The objectives of this study were to provide reliable data and information on reef fish in the northern Aceh region of Wehand Aceh islands based on management types. This research use underwater visual census techniques at 29 sites aroundWeh Island and Aceh Islands. Reef fish abundance in area that were protected under the management of Panglima Laot ofSabang Weh Island (32505 no.ha-1) and biomass (748 kg.ha-1) were also significantly higher than in Aceh Islands which is open access areas (abundance=9539 no.ha-1; biomass=396 kg.ha-1). Fish species from the family Pomacentridae (damsel fish) were highest in abundance and biomass at northern Acehnese reef. Population of carnivorous fish such as parrotfish (Family Scaridae) was low in all study sites which indicated that northern Acehnese reef is lack of reef resilience both in managed and open access area. Higher numbers and abundance of reef fish in marine managed areas, such as Panglima Laot in Sabang, could be considered for further conservation purpose of marine resources.Key words: Coral reef, reef fish, management type, northern Acehnese reef

This study aimed to analyze the effects of astaxanthin in commercial feed on growth and color intensity of green swordtail fish, Xyphophorus helleri. A total of 150 green swordtail fish (Xyphophorus helleri) had an average weight of ± 2 g per fish was used. A Completely Randomized Design (CRD) was used consisting of five treatments and three replicates. The treatments were A (0 mg/kg), B (50 mg/kg), C (100 mg/kg), D (150 mg/kg), E (200 mg/kg). Observation of color intensity had done once every 10 days for four weeks using TCF (Toca Color Finder). The result showed that the addition of astaxanthin into commercial feeds with different doses has a significant effect on the skin color intensity of green swordtail fish (Xyphophorus helleri). Hence, the concentration of 200 mg/kg Astaxanthin had the optimum skin color intensity of green swordtail fish (Xyphophorus helleri).

The objective of the present study was to study the diversity of marine macroinvertebrates in coral reef area in Aceh Besar waters. This research was conducted in September 2012 until February 2013in nine locations in the waters of Aceh Besar district, namely: AmatRamanyang, Lampuuk, PulauDituan, LhokKetapang, LhokSeudu 1, LhokSeudu 2, Deudap 1, Deudap 2, and Lamteung. The macroinvertebrates were recorded using three repeated 20 m belt transect in two different depths (2-4 m and 4-8 m) in each site. The result showed 46 species of macroinvertebratesbelonging toseven phyla were recorded. The diversity index in research station ranged between 0.88 - 2.26 (low to medium category).

The present study was aimed to catalog the coral reefs that are found in Ulee Lheue breakwater, and providing a baseline data that will be valuable in Aceh marine conservation plan in the future. The research was conducted from February to October 2015. The station of observations was designed by systematic sampling. The sampling stations were located on the outer side and inner side the breakwater with a station spacing of 250 m. Furthermore, 50 m roll meter was used in each station as the reference to laying squares transects (size 100 × 100 cm) for coral reefs observation. Then, the square transects placed on 0, 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50 m. The results showed the reef at the outer breakwater consists of 11 coral genus of 244 colonies. While on the inner side of the breakwater, eightgenera of 46 colonies were observed. Acropora and Pocillopora were the most common genus on the outer side of the breakwater, while Chypastrea and Porites were the most common on the inner side. 0-5 cm coral colony size was the most common size found on both sides of the breakwater. This result showed that the construction of artificial structures on the coast is not only important in the development of a city but also important for marine biology and ecology study.

Mangrove vegetation plays an important role and supplier of organic matter derived from litter fall and litter decomposition The purposes of this research was to obtain the productivity of mangrove vegetation by analyzing the litter fall, decomposition coefficient, and percentage of litter decomposed in the northern coast of Aceh Besar District. The research used purpossive sampling method to determine the 6 stations devided into 2 substations (landward and seaward). This research was conducted in July to September 2016. Each substation was put one of the litter trap. The litter trap method was used to know the mangrove litter production. Litter decomposition focused on R. mucronata leaves were studied by using litterbag technique. The litter bags were made of synthetic nylon which had size 20cm x 30cm and mesh size was 1 x 1.25 mm2. There were 3 types of mangrove found, litter production of Rhizophora mucronata as much as 79.21 g/m2/day, Avicennia marina as much as 0.70 g/m2/day and Sonneratia alba was 17.46 g/m2/day. Based on the substation influenced by tidal, mangrove litters found in the seaward higher than in the landward, the average litter fall was 52.05 g/m2/day and 43.32 g/m2/day. Result of mangrove decomposition showed that the percentage of decomposition for the 49th day in the seaward substation was 48.58% and the landward was 41.53%. Mangrove litter decomposition increased during the time at both substation. Decomposition rate of litter for Rhizopora mucronata species classified very quickly where the substation on the seaward was 0.012 (d−1) and landward was 0.010 (d−1). The half-time took in the leaf litter of mangroves for the landward was 69 days and seaward was 57 days, R. mucronata leaves litter decomposited in seaward substation was faster than landward.