9) Zooxanthellae are ________.
A) an endangered species of fish in the Pacific Ocean
B) symbiotic bacteria that decompose tissues of dead animals in oceans
C) symbiotic bacteria that fix nitrogen in oceans
D) symbiotic algae that provide coral reefs with energy via their photosynthetic activity
E) an invasive species of kelp in the Indian Ocean
10) Which of the following is TRUE of eutrophication in marine systems?
A) It can lead to algal blooms that kill fish.
B) It can aid corals by killing parasites.
C) It is rare and occurs only in bad weather.
D) It provides needed limiting nutrients.
E) It can aid corals by providing their symbiotic algae with nutrients.
11) Currently, the greatest ecological crisis facing marine systems is ________.
A) radiation
B) oil spills
C) plastic dumping
D) overharvesting
E) abandoned fishing nets
12) Hypoxia and eutrophication in Chesapeake Bay may in part be attributed to ________.
A) loss of kelp to take up nutrients
B) loss of otters to maintain kelp by controlling sea urchins populations
C) harvesting of oysters that previously would have filtered nutrients
D) harvesting of sea turtles that maintain sea urchin populations
E) overfishing salmon that maintain the entire system