“Coffee shop” talk often includes two or more farmers comparing their daily catch from crawfish ponds or sharing their predictions for future production and markets. Although many listeners of this banter may take these comparisons at face value, one should not read too much into comparisons without taking into account the type of production system employed for the production of crawfish. Production strategy governs to a large extent the level of expectation, how ponds perform under normal conditions and how ponds may respond in times of adverse weather patterns.
As most people living in the south know, crawfish thrive in the abundant back-water habitat of the Mississippi River floodplain. Sustained periods of river overflow permit crawfish to feed, grow, and mature. Temporary dewatering of the habitat promotes aeration of the bottom sediments, reduces abundance of aquatic predators, and allow for establishment of vegetation, which serves as cover for crawfish and food resources when flooded. Crawfish survive the dry intervals by digging or retreating to burrows where they can avoid predators and acquire the moisture necessary for survival. Crawfish have also adapted to reproduce within the protection of the burrow.
The methods used to farm crawfish are based on little more than limited control of the environmental conditions from which these animals have evolved in natural habitats. Flooding and draining of ponds mimic natural cycles, albeit the control achieved with aquaculture provides for a bit more control over some of the variables. There are three basic strategies for culturing crawfish. One main strategy is termed single-crop production, or crawfish monocropping. In this approach, crawfish is the sole crop harvested and production typically occurs in permanent ponds or in the same physical location for at least several production cycles.
Crawfish monocropping is often the production method of choice for small farms or where marginal lands are available and unsuited for other crops. Pond size and production input for this approach range from large impounded wetlands with little management to small intensively managed systems of less than 10 acres. The main advantage of a monocropping strategy is that producers can manage for maximum crawfish production without the various concerns associated when crawfish are rotated with other crops. Stocking is usually needed only in new ponds, when a pond has been idle for a year or more, or after extensive levee renovation. Subsequent crawfish crops rely on holdover broodstock from a previous cycle, so as long as a pond is in continuous production, the population is usually self propagating.
After the first year or two in continuous production, crawfish yields are typically higher in these systems than with the other strategies. Production is also usually more predictable and consistent from year to year with this strategy. Furthermore, because of a greater number of “holdover” crawfish, early reproduction, and early flood-up potential, these types of ponds usually start producing earlier and achieve a higher percentage of the annual yield earlier in the season. This is clearly an advantage because earlier harvests are almost always associated with higher prices and marketing advantages.
Although there are several advantages with the monoculture approach, disadvantages often include: (1) the need to construct ponds, whereas with rice/crawfish rotational cropping the established rice field serves the purpose; (2) cost must be amortized over one crop only; and (3) crawfish overcrowding frequently occurs after several annual cycles, particularly in the smaller ponds; therefore, yields become composed of small (stunted), low-priced crawfish that are difficult to market.
The other two main crawfish production strategies involve the integration of crawfish with a rice crop. The least popular strategy, and the most difficult to manage, is simply referred to as a rice-crawfish-rice rotation. This takes advantage of the seasonality of each crop to obtain two crops in one year. Rice is grown and harvested during the summer while crawfish are grown during autumn, winter, and early spring in the same field each year. As with monocropping systems, crawfish are only stocked initially – directly into the rice crop. Following grain harvest, the residual rice crop is reflooded and utilized to grow crawfish. Management practices are similar to those of a monocropping system with the exception of a shortened season to accommodate the establishment of the next rice crop. It is very difficult to obtain maximum yields in both crops under this strategy – usually one or both crops are compromised to some extent. When the crawfish yield is optimized, often at the expense of the rice crop, yields and predictability of production may be similar to monocropping systems.
Rice-crawfish-fallow or, more simply, a rice-crawfish field rotational system is the other cropping strategy involving rice and crawfish and comprises most of the acreage used to grow crawfish in Louisiana. As with the other rice-crawfish cropping system, crawfish follows the rice crop. However, the major difference in this cropping strategy when compared with rice-crawfish-rice is that under this production strategy, rice is not typically cultivated in the same field during consecutive years to aid in the control of diseases and weeds for maximum rice yield. Therefore, because the crawfish crop always follows rice production, crawfish production does not occur in the same physical location in consecutive years. The field rotational approach is based on sufficient land resources to allow staggered crops in different fields within a farm and is the preferred cropping system for the larger commercial rice farmers.
A major advantage of this approach is that both rice and crawfish can be more easily managed for optimal yield. Unlike with a rice-crawfish-rice approach, the crawfish season can also be effectively extended as late as necessary because there is no need to drain crawfish ponds early to plant rice. The rice crop would be planted in a nearby field. Crawfish yields under this management approach are not commonly as high as with monocropping systems, but with proper management and favorable weather patterns, yields can routinely be reasonable. Average crawfish size at harvest is often larger than with monocropping systems, and by rotating physical locations each year, overpopulation is rarely a problem.
Some disadvantages of the field rotational strategy compared with the other two production strategies are: (1) the need to restock every year; (2) low population densities are often common, sometimes resulting in low yields; (3) production from year to year is less predictable, probably as a result of inconsistent recruitment from introduced broodstock; and (4) frequently, the bulk of the harvest occurs late in the season when seasonal declines in prices are common and marketing is difficult because of abundant supply of crawfish (often exacerbated by the capture fishery).
Therefore, due to inherent differences in the various production strategies used for producing crawfish, one should not be surprised to learn that not all ponds yield the same, or that some ponds produce best earlier in the year while others produce better later, or even that some ponds produce large crawfish whereas others routinely produce smaller ones. Aside from typical differences associated with production strategy, production strategy may also explain why some ponds respond differently to unusual weather patterns.
For example, the unusual weather patterns during the latter half of 2005 may have hampered rice-crawfish field rotational systems more so than monocropping or even rice-crawfish-rice systems of production. Because field rotational systems typically have fewer broodstock, which are usually more synchronized in their reproductive cycle, a timely drought during the summer/fall could have had a greater negative impact on recruitment in those systems. A higher density monocropping system can “afford” to loose a greater percentage of its broodstock with less impact on subsequent production than a less dense field rotational system. Excessive flooding from the heavy rains of Hurricane Rita may have also generally impacted the crop rotation systems more due to the vast amount of vegetation decay that subsequently occurred; however, low lying monocropping systems, especially those that depend on surface waters, were equally impacted from poor water quality and fish introductions.
In conclusion, whether one is contemplating differences observed in crawfish ponds as normal occurrences or from unusual events, one has to take into consideration the type of production system employed and the nuances typically associated with those production approaches. In short, not all crawfish ponds are created equal and usually respond differently to different sets of conditions.
Originally published in Louisiana Farm & Ranch Magazine.