Final answer:
Hull fouling is the introduction of nonnative species to marine ecosystems through ship hulls. It is a vector for the introduction and spread of nonnative macroalgae. Modern non-toxic paints and high vessel traffic in marinas increase the risk of dispersal.
Step-by-step explanation:
Hull fouling is the introduction of nonnative species to marine ecosystems through the attachment of organisms to the hulls of ships. Seaweeds can attach to vessels as juveniles or developed thalli, and survive the journey conditions. Hull fouling is considered the most ancient vector for the introduction of alien species in the marine system.
Studies have shown that hull fouling on commercial ships and recreational vessels can contribute to the introduction and spread of nonnative macroalgae. While hull fouling is less important than aquaculture for the introduction of alien macroalgae, the use of modern non-toxic paints and the high number of vessels mooring in marinas increase the risk of dispersal of these species.