A Pushnet for Quantitative Sampling of Shrimp in Shallow Estuaries

The shallow estuaries and bayous of the Gulf Coast are used extensively as nursery grounds by several species of commercially important shrimp. In our studies on the estuarine phase of the life cycles of Penaeus setiferus and Penaeus aztecus, sampling for post-larval and juvenile shrimp in the nursery areas presents a problem. The young shrimp tend to concentrate in areas of stiff salt-cord grass (Spartina alterniflora) where it is difficult to operate a beach seine efficiently. Strawn (1954) describes a one-man pushnet used in shallow water grass flats by Florida bait shrimp fishermen and demonstrates its superiority over a seine for collecting in rooted vegetation. However, the Florida-type net apparently operates most efficiently in submergent vegetation such as turtle grass (Thalassia testudinum), which is less rigid than the salt-cord grass. Moreover, it was considered possible that repeated sampling with this net could excessively alter or disturb the stations of limited size occurring in our study area. Finally, we felt that a satisfactory index of abundance, based on a standardized unit of effort, could not be obtained using the Florida net (DBO).