SANCOR Newsletter Issue #171: September 2002
Student’s Corner
Seahorses found in Keurbooms estuary
Jackie Lockyear
Rhodes University
Knysna seahorses have long been known to occur in the Knysna and Swartvlei estuaries along the Cape south coast, but now a healthy population has also been found in the Keurbooms estuary.Previously, over the past decade there have been only occasional sightings of seahorses at Keurbooms – and none in the past two years – suggesting that the population was unstable or that they were perhaps strays from the Knysna estuary. Although on average only 0.05 seahorses are found every 10m2 in the Keurbooms estuary, a large and very unusual find of 60 seahorses in a 10m2 area, suggests that more seahorses may be present.
The Knysna seahorse, Hippocampus capensis, is endemic to South Africa and is regarded as the most threatened seahorse in the world. Its endangered status is derived primarily due to its exceptionally limited distribution as well as the threat from ever increasing developments around (and within) these estuaries. In addition, boating activities within the lagoon destroy numerous eelgrass beds, which form vital habitat for the seahorse.
The Seahorse Research Group is conducting a two-year research project aimed at establishing the status of seahorses in the southern Cape estuaries and determining guidelines for their conservation and management. It is being carried out under the auspices of Rhodes University, with funding from the Green Trust, made possible by Nedbank Green.
The project was started in 2001 and the main activities to date have been the underwater SCUBA surveys. For example, more than 450 dive-hours have been spent in the Knysna and Swartvlei estuaries alone, collecting data not only on the seahorses but also on the other organisms that occupy the same ecosystem, including pipefish, seahares, starfish, nudibranchs and the main seagrasses.
Numerous environmental conditions (current speed, substrate type, depth and salinity), have been recorded and together with the above mentioned biotic factors (invertebrates and seagrasses) will be used to understand more about seahorse habitat requirements and preferences. This in turn will form the "focal points" around which the guidelines will be developed. Probable guidelines will include the establishment of seahorse protected areas, the role of artificial structures and the management of the breaching of the Swartvlei, which usually leads to mass seahorse mortalities.The seahorse is indeed a unique and special fish. Not only does its unusual breeding behaviour, that is, with the male giving birth, satisfy women's feminist tendencies, but the seahorse is also a "flagship species" that can rally support for conservation initiatives and can serve as a measure of the conservation status of important estuaries.
If you would like to receive regular updates, additional information, kiddies supplements etc. join our Seahorse Club for R50/year. Corporate Memberships are R400/year. Email
JFL@worldonline.co.za.
SANCOR Students Travel Award 2002: The Italian Experience
Peter Teske
University of Stellenbosch
On June 13-16, I had the privilege of attending the Molecular Evolution conference in Sorrento (Naples, Italy). Sorrento is a small, vibrant town near Naples, and has a spectacular view of Mount Vesuvius on the opposite side of Naples Bay. What must be the world’s most famous volcano is due for a major eruption soon, so during breaks between talks, we would scan the horizon for any dust clouds moving in our direction. The town is amazingly clean (considering how busy it is), and this together with perfect weather made for a great week. Another bonus was that paying in Euro (»R10) rather than Lira made getting ripped off virtually impossible.
The Molecular Evolution conference had a wide scope and included anything from human to bacterial evolution. Many of the world's leading researchers in these fields were present, including Craig Moritz (probably most well known for his widely accepted definition of ‘evolutionally significant units’, a concept that is providing a more workable alternative to the concept of‘species’), Masatoshi Nei (who pioneered evolutionary models) and Emile Zuckerkandl, (who introduced the concept of ‘molecular clocks’, a widely used method to determine divergence times between lineages by relating the number of mutational changes between them to known geological events).
Sorrento was chosen as the town to host the conference in order to celebrate the 130th anniversary of the Marine Research Station ‘Anton Dohrn’, the world's oldest permanent laboratory of marine biology (and still one of the most active). Hence, one full day was dedicated to recent progress in the field of marine biology. Among the most prominent speakers were Steve Palumbi (of marine Wallace's Line fame), Giorgio Bernardi, who presented an interesting paper on inter-island genetic divergence in three Galapagos fish species which resembles the pattern found in Darwin's finches, and Nancy Knowlton, who shared some new insights into the relationships of certain zooxanthellae with coral bleaching. During this session, I was given the unique opportunity to give an oral presentation on my work on the Knysna seahorse, Hippocampus capensis. It was well received, particularly because of its wide scope, which included an investigation of gene flow between the different populations, population history, and phylogenetic placement among marine seahorse species inhabiting the Indo-Pacific. The contacts made with other marine biologists at this conference will certainly be highly valuable for my future work.
I would like to take this opportunity to thank SANCOR for the significant financial contribution made to enable me to attend this conference. I was one of only two South African speakers out of a total of 229 (not to mention hundreds of poster presentations), but I think I was able to show that our research is of a high standard. The only thing I regret is that I didn't stay longer -it would have taken an extra week to explore the ruins of Pompeii and Herculaneum and do some SCUBA diving in warm, crystal clear water to fully appreciate what the region has to offer. Two of many good reasons to go back some day.
If you too would like the opportunity of traveling as part of your studies apply for the SANCOR Students Award 2003 now! Contact Pavs Pillay (SANCOR Secretariat)
History and Science: Friends or Foes?
Robyn Scott & Natasha Kruger
University of Cape Town
When you think of History, what is the first thing that crosses your mind? Unscientific? Story-telling? Not useful to us as scientists, right? Why? The method of data collection and the data itself is unreliable. But is it really? Or is our judgement clouded by preconceived ideas on what reliable data are? Have we ever tried to understand the methods of historians? Can their data be used for Science? These were some of the ideas discussed at the History of Marine Animal Populations (HMAP) Summer School and Workshop for 2002, which was held at the University of New Hampshire, USA from 5-15 August. Several countries participated in this project, including Australia, Russia, USA, UK, South Africa and selected European countries.
HMAP is part of the Census of Marine Life (CoML) group. The HMAP global research programme sets out to answer four basic questions: How has the extent and diversity of Marine animals changed over the last 2000 years? Which factors have forced or influenced the changes? What has been the anthropogenic and biological significance of changes? And finally what has been the interplay of changing marine ecosystems and human societies? To answer these questions HMAP is dedicated to encouraging collaboration between the disciplines of History and Ecology in order to get a more complete idea of what was going on in our
ecosystems during earlier times. 
