Exposed only at low tides, growing amongst deep-water rocks on the open coast, a brownish red seaweed makes its home. During the peak flourishing months, locals harvest bunches of fresh karengo (species of seaweed found along Māori territory) from the rocky shore. Later in the day the seaweed hangs along fences, basking in the sun as it dries. Following traditional Māori kai (food from sea and forest) method, the karengo is cooked slowly until the tough flesh turns soft.
Paving the way for the future of New Zealand’s aquaculture industry, The Cawthron Institute is collaborating with Te Rūnanga o Ngāi Tahu and Wakatū Incorporation to study the native species of karengo. This red seaweed grows along intertidal shorelines, along the rocky east coast of the South Island, along with some parts of the North Island coast. The research program, “He tipu moana he oranga tangata: Revealing karengo as a high-value functional food,” predominantly took place in August and September, when the karengo flourished from around the Kaikoura to Bluff regions. Similar to Japanese nori, karengo has been used for centuries as a traditional Māori food source. The researchers have been working closely with Indigenous People to better understand the seaweed’s capabilities and Māori preparation. The study received $3 million to perform their research, courtesy of the NZ Ministry of Business, Innovation and Employment.
The aim of the study is four-fold: in order to identify the seaweed, develop a method for algae protein extraction to retain important components; assess the value of the algae when used in food products; analyze the composition; determine the health and nutritional benefits.
With these objectives in mind, the team hopes to help develop a high-value industry with this karengo seaweed at its center. In the words of team researcher and Head of Analytical Research & Development at The Cawthron Institute, Tom Wheeler, the end goal is to develop karengo-infused foods that are “desirable as well as being nutritious.”
In the process of experimentation, Wheeler and his team cataloged karengo samples and completed DNA-based sequencing to identify each karengo species. They identified each species based on form and structure (morphology), as well as the genetic basis. The team extracted the protein composition of each sample through the processes of transcription of DNA to RNA and translation from RNA to protein. Through holistic categorization, the team could distinguish between outwardly similar forms of algae.
Wheeler said in a statement that it could take between five to ten years for the program to conclude with the results they have in mind, but much has already been discovered. Through their protein-sequencing program, the team has already identified five species and 2 genera. They have found, to date, two species in the Porphyra genus and three in Pyropia. All of these species were found to have valuable nutritional properties, some including all essential amino acids, micronutrients such as Iron, and anti-inflammatory bioactives. These bioactives have been shown in other studies to help diminish pain and inflammation caused by conditions such as chronic lung and inflammatory bowel diseases. In an interview, Dr. Wheeler highlighted the importance of these findings, citing their nuance in a “plant-based protein from a source that hasn’t really been utilized so far in terms of the food industry sense.”
Karengo is no new discovery. Professor Mithen, Chief Scientist for the New Zealand High Value Nutrition National Science Challenge, notes that “Karengo is part of the exceedingly rich native flora of Aotearoa New Zealand.” What is worth the $3 million in funding is the massive potential of the seaweed industry for New Zealand. Mithen continues, saying, “Harvesting karengo in a sustainable manner will lead to the development of new foods to benefit the health of the people of New Zealand and offer innovative export opportunities for business.” As more people are beginning to realize the implications of the dairy and meat industries, the demand for alternative protein sources continues to increase. Another study on the structure of algae noted that the physical composition of algae makes it well suited for making nutraceuticals, or high-value nutritional supplements. Plant-based proteins are derived from all sorts of resources, with often a lessened environmental impact and heightened nutrition.
A new high-value industry would be monumental for New Zealand’s aquaculture industry, joining the broad market of fin-fish and shellfish. Research such as this project will help drive investment into the seaweed industry. Wheeler emphasizes that “this kind of research and development will inform investment and policy making that supports the sustainable long-term growth of the industry”. It is the hope of the research team and those funding their research that seaweed will become the third pillar of New Zealand’s aquaculture industry.
There is still much exploring left uncovered in the realm of seaweed research. Along the coast of New Zealand alone, there are hundreds of varieties of native seaweeds. Their unknown composition and bioactive potential alludes to years of future discovery.
It would be unjust to study karengo and its nutrition potential without acknowledging the traditions of the Māori people who have been using this seaweed for centuries. Researchers from The Cawthron Institute have collaborated closely with both Te Rūnanga o Ngāi Tahu and Wakatū Incorporation to incorporate Indigenous perspective into their work. Alongside these organizations, the researchers learned about traditional cultivation practices and preparation methods, as the Māori have been using karengo for its nutritional value as a staple in their diets. As this project continues, the team has acknowledged the importance of sustainable development of karengo cultivation and the seaweed market. Once the capitalist actors become involved, it is often difficult to maintain sustainability as a priority. Yet, without a positive environmental perspective, an irresponsible exploitation of karengo would quickly decimate the variety of species.
Although there are many components to sustainable development of such industries, it is essential to establish safe practices for the long-term wellbeing of the ecosystem. The project will work alongside local partners to determine the most conscientious methods for harvesting and preparation, with heavy emphasis on Indigenous knowledge. It will be interesting to see in twenty years how this project and others like it redefine New Zealand’s aquaculture industry and the lasting impacts –– the good, the bad, and the algae.