Edward W. Bonn

Use Of A Trawl For Sampling Freshwater Impoundments In Texas

A study was undertaken to determi ne the value of a small otter trawl as a collection tool in 11 reservoirs in Northeast Texas. The collection unit consisted of four sets of 150-foot experimental gill nets, two drags with a 26-foot bag seine and two runs with a la-foot trawl. The seine and trawl collections were made both during the day and at night. Seining accounted for most of the 44 species of fish taken, while trawling produced the greatest number of specimens. Four species were taken only from gill nets, six only by seining and trawling added two exclusive species of fish to...


Effects Of Hydrogen Sulfide On Channel Catfish (Ictalurus Punctatus)

The natural production of sulfides is responsible for poor channel catfish production in many acid lakes in Northeast Texas. The TLm of un-ionized hydrogen sulfide for channel catfish fry ranged from 0.8 ppm at pH of 6.8 to 0.53 at pH 7.8. At pH 7.0 the TLm of this gas is 1.0 ppm for fingerling catfish, 1.3 for advanced fingerlings and 1.4 for adult channel catfish. Small fish were also killed quicker when exposed to these concentrations. Maximum concentrations of hydrogen sulfide are produced in the spring. Channel catfish populations can be maintained by continued stocking of adult fish...