Effect of meteorological variables on crawfish harvest in Louisiana, USA

Abstract

This study examines the effect of meteorological variables, such as temperature, precipitation, cloud cover, and relative humidity on average monthly crawfish (Procambarus spp.) harvests at 6 research ponds located at the Aquaculture Research Station in Baton Rouge, Louisiana, USA, operated by the Louisiana State University Agricultural Center. Eight years (2006-2013) of harvest data were collected spanning February, March, and April of each year. Using multiple regression and model selection processes, the effect of meteorological variables was assessed at 3 different monthly lags (lag 0, 1, and 2) to determine which combination of variables best explained variance in average monthly crawfish pounds per trap (AMPT). The final model selected for lag 0 (adj-rsq = 0.73, p < 0.01), lag 1 (adj-rsq = 0.71, p < 0.01), and lag 2 (adj-rsq = 0.69, p < 0.01) generally included the same variables: monthly average low temperature, precipitation, and the preceding October/November precipitation (ON). Both monthly average low temperature and ON exhibited a statistically significant (p ≤ 0.05) positive effect on AMPT while controlling for other variables in the model, revealing the importance of warm temperatures and precipitation during October/November for crawfish harvests. Precipitation during the harvest month was not significant, but increased precipitation 1 and 2 mo before harvest significantly decreased AMPT. The number of hours with temperatures ≤0°C was also a significant variable negatively associated with AMPT 1 and 2 mo before harvest and, along with precipitation, could potentially be an early indicator for AMPT before harvests begin in southern Louisiana.