Hodgkin and Birch (1986) note loss or reduced growth of Ruppia beds as a result of phytoplankton blooms and smothering by algae and epiphytes triggered by nutrient enrichment. Other references to the sensitivity of tasselweed to changes in water quality are contained within Davison and Hughes (1998) who report that Ruppia species appear to be less sensitive to metabolic imbalance caused by internal high nitrate concentrations than eelgrass (Zostera) species. Sheader & Sheader (1999) reiterate that Ruppia spp. require good light conditions and are therefore usually marginal in deeper lagoons, occurring as beds in up to about 0.5 m water depth. Salinity tolerance is not well documented, but in England, dense beds of Ruppia spp. occur where seasonal salinity ranges from 10-40 psu (Sheader & Sheader 1999).

No information was found on the sensitivity of Potamogeton spp to changes in water quality in the Fleet Study Group archive or other references consulted as part of this project. However, a literature search was not conducted, and it is likely that information does exist, but relates to freshwater (rather than brackish) situations.

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