Sublethal Toxicity Tests of Mercury (Hg) to Nilem Fish (Osteochilus hasselti) Gills Tissue Damage

Abstract

Industry development in Indonesia resulted in sewage and polluting heavy metals such as mercury (Hg). These pollutants will be harm organisms that live at aquatic environment. Fish gills could be damage due to exposure by mercury. To know the influence of mercury’s toxic against aquatic organisms by using toxicity test. An aquatic organism, which is usually used as toxicity test, is nilem fish (Osteochilus hasselti). The objective of the study was to determine the value of LC50-96 hours in a toxicity test of nilem fish exposed to lead acetate; to determine the changes in the fish gill and to determine the concentration of lead mercury which causes tissue damage structure in the gills of nilem fish. The design used completely randomized design (CRD) with four concentrations (0; 0.08; 0.16 and 0.24 ppm) and three replications. The objective of the study was sublethal toxicity test. Lethal toxicity concentration data were descriptive and data from sublethal toxicity test were One Way. The analysis showed that there were highest edema 10% and 17% on day 4 and 12, the highest lamella fusion 35% and 59% on day 4 and 12, the highest hyperplasia 45% and 54% on day 4 and 12, and the highest necrosis the 65% and 80% on day 4 and 12. It was concluded that the value of LC50-96 hours in nilem fish (Osteochilus hasselti) toxicity test was 0,3938 ppm; and damage of fish gill tissue changes started to occur in the lead mercury (Hg) concentration of 0,08 ppm.

Sublethal toxicity test of mercury (Hg) in the flesh and tissue of Tilapia (<i>Oreochromis niloticus</i>)

“…Fish would efficiently absorb methyl mercury, but would at the same time slowly release it. In this study, sublethal concentration was used, in reference to the concentration below the LC50-96 hour of Hg toxicity in silver sharkminnow at 0.396 ppm (Siregar et al, 2018). Sublethal influence occurs in the fish organs, causing damages to the liver, decreasing the amount of blood, reducing the potential for breeding, growth and so on.…”

“…The design used in this study was a Completely Randomized Design (CRD), with 4 treatments and 3 replications, namely: Treatment A = 0.08 ppm; B = 0.16 ppm; C = 0.24 ppm; and control = without addition of Hg. The determination of this sublethal concentrations was based on previous research carried out by Siregar et al (2018) who found LC50-96 hours in bonylip barb fish (Osteochilus hasselti) through toxicity test of Hg at 0.3938 ppm. Fish were dissected, muscle was removed and washed in distilled water, then dried at 80°C for 72 hours.…”

Journal of Water and Land Development

“…Heavy metals are dangerous pollutants that are persistent and toxic, that cannot be metabolized and cannot be excreted through biological processes, because heavy metals can accumulate in various components of the ecosystem (water, sediment, flora, and fauna) [PRAYOGO et al 2016;SIREGAR, PRAYOGO 2017;SIREGAR et al 2018].…”