To measure the population of lake trout in a 250-hectare lake, 400 individual trout were netted and marked with a fin clip, then returned to the lake. The next week, the lake was netted again, and out of the 200 lake trout that were caught, 50 had fin clips. Using the mark-recapture estimate, the lake trout population size could be closest to which of the following?
A) 160
B) 200
C) 400
D) 1600
E) 80,000

Question

Quizplus · Accepted Answer

The mark-recapture estimate formula is:

population size = (number of marked individuals in first sample x number of individuals in second sample) / number of recaptured individuals in second sample

Plugging in the numbers from the problem:

population size = (400 x 200) / 50
population size = 1600

Therefore, the population size of lake trout in the lake is estimated to be 1600.

To Measure the Population of Lake Trout in a 250-Hectare