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ROOIELS RIVER ESTUARY: Ecology
  Flora
Phytoplankton/Diatoms
Various pennate diatoms and chlorococales associated with filamentous algae were present.
Algae
 
Aquatic Vegetation
Grindley (1978 unpublished) recorded that filamentous green algae were prolific along the edges of the water in the upper part of the estuary during April 1978.  Van Wyk reports the presence of Potamogeton at the top end of the blind channel.  During the ECRU surveys, Ulva sp., various filamentous algae including Chaetomorpha, Cladophoropis and threads of the diatom Melosira sp. as well as Ruppia (not Potamogeton) were noted in the estuary above the bridge and road embankment. (Ref 1)
Semi-aquatic Vegetation
Scirpus nodosus, Senecia halimifolius, Orphium frutescens, Ficinia sp., Chenolea diffusa, Camolus porosus, Sporobolus virginicus, Plantage carnosa, Carpobrotus sp., Prionium serratum.  (Ref 1)
Terrestrial vegetation
The geology and associated vegetatiion of the Hangklip area was described in detail by Boucher (1978).  He states "The vegetation is subdivided into three main categories, namely, Coastal plain vegetation, Mountain vegetation and Riparian vegetation".  According to him two main vegetation types occur within these three categories, i.e. Broadleaved Scrub and Fynbos.  The vegetation of the Rooiels estuary consists of both these types with Fynbos being dominant on the slopes.   (Ref 1)
The Acacia cyclops Woodland has the highest cover (90 percent) and the Agropyron distichum Dune Grassland the lowest (25 percent).  The Phragmites australis Reedswamp and the Ruppia spiralis Aquatic Grassland have the lowest species diversity with only one species recorded while the Muraltia satureioides/Chondropetalum microcarpum Low Restiod Shrubland has the highest with 27 species.  Only dominant species were listed so that the species list is in no way comprehensive.  The height of the communities varies from 3m of the Acacia cyclops Woodland to 0,20m of the Paspalum vaginatum/Sporobolus virginicus/Osteospermum fruticosum Herbland. (Ref 1)
 
 
Fauna
Zooplankton
No data
Aquatic Invertebrates

Periwinkels, Whelks, Ribbed mussel, Brown mussel, Sea urchin, Starfish, Cape reef-worm, Mussel worm, Sand prawn (Ref 1)
The most abundant animals in the mid-tide zone were isopods, but the whelk, Bullia digitalis and the white mussel, Donax serrs also occurred in this region.  The flat beach area had few benthic organisms which were however dominated by the isopods, Pontogeloides latipes and Eurydice longicornis. (Ref 1)
Talorchestia sp. and the crab Hymenosoma orbiculare were found in the upper tidal area while in the estuaring area E. longicornis, Melita zeylanica, Talorcestia sp., Assiminea ponsonbyi and the shrimp Palaemon pacificus also occurred.  (Ref 1)
Insects
 
Fish
White Steenbras, Harders, Psammagobius knysnaensis, Heteromyteris capensis, Lithognathus mormyrus and Hepsetia breviceps, Juvenile Mullet, Gobies and Steenbras. (Ref 1)
Amphibians and Reptiles
Tortoises:  Two species which are likely to occur in the region are the Angulate Tortoise, Chersina angulata and the Padlopertjie or Parrots-beak Tortoise, Homopus aerolatus which were recorded by Greig and Burdett. (Ref 1)
Snakes:  Common water snake, Black House snake, Common Mole snake, Common Egg-eater, Boomslang, Cross-marked Grass Snake, Cape Cobra, Aurora House Snake, Spotted House snake, Common slug-eater, Herald snake, Spotted Skaapsteker, Dapple-backed Sand snake, Spotted Dwarf Garter snake, Common Puff-adder.
Amphibians:  Cape Chirping frog, Common Platanna, Cape Ghost Frog, Raucous Toad, Cape Sand Frog, Cape River Frog, Clicking Stream Frog, Banded Stream Frog and Common Caco
Birds (click on image below to view list)
birdlist.jpg (80235 bytes)
Mammals
Baboon, Dassie, Cape Clawless Otter, Grey Mongoose, Leopard, Water Mongoose

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