The coast of Peru (3.5–18°S) is one of the most productive marine areas in the world. The updated seaweed checklist reports a total of 260 specific/intraspecific taxa, of which the Rhodophyta show the highest number (185 species), followed by Chlorophyta (41 species) and Phaeophyceae (34 species). Since 2012, an increase in molecular studies has been reported mostly in Rhodophyta, while Chlorophyta and Phaeophyceae have lagged far behind. Utilization of seaweed resources has been based on artisanal collection from natural beds. These are mainly consumed fresh or salt-dried ( Chondracanthus chamissoi and Porphyra/Pyropia species), or exported for polysaccharide extraction ( Lessonia nigrescens , Lessonia trabeculata , Macrocystis pyrifera ). Although some regulations for brown seaweed extraction exist, overexploitation is a constant threat that must be addressed. Biomass from seaweed farms accounts, at most, for only 4% of the total annual landings, and there is a decreasing trend on seaweed aquaculture production since 2012. However, some cultivation projects for C. chamissoi and Porphyra/Pyropia species are currently being undertaken. In addition, recent studies have started to explore new uses of commercial and non-commercial seaweeds. Uncovering the Peruvian seaweed diversity and establishing well sustained culture and management projects are essential for utilizing and preserving the seaweed resources of Peru.

Fucoidans encompass versatile and heterogeneous sulfated biopolysaccharides of marine origin, specifically brown algae and marine invertebrates. Their chemistry and bioactivities have been extensively investigated in the last few decades. The reported studies revealed diverse chemical skeletons in which l-fucose is the main sugar monomer. However, other sugars, i.e., galactose, mannose, etc., have been identified to be interspersed, forming several heteropolymers, including galactofucans/fucogalactans (G-fucoidans). Particularly, sulfated galactofucans are associated with rich chemistry contributing to more promising bioactivities than fucans and other marine polysaccharides. The previous reports in the last 20 years showed that G-fucoidans derived from Undaria pinnatifida were the most studied; 21 bioactivities were investigated, especially antitumor and antiviral activities, and unique biomedical applications compared to other marine polysaccharides were demonstrated. Hence, the current article specifically reviews the biogenic sources, chemistry, and outstanding bioactivities of G-fucoidans providing the opportunity to discover novel drug candidates.

Marine ecosystems such as kelp are gaining recognition for providing ecosystem services (ES) along the coastal regions worldwide. Here, we synthesize information from the last four decades of research on the structure, functioning and threats of kelp forests, and the ES they provide in the Humboldt Current System (HCS) where information is scarce. The SALSA (Search, Appraisal, Synthesis and Analysis) framework was used for the literature survey and review. From 86 selected articles, only 4 directly discussed kelp ES in Chile. Supporting services-related articles were the most prevalent (n = 59), followed by provisioning (n = 19), regulating (n = 3) and cultural services (n = 1). ES-related research was mostly conducted in Chile (n = 77). Studies in Peru (n = 5), and in Chile and Peru at same time (n = 4) were scarce. Our search also showed that Lessonia trabeculata presented the highest number of associated taxa (n = 213), followed closely by M. pyrifera (n = 210). However, the number of phyla reported was higher in M. pyrifera (n = 17) than in the Lessonia species (n = 7–13). Natural and anthropic impacts on the biodiversity of kelp forests using novel technologies would facilitate the quantitative study and economic valuations of the services provided by these ecosystems at the Humboldt Current System.

Peru is the second largest seaweed producer in the Americas. Nevertheless, the actual extent and trends of exports of various seaweeds are not known. This study is the first to summarize and analyze the official seaweed export statistics for Peru, which cover 1995–2020. Total exports showed a considerable increase from 2008, reaching their highest historical volume in 2019 (33,948 metric tons dry weight plus 3 metric tons of fresh/frozen weight). China dominated the market by importing 90% of the total Peruvian production of seaweeds. A low percentage of the exports (3%) corresponded to red seaweeds (mainly Chondracanthus chamissoi for industrial use). Export volumes of C. chamissoi have been decreasing since 2015, however prices have continued to increase. Brown seaweeds accounted for 97% of the exports. These were dominated by Lessonia berteroana until 2007 and then by Macrocystis pyrifera. The latter showed the highest overall growth rate (47%). Wet biomass estimations showed a gap between the data reflecting what is officially harvested versus what is actually exported. This “unreported biomass” might reflect the government’s lack of control of seaweed harvesting. Finally, the COVID-19 pandemic showed a negative impact on exports with M. pyrifera being the most affected species.

Chondracanthus chamissoi is an edible red seaweed with a high hydrocolloid content and food industry demand. This situation has led to a decline in their populations, especially in Peru. An alternative culture method based on the formation of secondary attachment discs (SADs) has shown several advantages over traditional spore strategies. However, there are still scarce reports of the SAD method in Peru. This work aimed to evaluate the best conditions for C. chamissoi maintenance prior to SAD development and the effect of locality on SAD formation using scallop shells as a substratum. Experiments were conducted with material collected from five localities in Pisco (Ica, Peru). Our results showed that the best conditions for C. chamissoi maintenance were: (1) fertilized seawater with Bayfolan^® (0.2 mL L⁻¹); and (2) medium exchange every two days or weekly. These conditions reduced the biomass loss to 9.36–11.14%. Most localities showed a similar capacity to produce SADs (7–17 SADs shell⁻¹). However, vegetative algae, especially Mendieta, tended to present a higher number of SADs. Vegetative fronds also showed lower levels of necrosis and deterioration compared to cystocarpic and tetrasporophytic samples. This study shows the technical feasibility of culturing C. chamissoi through SADs for developing repopulation and/or intensive cultivation projects in Peru.