Marine Biogeographic transitions on the east coast of South Africa

Biogeographic regions are one of the most important unit in biogeography. They are characterised by a specific history and specific environmental conditions that make their biota unique. At the boundary between two regions, there is a zone usually not well defined where species of both regions occur: the biogeographic transition zone.
I will start a small project on the marine biogeographic transition zone on the east coast of South Africa using coastal fish as model organism. The project consists first in having a discussion around biogeographic transitions in general (definition, implications and limits on questions related to biogeography) and then use the transition between subtropical and subtemperate coastal region in South Africa as a case study (with some homework for all involved).
I found a short but nice introduction to transition zone on a website that talk about the Durban transition zone, though it is on terrestrial environments (http://www.ceroi.net/reports/durban/issues/Terrestri/biogeog.htm).
If you are interested just send me an email and I'll organise the first meeting.