Microplastics is a problem that has been concerning, especially in marine habitat. The presence of microplastics in large quantities will have an impact on the environment and marine organisms. Marine organisms that are vulnerable to contamination by microplastics pollutants namely green mussels (Perna viridis). This study aims to determine the microplastics forms and concentration found in green mussels (Perna viridis) in Maccini Baji Waters, Labakkang District, Pangkejene Kepulauan Regency, South Sulawesi. The sampling of the mussels was carried out by the method of purposive random sampling with the sample was grouped into 3 groups of shells lengths, namely 2-3.9 cm, 4-5.9 cm and 6-7.9 cm with 33 individuals for each group. Microplastics observations were carried out using a stereo microscope. In addition to analyze microplastics concentrations, an analysis of the frequency of microplastics presence in shells was also carried out. The results showed that the microplastics was found in the form of fiber and fragments with several colors namely clear white, blue, black, red, and purple. The frequency of microplastics presence in green mussels was above 50% with an average of 71.7% exposure to microplastics. The highest frequency of microplastics presence and concentration in the range of shell lengths accounting for 2-3.9 cm.

The increasing demand for live ornamental fish for export needs triggers fishermen to start looking for alternative fishing techniques that are more effective and efficient. The technique commonly used is the anesthetic technique using potassium cyanide. The use of cyanide has been banned by the government because of the many impacts it has caused such as the degradation of coral reef ecosystems, high non-target fish mortality and pollution of coastal areas. Clove oil is an alternative anesthetic which can be utilized with many advantages compared to cyanide. The sampled fish used was sergeant major (Abudefduf vaigiensis) as many as 15 fish with a size of 9-12 cm obtained from fishermen's catch using a scoop. The purpose of this study was to determine the optimal concentration of clove oil as an anesthetic of Sergeant Major Fish (Abudefduf vaigiensis) based on induction time and recovery time. The experimental design used was a Completely Randomized Design (CRD). Analysis of the data used is One-Way ANOVA parametric analysis and Kruskal Wallis nonparametric analysis. The results obtained are five series of concentrations (20 ppm, 30 ppm, 40 ppm, 50 ppm, 60 ppm) which have a significant effect on induction time (20 ppm and 60 ppm) of sergeant major fish (Abudefduf vaigiensis) (P0.05).

Fish of the genus Oryzias have long been used as model fish or sentinel organisms in ecotoxicological studies. Intercalibration between laboratories is fundamental in producing test procedures in ecotoxicological studies. In the inter-calibration activities, the transport of materials used in testing is important. Research on the dry transport of embryos, Oryzias wolasi was conducted. The test was carried out using a 24 well microplate. The parameters analyzed were the incubation period, hatching success, and the total length of fish at hatching. The experimental results showed that there were no statistically significant differences (p> 0.05) in the incubation and hatching success of the embryos were incubated in embryo rearing media (ERM) and those were incubated with dry incubation. However, there were significant differences (p> 0.05) in the total length of newly hatched larvae. The average of the larvae total length that were reared dry was longer compared to those were reared in ERM. The study suggested that the fish embryos of Oryzias wolasi could be transported dry for ecological studies and others.

Microplastic contamination in the aquatic environment poses a serious threat to the survival of the ecosystem because it is persistent. This study aims to analyze the concentration of microplastics in the water column in the coastal waters of South Larompong. Sampling was carried out using the volume reduce method with the neuston net at four stations, namely Bonepute Beach, Ponnori Beach, Babana Beach and Damaci Beach. The results showed that there was microplastic contamination and found as many as 386 microplastic particles with an average concentration of 2.68 particles/m³. The results of the analysis of microplastic concentrations showed significant differences (P<0.05) between stations. The highest concentrations of microplastics are found on Bonepute Beach which is an area of aquaculture, fishing and densely populated settlements, then followed by Ponnori Beach which is a tourist area. Meanwhile, the lowest microplastic concentrations are found on Babana Beach, which is the estuary area of the Temboe River and Damaci Beach which is a nearby area. Several forms of microplastics were found, namely granules, fibers, films and fragments which were the most dominant forms. Several colors of microplastics were found, namely blue, brown, green, red, white, and black which were the most dominant colors. There are two types of polymer found, namely HDPE (High Density Polyethylene) and PVA (Polyvinyl alcohol). The conclusion of this study is that the coastal waters of South Larompong have been contaminated with microplastics so that more attention is needed regarding the handling of plastic waste, especially microplastics.

The current research demonstrated the use of simple biomarkers from Oryzias celebensis embryos to detect the effects of pollutants from the Tallo River. The biomarkers used in this research were somite number, egg biometrics, heart rate, survival rate, and hatching time. Pollutants were sampled from three hot spots in the Tallo River (Station 1 (S1), Station 2 (S2) and Station 3 (S3)). Two exposure models were used in this study: in situ and semi-in situ exposure. In situ exposure was carried out by placing ten embryos (stage 17) at each station for six days. Semi-in situ embryos (10 animals) were exposed to polluted water from each station and embryo rearing media (ERM) as a control at stage 17 until hatching in the laboratory. Biomarker data were analyzed using ANOVA (Analysis of variance) to determine the sensitivity of each biomarker used. Almost all the embryos used as model animals in the in situ experiment died, except for two embryos placed in stations 2 and 3. The embryos from station 2 hatched after 18 days. The embryos from station 3 died after 18 days. The semi in situ experiment showed that the number of somites and heart rate showed statistically significant differences between embryos exposed to water from S1 and control embryos (p < 0.05). Other endpoints did not show potential as biomarkers. This study suggested that the number of somites and heart rate of O. celebensis embryos could potentially be used as biomarkers in effect-based monitoring.