| dc.description.abstract | Various activities of the communities along the Kapuas River in West Kalimantan, such as domestic, transportation, harbor, and industries have an impact on the environment through waste water. Illegal gold mining in the upstream region also contributed to the decline in the quality of the Kapuas River. The existence of toxic metal in water and sediment could threaten the environmental health of the Kapuas Estuary through the process of bioaccumulation and biomagnification in the food chain, and threatens the sustainability of marine fishery products eventually. The availability of accurate data on the condition of the waters of the Kapuas Estuary is absolutely necessary. This is particularly useful in formulating strategic and anticipatory policies for the management of the marine environment and natural resources in the coastal areas of West Kalimantan. This study aims to determine the concentration and distribution of Hg, Cd, and Pb in the Kapuas Estuary as information for integrated management of the coastal marine environment in West Kalimantan. This research was conducted in April and September 2011 in the Kapuas River and coastal waters of the Kapuas Estuary with 20 sampling stations. Analysis of dissolved Hg refers to SNI 19-6964.2-2003, whereas analysis of dissolved Cd and Pb refers to Standard Methods for the Examination of Water and Wastewater 3111C. Analysis of Hg in sediments and TSS refers to US EPA 245.5 methods, whereas analysis of Cd and Pb in sediments and TSS refers to US EPA method 3050B. Analysis of Hg in fish tissue was based on the AOAC Official Method, whereas analysis of Cd and Pb refers to ASEAN Canada CPMS II. Physico-chemical characteristics of water such as salinity, pH, dissolved oxygen, temperature, TSS concentration and sediment characteristics (grain size and organic matter content) were also measured to determine the condition of the waters at the time of sampling. Physico-chemical characteristics of the Kapuas Estuary is characterized by a range of salinity between 0-31 psu. pH values varied between 3.24-5.11 in the Kapuas River, and 5.82-8.21 in coastal areas. Temperatures in the Kapuas River basin ranged from 28.4-30.0 °C, while in coastal areas varied between 21.1-32.2 oC. Dissolved oxygen concentration in the Kapuas River basin ranged from 4.74-5.60 mg l-1, while in coastal areas ranged from 4.5-6.8 mg l-1. Total suspended solids (TSS) had variation of the concentration between 56.90-107.80 mg l-1 in the Kapuas River, and 16.50-230 mg l-1 in the coastal areas. Dissolved Hg concentrations in the Kapuas River basin ranged from 0.05 -0.49 mg l-1, while in coastal areas ranged from <0.001-0.80 mg l-1. Hg concentrations in TSS in the Kapuas River basin ranged from 1.00-2.59 mg kg-1 dry weight, while in coastal areas varied between 0.20-4.01 mg kg-1 dry weight. Dissolved Cd concentrations ranged from 0.05-0.63 mg l-1 in the Kapuas River, and <0.001-0.73 mg l-1 in the coastal areas. Cd concentrations in TSS in the Kapuas River basin ranged from 21.66-69.33 mg kg-1 dry weight, while in coastal areas varied between 3.18-85.37 mg kg-1 dry weight. The concentration of dissolved Pb in the Kapuas River basin ranged between 2.15-3.44 mg l-1, while in viii coastal areas varied between 0.08-3.76 mg l-1. Pb concentrations in TSS ranged between 13.33-182.80 mg kg-1 dry weight in the Kapuas River, and 0.49-201.99 mg kg-1 dry weight in coastal areas. All the metals in dissolved phase has not exceeded the quality standards set by the government. Sediments in the Kapuas River basin and Kapuas Estuary generally dominated by clay (<0.063 mm) with a percentage of the coastal areas greater than in the river basin. The concentration of organic matter in the basin ranged from 8.67-35.53 %, significantly higher than in the coastal areas (0.73-15.06 %). Hg concentration in sediments in the Kapuas River basin ranged from 0.06-12.20 mg kg-1 dry weight, while in coastal areas ranged from 0.02-12.17 mg kg-1 dry weight. Cd concentration in the Kapuas River sediment ranged from 0.22-12.58 mg kg-1 dry weight, while in coastal areas ranged from 0.01-0.77 mg kg-1 dry weight. Pb concentration in the Kapuas River sediment varied between 6.7-44.4 mg kg-1 dry weight, while the coastal sediment has a concentration range between 1.02-39.03 mg kg-1 dry weight. Hg in Landak River and Peniti Luar Estuary has exceeded sediment quality guidelines applied in some developed countries, while Cd and Pb has not exceeded the guidelines. In addition to anthropogenic input influences, heavy metal distribution and fluctuations both in the coastal region of the Kapuas River and Kapuas Estuary associated with the factors that affect the transfer process of metal between the dissolved, suspended, and sediment phase. Kapuas Estuary are relatively shallow (±3.5 m) in most locations makes it very dynamic. Physical mechanisms such as turbulence of water mass that leads to sediment resuspension has a role to fluctuations in the concentration of heavy metals in these waters. Metals that were previously contained in the sediment will move into the water column. Fish samples were obtained from coastal areas, consisted of 84 pelagic and 41 demersal fish from northern areas and Kapuas Kecil Estuary. A total of 66 % was a predatory, 24 % was a benthophagous , and the rest was omnivorous and planctivorous. The concentration of Hg in pelagic and demersal fish varied between 0.14-0.52 mg kg-1 dry weight and 0.18-12.39 mg kg-1 dry weight respectively. The lowest and highest concentration of Hg respectively contained in Ikan Sotong kodok (Cuttlefish, Sepia sp.) and Ikan Sepekah (Shortnose ponyfish, Leionagthus brevirostris). Cd concentration in pelagic and demersal fish each ranged between 0.08-1.45 mg kg-1 dry weight and 0.09-0.76 mg kg-1 dry weight respectively. Lowest Cd concentration found in Ikan Timah-timah (Largehead hairtailfish, Trichiurus lepturusi), while the highest Cd concentration identified in Ikan Kembung (Short mackerelfish, Rastrelliger sp.). The concentration of Pb in pelagic and demersal fish ranged between 0.04-11.64 mg kg-1 dry weight and 0.04-1.75 mg kg-1 dry weight respectively. Lowest Pb concentration found in Ikan Manyung jahan (Estuarine catfish, Arius sp.), while the highest Pb concentration identified in Ikan Kembung (Short mackerelfish, Rastrelliger sp.). Hg concentrations in Ikan Sepekah (Shortnose ponyfish, Leionagthus brevirostris) from the Kapuas Kecil Estuary region has passed the quality standard and some other indicated approaching the maximum limit. The concentration of Cd and Pb indicated the same thing, where more than 90 % of fish samples have exceeded the maximum limit. | en |
