Chapter 2: Data Management and Statistical Techniques
Michael L. Brown, Micheal S. Allen, and T. Douglas Beard, Jr.
Fisheries professionals have a scientific and societal obligation to provide well-designed and appropriate evaluations and assessments of resource management activities (Brown and Guy 2007). Statistics is the science of sampling design and data analysis and interpretation; regardless of area of specialization or job description, almost every fisheries biologist must attain some knowledge of statistics. Because statistical methods are vital to responsible fisheries management, fisheries biologists must have a broad working knowledge thereof. Statistical and quantitative thinking are critical to all aspects of a management evaluation or research study, from observing a phenomenon or management concern to publishing a report or journal article (Brown and Guy 2007; Noble et al. 2007).
Biological systems and human exploitation of them vary considerably, which makes observation and management of fisheries resources an interesting and challenging profession. Statistics help us to understand and manage that variability. Biologists must quantify population or community level changes, assess management actions, and develop the most appropriate means of assessing human influence on the fisheries that they manage. Thus, biologists and researchers use a diverse array of statistical and data management tools to assess fisheries and aid in formulating and evaluating appropriate management activities. Being mindful of data management and statistical analysis while formulating a management or research study will aid in ultimately making the investigation more successful.
Much of a fisheries biologist’s time is spent in study development, data analysis, and formulation of recommendations based on the interpretation of those data. The time devoted to these activities, as opposed to time spent actually collecting data, is often surprising to fisheries students. Inexperienced researchers commonly consult statisticians for analytical help after collecting their data, only to learn that the data were insufficient or that the design was inappropriate for the problem. Consult a biometrician or statistician before data collection to avoid this problem. Similarly, public agency archives are replete with management investigations that were inadequate in scope to provide rigorous and honest evaluations of management activities. Given the constraints on agency resources (time and money), inappropriate or inadequate sampling is wasteful and must be prevented.