The present study investigates sponge species inhabiting gravelly stone and muddy depths within the circalittoral zone of Dardanos, a unique coral-based Marine Protected Area in the Çanakkale Strait. The species examined include Dysidea avara, Dysidea tupha, Halichondria (Halichondria) bowerbanki, and Amphilectus fucorum. Among these, Amphilectus fucorum represents the first record for the Eastern Mediterranean sponge fauna, while Halichondria (Halichondria) bowerbanki and Dysidea tupha are new additions to the marine inventory of the Turkish Straits System. Dysidea avara, a previously known Atlanto-Mediterranean species, is here confirmed from the Çanakkale Strait with additional distributional data. The taxonomy, morphological characteristics and distributional patterns of these species are described in detail. With these findings, the number of sponge species known from the Marmara Sea has increased from 84 to 87, highlighting the importance of the strait as a biodiversity hotspot and underlining the need for further systematic surveys and conservation of sponge communities in the region.