#02 2020

Science exploration and discovery at PSSA 2020

By Lucienne Human, Gavin Rishworth, Paul-Pierre Steyn, Pumlile Cotiyane, Daniel Lemley and Thomas Bornman

This year the Phycological Society of South Africa (PSSA) conference was co-hosted by SAEON’s Elwandle Node and Nelson Mandela University and held at the Wavecrest Hotel in January 2020.

Located along the South African Wild Coast, Wavecrest has a rocky shore, sandy beach and the Inxaxo and Ngqusi estuaries, which share a common mouth. The SAEON Elwandle Node’s biogeochemist, Dr Lucienne Human, completed his honours project on these estuaries 13 years ago.

As with all conferences, registration and the icebreaker event took place on the first day, on a sunset cruise up the estuary where we were welcomed by mangroves and fish eagles.

Icebreaker sunset cruise along the estuary (Photo: Paul Steyn)

On day two, Dr Gavin Rishworth, a senior lecturer in the Zoology Department at Nelson Mandela University, delivered a keynote address on life’s first ecosystem engineers, the stromatolites. Gavin highlighted the value of these unique habitats in the South African context, where living examples have recently been discovered. This was followed by a suite of excellent scientific talks spanning harmful algal blooms to the kelp industry.

After our day of invigorating talks, the organising committee suggested a hike in the forest to revive us. Unfortunately, the intense heat got the better of us and many were left lamenting the thought of the cool breeze left behind at the pool.

Although the views were spectacular on our hike in the forest, the heat was so intense that some of us wished we were back at the pool! (Photo: Gavin Rishworth)

Kelp forest along the rocky shore at Wavecrest (Photo: Paul Steyn)

Exploring the coastline

Day three was set aside for exploring and stromatolite hunting. After breakfast we departed to the rocky shore in search of adventure, heading south along the rocky shoreline.

Soon evidence of freshwater seepage was seen above the highwater mark and this spurred the expedition on. After about a kilometre of walking we found a small stromatolite accretion.

However, in the intense summer sun, the allure of the pool back at the hotel proved too great a temptation for some adventurers. While most of us returned to collect some macroalgae herbarium specimens, some continued onward in search of more stromatolites.

Those continuing the search soon realised that the rocky shoreline was in fact rich with stromatolite seeps – about 50 were seen in total. This is the first observation of these systems here and further research is planned in this idyllic location.

Some of the intrepid stromatolite hunters. From left – Dr Lucienne Human, SAEON, Prof Gavin Maneveldt, University of the Western Cape and Dr Daniel Lemley, Nelson Mandela University (Photo: Gavin Rishworth)

Finding stromatolite “gold” – a piece of the layered calcite-crystal accretion from a site south of Wavecrest Hotel (Photo: Gavin Rishworth)

Paul-Pierre Steyn of Nelson Mandela University and SAEON’s Tommy Bornman test the Diving PAM (Photo: Paul Steyn)

Snorkelling among the kelp. From left – Tommy Bornman, Lucienne Human and Pumlile Cotiyane (Photo: Paul Steyn)

During our time in the pools collecting macroalgae, we also had the opportunity to test SAEON’s Waltz Diving PAM fluorimeter. PAM, or Pulse Amplitude Modulated fluorescence measurement, is a method that uses chlorophyll fluorescence signals to collect data on the photosynthetic rate, stress response and light requirements of plants or algae.

The fact that it can be used underwater makes the Diving PAM different from most other such fluorescence measurement instruments. It will enable SAEON to monitor the health of our coral reefs, detect stress in seagrass communities and investigate the effect of seawater temperature change in kelp forests, to mention just a few applications.

Very few of these instruments are accessible in South Africa, and the newly acquired systems promise to provide Elwandle Node scientists with very valuable information.

The final day was set with some interesting scientific talks about kelp, followed by two intensive workshops on the use of algae in industry. The conference concluded with a gala dinner in the evening, where SAEON Elwandle Node student, Luca Stirnimann, was awarded the best student oral presentation.”