Spatio-temporal of heavy metal Pb (Lead) in seawater, sediment, and different organs of Cymodocea rotundata in Doreri Gulf, Manokwari, West Papua, Indonesia

Abstract

Abstract. Sembel L, Setijawati D, Yona D, Risjani Y. 2022. Spatio-temporal of heavy metal Pb (Lead) in seawater, sediment, and different organs of Cymodocea rotundata in Doreri Gulf, Manokwari, West Papua, Indonesia. Biodiversitas 23: 2482-2492. The Doreri Gulf is a high-activity area that serves as a collection point for pollutants from the mainland, which are conveyed directly or indirectly through five rivers in a semi-enclosed area. Cymodocea rotundata in Doreri Gulf is classified as a pioneer seagrass with high density in areas close to pollution sources. Therefore, analysis of Pb concentrations in aquatic and sedimentary environments as well as the reaction of C. rotundata to Pb in the Doreri Gulf is required considering its relevance in seagrass ecosystems. This research, then, aims to analyze the spatial and temporal distribution of Pb in waters and sediments, as well as determine the bioaccumulation in the organs of C. rotundata, such as roots, rhizomes, and leaves. Besides, an analysis was also carried out on the potential for bioconcentration and translocation of Pb in Doreri Gulf, Manokwari Regency, West Papua Province, from February to April and August to October 2020. The locations were divided into Yankarwar coastal, Nusmapi Islands, and Tanjung Manggewa. Parameter measurement refers to the Standard Methods for examining Water and Wastewater (APHA 2017). The heavy metal analysis was conducted using the SNI 6989.8:2009 procedure, and the temporal distribution showed that concentrations of Pb in water, sediment, and seagrass organs were high and low in the rainy and dry season. The spatial distribution of Pb in sediments between the Coastal Yankarwar and Nusmapi Islands, as well as between the Coastal Yankarwar locations and Tanjung Manggewa, were very different. However, there were no differences between the Nusmapi Islands and Tanjung Manggewa. Each location showed BCF bioconcentration <1, indicating the lack of ability to mobilize Pb from sediment to roots. Translocation factors for each location showed TF values < 1, showing the lack of ability of C. rotundata to transfer Pb to organ tissues. Additionally, translocation of elements from sediment to roots and within plant tissues was related to many factors, including pH, potency reduction, temperature, salinity, and organic matter content. Other factors such as seasonal variations and heavy metal concentrations contribute to bioaccumulation and internal translocation capacity.