This study aims to analyze the species diversity, distribution and status of fish found in the coastal waters of Banten Bay. Samplings were carried out 7 times at three locations namely Cengkok coastal waters (on February-March 2019), Bojonegara coastal waters (January-February, August-September 2020), and Kemayungan-Linduk coastal waters (February-April 2021) of the Banten Bay, using gill nets, trammel net, cast net, hand-line, beach seine, and mini trawl. Results of this study showed that the fish caught in the Banten Bay coastal waters consisted of 111 species, distributed at the three areas, namely Cengkok (32 species), Bojonegara (58 species), and Kemayungan-Linduk coastal waters (51 species). The diversity, eveness, and dominance indices were 2.185 - 3.763, 0.630 - 0.781, and 0.072 - 0.233 respectively, indicating the medium-high species diversity. These fish were spreading in marine water, fresh water, estuary, freshwater and estuary, marine and estuary, and marine, estuary and freshwater. The common species found at the study location were Ellochelon vaigiensis, Planiliza subviridis, and Leiognathus equula. In general, most of the fish found in Banten Bay were classified as least concern (LC), while two species were vulnerable (VU), one species was near threatened (NT), and ones species was endangered species (EN).

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The sustainability of amphidromous fishes is determined by the success of the larval recruitment process from marine to freshwaters habitats. This study aimed to determine the recruitment pattern of freshwater amphidromous fish to the Cimaja River estuary, Palabuhanratu Bay in terms of season and daily. Amphidromous fish were caught monthly on the 25th of Hijri or waning crescent from December 2020 to August 2021. Sampling in one whole day with observation intervals every 4 hours was carried out in June 2021 to reveal the time of larvae and juveniles of the amphidromous fish recruit to the Cimaja River estuary. A total of 13 species of amphidromous fishes representing five genera and two families was captured. The recruitment of amphidromous fishes into the Cimaja River occurs between the peak of the rainy season to dry season. Generally, amphidromous recruit into the estuary waters of the Cimaja River is at the juvenile stage (11.9-21.8 mm body length). However, the recruitment of some amphidromous fish species appears at the postflexion stage (6.9-11.9 mm BL). Based on diel observations, larvae and juveniles of amphidromous fish are generally preferred to recruit to the Cimaja River estuary in the early morning (03:00 am) and afternoon (03:00 pm). Recruitment of amphidromous fish larvae to the Cimaja River follows a semi-diurnal tidal cycle which is a tidal type in Palabuhanratu Bay. Amphidromous fishes use tidal flux to recruit and migrate upstream of the Cimaja River through estuaries.

Abstract. Study on runoff dynamics across different physiographic regions is fundamentally important to formulate the sound strategies for water resource management especially in the coastal watershed where peoples heavily concentrated and relied on water resources. The L−R diagram, a conceptual model by which the land-changes evapotranspiration (ΔL) was estimated as the difference between actual and climate evapotranspiration to identify the specific impact of land-use changes on annual runoff changes (ΔR), was developed using the 53-year hydro-climatic data of Jiulong River Watershed, a typical medium-sized subtropical coastal watershed in China. This study found that land-use changes have reinforced the impact of climatic changes on runoff changes where nearly all points were scattered in II and IV quadrant. Deforestation and expansion of built up area has diminished the water retention capacity in a catchment as well as evapotranspiration thus produce extra runoff accounting for 12–183 % of total runoff increase. In contrast, reforestation makes the significant contribution to decreasing annual runoff for about 21–82 % of total runoff loss. This study revealed the river runoff has become more vulnerable to intensive anthropogenic disturbances under the context of climate changes in a coastal watershed.

The current research was conducted to study the coral recruitment on concrete blocks at Gosong Pramuka, in Kepulauan Seribu. The concrete blocks were observed based on the wave exposure, i.e. the exposed area and sheltered area. A total of 247 coral recruits colonies was recorded on concrete substrates in Gosong Pramuka. The number of coral colonies in the exposed area (210 colonies) was higher than in the sheltered area (37 colonies). Coral recruit density in the exposed area was 1.37 colony/m2 and in the sheltered area was 0.23 colony/m2. A total of four genera was observed in these areas (Acropora, Porites, Montipora, and Pavona). The branching Acropora colonies were predominant for both areas, while encrusting non-Acropora was primarily found in the exposed area and massive non-Acropora was the major colonies in the sheltered area. The coral size of branching and encrusting Acropora in the sheltered area was significantly bigger than in the exposed area (P <0.05). In the exposed area, corals are found in the center of the concrete, but in the sheltered area, they are located in the corner and the edge of the concrete.