Rúben Marques1*, Adrian K.A. McLeod1, Norman Clough2, David H. Green1, Adam D.Hughes1
1 Scottish Association for Marine Science (SAMS), PA37 1QA Oban, United Kingdom
2W. L. Gore & Associates, Inc., Delaware, USA
The seaweed industry is a huge global industry worth over $11 billion per year, however cultivation technologies are still in relatively nascent stages of development in the UK and other parts of Western Europe. The successful production, deployment and growth of seeded materials is a principal concern in determining operational costs and subsequent yield. The search for efficient, reliable and durable cultivation materials (e.g., ropes, twines) contributes to the economic and environmental success of seaweed aquaculture. Seaweed producers can avoid high nursery costs and uncertain production yields, while promoting circularity of cultivation materials and sustainable practices.
We assessed the performance of different cultivation material microstructures on the growth and early development of gametophytes and spores of brown macroalga (Saccharina latissimi and Alaria esculenta) from the West coast of Scotland, UK.
For this, different microstructures were seeded either with (i) gametophytes, (ii) spores, or (iii) gametophytes in combination with hydrocolloid binders. The trials combined several controlled flume-based studies seeking to understand material microstructures, flow (50cm s-1), and binder interactions. Materials with high porosity and complex microstructures presented a range of cultivation benefits for gametophytes. Spore seeding showed promising results by an increase in the number of active growing loci per mm2, especially on microstructures with pore sizes of > 15µm. Binder trials demonstrated improved ‘seed’ retention in high-energy environments typical of many cultivation sites.
Overall, results suggest that the microstructure of seeding materials plays a crucial role in the growth and early development of cultivated macroalgae.