Browsing by Author "Johnson, Roy B., Jr."
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Item Ecological Changes Associated with the Industrialization of Cedar Bayou and Trinity Bay, Texas(Texas Parks and Wildlife Department, 1974) Johnson, Roy B., Jr.;Cedar Bayou (a tributary of Galveston Bay) and Trinity Bay were studied before and after construction and operation of two industries. Cedar Bayou is the discharge site for U.S. Steel Company, and the intake site for Houston Lighting and Power Company's Cedar Bayou Generating Station. Trinity Bay, near Point Barrow, is the discharge site for thermal effluents from the power plant. Intake and discharge canals and channels, and a 1,052.2 hectare cooling pond were built in the study area. Water was circulated for cooling at the power plant for the first time in September 1970, reversing flow in the lower 12.9 kilometers of Cedar Bayou. Thermal effluents were discharged for the first time in November 1970 when electrical power generation was begun.Item Effects of Engineering Projects on the Ecology of Jones Bay - Effects of Engineering Projects on Galveston Bay Estuaries - Evaluation of the Effects of Estuarine Engineering Projects(Texas Parks and Wildlife Department, 1966) Johnson, Roy B., Jr.; Texas Parks & Wildlife Coastal Fisheries Project Reports 1966In 1962 construction was begun on the Texas City and Vicinity Hurricane- Flood Protection Project, a program of the U.S. Corps of Engineers, which provided for a 16.2 mile long earthen seawall along the western shoreline of Galveston Bay. This levee, with a maximum height of 23 feet above sea level, was designed to protect low areas from tidal flooding during storms. In 1964, the Hitchcock Extension of the Hurricane-Flood Protection was proposed, a plan consisting of an 11.4 mile levee to protect the city of Hitchcock and vicinity. A portion of this levee crosses Jones Bay. Circulation in the bay would be provided by a closable tidal structure and culvert openings.Item Effects of Engineering Projects on the Ecology of Moses Lake - Effects of Engineering Projects on Galveston Bay Estuaries(Texas Parks and Wildlife Department, 1966) Johnson, Roy B., Jr.; Texas Parks & Wildlife Coastal Fisheries Project Reports 1966In 1964, preliminary work was completed on a portion of the Hurricane Protection Levee which crossd the mouth of Moses Lake, a protected estuary of the Galveston Bay System. During the three year period from 1964-67 this portion of the Hurricane levee remained incomplete, as a closable tide control and navigation structure has been under construction. During this period, exchange of water between Galveston Bay and Moses Lake has been through a temporary ditch, 155 feet wide and 10-12 feet deep, which was reduced to 35 feet in width in October 1966 after the ditch was closed up during a storm threat. Final procedures in construction will be the opening of the tide structure, and shaping and sodding of the levee.Item A study of Texas shrimp populations, 1975(Texas Parks and Wildlife Department, 1975) Johnson, Roy B., Jr.; Coastal Fisheries project reportsDuring April-May 1975 brown shrimp (Penaeus aztecus) were sampled with bar seines and otter trawls at designated stations in Galveston, Matagorda, Aransas and Lower Laguna Madre Bays to determine shrimp growth rates and time of bay-to-Gulf migration. Although small groups of brown shrimp emigrated from Aransas Bay to Lower Laguna Madre in April and May, the mass migration of shrimp was late. The 1 June starting date of the closed Gulf season was retained. Estimated growth rates were 1.5 mm per day in Galveston and Matagorda Bays and 0.9-1.1 mm per day in Laguna Madre. During June-October 1975 white shrimp (P. setiferus) and brown shrimp were sampled with otter trawls to determine percentages of legal size shrimp on commercial shrimping grounds of Galveston, Matagorda and Aransas Bays. These percentages were fairly high (16-67%) near the 15 August opening of the bay season, and more than 10% were legal size through October. In Galveston Bay samples collected in late November and December contained less than 1% legal size shrimp. During 1973-75 less than 22.7 million kg of brown and white shrimp (heads-off) were landed annually at Texas ports, compared with the record 28.1 million kg in 1967. In 1975 financial problems with the shrimp industry and low shrimp densities contributed to low landings. Floods lowered the salinity to less than 5 o/oo in parts of Matagorda and Galveston Bays during April-May, reducing the amount of nursery area available to brown shrimp on the upper coast.Item A study of Texas shrimp populations, 1976(Texas Parks and Wildlife Department, 1976) Johnson, Roy B., Jr.; Coastal Fisheries project reportsBrown shrimp, Penaeus aztecus, were sampled in March, April and May 1976 in selected bays to determine growth rates of immature shrimp and to estimate the time of bay - to - Gulf migrations. Hydrological conditions in sampled bays were excellent for brown shrimp growth and survival. Temperatures after 1 April were >/= 20 C and salinities in most nursery areas were > 15.0 o/oo. In March, post - larvae and juvenile shrimp in Galveston Bay grew 0.5 to 1.4 mm/day. In April and May, growth rates were 1.5 to 1.6 mm/day in Galveston Bay, 2.0 mm/day in Matagorda Bay, 1.7 mm/day in Aransas Bay and 0.9 to 1.4 mm/day in the lower Laguna Madre. Based on rapid growth rates and strength of early 1976 brown shrimp waves, an early starting date (17 May) of the closed Gulf shrimp season was set. The season was closed 60 days to allow a portion of brown shrimp to reach marketable size before harvest.