A) environmental stochasticity.
B) eutrophication.
C) dampened oscillations.
D) Allee effects.

A) At the peak of its outbreak in 1989, the biomass of this comb jelly was far greater than the world's entire annual commercial fish catch.
B) This comb jelly is a voracious predator of young fish and fish eggs.
C) By reducing the population sizes of zooplankton, this comb jelly indirectly caused phytoplankton population sizes to increase.
D) The comb jelly immigrated to the black sea naturally.

A) Its waters are well oxygenated from the surface to the floor of the sea.
B) Because it is nearly land-locked, it exchanges little of its water with other ocean waters.
C) Native predators and parasites failed to regulate its sea comb population.
D) The state of its ecosystem improved between the early 1990s and the late 1990s.