Overview of 3 year precommercial seafarming of Macrocystis pyrifera along the Chilean coast

Abstract

Chile is one of the main producers of seaweeds in the world; however, most of the production comes from harvesting natural beds and only 2.4% from cultures, dominated by the agarophyte Gracilaria chilensis. One of the most exploited resources is the giant kelp Macrocystis pyrifera, which is sold fresh for abalone feed and dry for alginate extraction. Recently, new possible markets are developing for this species, for example human consumption and biofuel/chemical production that could increase the demand and justify the development of a commercial cultivation system. The objective of this work was to present the recent development of the seafarming of M. pyrifera in Chile, focusing on the fundamental determinants of productivity in cultivated systems and the identification of the binding constraints to productivity. Three experimental plots (up to 21 Ha) were designed and deployed in three study areas (Caldera in northern Chile and Quenac and Ancud in southern Chile) to test different environmental conditions. During a period of 3 years, sporophytes produced in an indoor hatchery were deployed monthly, at different densities, and followed until harvest. Environmental parameters and biomass were monitored on a monthly basis. Our findings demonstrate the feasibility of Macrocystis seafarming on a large scale in Chile. Important differences in yield were observed between the study areas associated with either environmental physical or biological factors, such as the presence of herbivores. Our best production cycle reached 124 WMT Ha−1 month −1 in southern Chile, and the worst, less than 20 WMT Ha−1 month−1 in northern Chile. Finally, some direct and indirect constrains were encountered, including seeding season and depth, and the presence of pests and diseases, that are discussed.

Photoacclimation and Photoprotection of Juvenile Sporophytes of Macrocystis pyrifera (Laminariales, Phaeophyceae) Under High‐light Conditions During Short‐term Shallow‐water Cultivation1

“…Our results elucidate the photoacclimation mechanisms that can allow farming Macrocystis pyrifera in relatively shallow waters (Camus et al. , ). Shallow water cultivation reduces the challenges of installing, monitoring, and harvesting of final biomass in deeper waters (Altamirano ).…”

Feasibility study of Ulva sp. (Chlorophyta) intensive cultivation in a coastal area of the Eastern Mediterranean Sea

“…On a global scale, most offshore seaweed biomass is produced in Indonesia, the Philippines, China, India, and Tanzania, and is currently under investigation in US and EU biomass programs . The concepts of offshore marine biomass cultivation include farms for kelp growth, tidal flat farms, floating seaweed cultivation settings, ring cultivation systems, and, most recently, wind‐farm integrated systems and underwater ropes …”

Assessment of genetic and phenotypic diversity of the giant kelp, Macrocystis pyrifera, to support breeding programs

“…Pilot-production has demonstrated that 124 wet ton.ha -1 of M. pyrifera can be achieved using wild individuals to seed ropes for suspended systems [32]. The development of M. pyrifera aquafarming is expected to emerge rapidly for several reasons: established procedures for cultivation in hatcheries [33] and open ocean [32] allow for the testing of the agronomic performance of a large array of genotypes and pilot scale production; technology used to convert biomass to bioethanol implemented at the pilot scale [34,35]; and identification of novel components for food and pharmaceutical uses that add value to the biomass production [5,36,37]. M. pyrifera is considered to be a highly plastic species [38,39], yet some morphological traits were considered to express a strong phylogenetic signal.…”