Population biology and chemical composition of the red alga Callophyllis variegata (Rhodophyta; Cryptonemiales) in southern Chile

The cosmopolitan red alga Callophyllis variegata is harvested and exported as food to Asian countries. In anticipation of overexploitation problems, this study aimed to describe temporal changes in their population structures and chemical composition by comparing intact (Pichicuyén) and exploited populations (San Antonio) of southern Chile, by using linear mixed models. Abundance parameters and size classes were higher in summer months, whereas fertile stages tetrasporophytes and carposporophytes were more abundant in autumn–winter periods. Recruitment was plentiful toward late winter–spring months. Geographical differences were also detected, and San Antonio (C. variegata-exploited) stocks exhibited lower productivity but similar cover/density in comparison to Pichicuyen (intact location). Likewise, this population showed a size structure toward smaller individuals (e.g., recruits) and more sterile individuals than Pichicuyen. Phosphorous, protein, lipid, soluble carbohydrate, and fiber composition also showed a clear seasonal trend, but no differences between localities were found for lipids and soluble carbohydrates. Since C. variegata showed good productivity and interesting nutritional value, we concluded this species shows potential for exploitation and commercialization in southern Chile, as long as specific management protocols and market studies are developed.