Two Important Marine Food Webs Off the West Coast of North

Multiple Choice

Two important marine food webs off the west coast of North America are the phytoplankton  zooplankton  fish web and the kelp  sea urchin  sea otter web.How do these two food webs compare in terms of the primary control of energy flow?

A) Both have primarily bottom-up control; they are controlled by phytoplankton and kelp, respectively.
B) Both have primarily top-down control; they are controlled by fish and sea otters, respectively.
C) The first has primarily bottom-up control by phytoplankton; the second has primarily top-down control by sea otters.
D) The first has primarily top-down control by fish; the second has primarily bottom-up control by kelp.
E) Both food webs vary so much in resource availability that it is impossible to determine primary control.