Size-composition of Annual Landings in the White Shrimp, Litopenaeus setiferus, Fishery of the Northern Gulf of Mexico, 1960–2006: Its Trend and Relationships with Other Fishery-dependent Variable

The potential for growth overfishing in the white shrimp, Litopenaeus setiferus, fishery of the northern Gulf of Mexico appears to have been of limited concern to Federal or state shrimp management entities, following the cataclysmic drop in white shrimp abundance in the 1940’s. As expected from surplus production theory, a decrease in size of shrimp in the annual landings accompanies increasing fishing effort, and can eventually reduce the value of the landings. Growth overfishing can exacerbate such decline in value of the annual landings. We characterize trends in size-composition of annual landings and other annual fishery-dependent variables in this fishery to determine relationships between selected pairs of these variables and to determine whether growth overfishing occurred during 1960–2006. Signs of growth overfishing were equivocal. For example, as nominal fishing effort increased, the initially upward, decelerating trend in annual yield approached a local maximum in the 1980’s. However, an accelerating upward trend in yield followed as effort continued to increase. Yield then reached its highest point in the time series in 2006, as nominal fishing effort declined due to exogenous factors outside the control of shrimp fishery managers. The quadratic relationship between annual yield and nominal fishing effort exhibited a local maximum of 5.24(107) pounds (≈ MSY) at a nominal fishing effort level of 1.38(105) days fished. However, annual yield showed a continuous increase with decrease in size of shrimp in the landings. Annual inflation-adjusted ex-vessel value of the landings peaked in 1989, preceded by a peak in annual inflation-adjusted ex-vessel value per pound (i.e. price) in 1983. Changes in size composition of shrimp landings and their economic effects should be included among guidelines for future management of this white shrim

The U.S. Gulf of Mexico Pink Shrimp, Farfantepenaeus duorarum, Fishery: 50 Years of Commercial Catch Statistics

U.S. Gulf of Mexico, pink shrimp, Farfantepenaeus duorarum, catch statistics have been collected by NOAA’s National Marine Fisheries Service, or its predecessor agency, for over 50 years. Recent events, including hurricanes and oil spills within the ecosystem of the fishery, have shown that documentation of these catch data is of primary importance. Fishing effort for this stock has fluctuated over the 50-year period analyzed, ranging from 3,376 to 31,900 days fished, with the most recent years on record, 2008 and 2009, exhibiting declines up to 90% relative to the high levels recorded in the mid 1990’s. Our quantification of F. duorarum landings and catch rates (CPUE) indicates catch have been below the long-term average of about 12 million lb for all of the last 10 years on record. In contrast to catch and effort, catch rates have increased in recent years, with record CPUE levels measured in 2008 and 2009, of 1,340 and 1,144 lb per day fished, respectively. Our regression results revealed catch was dependent upon fishing effort (F=98.48df=1, 48, p<0.001, r2=0.67), (Catch=1,623,378 + (520) × (effort)). High CPUE’s measured indicate stocks were not in decline prior to 2009, despite the decline in catch. The decrease in catch is attributed in large part to low effort levels caused by economical and not biological or habitat related conditions. Future stock assessments using these baseline data will provide further insights and management advice concerning the Gulf of Mexi

Estimation of Standardized Effort in the Heterogeneous Gulf of Mexico Shrimp Fleet

In this paper we estimate nominal and standardized shrimping effort in the Gulf of Mexico for the years 1965 through 1993. We accomplish this by first developing a standardization method (model) and then an expansion method (model). The expansion model estimates nominal days fished for noninterview landings data. The standardization model converts nominal days fished to standard days fished. We then characterize the historical trends of the penaeid shrimp fishery byvessel configuration, relative fishing power, and nominal and standardized effort. Wherever possible, we provide comparison with previous estimates by the National Marine Fisheries Service, NOAA

Simulation of Tail Weight Distributions in Biological Year 1986–2006 Landings of Brown Shrimp, Farfantepenaeus aztecus, from the Northern Gulf of Mexico Fishery

Size distribution within re- ported landings is an important aspect of northern Gulf of Mexico penaeid shrimp stock assessments. It reflects shrimp population characteristics such as numerical abundance of various sizes, age structure, and vital rates (e.g. recruitment, growth, and mortality), as well as effects of fishing, fishing power, fishing practices, sampling, size-grading, etc. The usual measure of shrimp size in archived landings data is count (C) the number of shrimp tails (abdomen or edible portion) per pound (0.4536 kg). Shrimp are marketed and landings reported in pounds within tail count categories. Statistically, these count categories are count class intervals or bins with upper and lower limits expressed in C. Count categories vary in width, overlap, and frequency of occurrence within the landings. The upper and lower limits of most count class intervals can be transformed to lower and upper limits (respectively) of class intervals expressed in pounds per shrimp tail, w, the reciprocal of C (i.e. w = 1/C). Age based stock assessments have relied on various algorithms to estimate numbers of shrimp from pounds landed within count categories. These algorithms required un- derlying explicit or implicit assumptions about the distribution of C or w. However, no attempts were made to assess the actual distribution of C or w. Therefore, validity of the algorithms and assumptions could not be determined. When different algorithms were applied to landings within the same size categories, they produced different estimates of numbers of shrimp. This paper demonstrates a method of simulating the distribution of w in reported biological year landings of shrimp. We used, as examples, landings of brown shrimp, Farfantepenaeus aztecus, from the northern Gulf of Mexico fishery in biological years 1986–2006. Brown shrimp biological year, Ti, is defined as beginning on 1 May of the same calendar year as Ti and ending on 30 April of the next calendar year, where subscript i is the place marker for biological year. Biological year landings encompass most if not all of the brown shrimp life cycle and life span. Simulated distributions of w reflect all factors influencing sizes of brown shrimp in the landings within a given biological year. Our method does not require a priori assumptions about the parent distributions of w or C, and it takes into account the variability in width, overlap, and frequency of occurrence of count categories within the landings. Simulated biological year distributions of w can be transformed to equivalent distributions of C. Our method may be useful in future testing of previously applied algorithms and development of new estimators based on statistical estimation theory and the underlying distribution of w or C. We also examine some applications of biological year distributions of w, and additional variables derived from them

Possible Relationships between Realism and Comprehension in Elementary School Age Children

Young children lack the ability to differentiate their own thoughts from the external world. Therefore, they expect their opinions and understandings to be shared universally. As they get older, children begin to realize that what they perceive and what others perceive are different. This master thesis examines the relationship between a child’s listening comprehension and their ability to understand realism. The author hypothesizes that a greater understanding of objective reality would impact a child’s listening comprehension. To conduct the study, 32 elementary school children aged from six to eleven that attend an after-school daycare were tested for a five-week period. Students were given four different tests, including a modality test, a drawing test, listening comprehension, and a dream questionnaire, to determine if they could use realistic modes of reasoning and ability to differentiate their own point of view from objective reality. Of the sample, 64% showed considerable amount of subjectivism. 50% had listening comprehension skills 5 or more months above their age level. The remaining 50% were found to be at or below their age level. Only 1 student showed below average score in the drawing test. All others performed at their age, or above. While there was a trend, no statistically significant relationship between listening comprehension and realism scores were found. The author suggests a larger sample size might yield different results

End User Perception and Software Quality Assessment

The topic of software quality assessment is at the forefront of the software engineering movement. Many models of organization and quality control exist which serve to foster software quality and reliability (Bloom, McPheters & Tsiang, 1973; Brandl, 1990; Comer, 1988; Dunn, 1990; Kaplan, Clark & Tang, 1994; Livson, 1988; Musa, lannino & Okumoto, 1987). Some models now consider the software engineering project team and end users, but most still treat them as static contributors to the system. Major factors often ignored in most conventional models include the cybernetics of the process, and human factors which have a significant impact on the assessment of the quality of the software. Software environment, adaptability, and motivation have all been discussed as essential in creating a superior product. Yet, the factor of human perception has been either overlooked or avoided in the ensuing discussions. In software development the software engineers\u27 perceptions as well as those of all potential end users, must be considered in order to ensure software quality and reliability.End User Perception and Software Quality Assessmen

Archeological Assessments at 41GL57 and 41GL91, Enchanted Rock State Natural Area, Gillespie County, Texas

Archeological assessments at Sites 41GL57 and 41GL91 in Enchanted Rock State Natural Area are described in this report prepared by Steven M. Kotter and Linda A. Nance . Sponsored by the Texas Parks and Wildlife Department, these assessments represent an excellent example of sensitivity to cultural resources during the planning stages of development designed to enhance visitor utilization and appreciation of Enchanted Rock. Significant findings at Site 41GL57 include the identification of specific areas of intact prehistoric deposits which yielded artifacts of the Late Archaic and Late Prehistoric periods. Methods to achieve compatibility of development plans with the preservation of the sensitive archeological materials are provided. At Site 41GL91 , the prehistoric component was found to be badly disturbed and to be of insufficient integrity to warrant further archeological attention. The existing Historic Period structures at this site were all found to have been constructed after 1900; none are considered to be of archeological significance. Planned developments at Site 41GL91 will not conflict with identified significant cultural resources

SIUC Green Fund Research Project: Using Waste Motor Oil as Diesel Fuel

An update of the ongoing research project to validate the repurposing of waste motor oil into diesel fuel. This research was sponsored by the SIUC Green Fund. This project will benefit the University by: reducing WMO disposal fees, reducing diesel fuel costs, encouraging student participation, promoting alternative fuel research, reducing the SIUC carbon footprint, and generating credit hours for the University