Relationships between estuarine geomorphology, wetland extent and fish landings in New South Wales estuaries

Multivariate analyses of estuarine geomorphic variables and fish-catch data support the hypothesis that estuaries in New South Wales can be classified in terms of measurable geomorphic characteristics, and that these geomorphic characteristics exert an influence on estuarine biota. The clearest example of this association is the extent to which the area of seagrass, mangrove and central mud basin relates to geomorphic settings and the extent to which the area of these units in turn predict commercial landings of fish and crustaceans. Infilled estuaries with sand barrier entrances, with higher areas of mangrove and lower areas of seagrass and central mud basin yield a catch of fish different to estuaries which are not infilled, and contain relatively high areas of seagrass and central mud basin, and less mangrove. The species contributing most to these differences in assemblages are those which multiple regression analysis identifies to be consistently associated with seagrass area, and which ecological studies reveal to be dependant upon seagrass in their post-settlement phase.