Seventeen students gathered on Catalina Island around a long, rectangular pit filled with dirt, garden clippings and bits of food — banana peels, lettuce leaves, waffles. Eleven five-gallon plastic drums sat in a row nearby.
“What we’re going to be doing today is making compost,” said Liz Gustin, senior garden coordinator at the Catalina Environmental Leadership Program.
Gustin directed the students to pull the lids from the containers, revealing the remains of once-sumptuous meals. The drums contained egg shells, watermelon rinds, paper napkins and pineapple skins, among other items discarded at program’s cafeteria. Students weighed each drum to determine how much would be added to the compost heap. For the mixture to be effective, it must have the right balance of carbon, nitrogen, oxygen and water, Gustin explained.
“It’s kind of like weighing your luggage to make sure it’s not over the limit,” she said.
The day’s activities were part of the Science of Sustainable Food Spring Break program, held by the USC Wrigley Institute for Environmental Studies, under the auspices of the USC Dornsife College of Letters, Arts and Sciences. The weeklong program brought undergraduate and graduate students from USC and the State University of New York to the USC Wrigley Marine Science Center to study the science of sustainable food production, which included time in the rogram’s edible garden, learning how to use food waste to make nutrient-rich soil for growing vegetables.
After the students weighed the drums, they poured everything into the pit then mixed the concoction with large shovels. Handing out large cardboard boxes, Gustin instructed them to tear the cardboard into pieces the size of a credit card and toss them in the pit.
“The food has some carbon in it, but it’s mostly nitrogen-heavy,” Gustin said. “It’s wet, it’s green and if we just have food in there — picture what happens when you leave an apple core out — it turns to muck. But when we get the balance right by adding carbon-heavy cardboard, this is going to make some amazing potting soil in about six to eight weeks.”
Less trash for landfill
Catalina Island’s only landfill is roughly 10 years away from being filled, Gustin said. To reduce the amount of waste that’s dumped into it, workers at the facility hand-sort the garbage and pull out recyclable and compostable materials. Composting kitchen and food waste is one way the program helps to reduce the amount of trash pouring into the landfill.
“We hope this program will get students to think about where their food comes from and how they can contribute to the mounting movement of producing food in a more environmentally responsible and sustainable way to feed our growing population,” said Diane Kim, director of undergraduate programs for the USC Wrigley Institute. In addition to taking part in workshops and discussions, students also had the chance to hike, kayak and snorkel in the center’s pristine setting at Big Fisherman Cove.
Programming featured presentations from USC Dornsife researchers who are studying aquaculture — the farming of marine and freshwater organisms for consumption — as a sustainable means to supplement the dwindling amount of wild seafood available in the ocean.
Supply and demand
Since the 1980s, the amount of wild fish harvested from lakes, rivers and oceans has plateaued while the world’s population has ballooned to 7 billion people — a 2 billion increase in three decades. Meanwhile, per capita demand for seafood has continued to increase.
A number of USC Wrigley Institute researchers are looking at ways to grow aquatic species to meet the demand.
USC Dornsife postdoctoral researcher Scott Applebaum, who specializes in the physiology of marine animals, is part of the Future of Food From the Sea program at the institute. Along with other researchers in the program, Applebaum is studying how to breed fast-growing and more robust oysters to boost the seafood available for human consumption.
Under direction from Applebaum and USC Wrigley Institute aquaculture specialist Tyler Hild, students fertilized sea urchins and learned how to grow single-celled algae, which is used to feed farmed oysters.
Tony Michaels, adjunct professor of biology at USC Dornsife and founding director of the USC Wrigley Institute, provided students with an overview of current food and agricultural systems and the problems associated with them. For instance, many farmers use synthetic fertilizers that can pollute water supplies and contribute to nitrous oxide emissions. Michaels, who stepped down as director in 2008, shared a biological farming technique he has been cultivating that takes advantage of growing root vegetables, which have symbiotic relationships with microbes that naturally replenish much-needed nitrogen to soil.
Students also heard from Kenneth Nealson, holder of the Wrigley Chair in Environmental Studies and professor of earth sciences and biological sciences at USC Dornsife.
Nealson is working on a process to convert food waste into feed for animals — including fish raised in aquaculture — and liquid fertilizer for soil amendments using black soldier fly larvae. Nearly 40 percent of the food produced ends up thrown away, filling landfills and producing methane gases. A portion of the larvae could be harvested as feed for chickens and other livestock, minimizing the need to produce corn and soy for feed, which require large amounts of resources to produce.
The students also talked with Neelam Sharma, director of South Los Angeles’ Community Services Unlimited, which connects L.A. residents with sustainable food options and oversees community gardens and youth training programs.
“In addition to learning about the science of sustainable food, we wanted to include a social component so students could learn about the urban gardening that is taking place in L.A.,” Kim said. “We want students to know that sustainable practices are taking place in their own backyard.”
Kim created the spring break program in partnership with Applebaum and Ryan Lesniewski, a graduate student at USC Dornsife’s Marine Environmental Biology section.
Lesniewski is writing his PhD thesis on aquaponics, a food production system that makes use of a symbiotic relationship between plants and aquatic animals. Plants are grown in a system in which water is circulated from a fish tank to water the plants. The fish waste in the water is converted into highly beneficial nutrients for the plants.
“Compared with regular farming, aquaponics is 95 percent more water-efficient,” Lesniewski said.
Together with David Rosenstein, Western regional chair of the Aquaponics Association based in Annandale, Va., Lesniewski guided the students in building their own small-scale aquaponics system. Students planted seeds that should eventually yield 15 square feet of heirloom tomatoes, kale, Swiss chard, dill, snow peas and other vegetables.
Junior Louige Oliver said constructing the aquaponics system was a perfect way to learn about growing sustainable food. He plans to take the knowledge he gained home with him and put it to use.
“I think aquaponics will be the best method for my family because we love fish, and we love planting,” he said. “It will be a perfect way to grow food in our little side yard.”
The neuroscience major said the spring break program on Catalina Island gave him the opportunity to learn about various areas of ecology and sustainability.
“In neuroscience, it’s all about systems and making connections,” he said. “This program is a perfect large-scale view of how things connect to each other. In the brain, neurons connect to different neurons, which affect different areas. That is exactly what we learned about ecology — every element out of an ecosystem affects the whole structure.”
Tasting was incorporated into activities. Students learned to shuck oysters, enjoying them as a snack. Before learning about aquaculture and marine fisheries management and policy issues from two researchers in Mexico, the group dined on farmed Atlantic salmon.
Students also tasted some of the fresh produce being grown in CELP’s edible garden.
After the compost was mixed, students toured the garden harvesting chard, basil, garlic scapes and lemons. The group chopped and diced the ingredients, which Gustin tossed with olive oil and passed around served on top of freshly baked bread cooked in a solar oven.
“This is delicious,” said human biology major Maria Guzman. It was her first time trying chard.
“At home all I ever eat is lettuce and tomatoes — the standard stuff. Here we have a diversity of greens,” she said.
She plans to experiment by trying new fresh veggies at home. Her experience during the week was eye-opening, she said.
“I never really thought about where my food comes from and I never really thought about where the discarded food goes.”
Guzman said she would share what she learned with her friends and family.
Mariah Kim, a neuroscience major, said that the experience helped her understand how the food on her plate got to be there. Now she’ll be paying more attention to what she’s eating and where it came from.
“To have that knowledge about what you eat empowers you,” she said.