Autoecology of Ceratium furca and Chaetoceros didymus as potential harmful algal blooms in tourism and aquaculture sites at Teluk Pandan Bay, Lampung, Indonesia

Abstract

Abstract. Hasani Q, Yusup MW, Caesario R, Julian D, Muhtadi A. 2022. Autoecology of Ceratium furca and Chaetoceros didymus as potential harmful algal blooms in tourism and aquaculture sites at Teluk Pandan Bay, Lampung, Indonesia. Biodiversitas 23: 5670-5680. Harmful algal blooms (HABs) phenomenon has been observed around tourism and aquaculture sites in Teluk Pandan Waters, Lampung Bay. The dominant potential HABs found in Teluk Pandan waters were Ceratium furca and Chaetoceros didymus. This study aimed to analyze the relationship between the environmental physicochemical factors and the abundance of C. furca and C. didymus as potential HABs. Phytoplankton samples were collected from four stations (Hurun Bay, Sidodadi Coastal Waters, Sari Ringgung Beach and Cikunyinyi Bay) during May-August 2022. Physical parameters (temperature, depth, brightness, current velocity and salinity), as well as chemical parameters (dissolved oxygen, pH, phosphate, nitrite, nitrate and ammonia) were all measured in conjunction with phytoplankton sampling. Canonical correlation analysis and multiple regression were used to predict the effect of environmental parameters on phytoplankton density. Blooms of C. furca were found with the highest density at 5.417×106 cells/L in Cikunyiyi Bay, while C. didymus predominated in Hurun Bay (2.890×104 cells/L), Sidodadi Coastal Waters (3.923×104 cells/L) and Sari Ringgung Beach (3.531×104 cells/L). The main factors influencing the increase in C. furca population at Cikunyinyi Bay were pH, phosphate and nitrate. The increase in C. didymus population at Sidodadi Coastal Waters was affected by phosphate, nitrate and nitrite, while phosphate and nitrate influenced the increase in C. didymus population at Sari Ringgung Beach. Potentially HABs density was found to be higher near intensive shrimp farming sites. The use of fertilizer and artificial feed in high quantities is thought to be responsible for increased water eutrophication. Periodic monitoring and consistent determination of environmental carrying capacity for intensive shrimp farming activities are required to control HABs and ensure the sustainability of aquaculture and tourism activities in Teluk Pandan Waters.

Changes in density level and mangrove land cover on Teluk Pandan Coast, Lampung, Indonesia, after 10 years of community-based management

“…Teluk Pandan's coastal area is overgrown with mangroves and sea coral reefs, with a muddy sand beach type that has high genetic resources and is commonly used as a tourism destination (BPDASHL 2020). Teluk Pandan Sub-district is one of the most important coastal and beach tourism centers in Lampung Province (Purnomo et al 2019;Hasani et al 2022), including mangrove ecotourism. The coastal area of Teluk Pandan is also an important aquaculture activities center in Pesawaran District (Hasani et al 2012;Hasani et al 2022).…”

“…Teluk Pandan Sub-district is one of the most important coastal and beach tourism centers in Lampung Province (Purnomo et al 2019;Hasani et al 2022), including mangrove ecotourism. The coastal area of Teluk Pandan is also an important aquaculture activities center in Pesawaran District (Hasani et al 2012;Hasani et al 2022).…”

“…Before 2010, there had been a decrease in the area of mangrove forests in Teluk Pandan Sub-district. Coastal abrasion (Emiyati et al 2014) and the logging of mangrove forests for the expansion of shrimp ponds (Irawan et al 2015;Firdaus et al 2021;Hasani et al 2022), settlement (Emiyati et al 2014;Tresiana et al 2022) and tourism (Nabilah et al 2021) have resulted in a low area of mangroves in dense category. In 2015, some of the ponds were no longer in operation, therefore replanting or rehabilitation of mangroves was carried out on vacant land by the Maritime Affairs and Fisheries Agency of Pesawaran District, mangrove activists, volunteers and some local communities so that currently, there is an increase in the area of mangrove forests.…”

“…The area of mangrove forest in the dense category at Batu Menyan Village has decreased slightly by 0.25 ha (-2,12%), while in the rare-density category has increased by 28.05%. Land conversion into settlements, expansion of shrimp ponds, and abrasion appear to be responsible for such conditions (Hasani et al 2012;Emiyati et al 2014;Firdaus et al 2021;Hasani et al 2022). This situation has raised concerns among the community.…”

“…The area of mangroves in Teluk Pandan Sub-district has changed from year to year. The changes occur as a result of the use of mangrove forest land for settlement, tourism, and aquaculture, as well as natural factors such as beach abrasion (Emiyati et al 2014;Firdaus et al 2021;Hasani et al 2022). In several locations, coastal areas in Lampung Province are also often used as sand mining lands (Hasani et al 2021a;Hasani et al 2021b).…”