DNA barcoding and phylogenetic relationships of ecologically and commercially important seaweed species from the Azores (NE Atlantic)

Marine natural resources are increasingly demanded to support the livelihoods and wellbeing of humans facing multiple and simultaneous crises across the planet. Seaweeds, in particular, are renowned sources of bioactive marine compounds used for various purposes, including human and animal nutrition, soil fertilization, and healthcare markets. DNA-based tools are being adopted in integrative taxonomy and ecological research, as well as to monitor the supply chain of commercially important species. This research provides novel insights into the population genetics, phylogenetic relationships, and haplotype network of six commercially significant seaweed species that are abundant in the Azores archipelago and currently traded for industrial applications. This study provides a detailed assessment of the genetic diversity of the red seaweeds Asparagopsis armata, Asparagopsis taxiformis, and Pterocladiella capillacea, and the brown seaweeds Halopteris scoparia, Zonaria tournefortii, and Cystoseira pustulata, contributing with 17 newly generated barcodes of COI, rbcL, and 28 S rDNA gene records from the Azores region to the reference databases. Understanding the species identification and population dynamics is critical for understanding species composition in biodiversity hotspots. This knowledge supports taxonomy, conservation, environmental protection, and the sustainable use of marine resources.