Seaweed farming is a global business that is carried out in at least 56 countries around the world, although more than 99% of production is in Asia. In 2018, OECD countries accounted for more than 60% of the total export value (US$1 billion) of seaweed traded for direct human consumption or as raw material. European countries accounted for almost half of the value of global imports (USD 1.3 billion) of seaweed-based thickeners. Currently, algal biomass produced by aquaculture has expanded with a production of up to 32.4 million tons (FAO, 2020). In Mexico, algal exploitation has developed mainly in Baja California from natural populations, and recent aquaculture efforts have been successful. In contrast, on the Yucatan coast, even with the diversity of algae found, there is no current exploitation. Preliminary experiences showed that the Yucatan peninsula is ideal for algal culture; during 2002 the pilot culture of Kappaphycus alvarezii was successful in Dzilam de Bravo, with growth rates of up to 6.5 ± 1 % day-1 (Robledo et al., 2013). Recent experiences under Integrated Multitrophic Aquaculture cultivation have shown great potential for Solieria filiformis and Halymenia floresii.
Currently, SEPASY- Secretaría de Pesca y Acuacultura Sustentable de Yucatán is supporting the fisheries sector through the development of aquaculture, including seaweed culture. This study is part of that effort, in which an estuarine area was evaluated for the cultivation of algae of potential interest in Ría Lagartos, in collaboration with the fishermen’s cooperative "Pepineros de Río Lagartos". Vegetative specimens of native red algae, selected from wild populations and acclimatized strains, were cultivated in an experimental oyster farm (Table 1, Fig. 1). Outdoor culture systems use low-cost infrastructure under natural conditions; growth rates of each cultivar were determined, and environmental parameters were monitored during the study (2021-2022). The algae were subject to strong environmental changes, especially salinity and temperature, therefore growth rates were highly variable throughout the study period. Some species acclimated to estuarine conditions with positive growth rates (Rhodymenia pseudopalmata, Gracilaria cervicornis and Crassiphycus corneus), which varied by season and species. Rhodymenia pseudopalmata showed a growth rate of up to 8.0 ± 1 % day-1 during the summer of 2021, demonstrating a high potential for cultivation. Acclimatization and cultivar selection is crucial for successful cultivation and to evaluate different coastal zones to optimize cultivation.