Analisis Kadmium (Cd ) dan Pola Pita Isozim pada Organ Ikan Mas (Cyprinus Carpio) di Danau Lau Kawar, Kabupaten Karo Sumatera Utara

Abstract

Cadmium (Cd) is a heavy metal that has a high toxic effect, even at low concentrations. Lake Lau Kawar is one of the lakes that can be found in the Leuser Ecosystem (KEL). One of the bioindicators used to determine the level of contamination of heavy metal cadmium in waters, namely Cyprinus Carpio. This research aims to analyze the effect of physical and chemical factors in waters on the content of heavy metal Cd and to analyze the content of heavy metal Cd in the liver, kidney, gills, and muscle samples and to analyze the isozyme banding pattern shown by the sample organs. Samples were taken at Lake Lau Kawar in an inlet area geographically located in 3012'02.60" LU dan 98023'00.81" BT. The research uses descriptive methods (qualitative and quantitative), where the samples are taken by purposive sampling. Data analysis was in the form of a water chemical-physical factor test, test for heavy metal Cd content in water, sediment, liver, kidney, gill, and muscle samples using the AAS method, than analysis of EST and AAT isozyme banding patterns on fish organs using horizontal electrophoresis. The results showed that the water temperature was 22,6⁰C, the pH of the water was 6.5, the light penetration was 1.9 m, the DO values was 6,9 mg/l and BOD values was <3 mg/l. The results of AAS analysis, the Cd content of sediment and water, were 0.1 ppm and 1000 mg/kg. This data shows that the water quality in Lau Kawar lake does not pass the water quality standard. From the results of descriptive calculations, it was obtained that the mean ± SD value of Cd content in the kidneys, liver, gills, and muscle of fish was 0.0018 ± 0.0003; 0.0014 ± 0.0001; 0.0017 ± 0.0007 and 0.0017 ± 0.0009. The data explained that the Cd content in each organ did not pass the quality standard. The significance value of the analysis statistic of ANOVA test of heavy metal Cd in each sample organ at the 95% confidence level is 0.836. This means that the average Cd content in the gills, kidneys, liver, and meat in each fish is the same or not significantly different. Analysis of the isozyme band pattern in each fish organ showed a fairly varied expression of the EST and AAT isozyme bands. The results were observed to support each other, where the physical and chemical factors of the waters influenced the amount of Cd content in the sample organs and the value of the Cd content in the organs would determine the expression in the pattern of the isozyme band.

Kadmium (Cd) merupakan logam berat yang memiliki efek toksik yang tinggi, bahkan pada konsentrasi rendah. Danau Lau Kawar merupakan salah satu danau yang terdapat di Kawasan Ekosistem Leuser (KEL). Salah satu bioindikator digunakan untuk mengetahui tingkat pencemaran logam berat Cd dalam perairan yaitu Cyprinus Carpio. Tujuan Penelitian ini untuk menganalisis pengaruh faktor fisik dan kimia perairan terhadap konsentrasi logam berat Cd dan menganalisis konsentrasi logam berat Cd pada organ hati, ginjal, insang dan otot sampel serta menganalisis pola pita isozim yang ditunjukan organ sampel. Sampel diambil di Danau Lau Kawar pada daerah inlet yang secara geografis terletak pada 3012'02.60" LU dan 98023'00.81" BT. Penelitian ini menggunakan metode deskriptif (kualitatif dan kuantitatif) dan sampel diambil secara Purposive Sampling. Analisis data berupa uji faktor fisik kimia perairan, uji konsentrasi logam berat Cd di air, sedimen, organ hati, ginjal, insang dan otot sampel dengan metode AAS, dan analisis pola pita isozim EST dan AAT pada organ ikan dengan menggunakan elektroforesis horizontal. Hasil penelitian menunjukan bahwa temperatur air sebesar 22,6⁰C, pH air sebesar 6,5, penetrasi cahaya sebesar 1,9 m, nilai DO sebesar 6,9 mg/l dan nilai BOD sebesar <3 mg/l. Hasil analisis AAS konsentrasi Cd pada sedimen dan air yaitu sebesar 0,1 ppm dan 1000 mg/kg. Data tersebut menunjukan bahwa kualitas air di danau Lau Kawar tidak melewati standar baku mutu perairan. Dari hasil perhitungan deskriptif diperoleh nilai Mean±SD konsentrasi Cd pada organ ginjal, hati, insang dan otot ikan yaitu sebesar 0,0018±0,0003; 0,0014±0,0001; 0,0017±0,0007 dan 0,0017±0,0009. Data tersebut menjelaskan bahwa konsentrasi Cd di tiap organ tidak melewati standar baku mutu perairan. Nilai signifikansi dari hasil analisis data statistik uji anova konsentrasi logam berat Cd di tiap organ sampel pada taraf kepercayaan 95% yaitu sebesar 0,836. Artinya, rata-rata konsentrasi Cd pada organ insang, ginjal, hati dan otot di tiap ikan sama atau tidak berbeda nyata. Analisis pola pita isozim ditiap organ ikan menampilkan ekspresi pita isozim EST dan AAT yang cukup bervariasi. Data hasil penelitian ini teramati saling mendukung, adapun faktor fisik dan kimia perairan mempengaruhi jumlah konsentrasi Cd di organ sampel dan nilai konsentrasi Cd dalam organ akan menentukan ekspresi pola pita isozim.