Judul: Distribution and Bioaccumulation of Heavy Metals Related to Methionine, Cystine in Gonggong Conch (Laevistrombus canarium) in Coastal Waters of Bangka Island
Abstrak: Industry and the community have carried out tin mineral exploration on Bangka Island for a long time. Industrial mining has been going on for 200 years, while community mining has been carried out illegally (Unconventional Mining/UM). UM has increased since the period of regional autonomy in 2008. UM is carried out using the land opening method. It has a significant impact on the damage to the tailing’s expanse. The land becomes nutrient-poor, and many basins are formed (kolong). Tailings (fine grain) are suspected of containing heavy metals because, naturally, heavy metals are contained in soil minerals. Several studies have indicated the contamination of heavy metals in marine waters and their accumulation in aquatic resources. One of the commercial resources is the gonggong conch (Laevistrombus canarium). This study reveals the level of heavy metal contamination and the biological aspects of the gonggong conch resource related to the presence of tin mining exploration. The study was conducted by purposive sampling: areas affected by mining and far from mining activities. The samples used were sediment, seagrass and L. canarium. Sediment samples were taken at twelve points around Bangka Island. This sample describes the distribution of heavy metals on Bangka Island. L. canarium and seagrass data were collected using a quadratic transect (1 x 1m) in six L. canarium habitats. The research variables included measurements of heavy metal concentrations (Zn, Cu, Pb, Cd, Sn) in sediments and L. canarium (gills and meat), methionine and cystine in L. canarium (gills, meat) and hepatopancreas histology of L. canarium. The total heavy metals were measured according to APHA (2012) by Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-EOS). Amino acid preparation and measurement with modified AOAC (2005) method using Liquid chromatography-mass spectrometry (LC-MS). Statistical approach (Kruskal – Wallis and Pairwise Comparison test) was used to explain the effect of heavy metals due to mining activities on the habitat of L. canarium, the relationship between environmental conditions and the growth/health of L. canarium (population and structure/age group, amino acid content of methionine, cystine, and histology). The analysis reveals that almost all sediment samples are contaminated with heavy metals (Zn, Cu, Pb, Cd, and Sn). Concentrations of Zn, Cu, and Pb consistently show relatively high values in the environs of Teluk Kelabat and Tanah Merah Beach, as locations around mining activities. Based on the Enrichment Factor (EF) category, Zn and Cu contamination in the research area was still relatively small (EF < 2), except for Pb, which had undergone high enrichment (EF 5-20). The high Pb still requires further research to find the cause. Is it related to the soil geology of the Bangka area as an indication of tailings waste or anthropogenic impact?. The presence of heavy metals in these sediments can still be classified as relatively safe when referring to quality standards such as CCME or ANZECC/ARMCANZ. L. canarium is relatively low, with a density range of 6-8 ind/m2. The organism's condition also showed poor growth as indicated by the negative allometric growth form (b<3), and the body condition was classified as thin. A negative allometric is a growth
Keyword: Gonggong conch (Laevistrombus canarium), hepatopancreas, negative allometric, tin mining