A literature search on the sensitivity of fish to changes in water quality has not been carried out. Lagoons with good tidal exchange (such as parts of the Fleet) are known to be important in particular as nursery areas for juvenile marine fish. The one example of impacts on fish in lagoons due to changes in water quality was disappearance of fish and crabs from areas in an estuarine lagoonal system in Western Australia where water became deoxygenated as a result of dense blooms of a blue-green phytoplankton species in response to nutrient enrichment (Hodgkin and Birch 1982, 1986). Information from estuarine systems indicates that fish are likely to be impacted by depletion in oxygen, either directly or indirectly through effects on their prey species, including as a result of nutrient enrichment (Scott et al 1999) and by toxic planktonic algal blooms.

Other features of interest which may be found in some lagoons, such as the rich and interesting invertebrate communities of tidal rapids and narrows, are not specifically lagoonal, although the species making up such communities in areas of reduced salinity may differ from those in fully marine areas. A full literature search for information regarding the sensitivity of such communities has not been carried out, but it is likely that such a search would not identify specific information on the sensitivity of such species to changes in water quality.

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