Gumiri S, Ardianor, Syahrinudin, Anshari GZ, Komai Y, Taki K, Tachibana H. 2018. Seasonal yield and composition of aninland artisanal fishery in a humic floodplain ecosystem of Central Kalimantan, Indonesia. Biodiversitas 19: 1181-1185. Seasonal yieldof an inland artisanal fishery was studied in 2015 in the Takapan Floodplain Lake located along the Rungan River of Central KalimantanProvince-Indonesia. Record on daily fish catch consisting weight data and species composition was made in situ along with a one-yearrainfall data that was collected from the nearest Meteorological Station located in Palangka Raya City airport. Results showed thatthroughout the year, total annual yield of captured fishes reached 4.8 tons comprised of 34 commercial freshwater fish species. Seasonalyield varied considerably in which fish capture was higher during the rainy season than on the dry season. The transition period fromrainy to dry season was found to be the peak period of fish capture in the floodplain. Of the 34 fish species, the most abundant specieswas Channa striata that accounted to almost 50% of total annual fish yield. The two most abundant fishes, Channa striata, andKryptopterus palembangensis were a top predatory blackfish and an omnivorous surface water whitefish, respectively. This resultindicated that the studied floodplain habitat was still in good condition, however, conservation is needed to maintain the sustainability offreshwater fish resource in the future.

Algal biofuel research aims to make a renewable, carbon–neutral biofuel by using oil-producing microalgae. The freshwater microalga Botryococcus braunii has received much attention due to its ability to accumulate large amounts of petroleum-like hydrocarbons but suffers from slow growth. We performed a large-scale screening of fast-growing strains with 180 strains isolated from 22 ponds located in a wide geographic range from the tropics to cool-temperate. A fast-growing strain, Showa, which recorded the highest productivities of algal hydrocarbons to date, was used as a benchmark. The initial screening was performed by monitoring optical densities in glass tubes and identified 9 wild strains with faster or equivalent growth rates to Showa. The biomass-based assessments showed that biomass and hydrocarbon productivities of these strains were 12–37% and 11–88% higher than that of Showa, respectively. One strain, OIT-678 established a new record of the fastest growth rate in the race B strains with a doubling time of 1.2 days. The OIT-678 had 36% higher biomass productivity, 34% higher hydrocarbon productivity, and 20% higher biomass density than Showa at the same cultivation conditions, suggesting the potential of the new strain to break the record for the highest productivities of hydrocarbons.

Mangrove forests have a very important role as a provider of environmental services and economic support. The existence of mangrove forests in Seruyan Regency has suffered significant damage. The purpose of this study was to determine the most dominant type of mangrove landcover conversion and to calculate the rate of change. The method of analyzing changes in mangrove landcover using multitemporal Landsat images with visual classification. The classification accuracy test reached a value of 88%. The results of spatial analysis with a span of 41 years found a decrease in mangrove landcover area of 69% with an average rate of change of 71 hectares per year. The dominant cause of the decline in mangrove landcover is the landclearing of ponds, which has an average rate of change of 82 hectares per year. This activity has an impact on decreasing the diversity of mangrove vegetation types. In mangrove forests found at least two to five types of mangroves with sparse to dense densities, whereas in ponds as a result of pond clearing they are only found on the edge of ponds with sparse densities.

Generally, cultured fish are suitable in media with a pH of around 7, like mountainous river and borehole water.  However, peat water is known with low pH.  It is not suitable for fish culture, especially for fingerlings.  This study was conducted to examine the survival of African catfish fingerling (Clarias gariepinus) in the mixture of peat and borehole water with different pHs. Survival test of African catfish as subject applied bioassay method, LC50-96 hours.  Peat water as the agent was arranged for 11 concentration levels of 0% - 100% with no replication and placed in plastic basins with 20 liters each. Catfish fingerlings were used for subject fish (size 10-15 cm) and 10 individuals in each basin. Water quality, mortality, and behavior of fish were observed. Results showed that the survival ability of African catfish on peat water, the LC50-96 hours was 63.8%, with 95% CI between 53.3% and 76.4% in concentration. Behavioral response of fish fingerling exposed to peat water ≥ 40% in the beginning 2 hours was frequently swimming up to surface.  Lethal responses fingerlings were frequently taking up oxygen to the water surface, horizontally swimming, and moving vertically before death.  After death, the fish ran out of mucus, and the skin looked peeling and bruising.