FINS FOR FORESTS

by K. C. Jaehnig, Media & Communication Resources

Picture a fish that likes nothing better than to root through a flooded forest for fallen fruits and nuts--a healthy, fast-growing fish that will settle for kitchen scraps if that's all that's on offer. A fish that does well in captivity and makes mighty good eating--in short, a fish much like a pig, minus the stink and the squeal.

Such fish, members of two tropical species called pacu in the United States, are native to the Peruvian Amazon. They could provide a means not only to feed that region's poor but to save its rainforests, too, an SIUC zoologist believes.

"The destruction of the rainforest has been shown to have a tremendous effect on global climate change," says Christopher Kohler. Director of SIUC's Fisheries and Illinois Aquaculture Center, he has worked in the Amazon for the last 10 years.

"A lot of that destruction has occurred as a result of agriculture--people have to make a living. But agriculture isn't a sustainable practice there. Aquaculture is."

Aquaculture--raising fish for food--has become the main focus of SIUC research and outreach efforts in the Amazon. Working with native fish species, some of them endangered, scientists are devising ways to help Peru's rainforest residents feed themselves sustainably.

When people in the Amazon clear rainforest acreage for row-crop agriculture or cattle ranching, it's a losing proposition all around. The soil is too thin and poor to support these activities for more than a few years. Villagers must then move on to clear a new spot, and the cycle of destruction--and poverty--goes on.

Small-scale aquaculture offers an eco-friendly way of producing what is really their preferred food: fish. An important part of the diet, fish contributes 60 percent of their protein.

"Since we have been involved with this project, we have gone from a handful of people raising fish to several hundred doing it," Kohler says. "Although many of them were hunters and gatherers in the past, they have been adapting to this kind of activity readily, and it's good for the region--it leaves the trees."

It's a long way from Southern Illinois to South America, from hybrid striped bass to a fish that can forage on a flooded forest floor. The journey began with a Peruvian student. Luis Campos Baca had come to SIUC from the Universidad Nacional de la Amazonia Peruana, where he taught, to work on a master's degree. He asked Kohler if the two faculties could join forces to help his homeland.

"My first response was, 'I've never been to the Amazon, I know nothing about the Amazon, and anyway, we could never get any kind of funding for this,'" Kohler recalls.

But in 1993, the U.S. Information Agency, which operated a grant program intended to foster links between American and foreign universities, decided to emphasize conservation, with the Amazon a priority. Kohler learned of the program's existence three weeks before grant proposals were due.

"We had nothing, but we did have this student," Kohler says. "He was going back [to Peru], and he promised to get us letters of support.

"The Mississippi and the Amazon are the two largest river systems in this hemisphere. While we didn't know anything about the Amazon, the Peruvians didn't know anything about the Mississippi. [I thought] learning about the commonalities and differences might help us all."

Armed with that proposal, the SIUC team landed a three-year grant.

"We got as many faculty involved as we could, and it worked exactly like USIA wants these projects to work, with friendships and collaborations developing that would keep everything going after the grant ended," Kohler says.

Peruvian scientists came here to learn about the Mississippi and fisheries management in the United States. Meanwhile, SIUC scientists went south to research the Amazon. Much of their early work, led by SIUC zoologist Brooks Burr and involving a number of graduate students, centered on identifying fish species and collecting research samples.

SIUC now houses specimens of roughly 70 percent of the region's 800 fish species. The ichthyological research clarified much scientific uncertainty about these species.

"The Amazon River is home to the largest diversity of freshwater fish in the world," Kohler says. "For people who work with fish, it doesn't get much better than that."

As they worked, the SIUC researchers talked with local fishermen and discovered some troubling facts.

"The fishermen were fishing the river fairly intensively but had to go farther and farther to get their catch, and the fish coming in were getting smaller--classic signs of overfishing," Kohler says.

While sampling continued, researchers began to study the catch and to look at fish populations and came to a conclusion.

"If they were going to continue their consumption of fish, aquaculture would have to make up the difference," Kohler says.

And then the project got another lucky break. Although USIA support was coming to an end, Oregon State University had been awarded a grant from the U.S. Agency for International Development to put together an aquaculture venture. Its Collaborative Research Support Program linked American researchers with hosts in developing countries. It had no members in South America.

"We've been funded through that program ever since, and ours has become one of their prime sites," Kohler says.

SIUC scientists and graduate students work with their counterparts at the Universidad Nacional de la Amazonia Peruana and the Instituto de Investigaciones de la Amazonia Peruana. Both are located in Iquitos, in the heart of the rainforest. Fernando Alcantera and Salvador Tello head the Peruvian side of the collaboration, with SIUC researcher William Camargo serving as the chief liaison.

A key task for the team has been to investigate the suitability of native fish species for aquaculture. Much of their early work focused on pacu. These fish "look like a giant piranha, but without the sharp teeth," Kohler says. In the wild, they play a key role in dispersing seeds through the river ecosystem, but they are being overharvested. By taking the fishing pressure off the wild population, aquaculturists hope to help preserve the ecological balance.

Among other things, the scientists studied water-quality and stocking density requirements for two pacu species, Colossoma macropomum and Piaractus brachypomus. They experimented with techniques to increase the survival of fish larvae and young fish, and tried out various feeding regimens of locally available or prepared foods.

As a result of this work, both species can reliably be raised from larvae to 2-pounders--big enough to harvest--in just one year. Fred Chu-Koo, a Peruvian doctoral student at SIUC, continues to refine aquaculture techniques for these fish.

The project team began its work with aquaculture ponds, but lately, for villages in floodprone areas or sited on riverbanks, they're constructing fish pens directly in streams and rivers. Recently they've been experimenting with raising a fish called Arapaima gigas in these pens. This endangered species, which can grow to 9 feet long in the wild, is one of the most popular food fishes in the Amazon.

"The results are looking surprisingly good (for aquaculture)," Kohler says. "They grow extremely fast--we can get them up to more than 10 pounds in one year."

The team also is investigating the aquaculture potential of two native catfish species.

The project offers training to prospective fish farmers, who learn everything from how to construct and stock ponds or fish pens, to techniques for breeding and rearing the fish, to knowing when to harvest. It also provides intensive short courses for government and nonprofit agency personnel from Peru and neighboring countries, who then work as aquaculture extension agents. Those outreach activities are spearheaded by Camargo and Sue Kohler, associate director of SIUC's Office of Economic and Regional Development.

"We try to work with as many individuals as possible to turn them into 'master aquaculturists,' somewhat like 'master gardeners' here, so that other people can visit and learn from them," says Chris Kohler.

"We've also hired workers who go out to the 'hinterwaters' far and wide--places where there are no roads--to spread the word."

The project stresses sustainability. "Waste is not a problem in the ponds or rivers because it gets broken down--we're working at a subsistence level, not an industrial level," Kohler notes. "Farmers might have just one pond or one pen, but it allows them to have an income, produce some of their own food, even use kitchen waste [by feeding it to the fish]. It's also sustainable because we're working with native species, so there's no problem if there are escapes."

By helping the Peruvians, we also help ourselves--both in the near term and the big picture, Kohler believes.

"Several of the fish species we're working with have better attributes for aquaculture than species we currently use in this country," he says. "These are fish we might want to be producing ourselves someday.

"But it's more than that. Everything is interconnected. Sometimes you don't know what those connections are until you lose them, but once you lose a species, it's gone for good. Things that happen in the Amazon will affect all of us. That's something for mankind to keep in mind."

Fall 2003 Contents | Perspectives Home | SIUC Home