This dataset originated from a specific bio-surveillance field study conducted in the fishing port of Algiers during spring 2021 (Kacimi, 2021). Data was collected by scraping biological material from hard substrates like floating structures and port structures at specific stations. The dataset contains records of identified fouling species, including their taxonomic classification (across Porifera, Bryozoa, Ascidiacea), status (indigenous, non-indigenous, or cryptogenic), and estimated abundance (visual assessment or frequency). Taxonomic nomenclature was verified using the World Register of Marine Species (WoRMS). This dataset serves as a baseline for future assessments of NIS in Algerian ports, though acknowledging limitations in taxonomic coverage and sampling extent.