Date/Time
Date(s) - Mon 28 April
13:00 - 14:00
Environmental Research Institute, University of Waikato, seminar series.
Abstract:
Marine algal forests are dominant ecosystems around the world’s coastline and are of considerable ecological, economic, and cultural value. The health and productivity of these marine forests are dependent on good water clarity and underwater light levels, but healthy levels of coastal water clarity are jeopardised by the discharge of sediment resulting from extensive land-use (forestry, farming, urbanisation, coastal development) and the darkening of coastal waters. In this talk, we present recent techniques based on satellite measurements of ocean colour that allow us to quantify coastal water clarity and the characterisation of seabed light around Aotearoa New Zealand over the past 20 years. We show that the light environment at rocky reefs is undergoing contrasting changes, depending on regions and seasons. On shorter time scales, we propose the establishment of a novel framework, the “Marine Darkwaves” as periods of exceptional low-to-no light levels on the seabed in respect to light requirements to local macroalgal communities. We present work on the characterization of such extreme events based on in situ and satellite remote sensing case studies and we expand on current challenges and future opportunities. As part of the University of Waikato-led MBIE Endeavour Tau Ki Ākau Ridge to Reef program, this novel framework aims to connect catchments to coastal regions and will be instrumental in developing a future where land practices do not impair coastal ecosystems functioning and productivity.
Biography:
Francois (Frankie, he/him) is a postdoctoral fellow between the University of Waikato and the National Institute of Water and Atmospheric Research (NIWA), originally from France and based in Wellington. Within the Tau Ki Ākau – Ridge to Reef research project, his research investigates the availability of underwater light for coastal ecosystems around Aotearoa New Zealand, and in a multi-stressor context, such as changes in water clarity, coastal darkening, marine darkwaves and increasing marine heatwaves. To pursue it, he combines satellite remote sensing, optical modelling of underwater light and algal physiology. Previously, he was a PhD Student at the University of Canterbury (UC) in Christchurch.