Mesh Size Selectivity

Mesh Size Selectivity of Penaeid Shrimp in 6.1-m Shrimp Trawls, Galveston Bay, Texas

BILL BALBOA AND LANCE ROBINSON (Texas Parks & Wildlife Department,
Seabrook Marine Laboratory, P. O. Box 8, Seabrook, Texas 77586)

Since 1972 landings of large brown shrimp Penaeus aztecus have decreased with a subsequent increase in landings of small brown shrimp (above 67 count) on the Texas coast. The Texas parks and Wildlife Department, Coastal Fisheries Division initiated an evaluation of shrimp trawl mesh size selectivity as means to address a potential growth overfishing problem in the Texas bay shrimp fishery. Trawl mesh sizes of 35mm, 38mm, and 44mm were randomly paired and pulled simultaneously to allow for a comparative evaluation of shrimp catch between mesh sizes. Selection curves for white shrimp, Penaeus setiferus and brown shrimp, Penaeus aztecus were developed for each trawl mesh size. The effect of trawl mesh size and fall bay shrimp season (Aug. 15-Oct. 31) minimum shrimp size limit of 112mm TL (total length) was used to evaluate each selection curve. Approximate proportions of shrimp catch less than 112mm TL for brown shrimp in 35mm, 38mm, and 44mm trawl mesh respectively were, 90%, 85%, and 70%. Approximate proportions of shrimp catch less than 112mmn TL for white shrimp in 35mm, 38mm, and 44mm mesh respectively were 97%, 95%, and 37%.

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For More Information Contact:

Bill Balboa
Texas Chapter of the American Fisheries Society
Seabrook Marine Laboratory
P. O. Box 8, Seabrook, Texas 77586
Tel: 713-474-2811
Internet: lance.robinson@tpwd.state.tx.us