How to Destroy (and Maybe Save) the Chesapeake Bay

By the end of this simulation, students will be able to:

1. explain how human activities across cultural periods have altered the structure and function of the Chesapeake Bay ecosystem, identifying key feedbacks among species, habitats, and environmental conditions;
2. evaluate how the resilience or collapse of different taxa depends on life history traits, trophic role, and habitat use, using evidence from the simulation and historical data; and
3. propose and justify restoration or management strategies that address multiple trophic levels and ecosystem components, demonstrating an understanding of how past ecological and anthropogenic changes inform conservation decisions today.

This simulation is designed for upper-level undergraduate courses in Conservation Paleobiology, Historical Ecology, Marine Ecology, or Environmental Geoscience. It works best in small to medium-sized classes (12–24 students) where students can collaborate in pairs or small groups representing different ecological guilds. The activity functions well as an interactive lab or discussion-based lecture and typically requires one 100-minute class period (or two 50-minute sessions). I follow the activity with a quantitative lab, but this is not required for the activity to be effective.

No special equipment is required beyond printed information sheets. Optional materials may include whiteboards or large paper for mapping trophic links and tracking population trajectories through time. Access to r programming allows for an optional lab extension.

Students should already be familiar with basic ecological and paleoecological concepts, including trophic structure, feedbacks, biodiversity metrics, and anthropogenic drivers of change. Prior exposure to the Lotze et al. (2006) framework for cultural periods and general estuarine ecology will help students engage more deeply with the simulation.

This activity is situated in the middle of a conservation paleobiology or paleoecology course—after students have been introduced to the use of geohistorical records and before applying quantitative methods in lab. It serves as a bridge between conceptual understanding and data-driven analysis by encouraging systems-level thinking and hypothesis formation.

The simulation can be easily adapted to other estuaries or coastal ecosystems (e.g., San Francisco Bay, Gulf of Mexico, Wadden Sea) by modifying the taxa and regional impacts. More taxa can be added by constructing additional summary sheets (taxon lists are available in Lotze et al., 2006, supplemental material). It can also be scaled for introductory students with simplified guild interactions or for graduate seminars with added modeling or quantitative extensions (e.g., abundance tracking or trophic network reconstruction).

Teaching materials include: (1) a complete instructor guide, (2) a student worksheet, (3) Lotze et al., 2006 paper, (4) guild summary sheets, (5) optional lab extension packet, (6) spreadsheet for optional lab extension, (7) powerpoint presentation for mini-lecture before simulation, (8) powerpoint presentation for optional remediation activity to follow simulation

Instructor Guide (Microsoft Word 2007 (.docx) 30kB Oct15 25)

Student Worksheet for Chesapeake Bay Degradation Activity (Microsoft Word 2007 (.docx) 29kB Oct15 25)

Guild Summaries (Microsoft Word 2007 (.docx) 1.7MB Oct15 25)

Optional Lab Assignment (Microsoft Word 2007 (.docx) 27kB Oct15 25)

Spreadsheet for optional Lab Extension (Comma Separated Values 2kB Oct15 25)

Estuaries_Chesapeake.pptx (PowerPoint 2007 (.pptx) 11.6MB Oct16 25)

Lotze_recovery_lecture.pptx (PowerPoint 2007 (.pptx) 689kB Oct16 25)

This activity works best if students have read Lotze et al., 2006 first. I give a short introductory lecture on estuaries before beginning the activity (#7, additional files), introducing the Chesapeake Bay and its trophic web very briefly. If the optional lab extension is not included, I suggest providing a copy of Lotze et al., 2006, Figure 2 after the simulation as part of a discussion that compares estimates with empirical data on each guild (#8, additional files, note that Figure 2 is a compilation of data from across all studied estuaries, not only the Chesapeake Bay). Activity may be split into multiple class periods, separating degradation and restoration phases.

Encourage teams to think ecologically and inter connectedly - what happens to your population if prey species decline? If habitat changes? Record initial estimates for each round on the board and allow groups to adjust based on other groups' predictions of population change. NOTE: values are relative a baseline of 100% (ex: if a 10% drop is predicted from rounds 1 to 2, the recorded value for round 2 is 90%; if an additional 5% drop is predicted for round 3, the recorded value for round 3 is 85%). At some point mid-way through the simulation, it may be beneficial to provide students with the "final" (2000 AD) population abundances, but remind them that these are not necessarily the lowest values observed for each taxon throughout the interval.

This activity is assessed via full-group discussion and submission of reflection questions (included in the optional lab extension). Further summative assessment is included in course exams.

Data Source: Lotze, Heike K., et al. "Depletion, degradation, and recovery potential of estuaries and coastal seas." Science 312.5781 (2006): 1806-1809.