Mesh size selectivity study of Penaeid shrimp trawled from Galveston Bay, Texas.

Date

1985

Authors

Green, A.W.; Benefield, R.L.

Journal Title

Journal ISSN

Volume Title

Publisher

Abstract

The number and size of penaeid shrimp retained in trawls were found to be dependent upon the mesh size and twine size of the trawl. During the study, brown shrimp, Penaeus aztecus, were smaller (x=81.0 to 85.5 mm) than white shrimp, P. setiferus, (x=118.8 to 128.5mm). There were no significant differences in the total number of white shrimp caught by the different trawl mesh sizes. The larger mesh sizes resulted in significantly larger white shrimp being caught. Trawls with larger mesh sizes caught significantly fewer brown shrimp than did trawls with smaller mesh sizes; however, there was no significant difference among the mean size of shrimp caught. This suggested that when there was a wide range in the size of shrimp available, the larger mesh trawl caught larger shrimp without a decrease in the total number of white shrimp caught. When the shrimp were fairly uniform in size, trawls with larger meshes resulted in smaller total catches with no difference among the mean sizes of brown shrimp caught. Larger twines may change the effective mesh size; for example, a trawl made with number 12 twine having a stretched mesh of 47.6 mm may catch the same number and size of shrimp as a trawl made with number 9 twine having a stretched mesh of 44.5 mm. Towing trawls for relatively short periods affect the size of the shimp caught.

Description

p. 31-36.

Keywords

fishing gear; trawl nets; Penaeus aztecus; brown shrimp; Penaeus setiferus; white shrimp; penaeid shrimp; shrimp fisheries

Citation