This study aims to determine the distribution and abundance of reef fish families chaetodontidae in coral reef waters of Para Island Sub District Tatoareng. This study was conducted at 4 stations. Data collected was done using visual census on the 50-meter transect line at 5 meters depth. In addition to revealing the number of species and abundance of individuals chaetodontidae, data analysis aimed to determine number of species, individual abundance, and the community index. Based on the identification, obtained 27 species from 3 genera and 217 number of individuals.  The highest number of species found at station Para 1.  7 species are always found in all observation stations, Chaetodon kleinii, C. punctatofasciatus, C. lunulatus, C. trifascialis, C. vagabundus, Heniochus varius, H. chrysostomus. The species with the largest number of individuals that is Chaetodon kleinii (45 individuals). Chaetodontidae fish species diversity index ranged between 2.207-2.866. Dominance Index are categorized low in the range of 0.078-0.122.  Similarity index are categorized high in the range of 0.922-0.971. Keywords : coral fishes, chaetodontidae, coral reef, Para Island

This study was aimed at finding Gastropod species and studying the community structure in the coastal area of Kampung Ambon, Likupang, through species density, diversity, evenness and dominance analyses. It was carried out in August 2017. The study employed transect method with quadrats by placing the on the area covered with coral-sand mix substrates. Density analysis found total numbers of 168 individuals with mean density of 7 ind/m². Spesies of the highest indiviual numbers was Cypraea annulus with a total of 98 individuals. Species diversity (H’) was 0.632773. This value reflects that the species diversity is moderate. Species richness index was R ˃ 4 reflecting that there is high species richness. Species evenness index was ˃ 0,5 meaning that the gastropods in the area are sufficiently even. Dominance index ranged from 0.27 to 0.47 indicating no species dominance in the study site.Key Words : Gastropod,  density, diversity, evenness, dominance ABSTRAKTujuan dari penelitian ini adalah mempelajari jenis-jenis gastropoda apa saja yang ditemukan dan mempelajari struktur komunitas melalui analisis kepadatan, keanekaragaman, kekayaan, kemerataan, dan dominasi spesies di daerah intertidal perairan Kampung Ambong Likupang. Penelitian dilaksanakan pada bulan Agustus 2017.  menempatkan  pada  satu  macam   habitat   yaitu  kawasan   yang didominasi oleh substrat karang yang bercampur pasir. Hasil analisis kepadatan menunjukkan bahwa di ketiga transek pengamatan jumlah individu yang diperoleh berjumlah 168 individu dengan kepadatan rata-rata per kuadrat 7 ind/m². Spesies dengan individu yang terbanyak adalah Cypraea annulus dengan jumlah individu sebanyak 98 individu. Keanekaragaman spesies yang diperoleh yaitu H’ = 0.632773. Nilai ini tergolong pada tingkat keanekaragaman sedang. Indeks kekayaan diperoleh nilai R ˃ 4, kriteria ini tergolong pada indeks kekayaan yang tinggi. Indeks kemerataan spesies diperoleh nilai ˃ 0,5 yang berarti spesies yang ada cukup merata, dan indeks dominasi diperoleh pada kisaran 0,27 – 0,47 yang menunjukkan tidak ada dominansi spesies di lokasi penelitian.Kata Kunci : Gastropoda, kepadatan, keanekaragaman, kekayaan, dominasi

Nudibranchia are known as marine invertebrates that have uniq colors and body shapes. The research was conducted in Nudifall and Nudiretreat, Lembeh Strait, North Sulawesi. The aims of this study were 1) to identify the species of Nudibranchia in both locations, 2) to know the abundance of Nudibranchia in those locations, 3) to determine distribution patterns of nudibranchia, and to know diversity of Nudibranchia in both Nudifall and Nudiretreat. The results show that 11 species of Nudibranchia were found in both Nudifall and Nudiretreat. The species of Chromodoris annae, Chromodoris magnifica, Flabellina expotata, Goniobranchus fidelis, Halgerda batangas, and 1 unidentified species were found in Nudifall, while the species of Goniobranchus geometricus, Glossidoris cincta, Phylllidia ocelata, Phylllidia varicose, Nembrotha rutilans were found in Nudiretreat. H. batangas was found to be the highest abundance, then it was followed byC. annae, C. magnifica, G. fidelis, unidenfied species (species-1), and C. magnificain Nudifall. P. ocelatawas found to be the highest abundance, then it was followed by G. geometricus, G. cincta, P. varicose, andN. Rutilans  in Nudiretreat.  Nudibranchia in both locations wasidentified to have random and grouped distribution pattern. Nudibranchia was found to have the same diversity among Nudifall and Nudiretreat. Factors affecting abudance, distribution patterns, and diversity were discuss in this paper.Keywords: Nudibranchia, Distribution, Abudance, Lembeh Strait. Nudibranchia dikenal sebagai avertebrata laut yang memiliki warna unik dan bentuk tubuh yang bervariasi. Penelitian ini di lakukan di Nudifall dan Nudiretreat, Selat Lembeh, Sulawesi Utara.   Tujuan penelitian ini adalah 1) mengidentifikasi jenis-jenis nudibranchia di lokasi Nudifall dan Nudiretreat, 2) mengetahui kelimpahan jenis-jenis Nudibranchia di kedua lokasi, 3) mengetahui pola distribusi jenis-jenis Nudibranchia di lokasi Nudifall dan Nudiretreatdi, 4) dan keragaman Nudibranchia di Nudifall dan Nudiretreat. Ada 11 jenis Nudibranchia ditemukan di kedu lokasi penelitian.Nudibranchia yang ditemukan di Nudifall ada 6 jenis, yaitu Chromodoris annae, Chromodoris magnifica, Flabellina expotata, Goniobranchus fidelis, Halgerda batangas, dan 1  spesies belum teridentifikasi (spesies-1). Nudibranchia yang ditemukan di Nudiretreat ada 5  jenis,yaitu Goniobranchus geometricus, Glossidoris cincta, Phylllidia ocelata,  Phylllidia varicose, Nembrotha rutilans. H. batangas memiliki kelimpahan yang tinggi, kemudian diikuti oleh C. annae, C. magnifica, G.fidelis, spesies-1, dan C. magnifica.di Nudifall.P. ocelata memiliki rata-rata tertinggi, selanjutnya diikuti oleh G. geometricus, G. cincta, P. varicose, dan N. Rutilans di Nudiretreat.Pola sebaran acak dan berkelompok teridentifikasi pada kedua lokasi.udibranchia teridentifikasi memiliki keragaman yang sama di kedua lokasi. Faktor-faktor yang mempengaruhi kelimpahan, distribusi, dan keragaman didiskusikan pada tulisan ini.Kata kunci: Nudibranchia, Distribusi, Kelimpahan, Selat Lembeh.

Main coral reef building components, Scleractinian corals, has the highest distribution in Indonesia, at least 590 species known of 793 species in the world. Studies on damaged coral community transplantation have been done to observe their growth and adaptation ability. A four-month observation found that average length increment at 9 M deep was linearly 0.375 cm, 0.632 cm, and 0.732 cm at the first, second, and third month, respectively, at 6 M deep, it was 0.455 cm, 0.689 cm, and 1.012 cm, at the first, second and third month, respectively, and at  3 M deep, it was 0.55 cm, 1.05 cm and 1.1, at the first, second, and thrid month, respectively. Mean relative length increment at 9 M deep occurred every month as much as 4.25%, 8.23%, and 9.86% at the first, second, and third month, respectively. Similarly, it occurred in 6 M deep, 4.12%, 9.14%, and 11.28% at the first, second, and third month, respectively. However, at 3 M deep, it occurred only at the first and second month, 7.33% and 12.73%, while it declined at the third month, 11.7%. Keywords : Ecosystems, Coral Reef, Scleractinia, Malalayang, Manado

This study was aimed at revealing the structure of seagrass community in the coastal waters of Bahoi Village, West Likupang Sub-district, District of North Minahasa, North Sulawesi Province. Samples collection was conducted during the lowest tide period by deploying line transect and quadrate. Eight species of seagrasses were identified on this study, including species as follow: Enhalus acoroides, Thalassia hempricihii, Cymodocea rotundata, C. serrulata, Syringodium isoetifolium, Hlodule pinifolia, H. uninervis and Halophila ovalis. The highest density value ( 112.16 individual/m2) was calculated from transect III data on S. isoetifolium species. In term of relative density value, S. isoetifolium also has the highest value (35.176 %). Index dominance (C) was calculated as well from transect III data (0.477) while the highest diversity index  (H’) was calculated from transect I data (1.724). Keyword : structure, Analysis, seagrass ABSTRAK Penelitian ini bertujuan mengkaji struktur komunitas lamun di perairan pantai Desa Bahoi Kecamatan Likupang Barat Sulawesi Utara.Pengambilan sampel  dilaksanakan sekali pada saat surut terendah, data dikumpulkan berdasarkan garis transek dan kuadrat. Jenis lamun yang ditemukan dalam keseluruhan kuadrat di lokasi penelitian berjumlah 8 spesies yaitu : Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Cymodocea serrulata, Syringodium isoetifolium, Halodule pinifolia, Halodule uninervis, dan Halophila ovalis. Kepadatan individu tertinggi terdapat pada transek III yaitu spesies Syringodium isoetifolium 112,16 ind/m2. Kepadatan relatif tertinggi terdapat pada spesies Syringodium isoetifolium (35,176 %). Indeks dominasi (C) yang tertinggi terdapat pada transek III 0.477 indeks keanekaragaman spesies (H’) yang tertinggi pada transek I 1.724. Keyword : structure, Analysis, seagrass 1Mahasiswa Program Studi MSP FPIK-UNSRAT 2Staf pengajar Fakultas Perikanan dan Ilmu Kelautan Universitas Sam Ratulangi