This dataset presents a collection of macroalgae records obtained from Bustamante Bay and Camarones, situated within the Parque Interjurisdiccional Marino Costero Patagonia Austral (PIMCPA) in Argentina. The study area, known for its ecological importance and past exploitation of macroalgae, showcases a remarkable biodiversity of macroalgae, with the presence of Macrocystis pyrifera giant kelp forests. Through meticulous sampling conducted across seasons and through diving techniques, the dataset offers a robust and up-to-date resource for understanding the richness dynamics and distribution patterns of macroalgae in this coastal region. By selecting sites with visible and expansive kelp forests spanning over 100 meters, the study captures a representative sample of the macroalgae community assemblages associated with kelp forest, shedding light on their ecological significance within the marine protected area. The taxonomic identification of the specimens was carried out by a specialist using microscopes or magnifying glasses, histological sections and stains and each specimen was identified at the lowest taxonomic level possible. Additionally, each specimen was preserved through exsiccata and silica gel for long-term storage and reference purposes.