Seaweed for a sustainable future

Seaweed is a type of macro-algae generally live on the bottom of shallow waters that are exposed to sunlight. It is a lower level plant belonging to the thallophytic division. The classification of seaweed is divided into 4 classes based on its pigment content, namely green seaweed (Chlorophyta), red seaweed (Rhodophyta), brown seaweed (Phaeophyta) and blonde seaweed (Chrysophyta). All parts of the seaweed body are called the thallus. There are various forms of seaweed thallus, some are shaped like discs, tubes, pockets, hair, and so on. The thallus can be composed of only one cell, but most seaweed has a thallus that consists of many cells (multicellular). The nature substance of thallus are varies, some are soft like gelatin (gelatinous), some are hard because they contain calcareous substances, other are soft like cartilage (cartilaginous), fibrous and porous (spongeous) and so on (Soegiarto, 1978). The factors that affect the growth of seaweed are temperature, current, salinity, degree of acidity (pH), tides, substrate and nutrients. (Eidman, 1991). Seaweed as fast-growing algae uses energy from sunlight while absorbing nutrients and carbon dioxide from the seawater. Scientists also believe it could help fight global warming.

Seaweed production has according to the UN’s Food and Agriculture Organization grown exponentially in the century, with volume doubling between 2005 and 2015. More than 30 million tons are being processed annually and the value of companies in this sector has already reached 6 billion dollars. Seaweed is most often used in human food. However, cosmetics, medicines, toothpaste, and pet food often contain hydrocolloids derived from the plant, due to its gel-like nature. The production is a rapidly developing trend in many countries. Indicating that many seaweed farms have been established in Europe and North America due to the increase in demand in food and other sectors in recent years, seaweed can be used as a food and food source and can replace petroleum-based plastic in packaging. Further seaweed products being worked on are water capsules, drinking straws, textile and other plastic alternatives.

Ocean Rainforest from the Faroe Islands, located between Norway and Iceland, is one of several seaweed companies that have sprung up in Europe in recent times. However, the vast majority of commercial harvesting happens in Asia. Olavur Gregarsen, the company’s director, says they are growing seaweed on hundreds of nets stretched along these shores. There are 50 thousand meters long knitted nets in the harvest area. Gregarsen states that since the main body is 10 meters under water, it is not affected by waves. He emphasizes that the water temperature in this Danish region is 6-11 degrees, and that these deep and nutrient-rich waters are suitable for growing algae. Other companies are growing seaweed in on-shore ponds and tanks. For one thing, this enables the producers to more easily regulate the climate and conditions. One example of an inland farm is AlgaPlus in Portugal. Canada and South Africa also have inland farms. The labor-intensive process of harvesting is one reason it has been slow to catch on in Europe and America. Mechanization and up-scaling are still needed for the west to make it a viable business. Farming systems are also difficult to set up and there is usually no set formula; conditions for farming tend to be unique to the local area.

Seaweed also has great potential as a renewable energy. The concept of renewable energy has been known since the 1970s as an effort to keep pace with the development of nuclear and fossil fuels. The most commonly used definition is an energy source that can be quickly recovered naturally, and the process is sustainable. The main sources of renewable energy are geothermal, solar energy, wind, hydropower and biomass or biofuel. This term biofuel describes a diverse range of technologies that generate fuel with at least one component based on a biological system. Biofuels may provide a viable alternative to fossil fuels; however, the technology must overcome a number of hurdles before it can compete in the fuel market and be broadly deployed. These challenges include strain identification and improvement, both in terms of oil productivity and crop protection, nutrient and resource allocation and use, and the production of co-products to improve the economics of the entire system. Although there is much excitement about the potential of this biofuel, much work is still required in the field. The International Energy Agency expects that biofuels will contribute 6% of total fuel use by 2030, but could expand significantly if undeveloped petroleum fields are not accessed or if substantial new fields are not identified.

Seaweed has a high starch substance; cellulose and water making it suitable for bioethanol which requires energy and water in the production process. The production method used is with the help of enzymes to release sugar from seaweed starch, fermentation, refining and drying. The refining process requires energy intake in the form of heat.  Using Seaweed to generate fuel has thus far had very little traction in the biofuels industry. This is despite the fact that seaweed has an advantage compared to land based biofuel, it typically grows faster than land based crops and it is capable of being cultivated in a number of different climates. Seaweed also grows in marine environments so it avoids the issues associated with land-use and competition with traditional food crops.

Seaweed is increasingly gaining attention as a potential feedstock for biofuels. Technological aspects are showing promise. But as it being examined more widely, there are still some ways to go before seaweed becomes a viable option for producing fuel and some of the other uses being researched. It is clear that very little is known about the potential economic, social, environmental and political/legal issues that might arise in the development of this industry. But then again, technologies such as solar and wind energy were also once too costly to be realistic solutions. Further research is needed to ensure that a proactive approach is used to research and inform stakeholders who will affect the further technological development and commercialization of the industry. With the ever-increasing threat of energy security, oil price volatility and growing political pressure to reduce greenhouse gas (GHG) emissions, the need to develop a sustainable and economically viable alternative to traditional fossil-based fuels and to develop deep decarbonization strategies has never been greater.