HOW MANY FISH ARE IN THE LAKE… YOUR LAKE??? USE THE CAPTURE – RECAPTURE METHOD TO ESTIMATE THE TOTAL FISH POPULATION! Although we will be dealing with fish, this method can be used to estimate many other populations with similar characteristics to our fish. It is difficult, nearly impossible to count large, mobile populations as exist in wildlife/census/population situations exactly because of their characteristics….large and mobile. Accurate estimation of wildlife populations are used to implement controls as necessary. We will find the estimate, a good mathematically sound estimate, using ratios and proportions. Let p = total number in the population that we wish to estimate Let t = number of subjects tagged Let n = sample size from which to estimate population Let x = number of subjects tagged from the sample taken The method is based on the fact that the true population should mirror the ratio that exists in the sample(s), ie., x/n = approx. t/p where we are wishing to estimate p. By cross multiplying to solve for p we get xp = nt and p = nt/x. Let’s proceed with estimating our fish population by gathering appropriate data.