Essentials of Oceanography

Lesson 7 Introduction


About Lesson 7

Time to consider the shallow-marine environment and the impact of human activities on the critters that live there. Yes, we want to inject a bit about marine biology and ecology into this course, so this is a beginning. In this Lesson we will explore "Dead Zones" and "Bleached Reefs" and evaluate their causes and consequences. We will cruise around a bit, spending some time in the Caribbean Sea on coral reefs, floating out the mouth of the Mississippi River to visit the "dead zone" along the coast of Louisiana, and then sailing up Chesapeake Bay to examine hypoxia there, and, finally, checking out "red tides" off the coast of Florida and Massachusetts. Actually, we'll visit the dead zones first and spend quite a bit of study on Chesapeake Bay. After all, if you like oysters, crabcakes, striped bass and the like you should be concerned about the health of that water body.

What will we learn in Lesson 7?

By the end of Lesson 7, you should be able to:

  • Discuss the role of nutrients in production of marine phytoplankton
  • Outline the impact of changes in dissolved oxygen in seawater on marine biotas.
  • Outline and explain the causes of oxygen deficiency in marine environment
  • Describe the circulation of a large estuary.
  • Explain the nature and origins of red tides
  • Describe the impacts of red tides on humans and marine organisms
  • Outline elements of the ecology of modern coral reefs
  • Identify disease and other issues that impact corals and reefs.
  • Describe possible futures for coral reef systems.

What is due for Lesson 7?

As you work your way through these online materials for Lesson 7, you will encounter additional reading assignments and hands-on exercises and activities. The chart below provides an overview of the requirements for this Lesson. For assignment details, refer to the lesson page noted.

Lesson 7 Assignments
Activity 1: Chesapeake Bay hypoxia page 3 Yes- Word file with answers to queries, post blog to Canvas discussion
Activity 2: Dead zones page 4 Yes- Word file with answers to queries.
Activity 3: Ocean Acidification page 8 Yes - letter to humans posted to Canvas discussion


If you have any questions, please post them to our Questions? discussion forum (not e-mail), located under the Communicate tab in Canvas. I will check that discussion forum daily to respond. While you are there, feel free to post your own responses if you, too, are able to help out a classmate.