Abstract. Willard K, Aipassa MI, Sardjono MA, Rujehan, Ruslim Y, Kristiningrum R. 2022. Locating the unique biodiversity of Balikpapan Bay as an ecotourism attraction in East Kalimantan, Indonesia. Biodiversitas 23: 2342-2357. Balikpapan Bay is rich in biodiversity and natural beauty that present unique opportunities for the developing ecotourism industry in East Kalimantan, Indonesia. This study aimed to identify biodiversity hotspots with potential as ecotourism attractions. Four field surveys by boat, each survey taking between 10 to 22 hours duration, tracked the river and tidal flow through the Bay, recording highlights of biodiversity at 19 defined observation points. The study results recorded observations on five species listed in the IUCN protected species classification, namely: Lesser Adjutant Stork (Leptoptilos javanicus) - classified as a Vulnerable species; Proboscis Monkey (Nasalis larvatus), Irrawaddy Dolphin (Orcaella brevirostris) and Green Turtle (Chelonia mydas) - classified as Endangered species; and the Hawksbill Turtle (Eretmochelys imbricata) - classified as Critically Endangered. In addition, details were recorded of a unique variant of the mangrove species Rhizophora apiculata, with leaves that have a vibrant yellow color instead of the usual green. Combined with great views, including at night when there are enchanting displays of Fireflies (Lampyridae) on several riverbanks, the biodiversity of the waterways results in Balikpapan Bay having great potential as an ecotourism destination. Therefore, this study provides useful input to relevant agencies charged with responsibility for conserving and managing the natural resources of the Bay for the benefit of communities who stand to gain economically from developing this ecotourism potential.

East Kalimantan are able to produce dragon fruit throughout year, while, East Java are only in raining season. This fruit will be produced abundantly when the peak season comes and often becomes waste. To reduce this cellulosic waste from traditional market, we attempt to convert the dragon fruit waste become bioethanol. In this study, the ability of cocultures (A. niger and S. cerevisiae) and mono-culture (only S. cerevisiae) to produce bioethanol was evaluated. The red dragon fruit waste was treated with simultaneously saccharification and fermentation by using Aspergillus niger and Saccharomyces cerevisiae showed the highest concentration of alcohol was 48.0% after 3 weeks incubation. Subsequently, the use only S. cerevisiae to produce bioethanol was found to be able to produce 64.5% alcohol concentration after 2 weeks incubation. The highest concentration of alcohol was showed when the concentration of S. cerevisiae was 0.67%. These observations confirm that mono-culture has higher alcohol concentration compared to cocultures treatment.

The problem is that there is no certainty about the production capacity of the wells before evaluating the performance of production wells. The research objective was to describe the condition of oil and gas reserves in production wells and an economic picture of the MBR production resources after the recovery period by moving layers using the perforation method. This study used a used research method with a case study approach, namely the case that occurred in the MBR production well of PT. Medco E&P Tarakan operation area. The results of the evaluation of production capacity after displacement recovery based on the analysis of logging data at a depth of 850 MZ, it is known that the initial oil reserves (OOIP) are 284,304 STB with a recovery factor of 25%. The results of the calculation of the economic indicator for the proposed perforation of work to move layers, the total value of NPV. 15% was obtained in the eighth month in total lifting of 28,466, namely USD 123.561, the payout time for this work was 1.8 months with an IRR of 340% indicating that investment has the potential to provide benefits.