Mutu kualitas air suatu perairan sangat penting untuk menopang kelulushidupan organisme di dalamnya. Sebagai suatu sistem akuatik, penentuan status mutu air perlu dilakukan guna menjadi acuan dalam melakukan pemantauan pencemaran kualitas air. Penelitian ini bertujuan untuk mengkaji status mutu air di perairan Teluk Gorontalo. Terdapat 5 stasiun pengamatan yang dipilih berdasarkan kondisi pantai dan karakteristik ekologi Teluk Gorontalo. Pengambilan sampel parameter kualitas air dilakukan di sepanjang perairan Teluk Gorontalo pada bulan Mei-Juli 2017. Prosedur pengambilan sampel berdasarkan metode baku APHA. Data kualitas air yang ada kemudian dianalisis dengan menggunakan Metode Indeks Pencemaran. Hasil penelitian menunjukkan bahwa Teluk Gorontalo memperoleh skor indeks pencemaran rata-rata 4,74. Hal ini menunjukkan status mutu Teluk Gorontalo di bulan Juni hingga Juli 2017 tergolong dalam kategori tercemar ringan.

Kasim F, Kadim MK, Nursinar S, Karim Z, Lamalango A. 2019. Comparison of true mangrove stands in Dudepo and Ponelo Islands, North Gorontalo District, Indonesia. Biodiversitas 20: 259-266. This study aimed to investigate and compare the current status of mangrove areas, as well as the composition and species diversity of mangrove stands in both regions of Dudepo and Ponelo Islands. The results showed that the mangrove areas calculated using the segmentation method in classifying image of Landsat-8 OLI (acquisition on September 2017) were 279.46 ha (Dudepo Island) and 113.35 ha (Ponelo Island) respectively. A total of 13 species of true mangrove were recorded from both islands, using survey method from 9 transect lines (TL), with a distance ranging from 40 to 210 meters (1-6 quadrats) per transect. The mean densities of trees were 2133 ± 329.78 ha-1 (Dudepo Island) and 2111 ± 234.28 ha-1 (Ponelo Island), while those of saplings and seedlings were 58 ± 13.48 ha-1 and 1425 ± 113.96 ha-1 (Dudepo Island), and 79 ± 14.51 ha-1 and 2963 ± 443.22 ha-1 (Ponelo Island). The mean diameter and basal area were 19.73 ± 10.65 cm and 84.22 ± 67.67 m2ha-1 (Dudepo Island), 17.04 ± 1.46 cm and 60.07 ± 15.12 m2ha-1 (Ponelo Island), respectively. The Importance Value Index (IVI) ranged between 3.97-114.87 (Dudepo Island) and 6.04-82.18 (Ponelo Island). The dominant and codominant species based on IVI in both islands were Rhizophora apiculata Blume and R. stylosa Griff. The indexes of diversity, richness, and evenness of mangrove species in both islands were 0.34-1.70, 0.48-1.18, 0.47-0.94 (trees), 0.00-1.10, 0.00-1.82, 0.00-1.00 (saplings), and 0.00.-1.48, 0.00-1.44, 0.72-1.00 (seedlings), respectively. The Bray-Curtis similarity index between Dudepo and Ponelo Islands, based on the overall values of community attributes, was 0.75.

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Abstract. Arsad S, Putra KT, Latifah N, Kadim MK, Musa M. 2021. Epiphytic microalgae community as aquatic bioindicator in Brantas River, East Java, Indonesia. Biodiversitas 22: 2961-2971. One way to monitor water quality is by using biological indicators, namely epiphytic microalgae (periphyton). This study aims to analyze the epiphytic periphyton community structure and analyze the river health status using a saprobic index. The research location was in the Brantas River, Blitar District, East Java, Indonesia. The method used was a survey with sampling at three sites based on the purposive sampling technique. Periphyton samples were taken using the quadrant transect (5x5 cm²) method and then identified using the Lackey Drop Micro transect Counting Method. The results show that the periphyton community structure is in balance, and there are six divisions of 59 different genera. The six divisions found are Bacillariophyta, Cyanophyta, Chlorophyta, Charophyta, Ochrophyta, and Rhodophyta. The most identified genus is from the Bacillariophyta Division with 28 genera, while the least identified genus is the Rhodophyta division with 1 genus. The abundance ??ranges from 242,800-1,229,174 cells. cm-2, the relative abundance index ??of periphyton ranges from 3-60% (site 1), 9-57% (site 2), 1-62% (site 3), the diversity index ranges from 1.212-2.617 (moderate), the uniformity index ranges from 0.307-2.151 (high), the dominance index ranges from 0.105-0.549 (moderate), and the saprobic index ranges from-0.18 to 0.55. Moreover, supporting water quality parameters are still optimal, except for ammonia and total organic matter parameters that exceed the quality standard. Based on the saprobic value obtained, the water quality of the Brantas River in Tawangrejo Village can be classified into the category of ?/?-mesosaprobic to ?-mesosaprobic saprobic levels with mild to moderate levels of pollution.