Mr. Adamson must, however, keep predators out of his tanks: larger shrimp, fish, and crabs as
well as lizards, ocean mammals, land mammals, and various birds. The beautiful pink
flamingo, which gets its color from a chemical in shrimp, has a beak specially designed to
scoop shrimp right out of the water. Roseate spoonbills also love to dine on the little morsels.
Smaller birds will wade the shallows for small baby shrimp, and large herons wade into deeper
water to grab a snack. Pelicans swoop down into the water when shrimp swim close to the
surface. All of these creatures have easy access to aquafarms, so Mr. Adamson must be
particularly careful and watch his shrimp farm so that these predators do not eat all his profits.

The main point of paragraph 4 is that -

A wild shrimp are close to the bottom of the food chain
B Mr. Adamson needs to keep predators out of his tanks
C Mr. Adamson is an aquaculture technician
D most aquaculture shrimp are eaten by people