# Analysis of Seaweeds from South West England as a Biorefinery Feedstock
## 1 Introduction  
Annually, over 25 million tons of macroalgal (seaweed) biomass is harvested globally, with the vast majority (95%) of this produced in Asia. The total market is currently worth $5.6 bn, with food products for human consumption making up approximately $5 bn of this [1] and the rest predominantly from animal feeds, fertilizer, pharmaceuticals and cosmetics. Recently, seaweed consumption by cattle has even been suggested as a useful way to decrease greenhouse gas emissions and combat climate change: when _Asparagopsis taxiformis_ was used at 2% concentration in cattle feed, a significant reduction in methane production was observed [2]. With limited space for agricultural expansion in the terrestrial environment, the exploitation of seaweeds is gaining increasing attention in regions not traditionally associated with its mass cultivation and consumption. Whilst direct human consumption arguably remains the most easily accessible market in these \"new\" regions, a lack of cultural and social awareness and/or acceptance of the benefits will most likely hinder uptake. However,beyond food/feeds consumption, there is potential for seaweeds to be used as valuable feedstocks for biorefineries producing multiple products aimed at alternative markets [3]. \"Bio-refining\" separates biomass into a range of fractionated products in an attempt to maximise the value and use of biomass. Combining the production of high-value specialty chemicals and nutraceuticalals alongside lower value products, such as fuels, fertilisers, polymers and fillers, can create a sustainable production system where little to no waste flow is generated, therefore decreasing negative environmental impacts and improving economic viability [3; 4]. Europe is attempting to increase its level of seaweed production; however, almost all this production is by wild harvest rather than active farming [5]. The UK, with its extensive coastline and temperate waters is ideal for high-value seaweed production; yet, it was estimated that in 2013, the seaweed production from wild harvest in the UK was merely 2000-3000 dry tonnes, providing a huge opportunity for growth [5]. Commercially, the seaweed harvesting sector in the UK is underdeveloped, with only 27 UK-based companies--mostly small- to medium-sized enterprises (SMEs)--harvesting and selling seaweed, and just 16 of those harvesting within UK coastal waters [5]. Within the UK, there has been a recent flurry of activity from the academic community on seaweed biomass conversion (albeit low value), seeking to develop simultaneously created multiple fuel and fertilizer products, rather than a sole wholefood product, suggesting the biorefinery approach could gain momentum [6]. Indeed, several trials for seaweed cultivation in the UK are currently underway across the South West where high levels of sunlight provide favourable growth conditions. Plans for a seaweed farm in the South West, which could produce biofuels, medicines and bioplastics was submitted to the Marine Management Organisation at the end of 2018 [7], and a European Maritime and Fisheries Fund supported project to trial off-shore cultivation techniques in the South West has recently been supported and will begin in the summer of 2019. The potential interest in placing offshore wind farms in the South West may provide a potential site for co-cultivation with subsidised infrastructure costs; indeed, combining different commercial activities in a single area may help to mitigate the conflicts of interest that invariably arise when offshore waters are claimed for a variety of different, and often overlapping, uses [8]. However, even before the not insignificant regulatory hurdles can be overcome, the licence requirements must be ascertained and cultivation know-how established [5]; if this fledgling industry is to be successful, the identification of potential target markets outside of the limited domestic wholefood sector is of the utmost importance.