Life history and susceptibility of fishes in Galveston Bay, Texas to power-plant cooling-water operations

Abstract

Seasonal occurrence, abundance and susceptibility to cooling-water operations were determined for 89 species of fish occurring in intake and discharge canals of the P. H. Robinson Generating Station on Galveston Bay, Texas from February 1969 through March 1970. Biologic a l data were collected twice weekly from one revolving-screen station (sampled at 0700, 1500 and 2200 hr), 13 ichthyoplankton-net stations (six in the intake and seven in the discharge canal) and four trawl stations (two apiece in intake and discharge canals). Hydrological measurements including water temperature, dissolved oxygen, conductivity-salinity, pH, water velocity and discharge flow rate were taken simultaneous to biologial sampling. Six species including Gulf menhaden (Brevoortia patronus), bay anchovy (Anchoa mitchilli), sea catfish (Arius felis), sand seatrout (Cynoscion arenarius), spot (Leiostomus xanthurus) and Atlantic croaker (Micropogon undulates) compromised approximately 89% of the fish collected. Susceptibility of most species to cooling-water operations was dependent upon their life history, swimming ability, water temperature and current. Most young fishes entered the study area via a series of well-defined recruitment waves coinciding with noticeable drops in ambient water temperature during fall and winter. Intake-approach velocities averaging over 0.33 m/sec were instrumental in entrainment and impingement of small and/or weak-swimming individuals..