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Shallow water bryozoans
My PhD work on shallow water bryozoans collected during diving
fieldtrips at various sampling localities along the west coast of
South Africa (only accessible by 4X4), yielded 63 species of which
14 species were new to science.
Deep water bryozoans
During 1997-1999, De Beers Marine commissioned the Jago, a marine
submersible for the collection of specimens to establish baseline
benthic diversity data of their offshore mining areas. In excess of
20 collections of bryozoans and several hours of video footage were
used to determine the preliminary diversity and distribution of
bryozoans from the west coast of southern Africa.
Further deep water surveys are planned in collaboration with
Marine and Coastal Management, the South African National
Biodiversity Institute and various other organisations and
universities, with the aim of establishing offshore Marine Protected
Areas.
Aggregations of encrusting Bryozoa found on Flotsum (Plastics)
Bryozoans are well-known fouling organisms. They commonly foul the
hulls of ships, the insides of seawater inlet pipes and are even
found living epizooically on other organisms, eg., marine algae, sea
turtles and even sea snakes to name but a few. It is their
association with pelagic plastics that intrigues me most. This type
of anthropogenic interference may have widespread zoogeographical
implications, as increasing waste disposal due to population growth
and urbanisation may result in increased bryozoan distributions. I
was involved in a survey of bryozoans recorded from beach-cast
plastics along the west coast of South Africa and hope to expand on
this data set with the aid of a student in the future.
Alien invasive bryozoans
Unladen ships carry ballast water to ensure stability during long
voyages. Water is taken on board, along with tiny marine organism,
before the voyage begins. While loading their cargo at their port of
destination the ballast water is pumped out along with the surviving
"stowed" organisms. If these organisms are able to survive and
flourish under the prevailing environmental conditions they may
replace the indigenous species occurring there and may ultimately
cause damage to the ecosystem.
Port Authorities are legally bound to monitor the extent of
ballast water introductions of alien invasive species. I have
participated in various port surveys in South Africa, linked to the
Globallast Project, which aims to evaluate the global extent of
these invasions. I was part of the sampling team for the South
African pilot survey in Saldanha Bay. I also provided the taxonomic
identifications of all the bryozoans for this survey and those from
Richards Bay and Port Elizabeth. At least five species of bryozoans
have been identified as possibly being introduced to South African
waters via shipping. We are now branching out regionally into Africa
and I am currently looking at the specimens collected from Mombasa,
Kenya.
Diversity and biogeography of bryozoans
Although an impressive volume of literature exists on the
diversity and biogeography of South African marine organisms, some
faunas have remained neglected in this regard, e.g. bryozoans.
Following a compilation of all South African records, a dedicated
study of the shallow water (<30m) west coast fauna and an incidental
study on some south coast bryozoans, by myself, the South African
fauna is considered to comprise 269 valid species, representing
three orders (Cyclostomata, Ctenostomata and Cheilostomata), 73
families, and 130 genera.
I have conducted a preliminary biogeographical analysis, but the
data set is incomplete and using inferred species ranges reduces the
quality of the analysis. I therefore plan to build the data set
using the results of the projects listed above and by undertaking
fieldtrips both locally and regionally throughout at least
Sub-Saharan Africa.
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