This document discusses marine bio-deterioration caused by fouling and boring organisms. It defines bio-deterioration as undesirable changes to materials caused by living organisms. Fouling organisms like algae and animals settle on surfaces like wood and steel, while boring organisms like mollusks and crustaceans bore into and damage materials like wood. This causes economic losses for fishing boats and aquaculture infrastructure. The document covers the types and impacts of fouling and boring, as well as control methods like cleaning, coatings and preservatives. It explains that fouling occurs as organisms find surfaces to attach to, while boring provides shelter, food or aids in digestion for some organisms.