Pabean Bay is an estuary that has the potential of natural resources for fisheries. One of the organisms that has an important role here is phytoplankton. This study aims to analyze spatially and temporally the composition of phytoplankton abundance as fish food sources in Pabean Bay waters, West Java. Phytoplankton and physics-chemical parameters were taken monthly samples (June 2016-March 2017). Data analysis included the composition and abundance of phytoplankton, one-way variance analysis based on time and zone, the relation of physics-chemical parameters of aquatic to phytoplankton abundance, and phytoplankton used by fish as food. The abundance of phytoplankton differs on a monthly basis, but is not different in each zone. The phytoplankton found in the Pabean Bay is dominated by the Bacillariophyceae class. The dominant type of phytoplankton feeds from some of the captured fishes is Nitzschia and Pleurosigma from the Bacillariophyceae class.

The aims of this research was to identify the diet and composition item as well as niche breadth and niche overlap of mullet in Pabean Bay. Fish sampling was carried out from July to December 2016 using trap nets and gill nets. Data analysis including preponderance index, niche breadth, and niche overlap. Chelon subviridis and Moolgarda engeli are two species of mullet that much found in Pabean Bay. The size of body length C. subviridis observed on ranged of 73,34-185,72 mm with a weight of 8,23-115,50 g and M. engeli ranged of 67,51-160,00 mm with a weight of 6,91-96,70 g. Food menu of mullet consists of three groups, namely perifiton, larvae of marine organism, and detritus. Perifiton from Bacillariophyceae was a main diet, particularly Pleurosigma (35,81) in C. subviridis and Nitzschia (27,89) in M. engeli. Changed in composition of each item of diet occurred on any length size group during the observation. C. subviridis and M. engeli have a wide niche breadth with the value were 5,995 and 5,780. Niche breadth of each length group was different. Information on niche breadth indicated the adaptation of mullet to against the availability of diet in the water. AbstrakPenelitian ini bertujuan untuk mengidentifikasi jenis dan komposisi serta luas dan tumpang tindih relung makanan ikan belanak di Teluk Pabean. Pengambilan contoh ikan dilakukan pada Juli hingga Desember 2016 dengan menggu-nakan alat tangkap sero dan jaring insang. Analisis data meliputi indeks bagian terbesar serta luas dan tumpang tindih relung makanan. Dua jenis ikan belanak, Chelon subviridis dan Moolgarda engeli, merupakan spesies yang banyak ditemukan di Teluk Pabean. Ukuran panjang tubuh C. subviridis yang diamati berkisar 73,34-185,72 mm dengan bobot 8,23-115,50 g dan panjang tubuh M. engeli berkisar 67,51-160,00 mm dengan bobot 6,91-96,70 g. Menu ma-kanan ikan belanak terdiri atas tiga kelompok besar, yaitu perifiton, larva organisme, dan detritus. Perifiton dari kelas Bacillariophyceae menjadi kelompok makanan yang banyak dimanfaatkan, khususnya Pleurosigma (35,81) oleh C. subviridis dan Nitzschia (27,89) oleh M. engeli. Perubahan komposisi jenis makanan terjadi pada setiap kelompok ukuran ikan. C. subviridis dan M. engeli memiliki relung makanan yang luas dengan nilai luas relung berturut-turut 5,995 dan 5,780. Luas relung makanan pada setiap kelompok ukuran ikan berbeda. Informasi mengenai luas relung makanan dapat menunjukkan adaptasi ikan belanak terhadap ketersediaan makanan di perairan.

The Batang Toru River is a fairly long river, flowing from the North Tapanuli region and emptying into the Indian Ocean (South Tapanuli Regency). Increased deforestation in the Batang Toru River area has increased the potential for decreasing water quality of the Batang Toru River. The purpose of this study was to determine the condition of the water quality of the Batang Toru River. This research was conducted for 3 months (April, July, October), in the Batang Toru River and its surroundings (14 observation stations scattered from the area near the upstream to the coast). The data analysis used in this research is the analysis of the abundance and composition of the types of phytoplankton, the Diversity Index (H’), the Evennes Index (E), and the Dominance Index (C). Based on the research results, zooplankton in these waters consist of Six Phylum of zooplankton, such as Ciliophora (4 genera), Amoebozoa (2 genera), Cercozoa (1 genera), Rotifera (9 genera), Arthopoda (3 genera), and Annelida (2 genera). Diversity, Evenness, and Dominance Indices were around 0.349-1.847, 0.503-0.994 and 0.240-0.802. Based on the index value, it can be concluded that the Batang Toru River is classified as experiencing moderate ecological pressure.

The sea waters around Panjang and Pamujan Besar Islands (Banten Bay) are fishing grounds and recreation areas for local communities around the bay. The research activity on the macrozoobenthos community structure was carried out from May to July 2019 at 6 stations scattered around the islands. This study evaluates the macrozoobenthos community structure at the sea waters around these islands. Data analysis was carried out on density, diversity, evenness, and dominance indices. Based on the research results, there were 23 genera of the macrozoobenthos from four classes, namely Bivalvia (2 genera), Gastropoda (7 genera), Malacostraca (7 genera), and Polychaeta (7 genera). Pronospio sp., Nephthys sp., and Nereis sp. were the most common genera of macrozoobenthos found at each station. Based on the calculation results, the density varied between 58 and 406 ind/m2. The value of the diversity, evenness, and dominance indices at each station ranged between 1.00 and 2.842, 0.935 to 1.00, and 0.157 to 1.00, respectively. Based on these values, the sea water condition in Panjang and Pamujan Besar Islands has medium diversity, high evenness, and no dominant macrozoobenthos.

This study aims to analyze the plankton community in the sea waters around Panjnag and Pamujan Besar Islands. It was conducted for three months, from May to July 2019, at six locations around the islands. Analysis was carried out to estimate abundance and the diversity, evenness, and dominance indices. Based on the study, the observed phytoplankton consisted of 3 classes, i.e., Bacillariophyceae (30 genera), Cyanophyceae (2 genera), and Dinophyceae (5 genera). The most abundant genera were Chaetoceros sp, Spirulina sp and Rhizosolenia sp. Meanwhile, the zooplankton consisted of 8 classes, i.e., Bivalvia, Ciliata (6 genera), Malacostraca (13 genera), Gastropods, Polychaeta, Sarcodina (1 genus), Rotifera (1 genus), and Urochordata (1 genus), with Nauplius, Calanus, and Bivalve larvae as the most abundant biota. The abundance of phytoplankton and zooplankton varied, 38095-13038515 cells/m3 (phyto) and 4010-190475 inds./m3 (zoo), respectively. The diversity, evenness and dominance indices of the phytoplankton and zooplankton were 0.693-2.146, 0.694-1.00, 0.160-0.341, and 0.780-2.027, 0.275-0.861, 0.160-0.500, respectively. Based on the results, the diversity value is moderate with high evenness and no dominant genera.

Domas coastal waters, located east of Banten Bay, have an enormous potential for fisheries resources closely related to the presence of plankton in the area. This study was carried out for 6 months, from August 2021 to January 2022, to examine the biodiversity and community structure of zooplankton in the Domas coastal waters. Sampling was carried out monthly at six stations distributed from coastal areas to the sea. Data on the zooplankton were examined for abundance, diversity, evenness, and dominance indices. Based on the observations, zooplankton in these waters consisted of 19 classes, namely Actinopteri, Appendicularia, Bivalvia, Branchiopoda, Cirripedia, Cnidaria, Copepoda, Ctenophora, Enteropneusta, Gastropoda, Gymnolaemata, Hydrozoa, Malacostraca, Ostracoda, Ophiuroidea, Phoronida, Polychaeta, Sagittoidea, and Thaliacea. The zooplankton found in abundance were Calanoida, Cyclopoida, and Nauplius. The number of taxa and abundance varied according to sampling time and location, 7-34 inds/m3 and 627-41386 inds/m3, respectively. The diversity, evenness, and dominance indices varied, 0.885-2.108, 0.327-0.797, and 0.172-0.601, respectively. Based on the results of these calculations, it can be stated that the diversity, evenness, and dominance of the zooplankton in these waters are classified as moderate.

The Pabean Bay is an estuary area that inhabited by many fish species such as javelin grunt (Pomadasys kaakan Cuvier, 1830). The purposes of this study were to identify food item and determine the feeding habit of the javelin grunt in The Pabean Bay, West Java. Fishes were collected monthly from June to December 2016 using gill nets and trap nets. Observation food is in vitro by conducting an examination of the stomach and the intestines of an example and refer on the books of the identification by Carpenter and Niem. Analysis of fish diet includes index of relative importance, niche breadth, and niche overlap. Fishes were grouped into three groups based on the size length. The result showed that the javelin grunt was crustacivore. Generally, the diet of javelin grunt consists of Acetes sp., Penaeus sp., Portunus sp., Clupeid, Ambassid, Sciaenid, Gobiid, Sillaginid, and unidentified organisms. Penaeus sp. was the main food and could be found on each size of group in monthly observation. The proportion of index of relative importance value was changed in regard of length size groups of A (41-85 mm: 12.105), B (86-130 mm: 13.804), and C (131-175 mm: 7.561). The niche breadth of javelin fish was higher in the larger ones and a high diet overlap among size groups was found. According to prey item and feeding habit, the javelin grunt can be classified as benthic crustacean feeder.

The waters of the Bengawan Solo River estuary have an important role in enriching the waters of north Gresik and its surroundings areas, and become one of the fishing grounds for coastal fish in that region. This study aims to reveal the aquatic environment condition at the area as the basis for fisheries development. The study was carried out bimonthly through water sampling and analysis both in situ and ex situ at 5-8 stations from January to July 2022. Observations were made on water physical parameters (temperature, transparency, and turbidity) and water chemical parameters (pH, salinity, dissolved oxygen-DO, nitrite, nitrate, ammonia and phosphate). Based on analysis on the physical and chemical parameters, it was known that the range (and standard deviation) of waters quality varied, i.e. temperature 28.20-29.80°C (28.91±0.32oC), transparency 5.00-70.00 cm (21.61±16.19 cm), turbidity 5.84-947.00 NTU (324.40±325.80 NTU), pH 5.00-7.30 (6.66±0.45), salinity 0.00-28.00 psu (4.69±8.34 psu), DO 3.65-7.80 mg/l (5.48±1.09 mg/l). The concentration of nitrite, nitrate, ammonia and phosphate were 0.000-0.100 mg/l (0.007±0.021 mg/l), 1.000-5.000 mg/l (2.483±1.430 mg/l), 0.100.-0.600 mg/l (0.193±0.112 mg/l) and 0.100-6.000 mg/l (0.366±0.114 mg/l), respectively. From the analysis of the aquatic environment condition, it can be seen that the waters of the Bengawan Solo estuary are quite good, and suitable for fisheries development. However, based on the pollution index value, it can be stated that the estuary waters of the Bengawan Solo River are in good category