The purpose of this study was to determine the growth pattern of Lingula sp. based on its morphometric analysis. The method used in this research is purposive sampling method. he results showed that the number of Lingula sp. less in the Ujong Pancu beach area (66 individuals) when compared to the Syiah Kuala beach area (169 individuals). Based on the weight value of Lingula sp. in the Syiah Kuala area (5,861-7,786 g) it was higher than the Ujong Pancu area (0.082-2.007 g), and the length value was higher in the Syiah Kuala coastal area (39.6-49.4 mm) than the Ujong Pancu beach area ( 19.8-29.6 mm). Besides that, from the calculation of the value of length and body weight, it was found that the value of b at both stations was b> 3 (Ujung pancu, b = 1.9568 and Syiah Kuala, b = 2.896) so that the growth pattern of Lingula sp. classified as negative allometric whereas the length growth is faster than body weight, and the water quality factor in the Ujong Pancu beach area and the Syiah Kuala beach masig are within the normal life limits of Lingula sp.

The purpose of this research was to determine the community structure of macrozoobenthos in the last three years (2017, 2018, and 2019) through analysis of diversity index, evenness index, dominance index, and density. The research was conducted On March 2017, April 2018, and March 2019 in the Lamnyong River. This research used purposive random sampling method, which consisted of 3 stations based on the width of the river namely the right, middle, and left edges of the Lamnyong River. The results showed that during the last three years, 2017, 2018, and 2019, the community structure of macrozoobenthos in the Lamnyong River was classified as unstable because of the dominance of several macrozoobenthos species, but the quality of the river waters could still be tolerated by macrozoobenthos. The types of benthos was found in the Lamnyong River in 2017 is 3 families of macrozoobenthos namely Anomidae, Mytilidae, and Mactridae. In 2018, was found 5 species of macrozoobenthos which Tellina palatam, Lopha cristagali, Scylla serrata, Pinna bicolor, and Balanus sp., and in 2019 there was found 1 species of macrozoobenthos, namely Mactra luzonica.

This study aims to determine the condition of reef fish of the Chaetodontidae family in Krueng Raya and Ujong Pancu waters, Aceh Besar District. The study was conducted in October 2019, where six observation locations were representing the two regions. Fish observations were carried out using the Underwater Visual Census (UVC) method. The results of the study found four genera of Chaetodontidae fish consisting of 21 species. Benteng Inong Balee Station is the location with the highest number of individuals and species of Chaetodontidae fish, 38 individuals belonging to 11 species. On the other hand, Lhok Mee Station is the location with the least number of individuals and species of Chaetodontidae fish found, only 13 individuals belonging to 6 species. The highest abundance of Chaetodontidae fish was found at Ahmad Rhang Mayang Station (521.11 ind/ha). Meanwhile, the least abundance of Chaetodontidae fish was found at Lhok Mee Station, ( 115.38 ind/ha). The number of species, Krueng Raya waters have a higher number of Chaetodontidae fish species than Ujong Pancu waters. On the other hand, the abundance value Ujong Pancu waters have a higher average abundance value of Chaetodontidae fish than Krueng Raya waters. Overall, based on the biological index, the community structure of reef fish of the Chaetodontidae is still stable. Compared to previous study, the present study shows that, within a period of 6 years, the condition of Chaetodontidae fish in Aceh Besar waters has increased in the number of species, abundance, and diversity of fish.

Mangroves are plants that can live in tidal areas. The study aims to determine the condition of the mangrove ecosystem through a mangrove community structure approach in Lambadeuk Village, Peukan Bada District, Aceh Besar District. This research was conducted in November 2017 using the stratified sampling method. The results showed that there were only 2 types of mangrove species found in Lambadeuk Village, Peukan Bada District, Aceh Besar District, the first is Rhizophora apiculata as many as 36 individuals and the second one is Rhizophora mucronata as many as 116 individuals. The important value index (INP) tree and sapling of Rhizophora apiculata at station 1 and station 3 of 253.655% and station 2 of 183.789%. While seedling of Rhizophora apiculata at station 1 and station 3 of 250.04% and station 2 of 175.02%. The important value index (INP) tree and sapling of Rhizophora mucronata at station 1 and station 3 of 253.655%. While seedling of Rhizophora mucronata at station 1 and station 3 of 250.04%. The diversity (H') obtained is low where H' 2.0, dominance (C) is low where 0 < C 0.5 and evenness (E) is also low where 0 < E 0.5.

Ekosistem lamun merupakan salah satu ekosistem yang penting dalam pengelolaan wilayah pesisir sehingga dibutuhkan kajian-kajian sebagai acuan pengelolaan. Penelitian ini bertujuan untuk memberikan informasi terbaru sebagai acuan informasi yang berguna dalam pengelolaan dan pengambilan kebijakan yang tepat terkait kelestarian ekosistem lamun di perairan Ahmad Rhang Manyang, Kabupaten Aceh Besar. Penelitian ini menggunakan metode simple random sampling. Hasil penelitian menunjukkan bahwa terdapat 2 jenis lamun yang ditemukan yaitu Halodule pinifolia dan Halophila ovalis. Penutupan lamun tertinggi yaitu dari jenis Halodule pinifolia dengan nilai 4,70 % sedangkan jenis Halophila ovalis yaitu 0,03 %. Nilai kerapatan tertinggi dari jenis Halodule pinifolia yaitu 66,14 ind/m2, sedangkan dari jenis Halophila ovalis sebesar 0,93 ind/m2. Indeks penutupan lamun dari masing-masing spesies termasuk dalam kategori miskin/rusak.Kata kunci :  Ekosistem lamun, Halodule pinifolia, Halophila ovalis, Kerapatan lamun, Tutupan lamun.