Description of Green seaweeds ([Enteromorpha] spp. and [Cladophora] spp.) in shallow upper shore rockpools
Rockpools in the littoral fringe or upper eulittoral zone subject to widely fluctuating temperatures and salinity are characterised by ephemeral green alga of the genus Enteromorpha, along with Cladophora spp. and Ulva lactuca. Due to the physical stress imposed on these upper shore pools, grazing molluscs such as the limpet Patella vulgata and the winkles Littorina littorea and Littorina saxatilis are generally in lower abundance than eulittoral pools, allowing the green seaweeds to proliferate under reduced grazing pressures. The bright orange copepod Tigriopus fulvus is tolerant of large salinity fluctuations and may occur in large numbers in these upper shore pools, along with gammarid amphipods. Situation: Rockpools throughout the upper eulittoral and lower littoral fringe in bedrock. Temporal variation: Fluctuations especially in the abundance of the green seaweeds will occur due to marked changes in salinity and temperature during the year. Enteromorpha intestinalis can often be bleached during the summer.