MidWest Tour Day 11

Mt. Vernon and Poplar Bluff, Missouri...

One fish, two fish, Alligator Gar fish and some new fish

Chesapeake Fish Hatchery and Otter Slough Conservation Area

Written by: Renee Debruyn, Julie French, Aaron McKay, and Ashley Paul

map with days travel route, from Joplin to Poplar Bluff
Today’s total mileage: 484.4 km or 301 miles.


Diving right in… An Introduction

For our 11th day of the Midwest Crop tour, we focused our attention on fish and conservation. The theme of today’s learning was centered around fish production and conservation, as well as invasive species. Our first stop of the day was at Chesapeake Fish Hatchery in Mount Vernon, Missouri. We were taught about the process of hatching and growing fish used for stocking public lakes for sport fish restoration. We travelled for four hours, with a lunch stop at Ryan’s buffet, to Poplar Bluff, Missouri, home of the Otter Slough Missouri Conservation Authority. Here, we learned about conservation of wetland and wetland species, as well as the repercussions and control of invasive species.

Chesapeake Fish Hatchery…Something smells a little fishy around here

We left the hotel in Joplin, Missouri for the hour-long bus ride to Chesapeake Fish Hatchery at 7:00 am. Once there, we were greeted by Allison Leisenring, the technician #1 for fisheries. This is her fourth year working for the Missouri Department of Conservation. The Chesapeake Fish Hatchery is one of eight state-run hatcheries, 4 of which being warm water hatcheries like Chesapeake, and the other half being cold water hatcheries. Chesapeake Hatchery raises many different species of fish including bluegill, channel catfish, grass carp, hybrid sunfish, largemouth bass, walleye, and alligator gar. The hatchery takes up 40 acres of the 113 acres owned by the Department of Conservation. It has 13 1-acre ponds, 10 ½-acre ponds, a 3.8-acre solar pond, 12 7,875-gallon raceways and fish production rooms. The water is supplied by Chesapeake Spring, which has an average flow rate of 500-1,000 gallons of water per minute. However, if the spring is low, 2 wells provide an additional 450 gallons per minute each.  Yearly, there are 9 million fish produced, with 5 million fish stocked out to lakes annually. They only stock state impoundments, not providing stock to any private impoundments. The fish biologists must put their orders in for fish in the winter.

ponds and fish hatchery raceways
Some of the raceways (left and center) and the ponds (right) at Chesapeake Fish Hatchery.


There are plenty of fish in the sea…Fish breeding and production complexities

technician with multiple fiberglass tanks used to breed fish
Allison, our tour guide and technician, pictured with one of the fiberglass
tanks used to breed grass carp and walleye and for feed training of the largemouth bass.


Allison took us through their production room that had fiberglass and aluminum tanks. The fiberglass tanks are used for spawning of grass carp and walleye and feed training for the largemouth bass. The feed training happens over the period of a one to two months to convert the bass from zooplankton onto artificial feed to eventually hunt small fish. The bass are fed by an automated feed every 15 minutes. The water being brought in from the spring that isn’t filtered. The water leaving the facility either is pumped directly into the creek or into a pollution pond and a settling basin. There is an artificial manipulation of temperature for spawning, so the water goes through an evaporator before being pumped back into the stream to avoid disruption of the natural water ecosystem. Their breeding program is designed to produce the highest number of eggs possible. This time of the year is known as the growing out time, as there is no spawning going on. Spawning occurs at different times for each of the species, typically running from April until June. The aluminium tanks are for the catfish, with approximately 10,000 per tank. They grow the catfish in these tanks until they are about an inch long, stocking out in October. Warm water fish are raised in water temperature ranging from 50°F to 80°F. Fish production typically stops in November and starts up again in February, with most of the maintenance work being performed over the winter. Allison then had us all pack into the lab to look at the different production cycles they have for each fish species. The Chesapeake Fish Hatchery is the only hatchery in Missouri to spawn the Channel Catfish, and they send some of them to grow out at another hatchery. This is very different from other conventional animal agricultural systems, as the breeding protocol is unique to each species that the hatchery produces. Allison also discussed how walleye eggs are collected from the wild, where they lay an electric field to stun the fish to have better control of them. They inject the females with hCG to induce spawning and then harvest the eggs later. The eggs cannot get wet and need to be fertilized in the lab. This is quite different from other species like the largemouth bass, that spawn in tanks with males and females breeding naturally. The eggs are harvested out of the raceways after they have been laid. This really emphasizes the importance of having a good knowledge for the species that you are working with. Each fish species bred and produced here is very diverse and requires special care and attention to the breeding process. There is an advantage to having so much biodiversity of species within the hatchery. This allows the hatchery to be able to supply lakes with fish for people to sport fish, instead of overfishing natural ecosystems.


A little bait catches a large fish…Invasive species manipulation to control other invasive species

glass tubes containing fish embryos
One of the pictures Allison showed us depicting a fish embryo,
as she explained the difference between diploid and triploid eggs.


Allison discussed with us how the conservationists in Missouri have been demanding grass carp. Grass carp are not native to Missouri and are a type of Asian carp that are an invasive species. Hydrilla is an aquatic plant that is also an invasive species that has spread across Missouri. Grass carp naturally consume the hydrilla, making them useful in controlling the weed in the local ecosystems. However, given that grass carp are invasive in themselves, there needed to be a way to ensure they did not become a problem. The hatchery achieved this by creating sterile fish. After spawning, the eggs are harvested and taken to be put under hydrostatic pressurization. After 4 minutes of pressurization, the pressure stops the egg division, making the eggs 95-99% triploid. The triploid eggs are infertile and can therefore be put into the environment without fear of releasing a destructive invasive species into the environment. By using these species of fish to control the weed population, conservationists are manipulating the ecosystem to ensure the longevity of native plant species.


Fish are friends, not food…Fish nutrition and growth statistics not a huge concern…yet

feed room with bags of different sized feed
Allison answering questions about their feed regimen in the feed room,
showing us the different sized feed.


We took a look around the raceways at the alligator gar and around the ponds. We stopped to see the fish transportation trucks. We then went into the feed room and Allison talked a bit more about the nutrition of the fish. Typically, at fish production facilities, people are allowed to come and feed the fish. However, they are not allowed to at Chesapeake. The staff at Chesapeake formulate diets for each raceway or pond based on the species and the size of fish. The fish feed ranges in size from very finely ground feed to dog-kibble sized feed. Allison did mention that there is a lot of feed wastage, and they adjust for that by visually observing the amount of feed the fish are eating and adjusting the ration accordingly for the next feeding. They do not measure other data such as average daily gain of the fish, fish weights or feed to gain, they just feed the fish there. This is quite different from other animal production systems, like the beef industry, that can cater diets to the production of the animal. This may be an area for Chesapeake Hatchery to expand to in the future. 

We were given some reading material and thanked Allison for her time and enthusiasm before hopping on the bus destined for Poplar Bluffs. We stopped at Ryan’s Buffet for a filling lunch before continuing on to our next stop at Otter Slough conservation area.


Otter Slough Conservation Area…How about them alligator gar?

     At Otter Slough conservation area, Kevin Brunke and Salvador Mondragon spoke on the conservationist’s goals of protecting the area’s wild resources and the future of the conservation. Otter Slough manages 4,800 acres of which, 2,500 are floodable. This conservation is one of Missouri’s 15 intensive managed wetland areas. The main goal of this area is to provide the best possible habitat for waterfowl, fish and native trees and shrubs. In order to achieve this goal, intensive research and management strategies are required.


The study of everything conservation…Main goal is to have the best habitat to research and control species in

Missouri department of Conservation logo
The Missouri Department of Conservation’s logo.


Kevin and Salvador are both biologists at the conservation area. They were both quite interested in researching different species around the area. Currently, Salvador’s research project is devoted to the study of the alligator gar species and its effect on natural habitats. Conservation of native plant and animal species is one of the main goals of the conservation area. Otter Slough also has intensively managed wetlands, that allows waterfowl and shortbird populations to grow as they rapidly respond to wetland levels. They also have a program known as Moist Soil management, where they manage annual seed producing weeds and succession by disking. They manage many species on the conservation area by allowing controlled hunts. These hunting programs include Water fowl hunt programs, managed deer hunts and small game hunting. They also restrict hunting after the hour of 1:00pm and forbid the pooling of tag numbers. The conservation area is there to ensure that there is a plethora of native Missouri species that are able to grow and thrive in the area, without being outcompeted for resources by invasive species.  The restoration of Missouri’s natural wetlands via artificial manipulation of flooded land has increased the diversity of species, including the amount of transient birds in the area.


Making this place more like home…Restorative conservation efforts to resort back to native species

reclaimed flooded land now dry with new plant growth and mature trees
A previously flooded area, now dried up, demonstrating the ability
of the conservation area in manipulating the floodable land.


The wetlands at the Otter Slough conservation area are approximately 4,800 acres total and another 2,500 acres of floodable land. The conservation area uses wells to flood and water controls to mimic the natural environment for this area of Missouri. The conservation authority receives fish from hatcheries like Chesapeake each year to help restore the fish species within its ponds. It then controls invasive plants such as willows, lotus and spatterdock from spreading by controlling what time of the year they manually empty their ponds. This limits the amount of seeds that these invasive plant species are able to viably send out and grow in the emptied ponds, limiting future spreading of seeds. They aerate the ponds, pumping oxygen to help fish with higher oxygen needs. The US is also known for its population of feral hogs. The threat of feral hogs is very controlled, especially in this area. Feral hogs are an invasive species that are very destructive, with fast reproductive rates. The Otter Slough Conservation area has the goal to completely eradicate these animals from Missouri. The conservation efforts in conjunction with the restorative plans is keeping the area biodiverse and shows how much the Missouri area cares about the wildlife and surrounding habitat.


The stars of the show: The Alligator Gar…Restoring wetlands to preserve natural species

slide show map showing stocking locations for Alligator Gar
Salvador, a fish biologist, explaining how Alligator Gar are stocked
in rivers and other bodies of water around the United States.


The alligator gar, a native species to southern Missouri, that once was seen as a threat, is now making a re-emergence in wetland habitats. Alligator gar are an important figure in maintaining a biodiverse ecosystem. Alligator gar were originally targeted as they were viewed as a threat to popular game species like catfish and largemouth bass. Anglers started to recreationally bow-hunt these fish to remove the species. After some time, they realized that this was not necessarily correct information and that alligator gar are beneficial in many capacities. Alligator gar are especially useful in controlling invasive species, such as the Asian and silver carp. Currently, in controlled numbers, biologists are re-entering the alligator gar into ecosystems in attempts to control these invasive carp populations. This advancement in knowledge has allowed biologists to try to shift the ecosystem population by controlling the more dominant species and allowing some weaker species to survive.  Otter Slough works alongside other conservation areas and hatcheries to increase the alligator gar population. We saw the alligator gar they were raising to release and track at Chesapeake Hatchery earlier in the day. The alligator gar feed on the most abundant species available. This is key in helping control invasive species like the Asian carp. The alligator gars ability to concentrate its feeding habits promotes balance within fresh water ecosystems. A challenge with this species is there complex reproductive cycle. Male fish must be 7-8 years before becoming sexually mature, while the females take 10-11 years. Water levels are also essential within the spawning of these fish. The females will lay their eggs in flooded low areas, the males then fertilize their eggs. These eggs then attached to vegetation for 7 days before hatching. With current agricultural practices in the state of Missouri and extremely variant rainfall pattern and water levels, the area in which the alligator gar lay their eggs does not stay flooded for the 7 or more days required for the eggs to hatch. This limits the ability of the alligator gar to produce viable offspring. This is where the conservation areas and fish hatcheries have a major influence in being able to hatch and grow the alligator gar to release into the wild. They hold a key role in managing the biodiversity in these wetland habitats.

stock photo of alligator gar
A picture of an alligator gar sourced from https://www.littlestsimonsisland.com/blog/alligator-gar.


The Tail End… Conclusion

Overall, today was a day full of learning and information. Aquaculture is something that not many of us knew a lot about, therefore we took a lot away from today. Allison was very enthusiastic and was interested in teaching us about the concerns with the invasive plant, hydrilla. She also spoke to the effects of sterilizing grass carp, another invasive species, and letting it enter water to control the hydrilla. We learned about breeding techniques for different species of fish and the vast amount of knowledge required to breed fish. As well, we learned the difference between fish and many other livestock species is that they do not keep data on feeds to gain and continued monitoring of size like most livestock producers would. Later in the day, Salvador and Kevin told us that the main goal for the conservation area is to give the best habitat to research and control species, and that they as biologists are looking at restorative conservation. The conservation area is looking to restore original wetlands to preserve natural species of waterfowl and fish. We are very grateful to all of our hosts today and for all the insight they provided us with about the fish and wildlife conservation industry. All crop tour participants should have taken away a better respect for why conservation in Missouri, as well as around the world, is so vital and important to our ecosystems.