solve the CHAPTER MYSTERY

CHANGES IN THE BAY

According to one hypothesis, rising water temperatures have caused most of the changes reported in Narragansett Bay. The bay's temperature has risen more than 1.5°C (3°F) since 1960. This warmth encourages bluefish to stay in the bay later in the fall. It also allows predatory warm-water shrimp to remain in the bay all winter, feeding on baby flounder. Warmer water also enables zooplankton to graze heavily on marine algae. This eliminates the late-winter algal bloom whose primary production used to provide organic carbon to the entire food web. Those food web changes, in turn, seem to be driving unexpected shifts in the activities of bacteria that transform nitrogen. When the spring bloom provided organic carbon, bacteria denitrified the water, releasing nitrogen into the atmosphere. Now, the bacterial community has changed and actually fixes nitrogen, bringing more of it into the water. It is still not clear what this change means for the long-term health of the bay and adjacent coastal waters.

1. Compare and Contrast Compare the original situation in the bay with the current situation, taking note of changes in both the food web and the nitrogen cycle.

2. Infer Narragansett Bay harbors sea jellies that prefer warm water and have previously been present only in summer and early fall. These sea jellies eat fish eggs, fish larvae, and zooplankton. If the bay continues to warm, what do you think might happen to the population of sea jellies in the bay? What might that mean for the organisms the jellies feed on?

3. Connect to the Explain how the Narragansett Bay example demonstrates interconnections among members of a food web and abiotic environmental factors. Can you find similar studies in other aquatic habitats, such as Chesapeake Bay, the Everglades, or the Mississippi River delta? Explain.