Potential scale of Scottish seaweed-based industries: research paper

2 Overview of seaweed products and uses

2.1.1 Seaweeds can be used as a raw material for multiple end uses including human foods, animal feed, horticulture and fertiliser, hydrocolloids, bio-actives used in the nutraceuticals, pharmaceuticals and cosmeceuticals industries, and biofuels (Cefas, 2016; Stanley et al., 2019).

2.1.2 The categories of seaweed-based products used within this report to compare the industry in other countries with Scotland and for the economic analysis are summarised in Table 1 (with further description provided in Appendix B). It should be noted that some of these categories overlap by virtue of their eventual end uses. For example, hydrocolloids are used in both human food products and pharmaceuticals and other personal care products. Equally, nutraceuticals might be considered as human food as products are ingested as a dietary supplement, although for the purposes of this study, they have been considered within the bioactive category.

2.1.3 It should also be noted that there are other novel and innovative applications for seaweed that have not yet been taken up on a large scale and remain in development. This includes using seaweed as a feedstock for biotechnology processes, such as biorefining^[5] to extract a range of products (with a range of values) from the whole seaweed plant, and/or the production of novel biomaterials to create alternative packaging materials. These biotechnologies remain in development in Scotland and they have been considered further within the projected future scenarios within Scotland (see Section 6).

2.1.4 Conversely, although there has been considerable interest over the last decade in the use of seaweed (particularly kelps) as a feedstock to produce biofuels, seaweed-based biofuels still face issues such as scalability and economic viability, whilst competitiveness and performance against other feed stocks need to be considered (Bruton et al., 2009; SARF, 2016; Stanley et al., 2019). As such, biofuels are considered unlikely to contribute commercially to the seaweed-based industry in Scotland over the next 20 years and are not considered further within this study. In general, opinion obtained from a range of industry and wider stakeholders (e.g. researchers) consulted to inform this work agreed with this decision.

2.1.5 Alongside extractive seaweed industries and products, seaweeds have wider potential applications, for example carbon storage ('blue carbon') and bioremediation purposes^[6]. However, due to the emerging nature of these industries and the difficulty of evaluating such ecosystem services, such wider applications have not been considered further within the socioeconomic analysis.