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 reading a National Science Foundation press release about the projected collapse of currently fished seafoods. Students then use ImageJ image processing software to create a movie of global marine biodiversity maps spanning four decades, to 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:

• use ImageJ 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. Part A requires approximately 20 to 30 minutes for students to download the maps, create an image stack, and create their animation. 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. Reserve 5-10 minutes after the activity to have a class discussion about the implications of the worldwide decline in marine biodiversity over the last several decades.

Activity Overview and Teaching Materials

For Part A, student computers will need to be equipped with ImageJ ( This site may be offline. ) , a freely downloadable image processing tool capable of displaying, editing, analyzing, saving, and printing 8-bit, 16-bit, and 32-bit images. ImageJ supports TIFF, GIF, JPEG, BMP, DICOM, FITS, and "raw" image files; stacks of ordered images; and animation. Help for this tool is available at: ImageJ Documentation .

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

An Activity Sheet (Acrobat (PDF) 35kB Jan31 08) is provided for students to use during this activity. (The word processing version (Microsoft Word 25kB Jan31 08) of the activity sheet is also available.) "Stop and Think" questions are incorporated into the student webpages and the Activity Sheet serves as a place for them to record their answers.

Teaching Notes and Tips

As students interpret the species density graphs in Part B, 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.