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Renewed focus on Wild Coast places 13-year dataset in high value
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Wild Coast... a name affectionately and very aptly applied when describing the 300-km stretch coastline of the north-eastern shores of the Eastern Cape Province.
The Wild Coast is world renowned for its desolate beaches, spectacular rocky shores, steep coastal cliffs, friendly locals and some of the most pristine estuaries in the country. Ask anyone who has travelled this coastline and they will almost certainly, very confidently attest to these attributes.
Final frontier?
To the marine scientist the Wild Coast is a treasure trove of research opportunities. For a variety of reasons, what we know about the Wild Coast compared to other coastal regions of South Africa is but a drop in a bucket. Follow any discussion on mesoscale processes related to the southeast coast of South Africa, be it physical or biological in context, and invariably confident interpretations will make way for quiet ponderings and unsure speculative remarks over what “probably happens along the Wild Coast”.
This hiatus in available data and lack of understanding still experienced today, even after 20 years of democracy (being independent homelands pre-1994) and free and open access to this coastline, should be concerning to us all. This, despite the fact that most areas along the Wild Coast really are pristine, from where can be observed patterns and processes in the absence of many factors way more difficult to eliminate in the developed world.
Pristine habitats also provide unique opportunities for interrogation by means of conducting interesting field experiments. One can simply not ask for a better natural laboratory anywhere else in this country. To make things even more appetising to the marine scientist is the fact that this coastline forms a transition zone between subtropical and warm-temperate waters. This is where one would find marked changes in biological communities as compositions change from subtropical to warm-temperate species.
Being an area of overlap also means that species diversity in some communities is higher compared to those found in the adjacent biogeographical provinces. Arguably the most significant characteristic associated with transition zones is the notion that they are rather sensitive to environmental changes. Harley and co-workers (2006), who are authorities on the subject, argue very convincingly that populations living within transition zones are naturally stressed as here they exist near the edge of their natural distribution ranges. As such, the advent of predicted climate change - which includes expected changes to temperature regimes of coastal waters - is very likely to affect transition zone communities.
The most obvious change to be expected is a shift in species distribution ranges. Tropicalisation is the new buzz-word in this context. With rising sea temperatures, subtropical species are expected to venture further south and west, while the north-eastern limits of warm-temperate communities will become more contracted. Such responses have already been reported by local scientists (e.g. James et al., 2008).
To anyone mildly interested in climate change science, the light bulbs should start flickering right about now! Here we have a unique opportunity to study, in real time, the manner in which coastal communities respond to changes in coastal temperatures associated with climate change. No guessing, no speculation, a real opportunity to conduct actual and direct observation of change.
The social element
Why should we be concerned over changes in the biological communities of the Wild Coast? With industrial development and tourism expected to increase in the near future we should be concerned. There is no way impacts on natural systems from such activities (in conjunction with the potential effects of climate change no less!) can be measured or advised against without having in place sound knowledge of their basal functioning.
The same counts for the communities who call this part of the country home. Many have lived in relative harmony with nature and are still today very reliant on resources harvested from estuaries, beaches and rocky shores. It is for this reason that local communities are for the most part very protective of their natural surroundings and not as ignorant to the principles of conservation as many would think.
Case in point, on several occasions I have personally been interrogated by locals over what my intentions were with collecting so many small fish in plastic bags, asking quite assertively: "How are we to catch our fish tomorrow if you kill all the baby fish today?"
Of course the "baby fish" I was killing was no more than 500 grams of estuarine round herring (Gilchristella aestuaria) kept for measurement. Being super-abundant in Wild Coast estuaries we never thought of this being a problem; besides they are virtually impossible not to catch when pulling a seine net and almost always perish as contact is made with the mesh. Nonetheless the man could be forgiven for accusing us of killing their “baby fish”, seeing this species rarely exceed 7 cm in length once fully grown! The relief on the man’s face learning that we were in fact not “killing” their fish speaks volumes of the sense of ownership the local communities put to coastal habitats that have been sustaining them for many, many years.
This being true, how do we measure the impact of future development on local communities and their intertwined living with natural coastal habitats if we do not even understand the role they play in the coastal ecosystems we are yet to study? Now add the potential effects of climate change and you end up with a mighty concoction of uncertainty.
A flicker of light at the end of the proverbial tunnel
It is not all doom and gloom. There have been several champions pushing research along the Wild Coast from the 1970s to 1990s. Trevor Steinke performed important work on mangroves, Emile Plumbstead and Trevor Harrison on estuarine fish, Anton McLahlan on beach fauna, Arthur Dye on estuarine meiofauna and Allan Connell and Tris Wooldridge on beach and estuarine mysids (and zooplankton in general), to name a few.
Even so the majority of these studies were limited to specific habitats or regions and were generally short in duration due to no fault of their own - the Wild Coast was a challenging environment to work in back then as it is now. These projects and the data they produced laid the foundation upon which a number of “new generation” projects were built around the turn of the century.
I was fortunate enough to join one such a programme initiated by Prof. Tris Wooldridge in 2001 through the Zoology Department of the University of Port Elizabeth (now NMMU) . What was a team of three initially setting out to study zooplankton and subtidal macrozoobenthos in two adjacent but very different estuaries south of Port St Johns, namely Mngazi and Mgazana estuaries, became an army of students four years later studying everything from benthic algae to fish and trophic linkages between beaches and estuaries. In all, the programme provided a platform to numerous honours, 12 MSc and six PhD studies to date.
In 2007, the programme extended south to include bi-annual sampling in the Ngqusi/Inxaxo confluence at Wavecrest. The special aspect of this programme worth mentioning here is the fact that Prof. Wooldridge never stopped sampling despite the weaning number of student projects, availability of funds or equipment. The result is a very impressive dataset covering 13 years of observations from a data-poor region, notoriously difficult to work in. And the best part is, it is still ongoing!
The dataset includes biannual zooplankton species counts and complementary physico-chemical data from the Mngazi (2001 and ongoing), Mgazana (2002-2008) and Ngqusi/Inxaxo (2007 and ongoing) estuaries, as well as a very impressive continuously measured temperature data series from the Mngazi that stretches more than 10 years.
The importance of this dataset cannot be quantified. Locally there exist only a few examples of datasets exceeding this temporal range, the East Kleinemonde Estuary Fish Community Monitoring Programme (1993 and ongoing) run by the South African Institute for Aquatic Biodiversity (SAIAB) being one example (visit http://www.saiab.ac.za/dr-nikki-james/programmes/east-kleinemonde-estuary-fish-community-monitoring.htm). In terms of zooplankton, the Mngazi dataset is the longest standing collection to date.
Looking after such datasets is of paramount importance, particularly considering the recent spike in research interest in the coastal ecosystems of the Wild Coast. A number of student research projects are being run by Rhodes University and NMMU, with new ones coming on line each year. SAIAB has launched a long-term investigation into the influence of climate change on transition zone estuaries in 2010, focusing on several systems in the Dwesa-Cwebe Marine Protected Area, while Pennsylvania State University (via the Alliance for Education, Science, Engineering and Development in Africa ) in collaboration with several government, non-governmental and higher education institutions, has been driving the establishment of a Wild Coast Living Laboratory since 2012. Put all these initiatives on a map and the picture is starting to look much better!
An agreement has been reached to archive Prof. Wooldridge’s dataset with SAEON to ensure this information is kept safe for future work. The SAEON Elwandle Node will continue to support this programme logistically as much as possible to ensure it remains viable for years to come.
References:
Harley CDG, Hughes AR, Hultgren KM, Miner BG, Sorte CJB, Thornber CS, Rodriguez LF, Tomanek L and SL Williams. 2006. The impacts of climate change in coastal marine systems. Ecology Letters 9:228-241
James NC, Whitfield AK and PD Cowley. 2008. Preliminary indicators of climate-induced change in a warm-temperate South African estuarine fish community. Journal of Fish Biology 72: 1855-1863.
