Fish & Water
The topic of pond renovation on commercial catfish farms typically brings up a wide range of mixed feelings and opinions depending on the farmer. The majority of ponds in west Alabama and east Mississippi are watershed ponds instead of levee-style ponds, which are prevalent in the Mississippi Delta and Arkansas regions. While watershed ponds are typically deeper and produce more fish than levee style ponds, these ponds have several disadvantages. These include difficulties related to efficiently seining irregularly shaped deeper ponds and the inherent challenge and time associated with renovating a watershed pond. Farmers who choose to renovate a pond are faced with a situation in which it could be up to a year or more before the pond can be re-stocked with fingerlings. In addition to the actual cost of renovating a pond, there is a lost opportunity cost when that pond is not used to grow a crop of fish during a period of renovation. However, renovation has the potential of a long-term payoff due to smoother pond bottoms, better harvesting efficiency and decreased quantities of ‘big fish.’
In west Alabama, pond renovation is typically not a routine practice for many of the previously mentioned reasons. While there are certainly very real costs associated with pond renovation, there is also a price to pay for not renovating ponds.
It is widely accepted, both anecdotally and in the literature, that failure to renovate commercial aquaculture ponds can eventually lead to reduced yield over time. This is due to several different reasons that vary depending on each unique situation. Organic matter, fish waste, uneaten feed, and natural erosion of pond banks all contribute to the accumulation of excessive pond muck. The accumulation of pond bottom sediment can make it much more difficult to efficiently seine a pond as larger fish can often burrow into the muck and repeatedly avoid the seine. The accumulation of muck and sediment in large sections of the pond can eventually reduce pond depth.
Over time, paddlewheel aerators can create indentations in the bottom of ponds that serve as safe havens for fish, most notably larger fish, when the pond is seined. A reduction in pond depth results in less water volume in which to both grow fish and effectively maintain adequate levels of dissolved oxygen via aeration. Pond bottom sediments can serve as reservoirs for the accumulation of certain pathogens, including the virulent Aeromonas hydrophila, which can affect fish survival and overall production in a pond.
In 2021, the Fish Center is teaming up with Terry Hanson, an aquacultural economist at Auburn University, to develop partial enterprise budgets comparing net returns of catfish production from non-renovated ponds to those from renovated catfish ponds. This project is not grant-funded; however, there are many farms in west Alabama currently renovating or planning to renovate ponds. This presents an opportunity to capture some of this information while it is available and help the industry understand the benefits and costs of pond renovation. To collect this data, Alabama Extension’s aquaculture team plans to have Fish Center personnel meet one-on-one with eight to ten farmers to discuss pond renovation and collect cost and production data. Information gathered will be confidential, and the partial enterprise budget developed will be shared at the Alabama Catfish Conference in December 2021.
Researchers are also interested in tracking fish production in ponds before and after renovation to document improvements in yield following renovation. With this information, Fish Center personnel will be able to document current pond renovation costs and determine fish production levels needed to recoup the cost of renovating ponds.
This information will help farmers make decisions on whether to renovate their ponds or not. If you are currently renovating ponds (or have renovated ponds in the last two years) and are interested in participating in this study, contact Luke Roy at the Fish Center (334-624-4016; firstname.lastname@example.org).