Dong-Fang Deng

New Wisconsin Sea Grant aquaculture outreach specialist formulates “right food for the right fish”

On: September 22, 2023

In: aquaculture, Dong-Fang Deng, Harbor Fest

Aquaculture Outreach and Extension Specialist Dong-Fang Deng discovered her love for fish in the long, winding gut of a grass carp.

“I didn’t think I was going to do any animal research,” said Deng, but a fish dissection at the lab she worked at while an undergraduate sparked her interest. The fishes she examined—the grass carp, tilapia and Japanese eel—all had differently sized intestinal tracts, with the grass carp having the longest. Talking with her professor about the diets of each fish, Deng had a realization: A “different gut [is] related to different food.”

Aquaculture Outreach and Extension Specialist Dong-Fang Deng discusses stands behind a teal-colored fish tank in her lab.

Aquaculture Outreach and Extension Specialist Dong-Fang Deng discusses fish nutrition in her lab at the UWM School of Freshwater Sciences. Photo credit: Wisconsin Sea Grant

Unlike tilapia or Japanese eel, grass carp are herbivores, and a long gut allows them to break down and absorb nutrients from plants. Deng credits her professor for encouraging her curiosity.

“I really appreciate that my professor worked with me,” she said.

Deng’s curiosity propelled her into a career in animal nutrition. In addition to her Sea Grant appointment, which began in February 2023, Deng is also a professor at the University of Wisconsin-Milwaukee School of Freshwater Sciences, where she researches and develops fish feed for the aquaculture, or fish farming, industry.

“We want to make the right diet for the right fish, that’s our general goal,” said Deng.

Formulating fish food, however, is no simple task. Different fish have different nutritional needs, and what works for one fish may not work for another. Take, for example, the yellow perch. Unable to tolerate the high-fat diets of rainbow trout and salmon, yellow perch will accumulate excess fat in their liver, which affects their metabolism. “If the liver isn’t functioning right, they can’t grow very well,” said Deng. “We need to figure out how to optimize the feed.”

Another consideration is the cost and availability of food. Aquaculture researchers have been investigating alternative ingredients, like black soldier flies and fungi protein, to replace more expensive fish meal. Plant-based ingredients in aquaculture feed are also common. Said Deng, “Plant ingredients like corn and soy have been in research for decades.”

A small blue net holds a handful of pinky-sized lake sturgeon, which Deng researches in her lab.

Deng formulates feed for fish raised in aquaculture systems, such as these fingerling lake sturgeon. Photo credit: Wisconsin Sea Grant

Deng is currently experimenting with a new plant ingredient, alfalfa, which is a common forage crop for livestock like cows. She is researching whether the protein-rich plant could replace fish meal protein in the diet of rainbow trout.

While cheap, abundant ingredients are desirable, dietary changes shouldn’t negatively impact fish health, whether those fish are raised for food or for stocking purposes.

For example, Deng is working with Mole Lake Fisheries to develop a dry feed to replace the live minnows fed to walleye raised in outdoor ponds. Minnows are expensive, and while dry feed may be cheaper, walleye must be strong enough to be stocked in local lakes.

Deng must consider how the new diet impacts their long-term survival. “Can they run well in the lake?” asked Deng. “Can they survive? [Can they] still get used to catching live food?”

Working with fish farmers to develop a new feed or adopt a new technology is part of Deng’s work as an outreach specialist, but she also spends much of her time working with students—from high school to graduate-level. Some students seek out her lab because they love to fish; others just want to build their research skills. Deng then collaborates with students to tailor lab work to their interests or career goals. One undergraduate, Deng recalled, wanted to pursue dentistry, so she got creative.

“I asked him to look at different teeth of the fish to see the evolution of different food habits,” said Deng.

Deng holds up two yellow perch as two lab students look on.

Deng holds up two yellow perch for two students who work in her lab. Photo credit: Wisconsin Sea Grant

She has also worked with students interested in environmental law, public policy and communications and stresses that students don’t need to major in biology to work in her lab. “My goal is to open the window and the door to anyone who likes to learn,” she said.

And that includes the public. Deng offers educational tours of her lab to schools and community groups where participants learn more about aquaculture and get the opportunity to see tanks of juvenile sturgeon or eyelash-sized yellow perch. It’s a popular event, one that has inspired students to pursue working in her lab.

“You have to let the public learn what we are doing,” said Deng. “If you always close the door, then why are we here?”

Those interested in scheduling a tour of Deng’s lab should reach out to dengd@uwm.edu. Deng will also have open lab exhibitions at Harbor Fest in Milwaukee on Sunday, September 24, 2023.

The post New Wisconsin Sea Grant aquaculture outreach specialist formulates “right food for the right fish” first appeared on Wisconsin Sea Grant.

Original Article

News Releases | Wisconsin Sea Grant

https://www.seagrant.wisc.edu/news/new-wisconsin-sea-grant-aquaculture-outreach-specialist-formulates-right-food-for-the-right-fish/

Jenna Mertz

Filling water shoes

On: August 21, 2023

In: Alison Mikulyuk, aquaculture, Dong-Fang Deng, Emma Hauser, Freshwater Collaborative of Wisconsin, Sharon Moen, Summer Research Opportunities Program

Two new grants set to build water-related workforce development

The labor landscape in Wisconsin is closely bound to demographics and it comes down to this simple reality: shoes are not being filled.

U.S. Census data shows Wisconsinites of traditional retirement age, 65, have increased 42% since 2005. At the same time, the number of people entering the workforce is contracting because state birth rates have slowed and there are fewer young people. Another aspect of this workforce-shortage trend is that young people are bypassing Wisconsin, choosing to work and live elsewhere as they chase their American dreams.

Now, thanks to an infusion of two new grants, Wisconsin Sea Grant is positioned to facilitate the paths young people are considering as they sort through workforce choices, including where they may eventually want to find training and education, take a job and make a home.

With $592,332 in support from the Freshwater Collaborative of Wisconsin (FWC) over two years, the Freshwater@UW Summer Research Opportunities Program will continue its work to develop Wisconsin’s next generation of freshwater scientists.

The program matches water-related mentors from throughout the University of Wisconsin System with undergraduates to guide them in an immersive research experience and acquaint them with the many graduate school opportunities in Wisconsin.

The program just wrapped up its second summer, which attracted 31 students from across the nation to work on the system campuses at Eau Claire, Green Bay, La Crosse, Madison, Milwaukee, Oshkosh and Superior.

Alison Mikulyuk is coordinating the work of summer research scholars.

Sea Grant’s Alison Mikulyuk coordinates the program which, she said, is growing freshwater research and the workforce through collaborative, cross-system programming that trains and will, ultimately, recruit, retain and diversify the next generation of water professionals.

“The program attracts talented students to the Badger State where they gain skills that are directly applicable to future work in Wisconsin,” Mikulyuk said. “Having just seen these young people through the summer, I’m incredibly inspired. The students made an impressive showing at the recent Summer Research Symposium, and so many of them have had life-altering experiences that I know will fuel their future accomplishments.”

The second two-year FWC grant will provide $207,400 for a project called “Partnering to Boost Aquaculture Workforce Development in Wisconsin.”

Sharon Moen, food-fish outreach coordinator, conducted a 2020 needs assessment of Wisconsin’s food-fish farmers and heard over and over again the need to bring young people into the industry.

“The U.S. imports more than 70% of its fish and shrimp. About half of these imports come from overseas farms. Meanwhile, consumers are calling for locally produced food that supports American jobs, and the health of themselves and their loved ones. Wisconsin aquaculture, aquaculture being another word for fish farming, is primed to meet that demand,” Moen said. “The industry just needs workers and this project will expand training opportunities, linking commercial fish farms in the state to high schools, colleges and universities to foster farm experiences and skill-building workshops.”

Sharon Moen will work with colleagues on aquaculture industry workforce development.

She said one such idea for that skill-building will be supporting high school teams to participate in an existing annual aquaculture competition. Students design and build a system to grow fish.

Moen will work with Sea Grant colleagues Dong-Fang Deng and Emma Hauser, both aquaculture outreach and education specialists. Deng is based at the University of Wisconsin-Milwaukee and Hauser works out of UW-Steven’s Point Northern Aquaculture Demonstration Facility on the Bayfield Peninsula, not too far from Lake Superior.

“With Dong-Fang’s and Emma’s connections and our collective enthusiasm for this project, we are looking forward to successfully inspiring young people to enter the aquaculture workforce. It can offer a good standard of living and a remarkable quality of life,” Moen said.

The Freshwater Collaborative of Wisconsin is a partnership of Wisconsin’s 13 public universities, connecting with industry partners, local communities, policymakers and advocacy groups. Its mission is to establish Wisconsin as a world leader in freshwater science, technology, entrepreneurship and economic growth. The Freshwater Collaborative of Wisconsin is training the next generation of scientists to solve global water resource problems through academic programs, collaborative research and career development across the UW System.

The post Filling water shoes first appeared on Wisconsin Sea Grant.

Original Article

News Releases | Wisconsin Sea Grant

https://www.seagrant.wisc.edu/news/filling-water-shoes/

Moira Harrington