Estimating lionfish population sizes
Let’s focus on the lionfish in the Bahamas, a group of islands in the North Atlantic Ocean. Lionfish were first sighted there in 2004. Since then, biologists and citizen scientists have been tracking lionfish near several islands in the Bahamas. The data they’ve collected has helped estimate the population size of lionfish over time.
Watch the video to learn more about how to estimate population sizes of lionfish.
Transcript or description of video.
The graph below shows the estimated number of lionfish near three island groups in the Bahamas each year from 2004 to 2014. It is based on realistic data compiled from studies in which divers counted lionfish. The estimates are reported as the number of lionfish per 10,000 square meters (m2).
Interpret the graph to learn how the lionfish population changed over time. In particular, the size of the population may have reached a natural limit called a carrying capacity.
Drag the arrows to your estimated carrying capacity for this population of lionfish.
Density of lionfish from 2004 to 2014
Number of lionfish per 10,000 m2
Year
Lionfish population estimates for three island groups in the Bahamas. Estimates were based on realistic data from published studies.
An interactive line graph tracks the number of lionfish per 10,000 square meters in increments of 100 along the y axis for each year from 2004 to 2014 in increments of 2 years along the x axis. The line starts near zero in 2004, reaches just over 100 in 2006, then rises to just over 300 in 2007 and is approximately 780 in 2008. The population then declines to 550 in 2009 and 380 in 2010, then rises again to almost 600 in 2011, then 550 in 2012, to just over 400 in 2013 and up to 650 in 2014.
A horizontal orange bar along the bottom of the graph can be raised and lowered until the correct carrying capacity is reached. If the orange bar is below the carrying capacity, a pop-up says "Incorrect. The estimated carrying capacity is too low. The population becomes more stable at a higher number of individuals." If the orange bar is above the carrying capacity, a pop-up says "Incorrect. The estimated carrying capacity is too high. Although the population size is high at some points, the size is not stable at those points and decreases soon after."