Nonprofit journalism dedicated to creating a Human Age we actually want to live in.

Classroom Resources: Operation Sex Change

Article by Cynthia Mills

Read the article>>

Discussion Questions

1.    What are some of the strategies that have been employed to control exotic species?  What makes the use of intersex individuals different?
2.    Why would a population whose sex ratio was skewed by pollution become dependent on the pollution to avid extinction?
3.    What role can modeling play in developing control strategies for invasive species?  What information did Gutierrez’s model provide that could not have been determined intuitively?
4.    Why is the approach pioneered by Teem and Gutierrez limited to only a subset of invasive species?  Do these limitations affect the usefulness of this strategy?

Websites for Further Information

•    Invasive Species program of the U.S. Fish and Wildlife Service:

•    National Invasive Species Information Center of the USDA:

•    Florida Invasive Species Partnership:

•    Delivering Alien Invasive Species Inventories for Europe:

Invasive Fish Species in the News

•    On an Infested River, Battling Invaders Eye to Eye (New York Times, September 14, 2008):

•    California Battles an Invasive Fish, Again (New York Times, September 12, 2007):

•    Invasive Fish Species are Proving a Shock to the Ecosystem (New York Times, October 7, 2006):

Peer-reviewed Literature (in addition to the citations listed in the article)

•    Cotton, S., and C. Wedekind.  2007.  Introduction of Trojan sex chromosomes to boost population growth.  Journal of Theoretical Biology 249: 153-161.
•    Rahel, F.J., and J.D. Olden.  2008.  Assessing the effects of climate change on aquatic invasive species.  Conservation Biology 22: 521-533.
•    Bax, N.J., and R.E. Thresher. 2009. Ecological, behavioral, and genetic factors influencing the recombinant control of invasive pests. Ecological Applications 19: 873-888.
Key Concepts

•    Exotic species
•    Fisheries management
•    Genetics
•    Hormone pollution
•    Invasive species

Share This