Population Studies of the Sports and Commercial Fin-Fish and Forage Species of the Aransas Bay System - Analysis of Populations of Sports and Commercial Fin-Fish and of Factors Which Affect These Populations in the Coastal Bays of Texas
Rough estimates of the numbers of juvenile redfish, Sciaenops ocellata, and trout, Cynoscion nebulosus, in the Aransas Bay system were 2,000,000 and 4,000,000, respectively. Juvenile drum, Pogonias cromis, flounder, Paralichthys lethostigma and sheepshead, Archosargus probatocephalus, were not taken in numbers great enough to allow population estimates. The weight per unit of effort for forage fish dropped 60.88 per cent in 20-foot trawl samples in 1962 as compared to 1961. Croaker, Micropogon undulatus, brown shrimp, Penaeus aztecus and white shrimp, Penaeus setiferus; items which made up the largest portion by weight of 1961 and 1962 catches decreased considerably in 20-foot trawl catches in 1962. The decrease in these species caused a drop in total catch in 1962. Where shrimp, by weight, composed 29.26 per cent of the 1961 catch, they accounted for only 8.86 per cent of th total catch in 1962. Ten-foot trawl samples showed a difference in percentage weight of shrimp between primary and secondary bays. In Aransas Bay, a primary bay, 14.6 per cent of the total catch was shrimp, while in Copano Bay, a secondary bay, shrimp comprised 26.51 per cent of the total catch. Seine samples averaged 11.17 pounds of forage fish per acre in tertiary Mission Bay. In the adult game fish program 3.8 per cent of all trout tagged were recovered. Drag seine samples indicated a population of 0.60 pounds of trout per acre. Because of the nature of trout and their habit of schooling in deep water and around reefs, it was felt that the sampling methods now employed are not adequate for trout. Redfish has a 15 per cent tag return in 1962. That was the only fihs which had sufficient tag return data to allow reliable population estimates. It was calculated that the redfish population of the Aransas Bay area was 918,000 fish weighing 1,735,000 pounds, while the limits, using Peterson's formula, were 892,000 tp 1,442,000 fsih weighing between 865,000 and 1,837,000 pounds. Drum, flounder and sheepshead tag returns were too meager to allow estimates at this time. However, the data indicated that game fish populations other than redfish were underfished. In 1962 there were 3.4 per cent tag returns for drum, 8.3 per cent for flounder and 0.5 per cent for sheepshead.