Some marine geohazards, with the potential to affect offshore operations, are associated with seabed fluid flow. The petroleum industry, in particular, has learned from experience that these geohazards must be recognised and understood, and that safeguards must be in place if serious consequences are to be avoided. But seabed fluid flow is not always a negative thing. It provides resources such as methane and metals, and acts as a guide to others, particularly petroleum. However, the marine environment is sensitive and biological communities associated with vents and seeps are uncommon and fragile – they require protection.