Biodiversity & Conservation

Temperature range preferences - See additional information

Water clarity preferences - Low clarity / High turbidity
Poor clarity / Extreme turbidity

Limiting Nutrients - Data deficient

Other preferences - Low / Reduced salinity

This biotope was recorded at the riverine/estuarine transition, from steeply broken shale bedrock at +1 to 3m deep, dominated by a 100% cover of Cordylophora caspia (as lacustris), and from deeper sloping horizontal bedrock with scattered Cordylophora caspia, frequent Electra crustulenta and rare Balanus spp. (Hiscock & Moore, 1986; Moore et al., 1999). At this site the salinity was reported to always below 20psu and could drop to zero. In nature, well developed colonies of Cordylophora caspia are usually found in water of 2 -12psu where tidal influence is considerable or between 2 -6psu where conditions are constant (Arndt, 1989). Arndt (1989) regarded Cordylophora caspia to be truly brackish water species, requiring eutrophic or hypertrophic conditions to maintain growth and reproduction, thermophilic but limited by low temperatures declining once temperatures drop below 5 °C and not regrowing in winter until temperatures exceed 10 °C (see species review for detail). Hayward & Ryland (1998) note that Electra crustulenta is limited to estuarine habitats but euryhaline in tolerance and probably widespread in distribution but commonly confused with other brackish water and estuarine species of encrusting bryozoans (e.g. Conopeum spp.).