Evaluation and Proposed Refinement of the Sampling Design for the Long Term Resource Monitoring Program's Fish Component
Abstract : Environmental monitoring programs are frequently designed to track changes in key physical, chemical, and biological features of an ecosystem. As such, these programs provide critical information for detecting changes in system state, investigating causal mechanisms of the observed changes, and making resource management decisions. Because monitoring programs require significant investments of time, money, and human resources to implement and maintain, periodic evaluations of monitoring programs are necessary to determine if the sampling design adequately addresses program goals and objectives. Periodic evaluations also permit assessment of a program's ability to provide adequate and useful information for changing management and science needs. We evaluated the Long Term Resource Monitoring Program's (LTRMP) fish sampling design by analyzing data from stratified random samples collected from 1993 to 1999 in six Trend Analysis Areas (TAAs). Specifically, we investigated whether the sampling design could provide similar information with fewer sampling gears. Our goals were to identify and quantify information provided by each gear used to monitor fish in the LTRMP, develop alternative sampling design scenarios based on our analyses and expert opinion, and engage program partners in a discussion on the relative value of each gear within the present sampling design. Community characterization (presence or absence), community structure (relative abundance within the full community), and detection of annual changes in single-species catch-per-unit-effort (Lubinski et al. 2001) are the primary information provided by the fish component. Our analyses considered differences in these measures among TAAs, gear types, sampling strata, seasonal sampling period, and fish size. Results were made available to program partners through a Web site for review and comment. Based on these analyses, program partners developed a suite of potential options for component refinement.
The importance of host fish in long range transport of unionids in large rivers
Home ranges, the amount of space used by animals, are central to understanding habitat diversity, effects of fragmentation, and conservation potential. The size of an organism's home range yields information on spatial requirements, life history, genetics, foraging, and interactions with other organisms. Present theory suggests that home range is set by body size of individuals. Here we analyze data on fish home ranges in lakes and rivers to show that ecosystem size and shape influence home range. Using a review of 192 studies including 125 fish species on six continents, we show that home ranges increased with increasing ecosystem size across ecosystem shapes. This contrasts with past studies concluding that body size sets home range. We show that ecosystem size was a consistently significant predictor of home range, but that home range did not always increase with body size. The fraction of available ecosystem exploited by individual animals declined systematically with ecosystem size. Since habitat patches are decreasing in size worldwide, our findings have implications for ecology, conservation, and genetics of populations in fragmented ecosystems. Introduction Home range size and location are important bearing to the fitness and structure of populations (Fischer and Kummer 2000, Kramer and Chapman 1999, Winder et al. 2004). Home range is the area familiar to and used and reused by individuals (Wilson 1975) and is a behavioral
Image Projection in Immersive 3D Visualization Laboratory
In recent years, many centers in the world attempted to build a virtual reality laboratory. The main idea of such laboratory is to allow the user to “immerse” into and move in a computer-generated virtual world. In the paper, the underlying principles of the system of virtual reality (VR) are described. The selected implementations constructed by the research centers of the world are also presented. The cave automatic virtual environment (CAVE) installation is planned to be implemented at the Gdansk University of Technology. In this solution, the images will be projected on flat screens arranged in the form of a cube. The user will be located inside a transparent sphere freely rotating inside a cube, which allows simulation of free movement without changing the position of the screens. A walking motion of the user will trigger changes in the computer-generated images on screens surrounding the sphere thus creating an illusion of motion. The problems of visualization in the planned installation are outlined and discussed.