Namrata Chand began diving in the coral reefs and warm crystal-clear waters around her native Fiji. Diving to sample seaweed in Otago Harbour for her PhD is quite a different experience.
Namrata Chand prepares the equipment for Joe and Will to collect seaweed. Photo: RNZ / Claire Concannon
Follow Our Changing World on Apple Podcasts, Spotify, Stitcher, iHeartRADIO, Google Podcasts, RadioPublic or wherever you listen to your podcasts.
‘I describe it as refreshing’ she says, ‘My first dive in Dunedin was in nine-degree water’.
Namrata, or Nam, is studying a type of endemic (found only in New Zealand) red seaweed called Adamsiella chauvinii. Instead of attaching to rock like kelp, this seaweed species can grow on the soft sediment habitat found in Otago Harbour. It is thought to play important roles for this ecosystem including taking up nutrients from the water and providing habitat for a range of other seaweed species and marine creatures.
For her research, Nam wants to understand where this red seaweed grows in the harbour and in what quantities, which nutrient, light and temperature conditions it likes, and what other seaweed species grow with it.
Namrata Chand separates out different seaweed species to weigh them to get species biomass data. Photo: RNZ / Claire Concannon
To do this, she has been sampling seaweed at sites in three different areas of the harbour. The samples are taken back to the University of Otago's Portobello Marine Laboratory where Namrata sorts them into different species and weighs them to get the biomass of each type.
Alongside this, over the last two years, Nam has been gathering data on the light and temperature conditions in each area, as well as water samples to do seasonal nutrient analysis.
In the footsteps of female phycologists, Nancy Adams (after whom the species is named), and her co-supervisor Professor Wendy Nelson, Nam has also begun pressing some of the seaweed samples she has collected. This has helped her to get up close and personal with the different species, aiding her identification skills. But it will also be part of her PhD legacy – Nam will deposit her pressed seaweed collection into the University of Otago herbarium for future students to be able to view and use.
In this episode, Claire Concannon joins Nam on her Autumn seaweed sampling trip to learn more about this ‘underdog of the ocean’, and the art of seaweed pressing.
As part of her PhD work Namrata Chand has prepared seaweed pressings of different species in the harbour. Photo: RNZ / Claire Concannon
To learn more
- Scientists elsewhere in Aotearoa are growing macroalgae for research purposes and to explore potential uses of native seaweed and freshwater macroalgae. Listen to this episode about the Facility for Aquaculture Research or Macroalgae in Tauranga Moana.
- Read about the life and work of Nancy Adams in Te Ara and/or listen to this piece on Afternoons with Jesse Mulligan with Kate Hannah.
- Listen to this recent interview on Nights with the Seaweed Academy in the UK.
