The introduction of caulerpa, also known as killer algae, into california was ultimately the result of a. hull fouling b. the aquarium trade in exotic, nonnative aquatic species c. intentional release d. an algae farming company

The introduction of Caulerpa, also known as killer algae, into California was ultimately the result of;

A. Hull fouling

"Hull-fouling and aquaculture are the most significant sources of seaweed invaders and should be carefully regulated"

The correct answer is option a, that is, hull fouling.  

The manner in which the species can attach themselves with the hull of a ship at the time of voyage and get transported to long distances is known as hull fouling. It is a well familiar issue influencing vessels trading in warm water ports and is the outcome of the marine development on the hull. The fouling can be due to the gathering of plants, microorganisms, animals, or algae on the wetted surfaces.