Presence and potential presence of fish in lakes. Potential Presence or distribution data extrapolates from presence data to describe what species would probably be found in similar habitat for which there might not be any data. Presence data describes what species were found by sampling (sometimes not found) for a given place, time, and method. The purpose is to document the presence for a given fraction of a specie's range based upon actual observations. Often, only a target species and a few incidental species were enumerated. Therefore, one cannot say that a species absolutely does not occur for a given waterbody. Fish move and waterbodies change. The probability that a species is or is not detected increases with the number of surveys. The expert opinion used to generate the distribution updates is an extrapolation of the survey observations and published reports. Do use this presence data to get a snapshot of fish distribution for a given time, place, and methodology which can be extrapolated to similar water bodies. Do not use this presence data to say that there absolutely are not fish in this stream forever (check dates, methods, etc.). Do use the distribution data to get an estimate of the extent of a specie's range.FULL FGDC METADATA
