Ninety-five percent of the cultivated algal biomass is produced in Asia. Beyond the kelp Saccharina japonica and the eucheumatoid red algae, the genera Gracilaria and Gracilariopsis rank third in FAO´s global aquaculture statistics by biomass as of 2022. Among them, the red alga Gracilaria chilensis, has played a central role in Chilean aquaculture for decades, although production levels have shown fluctuations over time in response to market dynamics and environmental factors. Gracilarioids are primarily produced for the hydrocolloid industry (agar), with a smaller proportion also sold for human consumption in Asian countries (ogonori) or used to prepare beverages in the Caribbean islands. Gracilaria has also been demonstrated to be an efficient alga for bioremediating coastal waters. The primary culture systems used for farming gracilarioid species are floating culture lines. Bottom cultures on sandy shallow waters and intertidal systems are also used for farming. Land-based tank cultures have also been developed in various regions; however, due to their high costs, they have not been commercially implemented. Epiphytes and grazers are among the most relevant constraints that their cultivation faces today. Some pathogens have been identified but remain cryptic threats to gracilarioid cultivation. As with eucheumatoid algae, gracilarioids are clonally propagated. Studies support that these practices have reduced the genetic diversity of cultivated Gracilaria. For this reason, efforts have been made to seed ropes with carpospores, thereby reducing the risk of genetic diversity erosion. Nevertheless, the domestication of this species is still in its infancy; therefore, the potential success in facing stressful events must still be demonstrated. In contrast to Southeast Asian countries, where gracilarioids are successfully produced, cultivation in other regions, such as Chile, has decreased over the past few decades due to market demand restrictions. This decrease in its value has prevented the global expansion of gracilarioid farming. Here, we primarily cover culture systems and productivity, advantages and disadvantages of farming methods, the impact of epiphytes and grazers, and genetic and domestication efforts. We also drew on our experience cultivating G. chilensis to provide management recommendations, including integrated multitrophic aquaculture, biosecurity measures, and genetic diversification strategies, to guide the sustainable development of farming globally.

Open-sea cultivation of gracilarioids: The current state of Gracilaria chilensis cultivation in Chile

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发表日期：

2025年12月29日

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Alejandro H. Buschmann,
Sara Usandizaga

摘要

Ninety-five percent of the cultivated algal biomass is produced in Asia. Beyond the kelp Saccharina japonica and the eucheumatoid red algae, the genera Gracilaria and Gracilariopsis rank third in FAO´s global aquaculture statistics by biomass as of 2022. Among them, the red alga Gracilaria chilensis, has played a central role in Chilean aquaculture for decades, although production levels have shown fluctuations over time in response to market dynamics and environmental factors. Gracilarioids are primarily produced for the hydrocolloid industry (agar), with a smaller proportion also sold for human consumption in Asian countries (ogonori) or used to prepare beverages in the Caribbean islands. Gracilaria has also been demonstrated to be an efficient alga for bioremediating coastal waters. The primary culture systems used for farming gracilarioid species are floating culture lines. Bottom cultures on sandy shallow waters and intertidal systems are also used for farming. Land-based tank cultures have also been developed in various regions; however, due to their high costs, they have not been commercially implemented. Epiphytes and grazers are among the most relevant constraints that their cultivation faces today. Some pathogens have been identified but remain cryptic threats to gracilarioid cultivation. As with eucheumatoid algae, gracilarioids are clonally propagated. Studies support that these practices have reduced the genetic diversity of cultivated Gracilaria. For this reason, efforts have been made to seed ropes with carpospores, thereby reducing the risk of genetic diversity erosion. Nevertheless, the domestication of this species is still in its infancy; therefore, the potential success in facing stressful events must still be demonstrated. In contrast to Southeast Asian countries, where gracilarioids are successfully produced, cultivation in other regions, such as Chile, has decreased over the past few decades due to market demand restrictions. This decrease in its value has prevented the global expansion of gracilarioid farming. Here, we primarily cover culture systems and productivity, advantages and disadvantages of farming methods, the impact of epiphytes and grazers, and genetic and domestication efforts. We also drew on our experience cultivating G. chilensis to provide management recommendations, including integrated multitrophic aquaculture, biosecurity measures, and genetic diversification strategies, to guide the sustainable development of farming globally.