Preparation
- The jar represents the ocean, and the white beans are the North Atlantic cod.
- The dark beans represent all the other fish and creatures that live in the North Atlantic.
- Click the jar to mix the beans and begin population testing on the cod.
Capture Phase
Click the jar to go fishing again.
Marking phase
Toss back the fish that aren’t cod (click on the black beans).
Count the number of cod that you caught.
Write that number in the “Marked Phase (M)” row for this trial.
Continue
Make one thin ring of the Marking color (red) all the way around each
cod/bean that you caught (click on the white beans).
Capture Phase
Toss back the fish that aren’t cod (click on the black beans).
Count the total number of cod that you caught and write the number in the “Capture Phase (C)” row.
Continue
Now find any cod that you had marked for this trial only (red) and count only those.
Write that number in the “Marked fish Recaptured (R)” row.
Continue
Estimate the Population
Multiply your “M” row by your “C” row, then divide by the “R” row, and enter the result in the box below.
(M) x (C)
R=
Sorry, that is incorrect. Try again!Check your answerCorrect! Move on to the next trial
Calculate Your Average
Now calculate your average for the 3 estimates.
76.5 + 72.3 + 54.2
3=
Sorry, that is incorrect. Try again!Check your answerCorrect! Let's check out your results
Great Job!
The total number of actual cod (white beans) in the jar was: 77.
Here are your results:
TRIAL 1
TRIAL 2
TRIAL 3
AVERAGE
Marking Phase (M):
xxx
xxx
xxx
xxx
Marking color for this trial:
Red
Blue
Green
–
Capture Phase (C):
xxx
xxx
xxx
xxx
Marked fish
Recaptured (R):
xxx
xxx
xxx
xxx
Estimated Population
(M x C) ÷ R =
xxx
xxx
xxx
xxx
Play Again Export Results

Recaptured (R):
(M x C) ÷ R =