Day 11 - Wednesday
Aquaculture in Missouriby: Emily den Haan, Christine Littlejohn and Jocelyn Smith
On the way to our stop, we toured through the town of Joplin, Missouri where we saw the aftermath of the 2011 tornado that devastated parts of the town. We saw bare foundations of buildings and misshapen trees that had been damaged by the storm. It was evident that a great amount of work has been put into rebuilding the town by the amount of new homes and businesses in the area. This tour was followed by a four hour drive to the town of Poplar Bluff, MO where we met Paula Moore for lunch at Ryan's restaurant, which featured catfish in their buffet.
Paula Moore began fish farming with her father in 1979 after graduating from college with a major in biology. Her first ponds were on 20 acres of her father's land that was too poorly drained for grain production. Thirty-three years later, Paula and her family are farming 200 acres of water and grow largemouth bass, catfish, grass carp and minnows. Bass and catfish are marketed for human consumption while minnows are sold for the bait trade.
The Moore family farm is located on an aquifer that supplies groundwater to all of the ponds; ponds are not lined due to the silt loam and clay soil that prevents leaching. The soil and water interact differently in each pond requiring management practices specific to each pond. Pond floors are sloped from 3-4 ft. at the shallow end to 10-12 ft. at the deep end to ease the draining process. In the spring, fingerling or stocker fish are purchased from hatcheries for $1.25 per bass fingerling and $0.02 per inch for young catfish; each pond is stocked at a density of 3,500 fish per surface acre. Paula discovered that grass carp could be raised in a monoculture of rice plants in bar ditches (ponds beside rice fields) as these fish feed on rooted vegetation. Largemouth bass and catfish are fed a pelletized soybean-based ration once a day at a rate of 50-lb/surface acre using a broadcast feed spreader. As the fish grow, their rations are increased while still maintaining water quality. Paula heavily emphasized the importance of water quality for the fish with oxygen level being the critical measurement. Algae are a vital source of oxygen to the ponds, which are also constantly aerated using electric paddle wheels to increase oxygenation.
Oxygen levels are measured daily to ensure their concentration remains above 4 parts per million. If oxygen levels decline, emergency aeration takes place to prevent stress to the fish. When fish become stressed they are more susceptible to naturally occurring parasites or diseases; however these problems are usually minimal under the conditions and densities that Paula maintains. Predators such as egrets, blue herons, otters and snakes can sometimes be a problem and can only be controlled using scare tactics. Pesticides used by local grain producers can also cause injury to fishponds, therefore, careful application and good communication is crucial. Maintaining water quality through nutrient management is also important; lime and salt can be used to neutralize the byproducts of fish waste especially prior to overwintering. Fish are fed throughout the winter unless ice formation prevents this. Management practices such as these allow domesticated ponds to be populated at densities much higher than would be found in nature.
Once fish have reached market weight they are harvested by dip fishing where a net is used to capture the fish, weigh, and transfer them into oxygenated tanks on the back of flatbed trailers specialized for hauling live fish. The goal is to reach 80-90% marketable size at harvest and this is obtained by purchasing uniform stocker fish. While collected in nets they are sorted according to size; small fish are returned to the pond for continued growth while larger fish are removed for breeding stock or sport fishing.
The market price for live fish is determined by the customer; therefore the industry runs on a true supply and demand model. The major market for live fish is the Asian community in Toronto and large urban centres in the United States. Paula sells her fish to a wholesaler who then distributes to smaller retail fish markets. Although initially Paula grew catfish as her primary species, Asian countries have since flooded that market with lower production costs, especially compared to the rising grain and fuel expenses increasing production costs in the US. As a result, Paula now produces 50,000 lb of largemouth bass per year on 50 acres of water as this fish has become very popular among Asian consumers. Due to this high demand, live bass are priced at $5.50/lb while live catfish only bring in $0.85/lb. Paula has attempted to produce grass carp as well, but this market is currently suspended due to concerns surrounding the introduction of invasive carp species into the Great Lakes.
Aquaculture is a relatively new agricultural industry. One of the advantages of this fledgling industry is the small number of producers filling the demand thereby keeping prices relatively high; however there are also many challenges to the industry. The lack of production recommendations has resulted in costly trial and error by producers to determine best management practices. There are also bottlenecks to fish production such as limited stocker supplies and lengthy turnover limiting consistent supply. Basic research in fish production is greatly lacking including species specific management programs; several research opportunities exist in aquaculture to increase efficiency and management. Researchers are currently investigating the viability of crappy as a commercial fish species and their adaptation to pelletized feed. In order to open the Canadian border to grass carp and expand that market, research is needed on the risk of Asian carp species within the Great Lakes ecosystem.
Aquaculture is a sector that many of the students were not familiar with making this a very informative stop. Unfortunately, due to a storm, we spent most of the stop on the bus and weren't able to tour the facilities completely. Nonetheless, it was interesting to discuss a new production sector of agriculture where markets are yet to be fully developed and research is in high demand.