Jacob Nepper-Davidsen1,2, Christopher R. K. Glasson1,2, Philip M. Ross1,2, Rebecca J. Lawton1,2 and Marie Magnusson1,2
1Coastal Marine Field Station, School of Science, University of Waikato, Tauranga, New Zealand
2Environmental Research, Institute, University of Waikato, Tauranga, New Zealand
The native kelp Ecklonia radiata is a target for the emerging seaweed aquaculture industry in New Zealand, however, key knowledge regarding domestication and variability in biomass quality is still lacking. During my PhD, I have collected E. radiata samples from 12 sites within four regions around the North Island of New Zealand and analysed their genetic and biochemical composition. Using 13 microsatellite loci, I found that E. radiata shows strong genetic structure and low gene low both on local and regional scales and therefore recommend not to translocate cultivars of E. radiata outside their area of origin. Despite the strong genetic structure, no spatial patterns in biomass composition were found, and instead, an overall high content of commercially important components was found, including phlorotannins (6.6 ± 1.5 sd % dry weight), alginate (25.0 ± 2.4 sd % dry weight), and fucoidan (1.2 ± 0.1 sd % dry weight). Important components such as lipids, proteins, glucose, guluronic acid, nitrogen, phosphor and iodine showed significant seasonal fluctuations (measured by autocorrelation), underlining the need for timed harvest depending on the product of interest. Combining the biochemistry data with spectroscopy data, I constructed models for fast and easy determination of biomass quality for industrial purposes, and together these findings provide a foundation for developing sustainable aquaculture practices of E. radiata.