Harvest pressure on brown macroalgae of the Lessonia genus has increased in recent years in Peru and Chile, due to the high demand from the global hydrocolloid industry. After a taxonomic review, in 2012, the intertidal species Lessonia nigrescens was segregated into two species, being L. berteroana distributed in southern Peru and northern Chile (17-30°S). Based on genetic tools we confirm the identification as L. berteroana and report its presence up to 15°23’S. It is recommended to update the status of the species into Peruvian regulations and scientific publications.

The kelp genus Eisenia Areschoug is represented by two species in the Southeast Pacific: Eisenia cokeri, distributed in Peru and Chile, and E. gracilis, endemic to Peru. However, the taxonomic distinction between these species has long been questioned, and it remains unclear whether E. cokeri is conspecific with the Northeast Pacific species E. arborea. To address these issues, we conducted an integrative taxonomic assessment combining morphological analyses, molecular phylogenetics, and molecular species delimitation approaches. Sampling for morphological and molecular analyses was carried out in subtidal zones at five localities along the Peruvian coast, and an additional locality in Chile was included for molecular analyses where E. cokeri was documented. Peruvian Eisenia species exhibited consistent morphological differentiation, including differences in thallus size, holdfast diameter, stipe modifications (e.g., longitudinal division and pseudostipe formation), frond division, frond margins, and surface roughness, as supported by morphometric analyses. Phylogenetic reconstructions based on mitochondrial and chloroplast markers, together with concordant results from multiple species delimitation methods (ABGD, GMYC, and bPTP), consistently recovered three independent evolutionary lineages corresponding to E. cokeri, E. gracilis, and a distinct lineage of Eisenia from the Desventuradas Islands (Chile). Our results confirm the taxonomic distinctiveness of E. cokeri and E. gracilis, demonstrate that E. cokeri is genetically distinct from E. arborea, and reveal the presence of a previously unrecognized lineage of Eisenia in the Southeast Pacific. These findings refine species boundaries within the genus and provide a robust framework for the management and conservation of these endemic, foundation, habitat-forming species.

The kelp genus Eisenia Areschoug is represented by two species in the Southeast Pacific: Eisenia cokeri, distributed in Peru and Chile, and E. gracilis, endemic to Peru. However, the taxonomic distinction between these two species has been questioned. Additionally, it is uncertain whether E. cokeri is conspecific with the Northeast Pacific species E. arborea. To address these issues, we examine, for the first time, the morphology and the molecular phylogenetics of E. cokeri and E. gracilis across their geographic range. Sampling for morphological and molecular analyses was conducted at subtidal zones in five locations in Peru. Furthermore, a locality in Chile was sampled for molecular studies, where E. cokeri was documented. Peruvian Eisenia species exhibited notable differences in morphological characters, including size, holdfast diameter, stipe modifications (e.g., longitudinal division and pseudostipe formation), frond division, frond margins, and roughness, as evidenced by differences in thallus morphometric variables. Phylogenetic analyses using mitochondrial and chloroplast markers revealed three distinct genetic lineages and two endemic species: E. cokeri and E. gracilis from Peru, and a new Eisenia sp. from Chile. Moreover, we confirmed the distinctiveness of E. cokeri from E. arborea and provided updated information on the distribution of E. cokeri and E. gracilis in the Southeast Pacific. These findings are crucial for the management and conservation of these endemic, foundational species.

La legislación peruana norma los programas de prevención, la protección, el control y la remediación de los impactos negativos en los ecosistemas marino-costeros, que pueden generarse por la ejecución de los proyectos del subsector hidrocarburos. Sin embargo, la ausencia de información ambiental de las zonas marino-costeras vulnerables frente a un posible derrame de hidrocarburos constituye una problemática seria. Esto limita la evaluación de los reales efectos ambientales postsiniestro y, consecuentemente, dificulta la estimación de las sanciones de los responsables. Luego del análisis de los monitoreos realizados en las áreas afectadas por el derrame de petróleo ocurrido en la refinería La Pampilla en enero de 2022, y constatar la escasa disponibilidad de datos ambientales previos al derrame, se propone que los titulares de los proyectos del subsector hidrocarburos establezcan puntos de monitoreo en zonas vulnerables que puedan ser considerados como zonas «control» en sus programas de monitoreo, previamente identificados en sus instrumentos de gestión ambiental, con auxilio de mapas de sensibilidad ambiental.