Aquaculture intelligence with Hatch Innovation ServicesA framework for understanding the diversity of the seaweed industry

The discourse surrounding seaweed is often oversimplified – with many people speaking of seaweed in general while overlooking the intricate realities of seaweed farming in different contexts.

Although challenges such as warming waters and extreme weather events affect many commercially farmed species, each species and market faces unique issues. To better understand the current state of global seaweed production, we can categorise these challenges into four key dimensions: temperate versus tropical seaweeds and emerging versus established farming regions.

Temperate vs tropical seaweeds

Cultivating seaweed in the tropical belt is radically different compared to the temperate zones. Tropical seaweeds, such as Gracilaria and Eucheumatoids, allow for year-round production with growth cycles of only 30 to 45 days. This quick turnaround enables farmers to initiate, increase, or pause production in response to market trends or external factors. In contrast, temperate seaweeds are typically seasonal crops, primarily farmed during winter months in the Northern Hemisphere and summer in Southern Hemisphere. For example, kelps are seeded and harvested only once a year, with relatively short time windows for these activities. While Pyropia can be partially harvested throughout the season, it is highly perishable in its unprocessed form, necessitating processing facilities that can extend operations. Farmers of temperate species must thus meticulously plan ahead to ensure that their harvests align with market demand.

Whether they’re tropical or temperate has many other implications for the farming practices. Here are two of the more distinct ones:

In temperate zones, the seasonal nature of production requires a land-based hatchery stage to produce seed material for the following farming cycle. The land-based stage for temperate seaweed ensured investment into seedbanks and hatchery work, with the selection of the best-performing crop and improved seed material being available to farmers, either through cooperative hatchery operations (such as used in Japan) or privately owned hatchery operations (such ad used in South Korea). In contrast, tropical seaweeds do not necessarily require this step and have predominantly relied on clonal propagation since farming began in the 1970s. The lack of a similar infrastructure for tropical seaweeds has resulted in a decreased pool of genetic diversity, making crops more vulnerable to pests, diseases and climate change effects.

Another significant difference is in post-harvest handling methods. Sun drying is the most common method for stabilising biomass in tropical regions due to high sunlight exposure year-round. However, this relatively low-cost technique often leads to minimal innovation in processing steps and product development. Furthermore, sun drying can destroy valuable compounds in the seaweed. On the other hand, temperate regions face challenges related to having short weather windows for harvesting large amounts of biomass simultaneously. This has driven farmers to explore diverse alternatives to drying – especially given the high energy requirements involved – leading to the exploration of more diverse and innovative product applications.

Lastly, a strong differentiating factor between tropical and temperate seaweed farming lies in their socio-economic contexts. Tropical seaweed farming often occurs in developing countries within the global South and is dominated by smallholder farmers who operate small farms in less regulated environments. For many coastal communities in these regions, seaweed farming is one of the few sources of livelihood, increasing their dependency on this activity while also exposing them to exploitation risks.

In contrast, temperate regions—typically found in developed countries within the global North—feature more company-type farming businesses due to more regulated access to farming. Farmers do have other economic opportunities, so seaweed becomes either a “side gig” as we witness in many North American emerging seaweed farming regions, or the next generations of farmers are lacking due to more attractive employment opportunities in the cities, such as the Japanese and South Korean trends show.

Emerging vs established seaweed farming regions

When comparing established versus emerging seaweed farming regions, we see that established areas tend to exhibit a market pull that facilitates scale. For instance, East Asia has a long-standing cultural appreciation for seaweed as a staple food source. Similarly, Southeast Asia has experienced increased global demand for carrageenan and agar derived from cultivated seaweeds. In both cases, markets were initially supplied by wild-harvested seaweed; however, demand quickly outpaced supply, justifying the development of farming.

Conversely, many emerging seaweed farming regions perceive aquaculture as an opportunity for people, planet and profit but often lack a clear market pull to justify increased farming operations. This situation is frequently compounded by stringent regulatory environments due to the novelty of the activity and limited room for error. When seaweed farming began in now-established regions around 50 years ago, there were fewer regulations; now that these markets have matured, they tend to navigate existing businesses and supply chains.

Hatch Innovation Services, in collaboration with The Nature Conservancy, recently conducted a deep dive into policy frameworks for seaweed aquaculture across emerging, growing, and established seaweed farming nations to provide policy recommendations for nations at different stages of their seaweed industry development. The second part of this article series will share some of the findings.

In the third part, we will give our view on seaweed production trends. Since, of course there are also many nuances within the four categories presented here, we will go a bit more in-depth and share our predictions about where we can expect most of the seaweed biomass in the near future to come from.

Conclusion

To conclude this part, I suggest that we should go beyond talking about one generic seaweed industry. While discussing specific species may not always be practical, the four dimensions are presented instead. This approach will elevate conversations among stakeholders who strive to address the challenges faced by their respective seaweed sectors and apply targeted solutions tailored to their unique contexts. The most significant challenges from our perspective can then be summarised in the following overview.