BalanceBlue Lab Seaweed Safari: Part Two

Because seaweed is so important to the ocean as well as to people, the BalanceBlue Lab at the Anderson Cabot Center for Ocean Life is working to increase the adoption of environmentally responsible practices for harvesting and farming seaweed. BalanceBlue Lab is a science and innovation hub that utilizes cutting-edge research and market-based solutions to support responsible ocean use and promote a blue economy that protects our ocean. We drive entrepreneurs, ocean industries, and others toward ocean-friendly practices, sustainability goals, and climate adaptation strategies. 

Last year, we traveled all over the world to get up close and personal with many species of seaweed, and to learn more about different harvesting and farming practices. In part one, we visited Iceland, Australia, and Scituate, Massachusetts—right in our own backyard! Where will we go next? Read on to find out! 

August: South Sulawesi, Indonesia – Spinosum (Eucheuma denticulatum) and cottonii (Kappaphycus alvarezii) 

Three plane rides later, Matt and Lena went from cold, blustery Australian winter weather to warm and sunny South Sulawesi, Indonesia, which is a hotspot for seaweed farming. Local villages primarily farm two species of seaweed—spinosum, also known as Eucheuma denticulatum, and cottonii, also known as Kappaphycus alvarezii. Unlike the other types of seaweed we had observed on our journey so far, which were all species of brown algae, spinosum and cottonii are red algae, the most diverse group of magroalgae!   

We learned how to tie seaweed “seedlings” onto lines using a special innovation called the Made Loop (pronounced ma-day) after its inventor, Made Simbik, a pioneer in the seaweed farming industry… and we were lucky enough to be taught by the man himself! We also visited seaweed farms using wooden canoes powered by outboard motors. These farms are often close to shore, where the water is deep enough to farm using a longline, essentially an underwater clothesline. Seaweed farmers will repurpose plastic bottles and tie them to the longlines as floats. Because the bottles are so light, they will shake back and forth with waves and tides, which, in turn, agitates or shakes the seaweed. This helps the seaweed to grow. When the seaweed is large enough, farmers will collect the entire longline and bring it to shore, where the seaweed is removed and dried in the sun before it is sent for processing. One family farm might consist of between 200 and 1,000 50-meter (164-foot) longlines, each of which can grow about two metric tons of seaweed at a time!  

Farming seaweed has very different environmental factors that need to be considered compared to seaweed that is harvested from the wild. In tropical areas such as Indonesia, it is important that sensitive marine ecosystems, such as coral reefs and seagrass beds, are not removed or excessively shaded by seaweed farms. Seaweed farms are also vulnerable to pest algae and epiphytes growing over the farmed species and potential damage from herbivores, including rabbitfish and even sea turtles! However, with the use of good practices, such as carefully locating seaweed farms to avoid vulnerable habitats and marine life, these risks can be reduced.   

During our visit, our hosts treated us to an important part of local culture – lots of yummy food! Some of our favorites were nasi bakar (rice grilled in banana leaves) and pisang epe (mashed banana with chocolate).  

September: Norway – Cuvie (Laminaria hyperborea) 

After a short break, Lena was off again, this time with Michelle to southern Norway to check out another cold-water brown seaweed species, cuvie (Laminaria hyperborea). Unfortunately, the commercial seaweed harvesting fleet had moved farther north just as we arrived; however, several off-duty harvesters were kind enough to give us a demonstration. Like in Iceland, in Norway, seaweed harvesters use boats; however, in Norway, the entire seaweed is harvested, including the holdfast

Because this type of harvesting completely removes the seaweed, the Norwegian Institute of Marine Research monitors the locations where Laminaria is harvested for indicators of resource recovery. Other techniques to minimize environmental disturbance are also used; for example, areas open to seaweed harvesting are subdivided into “fields,” and neighboring fields are not harvested. Once a field is harvested, it is not harvested again for four to five years. These types of techniques may seem a little strange for a “fishery” that takes place in the ocean, but they share a lot of similarities with how land-based farms and forests are managed!   

On this leg of the trip, we also had a lot of fun (unsuccessfully) trying to befriend some of the wild sheep that roam the area, hiking, and sightseeing—we even managed to spot some Ascophyllum seaweed growing right at the base of the Langfoss waterfall!  

October: Massachusetts, USA  

After an action-packed few months, it has been great to be home and reflect on how very wide the wonderful world of seaweed is! Every site we visited was unique and had its own method of harvesting or farming seaweed, and yet all of them had welcoming and passionate harvesters who were excited to share their work with us. We will use this experience to inform our work supporting the adoption of more environmentally responsible practices throughout the seaweed industry. These approaches will need to be flexible, innovative, and collaborative, as it is clear that there cannot be a one-size-fits-all approach! 

Thanks for following along on our “seaweed-ventures!” 

Much of the work described above was made possible through a collaboration with IFF’s Responsible Seaweed Sourcing Program. The BalanceBlue Lab would also like to extend our thanks to the many wonderful seaweed experts who hosted us during our travels and shared their knowledge with us.  

For more information on IFF’s Responsible Seaweed Sourcing Program, you can visit The Science and Creativity of Seaweed