© SAMS
The researchers at the Scottish Association for Marine Science (SAMS) have recorded biomass doubling every week in the institute’s aquarium. Palmaria palmata is highly sought after as a high-end food product – it is roughly 40 times more valuable per tonne than kelp – and can be used in food, feed, dyes, cosmetics, and pharmaceuticals.
Despite its value, the industry has historically struggled with high mortality rates during the hatchery stage due to disease and a complex reproductive cycle. The cultivation method developed at SAMS, a partner of the UHI, has sought to overcome these challenges.
The team identified a bottleneck at the problematic hatchery phase, as the species has a short reproductive window and the sexual maturity period of males and females is different, posing challenges for growers to control its life cycle. Often, a mortality rate of 60 to 70 percent is seen in spores at the initial hatchery stage.
By rebalancing the microbiome after introducing natural grazers and adopting probiotic methods to limit the spread of disease, microbiologist Dr Frederik De Boever has drastically reduced mortality rates in the Palmaria palmata spores to around 10 percent.
“The growth is phenomenal,” said Dr De Boever in a press release. “We’re growing the seaweed from the spore stage to germlings, which increases resilience, compared with vegetatively cut thalli from established adult seaweeds. The spore to germling mortality rate is usually high but in the lab we have more control over that crucial life stage.”
Currently, the global red seaweed industry relies heavily on a few number of species cultivated in Asia. However, these crops are increasingly threatened by climate change and disease. The SAMS tank-based method offers a biosecure alternative with a more pristine biomass, lower iodine levels, and reduced metal accumulation compared with open-sea farming.
Dr Puja Kumari, who heads up the FABRICS cultivation project at SAMS, said: “Red seaweed cultivation is important for the seaweed aquaculture industry because it contributes to half the net worth of world seaweed production. There is therefore an urgent need to diversify seaweed cultivation practices to include important UK and European red seaweeds to help address the uncertainty in the red seaweed global market supply, as well as address sustainability and net zero targets.”
The FABRICS project, funded by UKRI-BBSRC, also involves commercial partners W.L. Gore & Associates, Inc. in the USA and SeaDyes, a start-up based at The James Hutton Institute in Scotland that creates natural dyes from seaweed for the fashion and textile industries.
“Through our involvement in the FABRICS project, SeaDyes is working to establish a scalable and resilient supply of red seaweed biomass to underpin our sustainable dye technologies,” said Jessica Giannotti, founder and chief executive officer of SeaDyes.
