Browsing by Author "Childress, U. R."
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Item Analysis of Forage and Predator Species - Oyster and Fisheries Investigations of Area M-5(Texas Game and Fish Commission, 1960-05-31) Childress, U. R.Objectives: To investigate the life histories and interrelationships of food, game, and forage fish in the San Antonio Bay area.Item Analysis of Forage and Predator Species Relationships - Oyster and Fisheries Investigations of Area M-5(Texas Game and Fish Commission Marine Laboratory, 1962) Childress, U. R.During this study period, ten species of vertebrates not collected in previous surveys were identified. About 725 fish, mostly Cynoscion nebulosys, were tagged and released. Twelve of these were returned. The returns indicate a general eastward movement of C. nebulosus during the winter months. The species of forage fish studied were abundant throughout the year of the study. This is possibly due to the very warm winter. The blue crab population decreased, probably due to increased fishing pressure.Item Construction of an Artificial Oyster Reef - Oyster and Fisheries Investigations of Area M-5(Texas Game and Fish Commission Marine Laboratory, 1961) Childress, U. R.Objectives: To build an experimental oyster reef in an area suitable for oyster production but where no natural reef exists at present. The artificial reef was built to supplement production and to check desirability of freshly opened shell as a reef building material and spat collector.Item Coordination of the Blue Crab Studies of the Texas Coast - Studies of the Blue Crab Populations of the Texas Coast(Texas Game and Fish Commission Marine Laboratory, 1963) Childress, U. R.; Texas Game and Fish Commission Marine Fisheries Project Reports 1961-1962This report is compiled from a total of 1307 samples. Of these 878 were trawl samples, 151 trammel or gill net samples and 278 seine samples. A total of 11,097 blue crabs were taken in these samples during the study period. There were 5,680 males (51.185%) and 5417 females (48.814%). Twice monthly sampling of blue crabs in the Texas Bays in 1961 and 1962 confirms there are at least three waves of juvenile blue crabs spawned and possibly more are indicated in some areas. Growth rates ranged from 10.1 mm per month to 16.2 mm per month with an average monthly growth rate of 13.1 mm for the year. A peak abundance was found from April to June with a lesser upper peak on the upper coast in November which was not present on the lower coast.Item Hydrographic and Climatological Data - San Antonio and Espiritu Santo Bays - Oyster and Fisheries Investigations of Area M-5(Texas Game and Fish Commission Marine Laboratory, 1961) Childress, U. R.The period of study covered a major flood in the area. San Antonio Bay had below normal salinities throughout this study period. At the same time water temperatures were above normal during the winter months sue to a mild winter. Turbidity was high through most of this time due to river water influx. The total precipitation for the year of this study was 77.37 inches. This is above normal.Item Hydrographic and Climatological Data - San Antonio and Espiritu Santo Bays - Oyster and Fishery Investigations of Area M-5(Texas Game and Fish Commission, 1960-09-27) Childress, U. R.Objectives: To maintain records of hydrographic and climatological conditions as an aid in evaluating ecological changes in the bay system.Item Hydrographic and Meteorological Study of the San Antonio Bay System - Analysis of Populations of Sports and Commercial Fin-Fish and of Factors Which Affect These Populations in the Coastal Bays of Texas(Texas Parks and Wildlife Department, 1964) Childress, U. R.Air temperatures from a monthly average low of 8 degrees C. in January to a high monthly average of 30 degrees C. in late August. Precipitation was below normal, averaging slightly over 1-inch per month. Two high months were June and November with 6.76 and 6.56 inches. Wind velocities were higher than in 1962, averaging 25-30 miles per hour in March, April, May, and June. During this same period in 1962 they averaged 12-18 miles per hour. Salinities were higher than in 1962. Range was 20 to over 40 parts per thousand, with the average being slightly over 30 parts per thousand. Water temperatures ranged from 8 degrees C. to over 30 degrees C., about the same as in 1962. Turbidities ranged above 50 parts per thousand in San Antonio Bay, and below 50 parts per thousand in Espiritu Santo Bay. River discharge for the period October 1962 to September 1963 was 550,900 acre-feet. This is below the year October 1961 to September 1962 when 932,500 acre-feet were discharged. These are both below the 28-year average of 1,527,900 acre-feet per year.Item Hydrographic and Meteorological Study of the San Antonio Bay System - Analysis of Populations of Sports and Commercial Fin-fish and of Factors which Affect these Populations in the Coastal Bays of Texas(Texas Game and Fish Commission Marine Laboratory, 1963) Childress, U. R.Water temperatures dropped to a low of 2 degrees Centigrade in mid-January, 1962. Then a steady temperature increase brought them to slightly above normal during July, August, and September, 1962. Salinities were about 14.5 parts per thousand at the start of this study and gradually increased to about 25 parts per thousand at the end of the study. Rainfall and riverflow were below normal for the study period. The below normal rainfall and river flow allowed the area to have fairly clear waters during the study, with 50 to 75 ppt turbidity being normal for the bay complex.Item Hydrographic and Meteorological Study of the San Antonio Bay System - Analysis of Populations of Sports and Commercial Fin-Fish and of Factors Which Affect These Populations in the Coastal Bays of Texas(Texas Parks and Wildlife Department, 1965) Childress, U. R.Air temperature ranged from 10.2 degrees C. in February to 29.5 degrees C. in August. Rainfall averaged 3.4 inches per month. September was the month of highest rainfall with 8.33 inches. Wind velocity was highest in spring and summer, ranging from 15 to 50 miles per hour at various times. Complete river flow data for the year were not available. Salinity averages ranged from 20 to 40 ppt in 1963. In 1964 salinities ranged from 18 to 30 ppt. Water temperature averages varied from a low of 10.6 degrees C. in January to a high of 32 degrees C. in September. Turbidities ranged from 25 to 250 ppm (parts per million). There are approximately 19.9 square miles of juvenile fish and crab nursery area in San Antonio Bay, plus 27 square miles of shrimp nursery area for a total of 46.9 square miles (approximately 30,000 acres). There are 37 square miles (23,680 acres) in Espiritu Santo Bay. Area habitat changes were mostly due to dredging operations. These dredging operations consisted of oil well locations, channel dredging, and mud shell dredging.Item Inventory of Macrofloral Forms Present and Utilization by Other Marine Forms - Oyster and Fisheries Investigations of Area M-5(Texas Game and Fish Commission Marine Laboratory, 1961) Childress, U. R.Objectives: To collect and identify the macroflora of the area. Determine species present and distribution of species. Evaluate ecological importance to area.Item Investigation into Levels of Concentration, Seasonal Variations, and Source of Pesticide Toxicants in Some Species from Selected Bay Areas(Texas Parks and Wildlife Department, 1966) Childress, U. R.; Texas Parks & Wildlife Coastal Fisheries Project Reports 1966Data presented in this paper indicate chronic pesticide levels present in oyster (Crassostrea virginica) tissue from all Texas bay areas sampled, including Galveston Bay. Random samples of fish and bird tissue show the scope of contamination is much greater than first suspected. These data indicate only the degree and sequence of pollution in specific areas. The need is shown for (1) an intensified investigation of persistant pesticides present in streams entering the areas sampled and (2) the effects of chronic levels of pesticide toxicants on the marine environment.Item Population Studies of the Blue Crabs of Espiritu Santo-San Antonio Bay System - Studies of the Blue Crab Populations of the Texas Coast(Texas Game and Fish Commission Marine Laboratory, 1963) Childress, U. R.Blue crab sample catches ranged in abundance from 14.2 per sample in September 1961 to 1.4 per sample in December 1962. Comparison of male and female catches indicate that female crabs were slightly more abundant throughout the study period. Shrimp trawls produced the most consistent catches of all the types of sampling gear used. Samplings indicate central San Antonio Bay has the most consistent population of any area sampled in San Antonio and Espiritu Santo Bays. Blue crab modes are fairly close in size from station to station most months of the study.Item Population Studies of the Blue Crabs of the San Antonio-Espiritu Santo Bay System - Studies of the Blue Crab Populations of the Texas Coast(Texas Parks and Wildlife Department, 1964) Childress, U. R.Trawls and trammel nets were the sample devices that caught enough Blue Crabs (Callinectes sapidus) for comparison studies. Trawls caught best February through June, and trammel nets, May through November. Most crabs taken by trawl were caught at station in low salinity areas. Trammel net catches were best in an area located between San Antonio and Espiritu Santo Bays. Abundance in samples ranged from 8.7 crabs (all sizes) per sample to 1.9 crabs per sample. A general downward trend in crab abundance appeared in 1963. Sample catches were composed of 54.8 per cent males and 45.2 per cent females. A total of 149 crabs were tagged and released. There were 80 males and 69 females tagged. Only one tag was returned, but no catch information was received. Commercial production decreased from 877,000 pounds in 1962 to 509,000 pounds in 1963.Item Population Studies of the Blue Crabs of the San Antonio-Espiritu Santo Bay System-Studies of the Blue Crab Populations of the Texas Coast(Texas Parks and Wildlife Department, 1965) Childress, U. R.Waves of juvenile blue crabs, Callinectes sapidus, were detected in March and August while the availability of crabs at sampling stations was largest in March and December. Three blue crabs were found infected with the parasite, Loxothylacus texanus.Item Population Studies of the Sports and Commercial Fin-Fish and Forage Species of the San Antonio Bay System - Analysis of Populations of Sports and Commercial Fin-Fish and of Factors Which Affect These Populations in the Coastal Bays of Texas(Texas Parks and Wildlife Department, 1964) Childress, U. R.In 1963, trammel nets used to sample adult game fish caught an average of 2.5 pounds per acre compared to 4.8 pounds per acre in 1962. Redfish were caught at only two stations. Peak months of abundance were September and November. In 1963, 86.3 pounds were caught as compared to 434.9 pounds in 1962. The catch per effort also declined. Speckled trout were taken at all stations. There were found most abundant in May through November. The total catch was up slightly, from the 1962 total of 117.6 pounds, to a total of 130.1 pounds in 1963. The catch per effort, however, declined sharply. Drum were taken at all stations. Peak catch months were March and November. Catch was up from 120.3 pounds in 1962 to 144.6 pounds in 1963. Flounder were caught at Stations 1, 2, and 4. The peak month of catch was July. Total catch for the year was 11.8 pounds, compared to 7.3 pounds in 1962. This catch per effort also declined sharply. Average monthly catch, all species, varied from 1.0 pounds per acre to 3.9 pounds per acre. Only 22 juvenile game fish were taken, and 14 of these were speckled trout. In 1962, 88 juvenile game fish were taken. The total poundage of forage species caught was considerably less than in 1962. Significant numbers were taken at only four stations. Those stations located in Espiritu Santo Bay did not yield appreciable numbers. A total of 646 fish were tagged and released. There were 13 tags returned. This compares to 360 fish tagged in 1962, and 20 returns.Item Population Studies of the Sports and Commercial Fin-fish and Forage Species of the San Antonio Bay System - Analysis of Populations of Sports and Commercial Fin-fish and of Factors which Affect these Populations in the Coastal Bays of Texas(Texas Game and Fish Commission Marine Laboratory, 1963) Childress, U. R.Fish sampling data seems to indicate a decrease in numbers of Speckled Trout during the study period with an accompanying increase of Redfish and Black Drum. Flounder appear to remain unchanged in population density. A total of 399 fish were tagged during the study period. Numbers of each species tagged were 52 Speckled Trout, 214 Redfish, 119 Black Drum, and 14 Flounder. There were 20 tag returns. The two most abundant of the forage species were croaker and anchovies.Item Population Studies of the Sports and Commercial Fin-Fish of the San Antonio Bay System - Analysis of Population of Sports and Commercial Fin-Fish and of Factors Which Affect These Populations in the Coastal Bays of Texas(Texas Parks and Wildlife Department, 1965) Childress, U. R.In 1964 the catch of juvenile game fish remained small, though greater than that of 1963. Adult game fish samples indicated that an average population of 0.75 pounds per acre of trout, Cynoscion nebulosus, 0.36 pounds per acre of redfish, Sciaenops ocellata, and 0.39 pounds per acre of drum, Pogonias cromis, existed in the area in 1964. Flounder, Paralichthys lethostigma, were caught in insignificant numbers. A total of 341 fish was tagged and 24 tags were returned. Commercial production of trout, redfish, drum, and flounder was 397,867 pounds.Item Populations of Juvenile Shrimp in the San Antonio Bay Complex - Study of Texas Shrimp Populations(Texas Game and Fish Commission Marine Laboratory, 1963) Childress, U. R.Sampling methods and stations were changed from previous study periods, and now conform with a standard method for the Texas coastal bays. Sampling stations were reduced from 14 to 6. This includes 2 primary bay stations, 2 secondary bay stations, and 2 tertiary bay stations. These sampling stations were derived from previous years sampling as being the best to show populations and consistent presence of shrimp over a long period of time. Brown shrimp were present in the area about 15 days earlier than in the two previous years; also they remained in this bay complex over a greater period of time than in the 2 previous years. They were present in both quantity and size suitable for commercial bait production from May through December 1962. White shrimp in samples were less abundant than in the two years previous to this study. However, production was not as low as may have been expected with the high salinities which prevailed from late June through the end of the study period. White shrimp (juvenile) appeared in this area in appreciable quantities almost one month later than in 1960 and 1961.Item Preliminary Survey of Oyster Bottoms in San Antonio and Espiritu Santo Bays - Oyster and Fisheries Investigations of Area M-5(Texas Game and Fish Commission, 1960-05-31) Childress, U. R.Objective: To map oyster producting areas with favorable conditions for oysters.Item Study of Oyster Growth and Population Structure in San Antonio and Espiritu Santo Bays - Survey of Oyster Populations and Associated Organisms(Texas Game and Fish Commission Marine Laboratory, 1963) Childress, U. R.The number of market oysters present in this area at the start of the study period in September 1961 was very low due to a flood in June 1961, that killed a large percentage of the oysters of the area. This condition gradually improved throughout the study period, but still only small amounts of commercial production had been observed in the area when the study period ended in December 1962. Spat set in the summer and fall of 1962 repopulated the area and the oysters have shown rapid growth. Without further natural mortality in the San Antonio Bay system oyster production during the 1963-1964 oyster season could approach the 1959-1960 peak. Harvesting of under legal size oysters in Espiritu Santo Bay caused a heavy reduction of oysters in this bay, and no commercial production occurred during the September through December portion of the 1962-1963 season from this bay.