From Indiana to your aquarium: Oldest private fish farm in the U.S. raises goldfish, koi

Kathie Wilson remembers getting goldfish from the fair when she was a young girl. Maybe it was from the game where you try to toss a ping pong ball into a bowl, or the ring toss, she can't remember.

She’d put them in a bowl and take care of them, but she never really thought about fish as pets. She knew nothing about them.

That changed about six years ago, when the Morgan County native took a new job at a farm down the road from where she was raised. Her father had done construction work there years earlier.

From above the place looks much like a grid, not unlike bird's-eye views of other Hoosier farms: A patchwork of clean lines and angular plots. But they’re not fields, at least not in the traditional sense. Rather, this is a farm that uses ponds to grows its crop — the very fish that Wilson won as a little girl.

“If you’ve been to a fair or a carnival," she said, "then you’ve picked up one of our goldfish."

Ozark Fisheries has been around for about a century, selling ornamental fish to pet suppliers as well as carnivals and water gardens. It’s one of the oldest private fish farms in the country, raising millions of fish each year in hundreds of small ponds near Martinsville, a town of about 12,000 between Indianapolis and Bloomington with the White River bordering its westside.

The Ozark farm, which got its start as Grassyfork Fisheries in 1899, produces multiple types of goldfish and even a couple different kinds of koi.

Fantail goldfish in tanks at Ozark Fisheries, Martinsville, Friday, May 20, 2022, formerly known as Grassyfork Fisheries, breeds various types of small aquatic animals including koi and bullfrog tadpoles.
Fantail goldfish in tanks at Ozark Fisheries, Martinsville, Friday, May 20, 2022, formerly known as Grassyfork Fisheries, breeds various types of small aquatic animals including koi and bullfrog tadpoles.

As with most agriculture, fish farming is a carefully run science project. It has seasons, the “fields” have to be prepared, it has pests that can harm the “crop,” it has fertilizer (in this case, fish food), it’s dependent on the weather, and it has specific windows for harvesting.

“A lot of it is the same: I’m raising a product that I’m growing,” said Margaret Cleveland, who helps run Ozark Fisheries with her father and brother. “We raise a crop, feed it, grow it out and do the best you can in hopes you have a good product to sell.”

That said, “keeping fish alive is pretty complicated,” Cleveland said. “Farming is a lot of work, any farmer would say that.”

Ozark Fisheries seemingly has it figured out, but they’ve had a lot of practice.

Farming fish for a century

Before it was Ozark’s fish farm, it was Grassyfork.

A man named Eugene Shireman inherited land in Martinsville in the late 1800s, but it was swampy and ill-suited for farming — traditional farming, that is. At that same time, goldfish were gaining popularity across the country after having arrived from China about 20 years before.

He first discovered the vibrant fish himself when the world’s fair came to the region in the 1890s. He was fascinated, Wilson said, captivated even. But sources in the U.S. for goldfish, which were becoming a novelty, were limited.

Shireman saw an opportunity, and had the perfect spot.

“He knew he couldn’t do row crops in that area," Cleveland said, "but water was pretty abundant.”

A couple years after establishing Grassyfork Fisheries in 1899, he bought 200 breeding goldfish. The business took off from there and over the years Shireman was able to purchase additional land in Martinsville to expand the farm.

Grassyfork became one of the largest goldfish hatcheries in the world and earned Martinsville the nickname “Goldfish Capitol of the World.” It’s also one of, if not the, oldest continuously-operated private fish farms in the country.

With the popularity of goldfish booming, others started to get in the game. By the early 1920s, there were more than 60 goldfish producers in the U.S. While Grassyfork was still a leader, others popped up in Maryland, Ohio and Pennsylvania.

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One competitor, Ozark Fisheries, opened in Missouri in 1926. It was started by Cleveland’s great grandfather. Initially a trout hatchery, the focus soon shifted to goldfish with an eye to the “fancy varieties.”

Grassyfork and Ozark were each other’s biggest competitors, Cleveland said, until they joined forces when Ozark acquired Grassyfork in the 1970s. Combined, they became a very big fish in a small pond.

There are a lot of ways to measure size: revenue, number of fish, acreage, etc. Cleveland boils it down to something more basic: “We’re the largest with what we do.”

Fantail goldfish in tanks at Ozark Fisheries, Martinsville, Friday, May 20, 2022, formerly known as Grassyfork Fisheries, breeds various types of small aquatic animals including koi and bullfrog tadpoles.
Fantail goldfish in tanks at Ozark Fisheries, Martinsville, Friday, May 20, 2022, formerly known as Grassyfork Fisheries, breeds various types of small aquatic animals including koi and bullfrog tadpoles.

They raise five different types of goldfish and two species of koi. Some are solid colors while others are mixtures of orange, white, black and even bluish hues. The goldfish can be as small as an inch but usually are a few inches while the koi can be as large as one to two feet.

Everything they raise is for looking at, Cleveland said, “not for eating.” The ornamental fish are meant for bowls, aquariums, fountains and ponds.

The goldfish and koi they produce are very nice, she said, but they aren’t trying to raise show-quality fish.

“We are like the Fords and the Chevys,” the fourth-generation fish farmer said. “You can buy Bentleys and BMWs, but we are going for more of a really pretty fish that’s really good quality and at a good price for people.”

In addition to the former Grassyfork farm, Ozark still operates a fish farm in Stoutland, Missouri, which sits between St. Louis and Springfield. Cleveland grew up on that farm with her brother, who now oversees things in Martinsville.

She said the work is very rewarding, but it’s also “very, very hard.” Still, she wouldn’t trade her job, and the title that goes with it. The Missouri farm, where Margaret Cleveland keeps an eye on things, also has some cattle that they raise.

“I don’t tell people I’m a cattle farmer, I tell them I’m a fish farmer,” she said. “It’s always been in my blood.”

Raising fish 'a really neat process'

The farming cycle starts with breeder fish. These are the goldfish and koi that have various qualities — such as coloring, fin size and shape, etc. — that Ozark wants to see passed on to their offspring.

“We will only keep the best of the best to have as broodstock,” Cleveland said.

Most of the goldfish brooders are about three years old while some of the koi are more than 10 years old. Those fish are about three feet long, Cleveland said: “They are like whales.”

Starting late in the spring, once the waters reach a certain temperature, it’s spawning time. The brood fish are moved to large tanks — the very tanks that Wilson’s father helped build on the farm — where they release their eggs over a short period of time. Mats at the bottom of the tank catch the eggs so they can be moved into the hatchery to what are essentially incubator tanks, Wilson said.

Those tanks are being monitored multiple times every day and workers are controlling the water temperature, amount of oxygen, and other factors to create the best growing environment. After two to three days, the eggs hatch in those tanks.

“When the fish are born, they are about the size of an eyelash,” Wilson said. Each tank in the hatchery on average holds about half a million baby fish and there are 60 tanks at the Martinsville farm.

Within just a couple days of hatching, those young fish are taken out to a pond to make way for more eggs in the hatchery. The farm hatches all its fish for the year in just a six-week period between late May and early July, depending on the weather. Needless to say, Wilson said, it’s busy.

There are roughly 300 ponds, each about an acre in size, across the farms in Martinsville. They stretch around trees and some are hidden behind little hills — from atop one, the ponds look almost like a coloring book crisply penciled in with varying shades of muted blues and greens. The small walkways in between become the borders to stay within, and if you zoomed out you’d expect to see a shape take form.

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Those ponds are where the fish are raised for the next few weeks and months. But the farmers’ work doesn’t stop there. The ponds have to be drained and cleaned in preparation for the fish. All the ponds in Martinsville are naturally fed from a creek that runs through the farm as well as surface and rain water that's collected.

The farmers will also carefully choose what type of fish and how many go in each pond, Wilson said. More fish means they will stay smaller because there is less space and fewer resources. Fewer fish in a pond, on the other hand, will allow them to get bigger.

Some of the dozens of ponds at Ozark Fisheries, Martinsville, Friday, May 20, 2022, formerly known as Grassyfork Fisheries, breeds various types of small aquatic animals including koi and bullfrog tadpoles.
Some of the dozens of ponds at Ozark Fisheries, Martinsville, Friday, May 20, 2022, formerly known as Grassyfork Fisheries, breeds various types of small aquatic animals including koi and bullfrog tadpoles.

Once the fish are older, the workers also feed them a special formula of food that has one key difference from typical fish food: It sinks. That’s on purpose to keep the colorful fish away from the pond’s surface — where they look tasty to herons and eagles in the area — while they eat.

The farm goes through a lot of fish food, Cleveland said. The farm's millions of hungry, growing fish go through about a tractor-trailer full every other week.

It takes about 60 to 90 days before the fish come to sellable size, Cleveland said. That’s also the same timeframe when they start to develop their distinct coloring based on sunlight, water temperature and food.

“People don’t realize what it takes to raise them,” Wilson said, “but it’s a really neat process.”

From ponds to people's homes

After a few months, it’s time to harvest.

Workers donning waders — some knee-high and some chest-high, all seemingly part of the uniform to work there — will collect the fish from the ponds. They range from about four to six feet deep, and each pond has a number. Wilson knows many of them, but she admits not quite all. Her domain is the sorting and shipping, which comes a bit later in the process.

The fish’s journey comes full circle as they make their way back to large concrete tanks. There they are sorted based on size and the fish also begin to be transitioned from the natural creek water to well water.

Every step of the way, the fish are given a couple days to destress — Ozark tries to handle its fish as little as possible to keep them happy and healthy. Not only are the fish sorted for size, but they also are checked for defects in their fins, scales, coloring, etc.

Still, nothing is wasted, Wilson said. Those that aren’t worthy of aquariums are sold instead as bait or feeder fish. That’s not all that Ozark sells: They also have minnows, crayfish and bullfrog tadpoles with bodies the size of a whole walnut. Those animals naturally occur in the ponds, Wilson said, so the workers collect them, too.

Last year, Ozark hatched just over 100 million baby fish, Cleveland said. By the time it comes to harvesting, however, only about 25% of those fish have survived. That’s not unusual — they might be eaten by herons, snakes, turtles and other critters. Still, the farm is always trying to do what they can to help more fish survive.

“Humans have few offspring but high survival rate,” Cleveland said. “Fish are at the opposite end and have lots of babies in the hopes that just a few survive and pass on genetics.”

The fish are shipped out to a variety of different places including big pet chains, small mom-and-pop stores, carnivals and now through online pet partner sites, can dropship directly from their farm to individuals' homes.

Shipping has evolved significantly overtime. Decades ago, shipments went out in large metal cans via the railway. But Ozark then developed and patented a specific type of packaging and system that measures the size of box needed based on the number of fish, as well as how much water and oxygen are needed. This innovation allowed the fish to be shipped with airfreight, landing on customers’ doorsteps within just 24 to 48 hours.

They can ship as many as a couple hundred small fish or one fish as big as 18 inches in a single package. Anything bigger than that needs to be picked up, said Wilson, the packaging and shipping is her expertise.

It took Wilson six months to be able to touch a fish after she started working there. She’s been at Ozark for six years now. “But it took me a year and a half to touch a crayfish,” she said, “those were harder for me.”

Harvesting happens multiple times a year and the farm is shipping out fish year-round. While they drain some ponds in the wintertime, they keep others open and move fish around to consolidate them.

Despite the hundreds of ponds and millions of fish, the farm smells anything but fishy. The air was clean and crisp, almost a little sweet — reminiscent of a day spent on the river. And it was peaceful. The sounds of I-69 running along part of the farm are quickly lost to the rippling sounds of the creek running through the acres of ponds.

Aquaculture in Indiana is changing

While Ozark may be the oldest and one of the most well-known fish farms in the state, it certainly is not the only such farm.

“People don’t think about the aquaculture industry at all in Indiana,” Cleveland said, “because it’s an inland state.” But it’s actually happening more than most Hoosiers might think — there are four other small fish farms operating just around Martinsville.

Amy Shambach, an aquaculture specialist with Purdue University as well as the Illinois-Indiana Sea Grant, couldn’t agree more.

“Aquaculture has always been in Indiana and it’s a really diverse industry, both in the species that are raised and how farmers have raised them,” she said. “Some are doing emerging species in experimental ways and some are doing things tried-and-true.”

Ozark’s production method using earthen ponds and natural water flowing through is the most basic aquaculture technique and something that’s been seen throughout the U.S. for decades, Shambach said. On the other side, Indiana has some of the most advanced aquaculture practices within its borders, too.

An indoor farm in northeast Indiana grows the country’s first bio-engineered salmon. And a farm in central Indiana that started by raising largemouth bass outdoors added a new indoor facility in recent years to grow barramundi indoors. An Australian fish, the barramundi require a warm, climate-controlled environment.

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In addition to these food fish, Indiana also has farmers growing other fish primarily for game-fishing and others for bait.

Throughout its long history, the aquaculture industry has continued to evolve over time, Shambach said.

“It has changed as technology has become available and as farmers’ interests have changed and also as markets have changed,” she said. “Some farms have expanded, some farms have come and gone and then seeing new species brought in.”

Shrimp in the Midwest is relatively new, as well as the salmon and barramundi. She sees aquaculture as a growing industry in the state and a new pathway that farmers can take — especially with the advent of indoor recirculating technologies that let farmers create the exact environment certain species need.

There are lot of different names for someone who works in aquaculture, Shambach said: “Aquaculturist, fish culturist, fish farmer — those are the top ones that come to mind. But my favorite is water farmer — I’m not farming soil, I’m farming water.”

With Ozark’s longevity, Cleveland said there aren’t as many fish farms as their used to be. Still, she loves telling people what she does and filling in the occupation line on paperwork.

“I enjoy the uniqueness of it and the fact my great grandfather had a passion for fish and was able to make something out of that,” she said, “and now my family keeps it going.”

Call IndyStar reporter Sarah Bowman at 317-444-6129 or email at Follow her on Twitter and Facebook: @IndyStarSarah. Connect with IndyStar’s environmental reporters: Join The Scrub on Facebook.

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This article originally appeared on Indianapolis Star: Grown IN Indiana: Fish farm raises millions of goldfish, koi each year