"Unveiling Hidden Drifters: New Records of Colonial Pelagic Tunicates in Lebanese Waters and the Levantine Sea"

Abstract

Colonial pelagic tunicates play a vital role in marine ecosystems, yet their distribution in the Levantine Basin remains poorly documented. This study presents the first confirmed records of Helicosalpa virgula (Vogt, 1854) (Thaliacea, Salpida) and the Giant Fire Salp Pyrostremma spinosum (Herdman, 1888) (Thaliacea, Pyrosomatida) in Lebanese waters, alongside new occurrences of the Big Salp Salpa maxima Forskål, 1775 (Thaliacea, Salpida). These records were obtained through a citizen-science initiative established by Tyre Coast Nature Reserve (TCNR) and Palm Island Nature Reserve (PINR), which engages fishers, divers, and marine stakeholders in monitoring marine biodiversity by documenting and reporting species encounters via social media platforms, WhatsApp groups, and direct communications with researchers. The findings significantly expand current knowledge of thaliacean diversity in the southern Levantine Sea, underscoring the importance of citizen science in marine biodiversity research and conservation. This study highlights the need for continuous monitoring to better understand the ecological roles and potential impacts of these organisms, particularly as their populations and blooms may influence trophic interactions, fisheries, and biogeochemical cycles.

Keywords: Colonial pelagic tunicates, Levantine Basin, Marine biodiversity, Citizen science.