20Th CONGRESS of THE

20th CONGRESS OF THE

PHYCOLOGICAL SOCIETY OF SOUTHERN AFRICA

28-30 January 2004

Magaliesburg Conference Centre

Hosted by the School of Animal, Plant & Environmental Sciences

University of the Witwatersrand

Organising Committee:

Stuart Sym (Convenor)

Claudio Marangoni (Administrator)

Shalini Dukhan

Acknowledgements:

National research Foundation for assistance with the guest speaker.

Imperial Car Rental for a complimentary vehicle.

South African Seaweeds Concessionaire Association (SASCA) for prizes.

University of the Witwatersrand for stationery.

PROGRAM

Wednesday 28 January 2004

Arrival of delegates at Magaliesburg Conference Centre

15h00Registration

19h00DINNER

Thursday 29 January 2004

09h00 - 09h10Welcoming and Opening - Grant Pitcher

SESSION A - Invited Speaker - Chair: John Bolton

09h10 - 10h00Millar, AJK - Phycological Forays _ the Good, the Bad, and the Algae

SESSION B - Oral presentations on Population Dynamics - Chair: Derek Du Preez

10h00 - 10h20Pitcher, GCet al. - Satellite monitoring of the evolution of a coccolithophorid bloom in the southern Benguela ecosystem.

10h20 - 10h40Skinner, Tet al. - Temporal and spatial variation in microphytobenthic biomass in relation to changes in physico-chemical characteristics of a small temporarily open/closed estuary in the Eastern Cape.

10h40 - 11h10TEA

SESSION C - Oral presentations on Population Dynamics (cont.) - Chair: Grant Pitcher

11h10 - 11h30Velikova, VN - The Black Sea phytoplankton seen through an “environmental window”.

11h30 - 11h50Du Preez, DR - Why don’t bacterial numbers increase in surf diatom patches?

11h50 - 12h10Gama, PT & Adams, JB - Seasonal distributions in phytoplankton size fraction by mass associated with changes in physical and chemical variables in a temporarily open/closed estuary in the Eastern Cape, South Africa.

12h10 - 12h30Clark, BJet al. - Microalgae as indicators of coastal pollution.

12h30 - 12h50Difford, M & Campbell EE - On curing macroalgae: The effect of salt on salt works.

12h50 - 14h00LUNCH

SESSION D - Oral presentations on Distribution - Chair: Eileen Cambell

14h00 - 14h20Anderson, RJet al. - Seaweed endemism in the proposed Pondoland marine protected area.

14h20 - 14h40Bolton, JJet al. - Seaweed diversity in sub-Saharan Africa: the known and the unknown.

14h40 - 15h00Maneveldt, GW & Bassier, A - The role of selected herbivores in the control of intertidal seaweed diversity.

15h00 - 15h20Tronchin, EMet al. - The diversity and distribution of Ptilophora (Gelidiaceae, Rhodophyta) including two new species from Kwazulu-Natal.

15h20 - 15h40Snow, GC & Adams, JB - Physico_ chemical factors determining benthic microalgal distribution in open South African estuaries.

15h40 - 16h15TEA

16h15PSSA Annual General Meeting

19h00DINNER

Friday 30 January 2004

SESSION E - Oral presentations on Biodiversity - Chair: Claudio Marangoni

09h00 - 09h20Mason, RM & Sym, SD - An unusual gymnodinioid dinoflagellate (Dinophyceae) from the waters off the South Western Cape.

09h20 - 09h40Sym, SDet al. - On the identity of a bloom-forming Tetraselmis from Saldanha Bay.

09h40 - 10h00Campbell, EE - The surf diatoms of Australasia.

10h00 - 10h20Dukhan, Set al. - Further studies on the marine dinoflagellate Lepidodiniumviride.

10h20 - 10h40Griffin, NJet al. - Cryptic biodiversity in Porphyra in southern Africa.

10h40 - 11h00Millar, AJK & Bolton, JJ - Sharing Marine Algae - Australia and South Africa.

11h00 - 11h30TEA

SESSION F - Poster presentations - Chair: Wendy Stirk

1. Kirton, Aet al. - Coccolith production over time in Pleurochrysis carterae under continuous light and dark conditions.
2. Buchanan, Set al. - Testing for exotoxin expression in Prymnesium nemamethecum.
3. Evans, AGet al. - Subtidal seaweed communities of Kwazulu-Natal: Their diversity and biogeography.
4. Campbell, EE & Smith AC - Dinoflagellates and diatoms indicate different water quality conditions in Algoa Bay.
5. Todkill, WBet al. - A sandy beach ecosystem health index and expert system for beach management in the Eastern Cape.
6. Difford, M & Campbell EE - On curing macroalgae: Looking for a less-nutrient-rich water source in the Swartkops estuary.
7. Salum, DM - Effects of north east (NE) and south east (SE) monsoons on growth of Kappaphycus alvarezii growing in Zanzibar.
8. Steyn, PP & Du Preez, DR - Cultivating Gelidium pristoides in a spray cultivation system.

13h00 - 14h00LUNCH

SESSION G - Oral presentations on Applications - Chair: Robert Anderson

14h00 -14h20Naidoo, K - Testing the suitability of local seaweeds as feed for abalone.

14h20 - 14h40Smit, A J - The current state of seaweed natural products (bioactive compounds) in drug discovery.

14h40 - 15h00Rand, AMet al. - Introducing a spatial geographic information system (GIS) into kelp management in South Africa.

15h00 - 15h30TEA

SESSION H - Oral presentations on Applications (cont.) - Chair: Gavin Maneveldt

15h30 - 15h50Robertson-Andersson, DVet al. - A preliminary investigation into modelling an integrated seaweed (Ulva lactuca) and Abalone (Haliotis midae) system.

15h50 - 16h10Rothman, MDet al. - The effects of kelp (Ecklonia maxima) harvesting on kelp population structure and kelp recruitment.

16h10 - 16h30Stirk, WAet al. - Potential benefits of using microalgae (Chlorophyta) as soil additives for agricultural application.

16h458th International Phycological Congress - Local Organising Committee

19h00DINNER & Prize Giving

Saturday 31 January 2004

Delegates depart after breakfast.

ABSTRACTS

SEAWEED ENDEMISM IN THE PROPOSED PONDOLAND MARINE PROTECTED AREA (oral)

Robert J. Anderson1, J. J. Bolton2, H. Stegenga3 and O. DeClerck4

1 Seaweed Unit, Marine and Coastal Management, Pvt Bag X2, Roggebaaai, 8012

2 Botany Department, University of Cape Town

3 Research Group Phycology, Ghent University, Belgium

4 National Herbarium Nederland, The Netherlands

Until recently, the seaweed flora of the east coast of South Africa was relatively poorly known. Recently we have made extensive collections in the Eastern Cape (Netherlands/SA project) and in Kwazulu_Natal (SA/Flanders project). From an analysis of our distribution records in 50_km blocks around the entire SA coastline of 3000 km, we have identified two areas with exceptionally high numbers of "endemics with very restricted distributions" (species recorded from ranges of 50_250 km). The two areas are the Cape Peninsula (not dealt with here) and Pondoland (in our analysis a 150_km stretch from just south of Port St Johns to just north of Port Edward). About 10 species of seaweeds (representing 35% of SA "restricted endemics" and including two undescribed genera) appear to be endemic to this short Pondoland region. Recent collections from this area (by ORI, Durban) confirm the unique character of the subtidal element of the seaweed flora. We discuss examples of these range_restricted species. These results, based on one of the few components of the marine biota that has been intensively sampled (seaweeds), further illustrate the exceptional biological value of the Pondoland coast and should aid efforts to conserve this area.

SEAWEED DIVERSITY IN SUB_SAHARAN AFRICA: THE KNOWN AND THE UNKNOWN (oral)

John J Bolton1, O. De Clerck2 and D. M. John3

1 Botany Department, University of Cape Town

2 Research Group Phycology, Ghent University, Belgium

3 Department of Botany, The Natural History Museum, London

This paper summarises a contribution put together for a workshop on 'Marine Biodiversity in Sub_Saharan Africa', which took place in September 2003, under the auspices of the 'Census of Marine Life'. Despite some gaps, the seaweed information was shown to be one of the most complete datasets on inshore marine biodiversity in the region. Recent advances, including web_based systems, are ensuring that the information which is available can be more easily accessed. In Tropical West Africa only a small number of countries are well_collected. South Africa and Namibia have quite well documented seaweed floras, although detailed collections, especially in the subtidal, or detailed studies of taxa, particularly using molecular methods, anywhere in the region are likely to bring up new species or records. South Africa has a very rich seaweed flora (ca. 850 species), due to its borders encompassing a portion of three of the four major biogeographic regions in sub_Saharan Africa. In Tropical East Africa the seaweed floras of Somalia and Mozambique are not well known. Figures for reasonably well_studied countries in Tropical East Africa are more than 400 species, whereas much of Tropical West Africa has lower numbers (e.g. 200 species in well_studied Ghana). Factors which may account for these major differences in diversity patterns are discussed. Training workshops in Africa are necessary to recruit a body of local scientists able to identify and work with seaweeds, and to make the wealth of information in the international literature available to African marine scientists. A network of national herbaria should contain a collection of correctly identified seaweed species.

TESTING FOR EXO_TOXIN EXPRESSION IN Prymnesium nemamethecum (poster)

Sean K. Buchanan, R. O’Shaughnessy and N. Tye

School of Animal, Plant & Environmental Sciences, University of the Witwatersrand

Prymnesium nemamethecum is a sand_dwelling marine species that resembles other species of the genus in size, organelle arrangement and swimming behaviour. Several species of Prymnesium have been known to produce exudates that are ichthyotoxic, and have been observed in toxic algal blooms in Europe. The potential of P. nemamethecum to be toxic needs to be tested. To this end, a unialgal isolate was cultured under 5 different nutrient regimes, consisting of varying concentrations of PES, and their ambient medium tested for ichthyotoxicity using Artemia shrimp as the bioassay organism. All culturing was achieved under uniform light and temperature conditions. Three replicates of each treatment were tested for toxicity. No significant difference in mortality was found across the treatments. The results indicate that under these conditions P. nemamethecum does not express an exo_toxin. Further studies are needed to elucidate whether this is true of the species under all conditions or whether it is an artefact of the culture conditions.

THE SURF DIATOMS OF AUSTRALASIA (oral)

Eileen E. Campbell

Botany Department, University of Port Elizabeth

Six diatom species are known to form semi_permanent brown discoloration in surf_zones. Generally, only one species will form these brown patches at a given time, and generally only one or two species will dominate at a sandy beach. This rule applies to all beaches studied with the exception of a beach on the north island of New Zealand. Five of the six species where recorded at this beach in a single patch. Diel and long_term dynamics of this phenomenon were investigated. Some species are semi_permanent features of the beaches where they are recorded (e.g. Attheya armatum), others may be episodic (e.g. Asterionellopsis glacialis), while others appear or disappear depending on the surf conditions (e.g. Anaulus australis). Finding all these species at one beach offers a unique opportunity to compare their different dynamics.

DINOFLAGELLATES AND DIATOMS INDICATE DIFFERENT WATER QUALITY CONDITIONS IN ALGOA BAY (poster)

E. E. Campbell and Andy C. Smith

Botany Department, University of Port Elizabeth

Phytoplankton samples were assessed for abundance of dinoflagellates and diatoms over a diverse grid of stations in Algoa Bay. The grid enclosed three islands _ their presence creating pools of nutrient_rich water in an oligotrophic system. Dinoflagellate and diatom species composition was assessed using multivariate analysis and spatial analysis using Kriging algorithms. The different groups of microalgae dominated in different water conditions. While this phenomenon is known for large_scale nutrient conditions, it is now shown to apply on a smaller scale. Microalgal assemblages were found to be associated with island_enriched waters.

MICROALGAE AS INDICATORS OF COASTAL POLLUTION (oral)

Belinda J. Clark, E. E. Campbell and D. R. Du Preez

Botany Department, University of Port Elizabeth

Internationally, most countries report that the major threat to their coastal environment is nutrient enrichment, arising mostly from stormwater runoff or leaks in septic tanks and run_off from agricultural lands. Along the South African coastline, there are 63 waste discharge pipelines and numerous storm water pipes, therefore the potential for nutrient enrichment and associated problems is high if discharges from these outlets are not monitored and properly managed. The White Paper recognises our coast as being a national asset belonging to all the people of South Africa. It recognises the coast as being a place of value, opportunity and potential, whose products account for approximately 35% of our national Gross Domestic Product with enormous future development potential. Therefore, we need to manage our coast wisely, which includes maintaining the diversity, health, and productivity of coastal ecosystems. Proactive monitoring efforts can identify problem areas, allowing steps to be taken prior to the collapse of a system.

In order to characterise anthropogenic impacts on ecosystems more accurately, environmental monitoring has moved in the direction of using measures of ecological condition rather than chemical indicators. Historically, algae have been an important part of biological monitoring programs, providing unique information because of their nutritional needs and position at the base of the food web. Algae respond rapidly to a wide range of pollutants and serve as early warning signals of deteriorating environmental conditions.

The aim of this study was to assess pollution levels (in terms of nutrient enrichment) and associated microalgal species composition in surf_zones of sandy beaches along the South African coastline, with the hope that certain species would be highlighted as indicators of environmental condition. Nine beaches were selected for study and were sampled four times. Surf_zone water samples collected were analysed for inorganic nutrients; and pH, temperature and salinity levels. Surf_zone widths and wave heights were estimated, and microalgal species present were identified and counted.

The following microalgal species were indicative of particular environmental variables on a number of beaches on more than one occasion:

•Ammonium: Scrippsiella trochoidea, Prorocentrum micans, Dinophysis ovum

•Nitrate and Phosphate: Chaetoceros species in general, Pleurosigma normanii, Rhizosolenia styliformis, a silicoflagellate species, Bacteriastrum delicatulum, Aulacodiscus johnsonnii

•Temperature: Protoperidinium diabolum, Chaetoceros curvisetus, Ditylum brightwellii

ON CURING MACROALGAE: THE EFFECT OF SALT ON SALTWORKS (oral)

Mark Difford and E. E. Campbell

Botany Department, University of Port Elizabeth

Swartkops Sea Salt, on the outskirts of Port Elizabeth, is the largest individual producer of sea salt in South Africa. High nutrient levels in the brine_source, coupled with low salinity in the early and middle ponds of the system, have led in recent years to an increasing number of macroalgal blooms.

The breakdown products of these blooms, in the form of blackened detrital particles, enter the crystallisers, where they interfere with crystallization and deleteriously affect the quality of the salt.

During the past year a number of remedial measures to alleviate this problem have been implemented. These have included (1) decreasing pond depth and (2) increasing the salinity of the middle pond of the system. The effects of these changes are described.

ON CURING MACROALGAE: LOOKING FOR A LESS NUTRIENT_RICH WATER SOURCE IN THE SWARTKOPS ESTUARY (poster)

Mark Difford and E. E. Campbell

Botany Department, University of Port Elizabeth

Physico_chemical factors in the Swartkops estuary were assayed on a weekly basis for seven weeks, during six hours of the tidal cycle. Several sites (prospective sites for a new pump_house), including that of the current pump_house, were studied. The purpose of the survey was to rank the sites in order of brine_quality, suitable for use in a solar saltworks. Nutrient concentration and salinity were therefore chosen as the appropriate ranking_factors. At all sites, tidal factors strongly influenced brine_quality. Site_distance from the mouth is therefore critical, as, from a remedial standpoint, is the pumping regime of the salina. With the exception of a proposed site near the mouth, the site of the present pump_house was found to be the best of the sites examined.

FURTHER STUDIES ON THE MARINE DINOFLAGELLATE Lepidodinium viride (oral)

Shalini Dukhan, S. D. Sym and R. N. Pienaar

School of Animal, Plant & Environmental Sciences, University of the Witwatersrand

Lepidodinium viride has a bright green pigmentation due to the presence of the prasinophyte endosymbiont harboured within the dinoflagellate. However, colourless cells are encountered in culture. It was initially thought that the presence of colourless cells was due to an uneven division of the enodsymbiont, which prompted investigations on endosymbiont division. Preliminary light microscope investigations revealed that the study of the division of the endosymbiont would be complex as the endosymbiont is already highly dissected and it would therefore be difficult to determine when cytokinesis of the endosymbiont begins or ends. There was no evidence of an unequal division of the endosymbiont between daughter cells. Only pigmented daughter cells were ever observed to develop from a pigmented parent cell. It is thought that colourless cells develop through an ageing process, which results in the degradation of the chloroplasts into accumulation bodies. Eventually even these accumulation bodies are broken down by the cell, thus rendering the cell colourless.

The athecate gymnodinioids were traditionally divided into three genera, Amphidinium, Gyrodinium and Gymnodinium. However, more recent DNA analysis has shown that this system is too simple and more genera (e.g. Karenia) are required. According to this system, Lepidodinium viride has now been reclassified into Gymnodinium based on light and electron microscopic features (e.g. cytoskeletal studies, division, nuclear envelope structure, cingular displacement, the position of the apical groove). Observations to confirm the presence of these distinguishing features in Lepidodinium viride will be presented.

WHY DON'T BACTERIAL NUMBERS INCREASE IN SURF_DIATOM PATCHES? (oral)

Derek du Preez

Botany department, University of Port Elizabeth

Surf_diatom accumulations, or patches, in surf_zones are the result of the accumulation of the cells of certain diatom species (six the world over) to concentrations often in excess of 1 million cells per millilitre. In South Africa the species most commonly responsible for the patches is Anaulus australis. In South America it is Asterionellopsis glacialis. In accumulations of both species it has been noted that the bacterial numbers are not significantly higher than they are in the surrounding water, where diatom numbers are very much lower. This is surprising in light of the fact that the cells exude into the water, in the form of various organic compounds, about half of the carbon that they fix during photosynthesis. This high concentration of organic compounds should enable bacteria to grow very well within the diatom accumulations and yet their numbers do not increase.

Various reasons for the lack of high bacterial numbers in the patches have been put forward. The most plausible of these is that anti_bacterial compounds produced by the diatoms inhibit the bacteria. In this paper I suggest another possibility and that is that the bacterial numbers do not increase in the patches simply because the bacteria, like other microalgal species that occur in surf_zones, do not have the mechanism that allows them to accumulate in the same way as the specialist surf_zone diatoms do.

SUBTIDAL SEAWEED COMMUNITIES OF KWAZULU_NATAL: THEIR DIVERSITY AND BIOGEOGRAPHY (poster)

Adrian Evans1, R. J. Anderson2 & J. J. Bolton1