Stratified random sampling is a method of sampling that divides a population into smaller groups that form the basis of test samples.
Wildlife managers in North Dakota and Minnesota use a variety of surveys to gather population indices for coyotes and other furbearers. The surveys tally trends rather than population estimates.
An investigation of TPWD by NOAA halted a 50-year-old data set that has helped make Texas bays one of the most productive coastal fisheries in the nation.