<Li> <P> Desert pupfish </P> </Li> <Li> <P> Mayan cichlid </P> </Li> <Li> <P> Crevalle jacks </P> </Li> <P> The level of salinity in intertidal zones can also be quite variable . Low salinities can be caused by rainwater or river inputs of freshwater . Estuarine species must be especially euryhaline, or able to tolerate a wide range of salinities . High salinities occur in locations with high evaporation rates, such as in salt marshes and high intertidal pools . Shading by plants, especially in the salt marsh, can slow evaporation and thus ameliorate salinity stress . In addition, salt marsh plants tolerate high salinities by several physiological mechanisms, including excreting salt through salt glands and preventing salt uptake into the roots . </P>

Where are euryhaline and stenohaline organisms more likely to be found in an estuary