The West Coast of New Zealand's South Island is a windward shore that transects a westerly temperate ocean current system. The coastline structure is very much dominated by its history of glaciation and tectonic uplift, and its high sediment loading, which combine to give this marine region a distinctive ecological character. Within the region, three marine ecological districts (Buller, Westland and South Westland) can be distinguished. Although the biomass of seaweeds on the West Coast's rocky shores and estuaries is often reduced by heavy sediment abrasion and other influences, over 175 taxa are recorded from historic and recent collections in the region. Significant features of the region's algal flora are hard to discern on the basis of existing knowledge, but include the virtual absence of some common New Zealand species, and extensions to the known distribution of others.

Marine algae, West Coast South Island New Zealand, biogeography.