The Joplin Globe, Joplin, MO

Local News

March 17, 2013

VIDEO: Reporter following growth, development of 60,000 fry at Roaring River

CASSVILLE, Mo. — It was time to see the 60,000 trout babies I’d helped spawn 29 days earlier. I felt like there should be a drum roll.

But the Roaring River State Park hatchery manager, Paul Spurgeon, unceremoniously unwraps the incubation tube through which spring water flowed, and gently sets aside the piece of black plastic that had been shielding them from light.

He has hatched enough trout — 250,000 per year for decades — that to him this is just part of the routine.

I, on the other hand, am excited. Since I joined hatchery personnel on Feb. 13 in helping to extract eggs from the female broodstock and milt from the males, and then fertilized them, I’ve thought of these potential trout often.

A quick peek when I dropped by the hatchery on March 1 for Opening Day of catch-and-keep trout season allowed me to happily check the first major milestone off of their development chart — they had eyes.

Now, 11 days later, I hope they have hatched. The stage they just completed was the most fragile of their life cycle; Brad Farwell, assistant hatchery manager, noted that any number of variables can negatively impact it.

I hold my breath and lean in to look.

“We have fish,” Farwell said with a smile.

Gone are the school-bus yellow eggs, replaced by translucent amber, half-inch long baby trout.

Spurgeon’s experienced glance at the tube tells him that about 60 percent of the eggs we’d fertilized had survived; the ones that did not were the pasta-colored eggs that remained in the tube, he explained.

“That’s an excellent mortality rate for this water temperature,” he said, happy with the results.

At this point the tiny trout are called “sac fry.” They are named for the sac of nutrients attached to their underside when they hatch.

That sac is like the yolk of an egg, Farwell explained. For the next 14 to 20 days, our sac fry will get their required nutrients only from their sacs, then scales and skin will grow around the sacs and the fish will be called just “fry.”

As Farwell cleans the long metal trough into which we plan to pour the sac fry, he explains that they will spend until the end of March in the trough, and the attention to cleanliness reduces the chance for deadly fungus to develop.

“This is the second most fragile stage of their development,” Farwell said.

My sac fry will have some company: In troughs nearby, three more incubator tubes hold approximately 200,000 trout eggs spawned at Shepherd of the Hills Hatchery last month.

“The state’s five hatcheries work hand-in-hand in the trout-rearing business,” Spurgeon said. “When one hatchery isn’t producing the numbers it needs, or when one has too many, we all share.”

In six indoor raceways, there are a few other neighbors, too: Fry that already have absorbed their sacs and are growing at a steady rate of one inch per month. There are, unbelievably, 80,000 of them.

Much more demanding than newborn human babies, hatchery personnel must feed the developing trout every hour. They use a complex feeding formula based on the percentage of body weight and the size of fish desired, which here is about 12 inches when it’s released into Roaring River.

“I try to feed them as much as I can while they’re inside so I can move them fast,” Farwell said.

The fish meal the hatchery crew uses to feed them is, in itself, a story: Fishermen off the coast of South America net a species of fish called menhaden, which are used to create the fishmeal. It comes to Roaring River by way of Utah, to the tune of 296,320 pounds last year.

It’s not cheap.

“Our food costs have doubled in the last five years,” Spurgeon said. “Our budget is $180,000 for food.”

Using about 1,000 pounds a day at his hatchery, that figure isn’t surprising. But with that food comes an obvious side effect by way of the trouts’ digestive tract: waste.

Three or four times a day, the crew comes in to clean the waste and excess feed out of each metal trough and concrete raceway.

Beyond keeping the trout alive, the goal is to continually make space for others in an assembly line-style production. As trout grow, hatchery personnel thin them by dividing one group housed in one raceway to two groups in two raceways — 8,000 becomes 4,000, and then 4,000 becomes 2,000, and so on.

By late April, the hatchery’s inside raceways will be at maximum capacity. As soon as my trout hit three inches, probably by late May or early June, they will be moved to the outdoor raceways.

Next year at this time, the trout I spawned will be in the river. I consider that as I walk to my car and see anglers dotting the banks, a few already with trout on their stringers.

My trout might end up on a hook, then down at the cleaning station and eventually on a plate. I am an angler who comes here often — perhaps it will be my own.

I am OK with that, though. We joked when I fertilized them that we’d need to come up with 60,000 names. We joked when we unveiled the incubator tube that a few of them had my eyes. But of course they aren’t my offspring.

They are the reason, mostly, that 100,000 people visit Roaring River State Park each year, and have been since 1928.

Keeping tabs

Andra plans to help net her trout to transport them to the outdoor raceways as the summer season gets under way at Roaring River State Park. There, visitors to the park can help the hatchery crew feed them as the trout grow to the desired 12 inches.

 

1
Text Only
Local News
Must Read
Sports
Photos


Facebook
Poll

Missouri's sales tax-free weekend begins Friday. Do you plan purchases around this weekend?

A. Yes.
B. No.
     View Results
Opinion
Twitter Updates
Follow us on twitter