05.01 MARINE ECOSYSTEMS NOTE GUIDE Objectives: In the lesson you will: • describe biotic and abiotic factors • compare and contrast biotic and abiotic factors in freshwater, marine, and

terrestrial ecosystems Focus Questions: • How do biotic and abiotic factors contribute to the health of an ecosystem? • What factors caused a decline in blue crab population during this time? • What are the biotic and abiotic factors in freshwater and on land that affect an ecosystem? • How do biotic and abiotic factors interact? Vocabulary: • Biotic • Abiotic Big Ideas: Describe one way abiotic factors affected the blue crab population of Chesapeake Bay. Why is the health of the Chesapeake Bay ecosystem important? Think About It! The Case of the Missing Blue Crabs What is the blue crab population trend between 1990 and 2008? Do you think counting the number of adult female crabs gives a good representation of the population? Why or why not? Do you think the population counts in 1991 and 1999 are accurate? Why or why not? How Do You Repair an Ecosystem? Very Carefully. Does it appear that the efforts made starting in 2008 are working? What may have occurred to explain the change between 2009 and 2011? Why is it important to keep the number of crabs at spawning age above a threshold level?

See notes template from p 1 above