eggs and resulted in the highest rates of fertilization, hatching and larval survival. None of the injected fish released its eggs, and only some of the fish with the implanted hormonal pellets did.
Maria de Jesus Contreras Garcia, a graduate student helping conduct the research, suspects that stress, which can adversely affect reproduction, may be to blame. Human contact may have frazzled the fish because researchers injected the hormone into each of them on three different occasions, she says. They handled the fish with implants only once.
On one occasion, Contreras Garcia wanted to know how much time would pass between implantation and spawning so she and a colleague chaperoned three fish for 24 hours. They slept in a hammock and sofa bed in a makeshift house on the beach and set an alarm to sound every hour so they could alternate shifts. With flashlight in hand, she'd groggily lumber to the holding tank and scan the water for eggs. No luck.
Other snooks did spawn though. Almost all of the eggs hatched. But the tiny fish, still in their larval stage, lived for just eight days and were only about as long as the thickness of three stacked dimes. Autopsies revealed empty bellies. The food they were given, although microscopic, was too big for their small mouths, Contreras Sanchez says.
He thinks they might survive if fed the same diet that recently hatched wild snooks around Jalapita feast on. He plans to hire local fishermen to collect microscopic animal and plant plankton as well as snook larvae from nearby spawning grounds. Researchers will dissect their wee stomachs to see if the grub inside is the same as the collected plankton. They then hope to customize a recipe for a locavore diet that they can duplicate in mass quantities in the lab.
They'll also inspect snooks' stomachs, intestines and pancreases to identify enzymes that help digest their food. Certain enzymes break down certain substances, so if they can indentify the enzymes, they'll know what to feed the fish, Contreras Sanchez said. Additionally, they're continuing to refine their work with hormonal injections and implants to see if they get better results. And they've added a third species to their research, the Mexican snook.
About a mile up the road from the research facility, fisherman Ramon Dominguez Sanchez is eager for results. He's eating a mango from a tree in his dirt yard as two women scrub clothes by hand. A few feet away, one of his sons sits under the hood of a truck and replaces the fuel filter. It smells of gas.
The broad-shouldered, thick-necked, flip-flop-wearing Dominguez is the president of a fishing cooperative in Jalapita that would like to buy young snooks from the university, rear them and sell them. The sooner the co-op can do this the better because harvests, at least for him, are declining, says Dominguez, 54, who has been hauling in nets for 40 years. During the previous week he pulled in about $10 worth of fish but there wasn't a snook in the bunch, he says. So Dominguez wants to see the research succeed.
Perhaps it's this pressure to perform that's causing some of the snooks not to cooperate. Back at the beachside research station, the two couples that were checking each other out in the pool have lost interest. Apparently, they're just not that into each other. Researchers vow to keep trying though. Sometimes love just needs time.
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About the AquaFish Collaborative Research Support Program: AquaFish CRSP supports aquaculture and fisheries research in 16 countries that aims to improve diets; generate income for small-scale fish farmers and fishers; promote sustainable environmental practices; and enhance trade opportunities. It is funded by the U.S. Agency for International Development. Oregon State University serves as the lead institution responsible for technical and programmatic leadership of the CRSP in the United States and abroad.
Photos are for download purposes, please give appropriate credit to the photgrapher. To Download Photos, left click image to view full resolution, then right click on the photo, select "save image as..." you will then be prompted to save the image to your harddrive.
 | Women such as this street vendor selling dried tilapia on the outskirts of Lake Victoria are empowered in Kenya’s new aquaculture. -Photo By Victor Motari |
 | Kenya's farmers are building fish ponds in huge numbers in response to the new Economic Stimulus Program. -Photo By Ford Evans |
 | Dinner-plate-sized tilapia matches consumer preferences. -Photo By Victor Motari |
 | Under pressure to produce massive numbers of fingerlings, Dominion Farms Aquaculture Manager Enos Mac'Were inspects his ponds. -Photo By Jeff Hino |
 | Value-added tilapia for sale in a Kisumu open-air restaurant are pre-cut and dried. -Photo By Victor Motari |
 | Long-line fishermen on Lake Victoria working for a day’s catch of Nile perch. -Photo By Jeff Hino |
 | Ready-to-grill tilapia on display at an open-air fish restaurant in Kisumu. -Photo By Victor Motari |
 | Kenya’s youth are actively engaged in pond construction. -Photo By Jeff Hino |
2-02-11
With U.S. help, Kenya aims to boost economy via fish farming
By Jeff Hino, 541-737-2807, jeff.hino@oregonstate.edu
Source: Hillary Egna, 541-737-6415, hillary.egna@oregonstate.edu
CORVALLIS, Ore. - Aquaculture is helping jump-start Kenya's struggling economy, thanks in part to an international program led by Oregon State University.
Kenya is in the midst of rebirth: The East African nation signed a new constitution in August, and has launched an economic stimulus program that includes a novel $16 million effort to increase fish farm production from 1,000 tons in 2008 to 15,000 tons in 2012.
The initiative comes as natural fish stocks in Lake Victoria are declining from overfishing and demand for fish is increasing. Government officials are counting on fishponds - which will be home to millions of tilapia, catfish and ornamental fish - to supply a more sustainable source of protein and income.
A key partner in the efforts is the Aquaculture & Fisheries Collaborative Research Support Program, known as AquaFish CRSP. It's funded by the U.S. Agency for International Development (USAID) and is headquartered at OSU. The program works with developing countries to improve the livelihoods of the rural poor while growing their aquatic product industry. Other projects include researching beneficial bacteria for tilapia ponds in Mexico and evaluating the effects of invasive species in China and Vietnam.
"It's less about fish than about poverty reduction," said OSU's Hillary Egna, the director of AquaFish CRSP. "We work with people who work with the poor, and we help them build capacity for small-scale economic development."
AquaFish CRSP has been helping improve Kenyan aquaculture since 1997. One beneficiary is George Ambuli, the CRSP-trained chairman of a fish-farming cooperative in a small village near Lake Victoria.
"I'm proud to say that fish farming has made me what I am today," he said. "I eat fish, I have a cell phone in my pocket, and I am paying the school fees for my 9-year-old daughter, all with my fish money."
The aquaculture component of the stimulus package was created in late 2009. The program aims to increase the country's fishponds from 7,500 to 48,000. "Fish production in Kenya was a very small industry prior to this cooperative research program," said Kwamena Quagrainie, a lead U.S.-based researcher for CRSP's projects in Africa. "CRSP started with research to understand the whole fish production industry, including pond construction, management and the varieties of fish species that can be produced."
The initiative is expected to benefit some of the country's poorest farmers, as well as two traditionally underprivileged groups: women and youth. Though fishponds continue to be owned almost exclusively by men, women are increasingly involved in all phases of fish farming, including feeding, fertilization and predator control. Kenya's vastly underemployed youth, meanwhile, are finding jobs and gaining skills in pond construction.
But the huge growth in fish farming has presented some cultural and economic challenges. The demand for fingerlings to stock the fast-growing number of fishponds has skyrocketed from 1 million to 28 million in less than a year, forcing the government to lean heavily on private industry. Officials plan to upgrade more than 30 of the nation's hatcheries to help meet demand.
Another obstacle is a sudden need for programs to train new fish farmers how to manage their ponds and market their fish. On top of that, farmers who have built their own ponds without stimulus funding are looking to the government for guidance and training. The government is working to meet these demands as it phases out its involvement over the next 18 months.
As Kenya's aquaculture program expands, fisheries officials plan to put additional marketing structures into place. Outreach efforts include encouraging farmers to improve their income by including value-added activities like gutting, scaling and drying fish for market. The government is building 80 small refrigeration centers around the country, which will help farmers sell fish beyond neighborhood markets. Although perception persists that farmed fish are not as good as captured fish, Fisheries Director Godfrey Monor is confident that in time, half of the fish consumed in Kenya will be farm-grown.
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About Oregon State University: OSU is one of only two U.S. universities designated a land-, sea-, space- and sun-grant institution. OSU is also Oregon's only university to hold both the Carnegie Foundation's top designation for research institutions and its prestigious Community Engagement classification. Its nearly 24,000 students come from all 50 states and more than 90 nations. OSU programs touch every county within Oregon, and its faculty teach and conduct research on issues of national and global importance.
About the AquaFish Collaborative Research Support Program: AquaFish CRSP, which supports aquaculture and fisheries research in 16 countries, aims to improve diets; generate income for small-scale fish farmers and fishers; promote sustainable environmental practices; and enhance trade opportunities. It is funded by the U.S. Agency for International Development and by participating U.S. and host-country institutions. Oregon State University serves as the lead institution responsible for technical and programmatic leadership of CRSP in the United States and abroad.
 | Beatriz Adriana Hernandez Vera tries to weigh a flopping Mayan cichlid as part of a project that aims to develop a genetically superior broodstock of Mayan cichilds and bay snooks for use in fish farming. She is a graduate student at the Autonomous Juarez University of Tabasco in Villahermosa, Mexico. -Photo By Tiffany Woods |
 | Beatriz Adriana Hernandez Vera weighs a Mayan cichlid as part of a project that aims to develop a genetically superior broodstock of Mayan cichilds and bay snooks for use in fish farming. She is a graduate student at the Autonomous Juarez University of Tabasco in Villahermosa, Mexico. -Photo By Tiffany Woods |
 | Enrique Hernandez Gonzalez inspects a mesh cage of Mayan cichlids. He's a student at the Autonomous Juarez University of Tabasco in Villahermosa, Mexico, who is helping conduct research that aims to develop a genetically superior broodstock of Mayan cichilds and bay snooks for use in fish farming. -Photo By Tiffany Woods |
 | Enrique Hernandez Gonzalez inspects a mesh cage of Mayan cichlids. He's a student at the Autonomous Juarez University of Tabasco in Villahermosa, Mexico, who is helping conduct research that aims to develop a genetically superior broodstock of Mayan cichilds and bay snooks for use in fish farming. -Photo By Tiffany Woods |
 | Rosa Aurora Perez Perez, a graduate student at the Autonomous Juarez University of Tabasco in Villahermosa, Mexico, writes down the weight and length of a Mayan cichlid. She's helping conduct research that aims to develop a genetically superior broodstock of Mayan cichilds and bay snooks for use in fish farming. -Photo By Tiffany Woods |
 | Fishmonger Candelario Jimenez Hernandez holds up a small Mayan cichlid at a market in Villahermosa, Mexico. He also sells tilapia (in foreground) and bay snooks (the yellowish, spotted fish in center). -Photo By Tiffany Woods |
 | Bay snooks are for sale at a market in Villahermosa, Mexico. -Photo By Tiffany Woods |
The above photos can be downloaded. Left click the image to view full resolution, then right click on the photo and select "Save Image As." Please credit Tiffany Woods as the photographer.
6-27-11
Researchers aim to boost production of two native fish species in Mexico
By Tiffany Woods, 541-737-2940, tiffany.woods@oregonstate.edu
Source: Hillary Egna, 541-737-6415, hillary.egna@oregonstate.edu; Kevin Fitzsimmons, 520-820-0643, kevfitz@ag.arizona.edu; Wilfrido Contreras Sanchez, 011-52-993-358-1500 ext. 6400, contrerw@hotmail.com
REFORMA, Mexico – Rafael Fernandez Guzman raises tilapia out in the lush, green Mexican countryside. It's a place where cows graze and the roads are lined with stands selling tortillas, papayas, potted plants, bananas and roasted chickens.
The straw hat-wearing, cell phone-carrying former cattle rancher farms the fish in rectangular, excavated earthen ponds roughly the size of basketball courts not far from the city of Villahermosa. His customers drive up and buy them fresh from the water, still breathing and flopping. He sold 120 metric tons of tilapia in 2009, the equivalent of 230,000 fish, he says.
Now he wants to branch into popular native species like Mayan cichlids and bay snooks (they're not actually related to snooks) because customers regularly ask for them, he says. The problem is, though, that he's not sure if these fish would be as lucrative as tilapia. He wouldn't stray from tilapia, he says, unless he could earn a profit margin of at least 25 percent.
Researchers at the Autonomous Juarez University of Tabasco in Villahermosa are trying to make sure that he can. Through systematic breeding, they're working to develop improved broodstocks of Mayan cichlids and bay snooks that would produce fast-growing, meaty fish that are consistent in size and quality and could compete economically with tilapia when raised in farmed conditions. The university aims to sell the juveniles, known as fingerlings, to fish farmers in southeastern Mexico.
Production of these species in captivity is also necessary because environmental degradation and overfishing have reduced their populations, says Kevin Fitzsimmons, a professor at the University of Arizona and a former president of the World Aquaculture Society.
He's one of the participants in the project, which is partially funded by the U.S. Agency for International Development through its AquaFish Collaborative Research Support Program headquartered at Oregon State University. Hillary Egna, the program's director, initiated the project.
For nearly a decade, the university in Villahermosa has been breeding and raising these native cichlids in captivity and selling them to the state of Tabasco and local governments for repopulation efforts, but this is its first attempt to improve the genetics of farmed stocks, says Wilfrido Contreras Sanchez, the lead Mexican researcher on the project.
The omnivorous Mayan cichlid, known locally as castarrica, is native to the fresh and brackish waters of Central America and southeastern Mexico. It has black vertical bands on its sides and is just the right size to fit on a dinner plate. The carnivorous bay snook, also known as tenguayaca or giant cichlid, has a line of large black spots on its sides, inhabits fresh waters in southeastern Mexico and Central America and grows slightly bigger than the Mayan cichlid.
Researchers chose these two species because they have been overexploited, they fetch higher prices than tilapia in local markets, consumers like them, and fish farmers want to raise native species because of their popularity, Contreras says.
The challenge, however, is to produce fish that grow fast enough to compete with the quick-growing tilapia, a popular, easy-to-raise, non-native farmed cichlid that is ready for market after six months in grow-out ponds. The reason for wanting to speed up their growth is simple: The longer fish take to reach market sizes, the more money producers have to spend on feeding them.
Contreras doubts that these native species could ever grow as fast as tilapia. But, he says, if the time were shortened even just partially, the economics might work out in the end because of their more lucrative price. At local fish markets, one kilogram (2.2 pounds) of tilapia sells for around 40 pesos (about $3.40) but bay snooks and Mayan cichlids command at least twice that.
Libido Rivera Lopez knows about the economics. The wiry, soft-spoken fish farmer and other members of a cooperative in the community of Cucuyulapa took a stab at raising Mayan cichlids but threw in the towel because the fish took too long to reach a marketable size. They went back to their trusty tilapia.
But if the researchers' work is successful, Rivera might have a second chance. At one of the university's campuses near Villahermosa, the project is in full swing. Dozens of mesh cages holding Mayan cichlids and bay snooks float in two earthen ponds. The fish are the offspring of nearly 200 wild progenitors that underwent a rigorous physical exam, including blood cell counts, before being deemed healthy enough to be parent material. Once the blood work was done, the fish consummated their relationships in nuptial tanks and spawned hundreds of thousands of small fry.
Researchers have been gradually weeding out the slow-growing offspring. It's tedious, repetitive, slimy, sweaty, wet work. The kind you give to students – like Enrique Hernandez Gonzalez. The biology undergraduate is up to his waist in the pond water, dragging the cages to shore and scooping Mayan cichlids into a bucket. Standing in the sweltering humidity under a tree, graduate student Beatriz Adriana Hernandez Vera then weighs and measures their flopping, slippery bodies as Rosa Aurora Perez Perez, also a graduate student, records the data on a clipboard. Thousands of squirming fish have passed through their hands since the selection process started in 2009.
They'll keep an elite group of the largest and heaviest ones. They'll then breed those lucky few, cull their undersized offspring, breed the survivors, discard the lightweights and voilà, several crosses later, they'll have the final crème de la crème parent stock: 880 hearty Mayan cichlids and 960 robust bay snooks, with both groups equally split by gender. They'll be maintained as broodstock to supply a steady stream of fingerlings to fish farmers.
One day, those offspring just might end up at Rafael Fernandez's fish farm.
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About the AquaFish Collaborative Research Support Program: AquaFish CRSP, which supports aquaculture and fisheries research in 16 countries, aims to improve diets; generate income for small-scale fish farmers and fishers; promote sustainable environmental practices; and enhance trade opportunities. It is funded by the U.S. Agency for International Development and by participating U.S. and Host Country institutions. Oregon State University serves as the lead institution responsible for technical and programmatic leadership of AquaFish CRSP in the United States and abroad.
Photos are for download purposes, please give appropriate credit to the photgrapher. To Download Photos, left click image to view full resolution, then right click on the photo, select "save image as..." you will then be prompted to save the image to your harddrive.
 | AquaFish CRSP collaborates with researchers at Igang Marine Laboratory in Iloilo, the Philippines, where studies are ongoing to develop polyculture techniques for marine aquaculture. -Photo By |
 | Floating pens at Igang Marine Laboratory in Iloilo, the Philippines, contain experimental communities of finfish, shellfish, and seaweeds. Results from these experiments will be shared with local fish farmers in workshops sponsored by AquaFish CRSP. Such polyculture techniques can help small-scale producers diversify income and reduce environmental impact of marine aquaculture. -Photo By |
 | AquaFish CRSP sponsors workshops throughout the Philippines to share research results with small-scale fish farmers. Workshop participants learn the fundamentals of polyculture and marketing products such as seaweeds and high value shellfish as well as more traditional finfish. -Photo By |
 | Students of all ages are engaged in an extension workshop sponsored by AquaFish CRSP in Pandan, the Philippines, where small-scale fish farmers are learning techniques to diversify their aquaculture production. AquaFish program support facilitates the connection of research and extension, so the results of research are used to improve to the lives and livelihoods of the local community. -Photo By |
12-09-11
Small-scale changes could make long-term improvements in Asian aquaculture
By Peg Herring peg.herring@oregonstate.edu
Sources: Russell Borski (russell_borski@ncsu.edu and 1-919-515-8105); Evelyn Grace D.J. Ayson (edjayson@seafdec.org.ph and 63-9173081182)
Iloilo, Philippines - Shrimp monoculture in Southeast Asia has had a checkered reputation in the past, and has been blamed for the reduction of mangroves, diminished water quality, and the spread of shrimp diseases.
To address these problems, researchers are helping small-scale fish farmers in coastal parts of the Philippines and Indonesia forge a cleaner, more profitable future with polyculture.
Polyculture is the opposite of monoculture; it involves growing different kinds of plants and animals together so that they feed on different things and recycle each other's leftovers.
With support from the Aquaculture & Fisheries Collaborative Research Support Program or AquaFish CRSP, researchers are teaching small farmers sustainable polyculture technologies that are mangrove-friendly and keep from loading coastal waters with pollution.
Headquartered at Oregon State University, AquaFish CRSP is funded by the U.S. Agency for International Development (USAID). Mirroring the diversity of species being promoted in polyculture, the CRSP research team itself represents several U.S., Filipino, and Indonesian agencies and universities.
Evelyn Ayson is part of the AquaFish CRSP Filipino team. A fisheries scientist with the Southeast Asian Fisheries Development Center in Iloilo, Ayson heads the research division of SEAFDEC's aquaculture department.
To design a polyculture system takes knowing which aquatic organisms are compatible. Much experimental work happens at SEAFDEC's Igang Mariculture Park in Guimaras, where floating cages just offshore harbor nurseries of everything from microscopic larval abalone to grouper broodstock the size of small whales.
"We are testing dozens of species for polyculture in brackish water ponds and marine cages," said Ayson.
First, the creatures need to get along, especially in open-water cage culture. For example, sea cucumbers (sediment-dwelling mollusks prized in Asian cuisine) are intimidated by rabbitfish that sometimes invade the cages and force the mollusks to hide under the sand and stop feeding. Similarly pufferfish, which also are not part of the polyculture study, feed on sea cucumbers. Pufferfish share the same marine habitat and have, on occasion, made their way into the cages and devoured Ayson's experiments at Igang.
Eventually, what researchers learn here is used to teach polyculture methods to small-scale and subsistence fish farmers in the Philippines and Indonesia. Focusing on communities hit hard by natural disaster or poverty, the AquaFish CRSP has co-sponsored a series of workshops on seaweed culture to audiences of local fish farmers.
Seaweeds in polyculture help absorb dissolved nitrogen and phosphorus that can build up in water from the uneaten feed and waste that accumulate around fish cages. Seaweeds are also valuable as a source of agar, a thickening agent for candy, and in highly refined form, a laboratory medium for medical research.
At a recent workshop in Aceh, Indonesia, where the 2005 tsunami wiped out much of the shrimp monoculture ponds, fish farmers learned about seaweed varieties and the basics of planting, harvesting, drying, and marketing. None of these farmers individually could hope to harvest enough seaweed to attract a significant market, but working as a collective, it could be possible.
"We are training farmers how to process their raw seaweed into more marketable forms and providing them with a new opportunity for income, especially small businesses operated by women," said Russell Borski, a professor of biology at North Carolina State University in Raleigh, who is the U.S. lead in the multinational CRSP research team.
This was one of several dozen extension training sessions the AquaFish CRSP collaborative research team facilitates each year. Another workshop focuses on culturing sea cucumber, as both a valuable seafood product and as an important scavanger in many polyculture systems. for the sustainable fish farm community that researchers are testing.
That's the twin goal of the AquaFish CRSP research, according to Borski. "It's about finding sustainable solutions and creating meaningful work for the poorest people of the world."
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About the AquaFish Collaborative Research Support Program: AquaFish CRSP, which supports aquaculture and fisheries research in 20 countries, aims to improve diets; generate income for small-scale fish farmers and fishers; promote sustainable environmental practices; and enhance trade opportunities. It is funded by the U.S. Agency for International Development and by participating U.S. and Host Country institutions. Oregon State University serves as the lead institution responsible for technical and programmatic leadership of AquaFish CRSP in the United States and abroad..
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 | Ground-breaking studies at Central Luzon State University, in collaboration with research at North Carolina State University, have revolutionized feeding strategies, and increased profits, for tilapia fish farmers across the Philippines. This is one of many long-term, high impact studies supported by the AquaFish CRSP, and one that has made a measurable improvement to the profits of small- and medium-scale fish farmers in southeast Asia. -Photo By |
 | Dr. Remedios Bolivar, third from left, immerses her graduate students in field-based research. Remedios, a professor at Central Luzon State University and a collaborative researcher with AquaFish CRSP, has been instrumental in documenting the success of reduced feeding strategies for tilapia aquaculture in the Philippines. -Photo By |
 | A parade of beautifully painted boats launch onto Lake Taal, where fish farmers monitor hundreds of tilapia cages offshore. AquaFish CRSP sponsored research has helped low-income Philippine fish farmers increase profits and protect water quality by changing the way they feed their fish. -Photo By |
 | Fish farmers head to tilapia cages in Lake Taal before dawn for the first of several daily feedings. AquaFish sponsored research has shown that for tilapia grown in earthen ponds with plenty naturally occurring pond foods , fish farmers can save as much as 60 percent on the cost of feeds by reducing feed rations. -Photo By |
 | Among tilapia fish farmers in the Philippines, as much as 70 percent of variable production costs go to buying supplemental feed. And some of the uneaten feed inevitably drops to the bottom beyond the suspended cages, wasted as food for fish and polluting the water. AquaFish CRSP research points to a practical solution: feed fish less food. -Photo By |
 | Farm-raised tilapia are sold live throughout the back roads of the Philippines. AquaFish CRSP is working with small-scale fish farmers to develop feed reduction strategies that save farmers money and still produce healthy, full-size tilapia within the standard 150-day grow-out period to reach market size. -Photo By |
12-09-11
USAID research increases profits for small-scale fish farmers in southeast Asia
By Peg Herring peg.herring@oregonstate.edu
Sources:Russell Borski (russell_borski@ncsu.edu and 1-919-515-8105); Remedios Bolivar (rbolivar@mozcom.com and 63-44-4565279, 4560680); Evelyn Grace D.J. Ayson (edjayson@seafdec.org.ph and 63-9173081182)
Nueva Ecija, Philippines - The Philippines made its debut at the world's largest seafood fair in Brussels, Belgium, this year, showcasing some of the products that have made the Philippines the 8th leading fish-producer in the world.
Back home and out of the limelight, equally important breakthroughs are occurring for the more than 40 percent of the fish farmers in the Philippines who live in poverty. Small-scale, low-income Filipino fish farmers are increasing profits and protecting water quality by changing the way they feed their fish.
As much as 70 percent of a fish farmer's variable production costs go to buying supplemental feed. And some of the uneaten feed inevitably drops to the bottom of their freshwater ponds, wasted as food for fish and polluting the water.
The solution? Feed fish less food.
Remedios Bolivar, a professor at the College of Fisheries, Central Luzon State University in the Science City of Muñoz, and her U.S. research partners Russell Borski, a professor of biology at North Carolina State University in Raleigh, and Christopher Brown of the National Oceanic Atmospheric Administration are working with small-scale fish farmers in the Philippines to develop feed reduction strategies that save farmers money and still produce healthy, full-size tilapia within the standard 150-day grow-out period to reach market size.
Brown, Borski and Bolivar tested three different approaches to reducing feed for pond-raised tilapia: delay the start of supplementary feeding, feed every other day, or feed below the level of satiation.
Their results document that tilapia grown in earthen ponds with plenty of algae and other natural pond foods can do just fine with any of these reduced feeding regimes, effectively reducing supplemental feed costs without significantly reducing growth, survival or market yield.
"By reducing feed rations, fish farmers can save as much as 60 percent on the cost of feeds which can enhance the profitability of growing fish by as much as 40 percent relative to fish grown on a typical full daily ration," Borski said. "That's big."
Evelyn Grace D.J. Ayson, who also works with Borski, found similar results--up to 60 percent savings in feed costs--with reduced feeding of milkfish, a regional favorite marine fish.
"Equally important are the reduced environmental impacts that come with reduced feeding strategies," said Ayson, who heads the Research Division of the Southeast Asian Fisheries Development Center in Iloilo.
Ayson and her research team documented reductions in dissolved nitrogen and phosphorus in the water and reduced hydrogen sulfide in marine sediments around the cages where feed was reduced, compared to cages where milkfish received regular full daily rations.
This research means big change for low-income fish farmers in the Philippines and elsewhere in developing parts of the world. It is the work of the Aquaculture & Fisheries Collaborative Research Support Program (AquaFish CRSP) which is funded by the U.S. Agency for International Development (USAID).
Ayson, Bolivar and Borski are part of the AquaFish CRSP, an international research program headquartered at Oregon State University that connects U.S. university scientists with research partners in developing countries.
The idea of delayed feeding came from another AquaFish CRSP researcher, James Diana of the University of Michigan, while he was working with fish farmers and scientists in Thailand during the 1990s.
"We saw how reduced feeding of tilapia could save money on feed costs and reduce pollution of the water ," Diana said. Through the AquaFish CRSP network, reduced feeding strategies are now being tested by fish farmers and researchers in other parts of Asia, Africa and Latin America.
Like most larval fish, tilapia retain a yolk-sac for the first few days of life. Living off the stored nutrients in this sac, young tilapia can gradually adjust to the plant-eating life of an adult. Historically, fish farmers added no supplemental feed for tilapia, choosing instead to fertilize the pond to feed the plankton and let the pond feed the fish.
As tilapia aquaculture developed and became more intensive, fish farmers began using supplemental feed to speed the growth and increase the size of fish at harvest. But as the cost of feeding fish increases, it may be worthwhile to consider these cost-saving strategies, according to Bolivar.
To reach Filipino fish farmers, and anyone else in the world, with information on these new strategies, Borski and his colleagues have produced a series of podcasts describing the reduced feeding strategies. The Tilapia Podcasts are available at: (https://deimos.apple.com/WebObjects/Core.woa/BrowsePrivately/ncsu.edu.1784740579.01784740581)
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About the AquaFish Collaborative Research Support Program: AquaFish CRSP, which supports aquaculture and fisheries research in 20 countries, aims to improve diets; generate income for small-scale fish farmers and fishers; promote sustainable environmental practices; and enhance trade opportunities. It is funded by the U.S. Agency for International Development and by participating U.S. and Host Country institutions. Oregon State University serves as the lead institution responsible for technical and programmatic leadership of AquaFish CRSP in the United States and abroad..
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The Aquaculture & Fisheries Collaborative Research Support Program ( AquaFish CRSP ) is funded under USAID Leader with Associates Cooperative Agreement No. EPP-A-00-06-00012-00 and by the participating US and Host Country partners. | 216 Strand Hall Corvallis, Oregon 97331 541-737-6426 Questions for or about the AquaFish CRSP? Comments about this site? Email aquafish@oregonstate.edu |
