Browsing by Author "Schultz, Ronnee L."

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Hydrographic and Climatological Conditions in Aransas and Copano Bays - Fisheries Investigations in the Aransas-Copano Bay System
(Texas Game and Fish Commission Marine Laboratory, 1962) Schultz, Ronnee L.
The object of this study was to gather hydrographic and climatological data to aid in evaluating changes in flora and fauna.
Hydrographic and Meteological Study of 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
(Texas Game and Fish Commission Marine Laboratory, 1963) Schultz, Ronnee L.
Salinities in the Aransas Bay area increased in 1962 as compared to 1961. Aransas and Mesquite Bays reached salinity levels above 35 ppt in August and September of 1962. Copano Bay salinity averages were lower than Aransas and Mesquite Bays. Rainfall in 1962 was 61 per cent less than that measured in 1961. Water temperature in 1962 was similar in pattern to temperatures recorded in 1961, except for a low in January 1962, when a hard freeze occurred.
Hydrographic and Meteorological Study of 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
(Texas Parks and Wildlife Department, 1964) Schultz, Ronnee L.
Salinities in the Aransas Bay System were higher in 1963 than in 1962. Copano Bay salinities reached a high of 49 ppt in 1963 as compared to 32 ppt in 1962. Rainfall in 1963 was 15 per cent less than in 1962. Water temperatures in 1963 were of a pattern similar to years past. Although a freeze was recorded, in January of 1963, the lower water temperature reading recorded was 4.5 degrees C.
Hydrographic and Meteorological Study 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
(Texas Parks and Wildlife Department, 1965) Schultz, Ronnee L.
Bay salinities were lower in 1964 than in 1963. Water temperatures were lower in April 1964 than for the same period in 1963. Maximum and minimum salinity records for the Aransas Area in 1964 were 44.2 ppt for St. Charles Bay in September and 21.2 ppt for Mission Bay in December. The minimum recorded temperature of 9.9 degress C. occurred in Aransas Bay in January 1964. The maximum temperature of 35.5 degrees C. was recorded in Mission Bay in July.
Hydrographic Studies in Mesquite Bay and Cedar Bayou Pass - Fisheries Investigations in the Aransas-Copano Bay System
(Texas Game and Fish Commission Marine Laboratory, 1962) Schultz, Ronnee L.
Maximum and minimum water temperatures for the study period were 32.3 degrees Celsius and 10.8 degrees Celsius. Maximum and minimum salinities were 35.9 ppt and 0.4 ppt. The lowest temperatures were recorded during January, February and March. The highest rainfall occurred during September, October and November, which corresponds to the low salinities recorded in November. The greatest single factor affecting the salinity of Mesquite Bay is rainfall.
Hydrographic Survey of Aransas, Copano and Mesquite Bays - Fisheries Investigations in the Aransas-Copano Bay System
(Texas Game and Fish Commission Marine Laboratory, 1962) Schultz, Ronnee L.
Salinity was fairly stable in 1961 and averaged somewhat lower than during 1960. The bay water was found to be more turbid in the winter.
Population Studies of the Blue Crab Callinectes sapidus Rathbun in the Aransas Bay Area - Studies of the Blue Crab Populations of the Texas Coast
(Texas Parks and Wildlife Department, 1965) Schultz, Ronnee L.
In 1964 10-foot trawl samples, blue crabs (Callinectes sapidus) were 92 per cent less abundant than in 1961, while bar seine samples showed a 56 per cent decrease in abundance over 1962 figures. Bar seine samples in 1964 showed an increase in crab abundance by 25 per cent as compared to 1963. The decrease in crab landings since March 1962 may be contributed to a reduction of river flow and runoff which have induced higher salinities throughout the bay system.
Population Studies of the Blue Crab, Callinectes sapidus Rathbun, in the Aransas Bay System - Studies of the Blue Crab Populations of the Texas Coast
(Texas Parks and Wildlife Department, 1964) Schultz, Ronnee L.
In 1963, blue crabs were 80 per cent less abundant in 10-foot trawl samples than in 1961 and 15 per cent less abundant than in 1962. The sampling device best suited for sampling sub-adult crabs in 1963 was the bar-seine. The 60-foot seine was least selective in terms of size. Female crabs of sub-adult and adult sizes outnumbered males by 14 per cent and 9 per cent, respectively. Salinities have increased 75 per cent since 1961, and commercial crab landings have decreased 50 per cent.
Population Studies of the Blue Crab, Callinectes sapidus Rathbun, in the Aransas Bay System - Studies of the Blue Crab Populations of the Texas Coast
(Texas Game and Fish Commission Marine Laboratory, 1963) Schultz, Ronnee L.
Ten-foot trawl samples in 1962 has a lower crab catch by 65.6 per cent compared to 1960 figures. No data were gathered in 1961 as work was concentrated on habitat studies. Commercial crab production for three years starting in April 1960 averaged 1,451,240 pounds per year in the Aransas area. A total of 4,355,720 pounds of crabs were harvested commercially during those three years. Whether the crab fishery in Aransas Bay can be maintained cannot be ascertained at this time. When more records become available through more intensive sampling, it may be possible to predict the annual crab catch and predict a rise or fall in abundance.
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
(Texas Game and Fish Commission Marine Laboratory, 1963) Schultz, Ronnee L.
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.
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
(Texas Parks and Wildlife Department, 1964) Schultz, Ronnee L.
Juvenile trout, Cynoscion nebulosus, catch in 1963 was similar to that in 1962. A peak juvenile trout population of 9.7 million fish was calculated for September-November 1963, as compared to 8.8 million in 1962. Limited tag returns for adult trout indicated an annual fishing mortality of 5.9 per cent and "other losses" of 93.6 per cent. Adult trout population estimates were calculated from tag returns and by a catch per unit effort method. The results varied considerably. Juvenile redfish, Sciaenops ocellata, catch decreased 96 per cent compared to 1962. A freeze in 1963 was thought to be one reason for this decrease. Tag return data for adult redfish show 26 per cent return per year for three years. The adult redfish population, as computed by the area density method, was estimated to be 480,000 fish compared to the 1962 estimate of 918,000 fish. Per cent tag returns indicated a population of about 900,000 fish. The annual fishing mortality for redfish was estimated to be 25.8 per cent. The estimated drum, Pogonias cromis, population was 1 million pounds for 1963. An annual fishing mortality of 6.8 per cent was calculated for drum while other losses were estimated to be 45.7 per cent. The sheepshead population was estimated to be about 1 million pounds. There was a 75 per cent decrease in catch per unit effort for forage fish species in 1963 compared to 1961. Salinities increased 80 per cent. Croaker and menhaden catches reflected this increase in bay salinities by a decrease in abundance.
Population Studies of the Sports and Commercial Fin-Fish 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
(Texas Parks and Wildlife Department, 1965) Schultz, Ronnee L.
In 1963 the estimated population of juvenile trout, Cynoscion nebulosus, in nursery areas (waters less than 4 feet deep) of the Aransas Bay System was 9.7 million compared to 11.7 million in 1964. There was a 43 per cent increase in catch per unit effort for adult trout. Young of year redfish, Sciaenops ocellatus, collections were 24.7 per cent less than 1962 catches compared to a 96.0 per cent decline in 1963. A calculated average redfish juvenile population of 6.3 million fish was derived for 1964. The adult redfish catch per unit effort declined 14 per cent in 1964. Catches of drum, Pogonias cromis, in juvenile seine samples were very good in 1964, giving an average population estimate of 4.9 million. The adult drum population for 1964 was calculated as 1.1 million pounds. Juvenile sheepshead, Archosargus probatocephalus, had an average population of 3.3 million. The adult sheepshead population was calculated as approximately 680,000 pounds in 1964. Commercial landings in the Aransas Bay area declined. Biological catches in closed waters exceeded those in open waters and it is believed that the largest portion of the fish population was unavailable to commercial fishermen.
Study of Populations of Juvenile Shrimp in the Aransas Bay Complex - Study of the Texas Shrimp Populations
(Texas Parks and Wildlife Department, 1964) Schultz, Ronnee L.
White shrimp, Penaeus setiferus, landings were higher than catches in 1962 by 22 per cent. Brown shrimp, Penaeus aztecus, were most abundant in 10-foot trawl catch in April, May, and June when the shrimp were 60-90 mm long. In 1963, brown shrimp catches with the 6-foot bar seine and the 10-foot trawl were higher than in 1962. In 1963, fewer brown shrimp were caught in 20-foot trawl samples than in 1962. White shrimp increased in 20-foot trawl samples by 8 per cent. White shrimp also showed an increase in 6-foot bar seine samples in 1963. Rainfall was 15 per cent less than in 1962. there were two periods, one in June and one in September, when 5 and 6 inches of rain fell, respectively. Immediately after these periods of rain, juvenile white shrimp were taken in tertiary samples.
Study of Populations of Juvenile Shrimp in the Aransas Bay Complex - Study of the Texas Shrimp Populations
(Texas Game and Fish Commission Marine Laboratory, 1963) Schultz, Ronnee L.
Brown shrimp were 69.1 per cent less abundant in 10-foot trawl samples in 1962 than in 1961. White shrimp were 69.3 per cent less abundant. Twenty-foot trawl samples had 96.7 per cent less browns and 93.2 per cent less whites. There was 61 per cent less total rainfall in 1962 than in 1961. Bar seine samples in tertiary Mission Bay were void of white shrimp in 1962. Shrimp achieved a higher modal size in 1962 than in 1961. Commercial shrimp production in the Aransas Bay area increased 37.7 per cent for brown shrimp and dropped 86.2 per cent for white shrimp in 1962. It is difficult to compare commercial production to figures from this study because commercial landings reflect legal sized shrimp only. Higher salinities in Mission Bay caused habitat changes in 1962.
Study of the Hydrography and Meteorology of the Texas coast - 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) Schultz, Ronnee L.; Texas Parks & Wildlife Coastal Fisheries Project Report 1964
Each bay area along the Texas Coast is an entity with its own particular hydrographic problems. Tha Galveston, Matagorda and San Antonio Bay Systems have an average annual rainfall in excess of 25 inches, plus large river drainage systems which tend to maintain relatively low salinities. From Aransas Bay to the Laguna Madre, rainfall decreases to less than 20 inches and hypersalinity becomes a problem. Fisheries landings indicate that hydrographic conditions affect the productivity and abundance of shrimp, crab and some species of fish. During drought periods salinities become high and catches decline, while during periods of normal rainfall salinities become comparable to those of true estuarine systems and catches increase.
Survey and Inventory of the Vertebrate Species Present in Mesquite Bay and Cedar Bayou - Fisheries Investigations in the Aransas-Copano Bay System
(Texas Game and Fish Commission Marine Laboratory, 1962) Schultz, Ronnee L.
The major differences between vertebrate populations in Mesquite Bay before it was opened and after this occurred is the increased abundance of high salinity forms near the bay mouth. Such as Elops saurus, Oligoplites saurus, Vomer setipinnis, Selene vomer, and Hemicaranx amblyrhynchus, not previously found, were quite common during this period of study.
Survey of Adult Game and Food Fish - Fisheries Investigations in the Aransas-Copano Bay System
(Texas Game and Fish Commission Marine Laboratory, 1962) Schultz, Ronnee L.
Redfish, trout, drum, sheepshead, and flounder were captured with trammel nets, gill nets, seines, and hooks and lines. They were then tagged with monel maxillary tags or Peterson disc tags and released. Redfish yielded 14.65 per cent return; trout, 2.67 per cent; drum, 1.42 per cent; and sheepshead 1.30 per cent. Data were too meager to allow valid comparison between struck and pulled trammel nets or to allow computations of populations.
Survey of Commercially Important Shrimp in the Aransas-Copano Bay Area - Fisheries Investigations in the Aransas-Copano Bay Area
(Texas Game and Fish Commission Marine Laboratory, 1962) Schultz, Ronnee L.
Six stations in Aransas, Mesquite, Copano and Mission Bays were sampled semi-monthly with other trawls and bar seines. Results indicate that shrimp were far lass abundant in 1961 than in 1960. Peaks of abundance occurred prior to maximum model size. Salinity was higher in 1961 than in 1960 and may have affected shrimp populations.
Survey of Fish Present in Aransas and Copano Bays - Fisheries Investigations in the Aransas-Copano Bay Systems
(Texas Game and Fish Commission Marine Laboratory, 1962) Schultz, Ronnee L.
The most abundant fish caught in otter trawls was the croaker with a unit of effort catch of 19.7 fish. Next was the pinfish with 8.78. An abundant fish, the anchovy, had a unit of effort catch of 7.47, but due to the selectivity of the trawl this figure is invalid. A total of 88 species of fish was taken during the survey period. Few changes were noted in species composition in this survey and one reported by Gunter (1945). Some seasonal differences were noted and there was some variation caused by the use of different sampling techniques and stations.
Survey of Forage Fish - Fisheries Investigations in the Aransas-Copano Bay System
(Texas Game and Fish Commission Marine Laboratory, 1962) Schultz, Ronnee L.
It appears from this study that increases in the abundance of forage fish have occurred since 1960. A difference in seasonal peaks of abundance was noted in 1961. Cooler spring weather in 1961 is possibly a factor accounting for the later peaks that year. The efficiency of the twenty-foot otter trawl is believed to be greater than that of the ten-foot otter trawl by a factor larger than two.