Blood glucose of tilapia fish oreochromis mossambica as a water bioindicator in the downstream of brantas waters, east java

Blood glucose is one biomarker that can be used as an indicator for fish which is contaminated by industry or domestic pollutant. This research was conducted in downstream Brantas (Sidoarjo and Mojokerto). The purpose of this research was to analyze tilapia fish blood glucose levels as health water indicators in the Brantas River. This research used a descriptive method. Wilcoxon – Mann – Whitney test were used to analyze the data. The result of this research showed that blood glucose in Station 1 about 118-161 mg dL^-1 and Station 2 about 145-209 mg dL^-1. Blood glucose levels of tilapia fish from the two places showed that blood glucose tilapia exceeded the normal limit, and it was more than 100 mg dL^-1. This result indicated that tilapia was under stress because the environment was contaminated. The total blood glucose in Sidoarjo River was higher than that in the Mojokerto River. The results of water quality measurement showed that the temperature range was 29-30^oC, pH was 7.7-8.7, DO was 3.3-4.0 mg L^-1, Ammonia was 0.035-0.052 mg L^-1, TSS was 110-132 mg L^-1 and COD was 50.74-87.84 mg L^-1 and Chlorin in Station 2 was 0.02 mg L^-1. It is inferred that at blood glucose in fish can be used as an effective and fast biomarker for determining the environmental health of contaminated waters.