Plenty of Fish in the Sea?

The lab activity described here was created by Erin Bardar of TERC for the EarthLabs project.

Investigation Summary and Learning Objectives

Students begin this investigation by watching a National Geographic slideshow presentation about some of the impacts that declining fish populations are having on humans around the world. In Part B, students use ImageJ image processing software (if available) to create an animation of global marine biodiversity maps spanning four decades, and look for hotspots and overall changes in species diversity over time. The investigation concludes with students interpreting graphs of tuna and billfish species density by ocean, and applying what they have learned to understanding why species diversity is important for maintaining the overall balance of marine ecosystems.

After completing this investigation, students will be able to:

• explain some of the ways humans are affected by the declining health and productivity of fisheries;
• use ImageJ (if available) to animate a series of time-sequenced images;
• evaluate changes in global marine biodiversity over time by visual inspection of an animated sequence of images;
• interpret trends in graphical data; and
• explain why species diversity is important to the health of marine ecosystems and the sustainability of fishing.

Context for use

This is the first lab in the EarthLabs Fisheries unit. Students are introduced to the importance of marine biodiversity and sustainable fishing practices for maintaining the overall health of our planet. This investigation also provides students with experience in manipulating and interpreting scientific data and graphs.

The entire lab should take one 50-60 minute class period. The slideshow presentation in Part A is approximately 7 or 8 minutes long. If using ImageJ, Part B will require approximately 20 to 30 minutes for students to download the maps, create an image stack, and produce their animation. If not using ImageJ, Part A will only take about 10 minutes for students to study and analyze the embedded animated .gif image of the marine biodiversity maps. Part B can be assigned as homework, or can be completed in the remaining class time. Students should need only 5-10 minutes to interpret the species density graphs and answer the analysis questions. If possible, reserve 5-10 minutes at the end of class to discuss students' ideas about the implications of the worldwide decline in marine biodiversity over the last several decades.

Activity Overview and Teaching Materials

In order to view the National Geographic slideshow presentation in Part A, student computers must be equipped with the Adobe Flash Player .

For Part B, it is recommended that student computers be equipped with ImageJ (more info) , a freely downloadable image processing tool capable of displaying, editing, analyzing, saving, and printing digital image files. ImageJ also supports stacks of ordered images and animation. Help for this tool is available at: ImageJ Documentation . If ImageJ is not available, students can complete the activity by studying the animated .gif image provided on the student page. No additional tools or materials are required if using this method.

In Part C, students can view and interpret the species density graphs directly on the student activity page.

Printable Materials

• Activity Sheet (PDF (Acrobat (PDF) 34kB Jan28 08) and Word (Microsoft Word 25kB Jan28 08))
• Suggested Answers (Acrobat (PDF) 51kB Jan28 08)
• So Long Seafood? (Acrobat (PDF) 112kB Jan15 08)

Teaching Notes and Tips

For Part A, you may wish to project the slideshow presentation and have the entire class watch it together.

As students interpret the species density graphs in Part C, be sure they are carefully examining the scale of each graph, as they are not the same for each ocean.

Assessment

You can assess student understanding of topics addressed in this Investigation by grading their responses to the Stop and Think questions.

State and National Science Teaching Standards

Additional Resources

Background Information

• Read the Science Magazine article "Global Patterns of Predator Diversity in the Open Oceans" by Worm et al. for more detailed information about the global marine biodiversity study and its relevance to marine ecosystem conservation.

Pedagogic Considerations

• The NAGT/DLESE On the Cutting Edge project's Best Practices from Education and Cognitive Science Research provides information about what cognitive science research says about why teaching with visualizations (including time-lapse animations) is effective.

Content Extension

• The report, Food and Agriculture Organization of the United Nations (FAO): The State of World Fisheries and Aquaculture 2006, is published every two years to provide objective and global views of capture fisheries and aquaculture, as well as associated policy issues.