The ecological effects of bioturbation on the eelgras Zostera capensis : community interactions and the impacts on the biota of an intertidal sandflat

Thalassinidean prawns in the genus Callianassa have been singled out as important bioturbators because of their size and activity, and because they often occur at high densities and burrow deep into the sediments. The ecological effects of bioturbation by Callianassa kraussi on the eelgrass Zostera capensis, and its indirect effects on the sedentary mudprawn Upogebia africana and the biota of an intertidal sandflat were assessed at Langebaan Lagoon, South Africa, through comparative surveys, observations and field experiments. I hypothesised that C. kraussi and Z. capensis have mutually detrimental effects on each other, with bioturbation by C. kraussi leading to smothering of Z. capensis, and stabilising of sediments by Z. capensis impeding burrowing of C. kraussi. I also hypothesised that C. kraussi would be negatively correlated with U. africana because the latter relies on semi-permanent U-tubes to filter-feed, and bioturbation is likely to disrupt these.

Grantor dc:publisher.institution

Department of Biological Sciences

Year dc:date.issued

2003

Author dc:creator

• De Vos Siebert, Timony-Lee

Advisor dc:contributor.advisor

• Branch, George M

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/6970

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/6970