Comparative assessment of Ulva spp. in the port areas in Mabini, Batangas

Abstract

Port areas in Mabini, Batangas are vulnerable to anthropogenic influences from different sources such as sewage outflows, human and port-related activities. Monitoring Ulva spp. could provide information about the possible impacts of these anthropogenic factors, as these species were being utilized as bioindicators. The ports of Anilao and Talaga in Mabini, Batangas, were assessed for Ulva spp. composition, abundance, and dominance using the line transect-quadrat method. Physicochemical conditions of water, such as pH, salinity, dissolved oxygen, temperature, light intensity, phosphate, and nitrate of the sites, were assessed as well as to determine the possible influence on the composition, abundance, and dominance of Ulva spp. Three Ulva spp. were identified, namely Ulva intestinalis, U. lactuca, and U. clathrata. In Talaga port, U. intestinalis and U. clathrata were the dominant species, whereas the former was found to be the most abundant species, and U. lactuca was found to be the least abundant. In Anilao port, only U. clathrata was the only species present. Physicochemical conditions on both sites were relatively close in value except for salinity, dissolved oxygen, irradiance, and nitrate content. Nitrate content has a relat ively huge difference between ports. However, Anilao port has a lower nitrate content of 1.9530 mg/L, while Talaga port has a higher value of 5.0843 mg/L, which might be caused by sewage outflows present in the latter. Overall, nitrate content had a possible effect on the composition, abundance, and dominance of Ulva spp. on each site.