http://repository.unmul.ac.id/handle/123456789/763 2026-07-12T23:56:24Z http://repository.unmul.ac.id/handle/123456789/58836 Chlorophyll‐a variation in response to precipitation in a tropical urban lake Hamdhani, Hamdhani; Musyiir, Sharaha; Drew E., Eppehimer; Samsul, Rizal With increasing urbanization, urban lakes are becoming more common and serve as important flood control infrastructure, recreational uses, as well as habitat for a variety of biota. However, given their construction, function and location, urban lakes are susceptible to disturbances including stormwater runoff from metropolitan catchment areas. For example, nutrient loading from stormwater runoff can cause eutrophication. Chlorophyll-a concentration is an important water quality parameter because it is used to assess water quality and determine trophic state. Chlorophyll-a is known to be impacted by a number of environmental factors including precipitation and associated runoff. Previous studies indicate that the relationship between precipitation and chlorophyll-a is complex and often site-specific. In this study, we examined the relationship between chlorophyll-a and precipitation in an urban, tropical lake located in East Kalimantan Province, Indonesia. From October through December 2022, chlorophyll-a, turbidity, phosphate (PO4), pH, dissolved oxygen, temperature, total dissolved solids and conductivity were measured at five sampling sites in Air Hitam Lake, and precipitation was measured adjacent to the lake. These data indicated that chlorophyll-a concentrations were negatively correlated with recent precipitation (r2 = .71, p < .05). This relationship was likely a result of dilution from increased lake volume. Although urban runoff is expected to increase nutrient loading, our monitoring indicated that dilution can mediate this process in the short-term. Our findings suggest that timing matters when monitoring water quality in tropical, urban lakes. Sampling immediately following heavy precipitation and stormwater runoff can lead to an underestimation of normal chlorophyll-a concentrations due to dilution. As a result, dilution effects should be examined when studying and managing urban lentic ecosystems with strong precipitation dynamics. Further studies are necessary to better understand these urban aquatic ecosystems to continue to improve future management efforts. https://onlinelibrary.wiley.com/doi/abs/10.1111/lre.12447 2024-01-19T00:00:00Z http://repository.unmul.ac.id/handle/123456789/58835 Microplastic Pollution in Waters and Sediments in a Lentic System: A Case Study in a Tropical Wet Urban Lake of Samarinda, Indonesia Hamdhani , Hamdhani; Drew E., Eppehimer The widespread use of plastic materials globally has sparked concerns regarding microplastic (MP) pollution, which is prevalent in water bodies worldwide and poses threats to aquatic life. Despite this, there remain uncertainties regarding the quantity, types and chemical makeup of MP, particularly in tropical urban lakes. This study aimed to examine the presence, distribution, types and chemical composition of MP in both the surface water and sediment of Air Hitam Lake, located in Samarinda City, East Kalimantan, Indonesia. Field sampling was conducted in February 2023 at 10 sites within the lake. The average concentration of MP in water was measured at 0.91 particles per litre, while sediment concentrations reached 375 particles per kilogram of dried sediment. Higher concentrations were observed near the lake inlet. Fibres were the most commonly observed type of MP in both surface water (79%) and sediment (76%) samples, followed by fragments and films. There was no significant correlation between MP concentrations in water and sediment. Fourier Transform Infrared (FTIR) analysis revealed the presence of polyester, polypropylene, nylon fibres, polyethylene, polystyrene polyvinylchloride in the samples, with polyethylene being the predominant compound, accounting for 46% of all surface water and sediment samples. The presence of MP derived from the degradation of larger plastic debris originating from visitors and the local community who dispose of plastic trash improperly highlights the importance of implementing effective plastic waste management strategies in communities surrounding the lake. This is crucial for preserving the ecosystem benefits provided by the lake. This study contributes to addressing knowledge gaps regarding MP pollution in tropical urban lakes and lays the groundwork for further research into inland freshwater environments. https://onlinelibrary.wiley.com/doi/abs/10.1111/lre.70008 2025-04-14T00:00:00Z http://repository.unmul.ac.id/handle/123456789/58679 Piagam Penghargaan Narasumber Manajerial Pada Pelatihan Manajerial Sarjana Penggerak Pembangunan Indonesia (SPPI) Batch-3 Fitriyana Narasumber Penyelenggaraan Rekrutmen Sarjana Penggerak Pembangunan Indonesia batch 3 Penghargaan Sebagai Narasumber Manajerial Pada Pelatihan Manajerial Sarjana Penggerak Pembangunan Indonesia (SPPI) Batch-3 2025-07-14T00:00:00Z http://repository.unmul.ac.id/handle/123456789/58382 Analisis Karakteristik Habitat dan Distribusi Spasial Belangkas (Tachypleus gigas) Juvenile di Perairan Teritip, Kota Balikpapan, Kalimantan Timur Alimin, Mohammad; Ramadhan Ritonga, Irwan; Nurfadilah, Nurfadilah Belangkas (Tachypleus gigas) merupakan salah satu biota perairan yang mempunyai peranan penting diperairan. Namun, berdasarkan International Union for Conservation of Nature (IUCN), spesies Tachypleus gigas berstatus kekurangan data (data deficient) dan hewan yang terancam punah. Tujuan dari penelitian ini adalah untuk menganalisis distribusi spasial dan karakteristik habitat spesies Belangkas (Tachypleus gigas) juvenile di perairan Teritip. Penelitian ini dilakukan di perairan Teritip, Provinsi Kalimantan Timur dengan menggunakan metode kuantitatif. Penentuan lokasi sampling dilakukan dengan metode random sampling dengan kuadran 8 x 8 m2 di 10 stasiun yang berbeda. Berdasarkan hasil analisis, tingkat kepadatan spesies Belangkas (Tachypleus gigas) di perairan Teritip Balikpapan Timur adalah 106 individu dengan rata-rata 0,16 ind./m2. Berdasarkan hasil analisis PCA, hubungan parameter substrat dan kualitas air mempengaruhi jumlah kelimpahan Belangkas dengan tingkat kepercayaan sebesar 64,2%. Hal ini ditunjukkan jumlah kepadatan Belangkas lebih banyak ditemukan di stasiun 3, 6 dan 9 yang berada di dekat pantai. Kondisi suhu di lokasi tersebut berkisar 30,7 – 31,70C, nilai salinitas berkisar 25,9- 29,1 (ppt) dan jenis substrat di stasiun tersebut yaitu lepung berpasir. Karakteristik habitat Belangkas di perairan Teritip, di dukung parameter oseanografi dan substrat di sekitarnya. 2025-01-27T00:00:00Z