Macrophyte abundance and distribution in Leschenault Inlet, an estuarine system in South-Western Australia

The aquatic flora of Leschenault Inlet is similar to that in other southern estuaries, except that Leschenault Inlet has a relatively high diversity of red algae, and Hormophysa triquetra is the dominant brown alga. Total plant biomass was generally 3 000-5 000 t dry weight, with a maximum in spring. There were large differences in the biomass of seagrass and macroalgae between individual surveys, but in general seagrass biomass and total macroalgal biomass appear relatively stable in the long term. Total plant biomass per unit area in Leschenault Inlet was similar to that in the Peel-Harvey estuarine system. The major difference was the relative proportions of total biomass accounted for by seagrass, brown algae and green algae. Macrophyte biomass in Peel-Harvey is dominated by green algae, whereas in Leschenault Inlet seagrass and brown algae are dominant. The inlet appears to have been in an acceptable state under the nutrient loading regime and hydrodynamic conditions of the years when the surveys were carried out