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All Journal AQUATIC SCIENCE & MANAGEMENT JURNAL ILMIAH PLATAX
Mandagi, Stephanus V.
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Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Environmental Science

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Mapping of Mangrove Diversity in Kelurahan Tongkaina, Bunaken Sub-District, Manado Puasa, Rio N.; Wantasen, Adnan S.; Mandagi, Stephanus V.
Jurnal Ilmiah PLATAX Vol 6, No 1 (2018): ISSUE JANUARY-JUNE 2018
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.6.1.2018.19542

Abstract

This research was conducted in coastal area of Tongkaina Village, Bunaken Sub-district, Manado City, North Sulawesi Province. The purpose of this study was to calculate the diversity of mangrove plants and map the zoning of mangrove species distribution in three research sites. The data collected are categorized as primary and secondary data. Primary data collection related to biophysical condition of mangrove ecosystem, including vegetation structure and area of mangrove cover in study site and further analyzed. Secondary data were collected from various literature studies, documentation and scientific papers and related legislation. Based on  the obtained results, it was known that the diversity index of mangrove in Tongkaina is 1.71 which is categorized as medium in term of its diversity, because the value of H 'is greater than 1 and smaller than 3. This value means also that there was enough productivity, ecosystem condition is quite balanced, and moderate ecological pressures. The highest species diversity index was found in Sonneratia alba with an index of 0.37 and the lowest was in the Bruguiera gymnorrhiza species with index of 0.06. Mapping of mangrove species is done by taking coordinate points within quadrant at three research sites. Color degradation with rounded symbols are used to distinguish each species. The aims are designed to be able to easily distinguish between species visually and can be used as one method of mapping study on the diversity of mangroves. This study reveals the known levels of mangrove diversity are moderate. The existence of fishing activities and mooring boat by the local community contribute to mangrove land degradation. Indispensable protection or conservation through knowledge transfer and building awareness to the community, as well as providing an economic alternative for those utilizing mangrove for both household and commercial needs, in order to maintain better conditions are equally important.Keywords: Mapping, Mangrove, Diversity, TongkainaAbstrakPenelitian ini berlokasi di kawasan pesisir pantai Kelurahan Tongkaina, Kecamatan Bunaken Kota Manado Provinsi Sulawesi Utara. Tujuan dari penelitian ini yaitu untuk menghitung keanekaragaman hutan mangrove serta memetakan zonasi pembagian jenis mangrove di tiga stasiun penelitian. Data yang dikumpulkan adalah data primer dan data sekunder. Pengumpulan data primer berkaitan dengan kondisi biofisik ekosistem mangrove yaitu, struktur vegetasi dan luasan mangrove di daerah penelitian dan selanjutnya dianalisis. Kemudian data sekunder dikumpulkan dari berbagai kajian literature, dokumentasi dan tulisan-tulisan ilmiah serta peraturan perundang-undangan terkait. Pada hasil yang diperoleh diketahui nilai indeks keanekaragaman mangrove di Tongkaina adalah 1,71 dimana nilai indeks ini tergolong dalam kategori keanekaragaman sedang, karena nilai H’ lebih besar dari 1 dan lebih kecil dari 3, yang berarti produktivitas cukup, kondisi ekosistem cukup seimbang, dan tekanan ekologis sedang. Indeks Keanekaragaman spesies tertinggi didapati pada Sonneratia alba dengan nilai indeks 0,37 dan terendah ada pada spesies Bruguiera gymnorrhiza yang memiliki nilai indeks yaitu 0,06. Pemetaan jenis mangrove dilakukan dengan cara pengambilan titik koordinat pada kuadran di tiga stasiun penelitian. Degradasi warna dengan simbol bulat di pakai untuk membedakan tiap spesies. Hal ini bertujuan agar dapat dengan mudah membedakan antar spesies secara visual serta dapat dijadikan salah satu metode kajian untuk memetakan keanekaragaman mangrove. Diketahui tingkat keanekaragaman mangrove tergolong sedang. Adanya kegiatan pertambakan dan tambatan perahu masyarakat membuat lahan mangrove semakin berkurang. Sangat diperlukan adanya perlindungan atau pelestarian melalui pengetahuan dan penyadaran kepada masyarakat, serta memberikan alternatif ekonomi bagi yang memanfaatkan mangrove baik untuk kebutuhan rumah tangga ataupun komersial, demi menjaga perkembangan kondisi yang lebih baik.Kata kunci:      Pemetaan, Mangrove, Keanekaragaman, Tongkaina
Current condition of shallow-water benthic foraminifera in Manado bay, Indonesia Mamuaja, Jane M.; Mandagi, Stephanus V.; Lasut, Markus T.
JASM Vol. 11 No. 1 (2023): APRIL
Publisher : Universitas Sam Ratulangi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jasm.v11i1.56113

Abstract

Coral reef community in Manado Bay is under pressure due to human activities in areas in and around Manado. In order to be able to wisely manage the bay area and the coral reefs in it, information about present conditions is needed. The use of marine organisms as bioindicators is one way to find information about the condition, and organisms such as foraminifera have the potential to be used as some species share the same requirement for water quality as the corals. Sampling for the foraminifera was carried out at 10 locations, and the depth of water ranged from 2.5 m to 7.0 m. The samples obtained were washed through a 63 μm sieve and dried. The separation of foraminifera tests from other sediments was done under a stereomicroscope and they were then identified to genus level. A total of 40 genera was identified among 3194 specimens. To get the FoRAM Index value, the foraminifera was categorized into three functional groups. 8 genera were categorized as symbiont-bearing group, 8 as opportunistic group, and 29 as heterotrophic group. FoRAM Index was found to be varied from 2.06 to 9.19 which indicated that Manado Bay water condition is also varied among the sampling area. In general based on the data obtained, it is assumed that water in Manado Bay is conducive for coral reef growth.
Gastropod Community On Seagrass Ecosystem in Makalisung coast Kaseger, Cindy; Lalita, Jans Djoike; Tilaar, Ferdinand Frans; Tombokan, John L.; Mandagi, Stephanus V.; Ngangi, Edwin L. A.
Jurnal Ilmiah Platax Vol. 9 No. 2 (2021): ISSUE JULY-DECEMBER 2021
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v9i2.34974

Abstract

The aim of the research is to know various species of gastropods and gastropod community structure through species density, percent density, dominant species, and association of species of gastropods on seagrass ecosystem. Research with the method of quadrat transect is put perpendicular to the coastline. Gastropod species are found in the seagrass ecosystem on the Makalisung coast consist of 9 species, 7 families, and 4 ordos. Gastropod community structure on seagrass ecosystem is found with species density is highest Cymbiola nivosa as big as 0.64 (ind/m2) with highest percent density 34.04 %. Diversity of species of gastropods on four-station that H’> 1 highest in fouth station as big as H’= 1.72. The dominance of species is highest Cymbiola nivosa as big as C=0.44, where the result of research in generally dominancy C < 0.25 belong to low. Association of species of gastropods on seagrass ecosystem found three characteristics, (1) classifying of positive association is Cypraea tigris and Monetaria annulus, Cypraea tigris and Cymbiola nivosa, Strombus labiatus and Cyclope pellucida, Strombus labiatus and Cymbiola nivosa, Monetaria annulus and Cerithiun nodulosum, Cymbiola nivosa and Cerithiun nodulosum; Cerithiu nodulosum and Angaria dephinus and Faunus ater. (2) Classification of not associated Angaria dephinus and association close to zero (0,04) is Monetaria annulus and Cymbiola nivosa. (3) Classifying of negative association based on the result of the research shows most of the negative pairs of gastropod species on seagrass ecosystem.Keywords: Gastropod; Density; Diversity; Dominance; AssociationAbstrakTujuan penelitian ini adalah mengetahui jenis-jenis Gastropoda dan struktur komunitas Gastropoda melalui Kepadatan spesies (Ind/m2), Kepadatan relatif (%), Dominansi spesies (C), dan asosiasi antarspesies Gastropoda pada ekosistem lamun. Penelitian dengan metode garis transek kuadrat yang ditempatkan tegaklurus garis pantai. Spesis gastropoda yang ditemukan di ekosism lamun pantai Makalisung, terdiri atas 9 spesies , 7 famili,  dan 4 ordo. Struktur komunitas gastropoda di ekosistem lamun ditemukan dengan kepadatan total spesis tertinggi pada Cymbiola nivosa sebesar 0,64 (ind/m2) dengan kepadatan relatif tertinggi 34,04 %; keanekaragaman spesis gastropoda keempat stasiun H’> 1 di mana tertinggi stasiun 4 sebesar H’= 1,72; dominansi total tertinggi adalah spesis Cymbiola nivosa sebesar C=0,44, di mana hasil penelitian secara umum dominansi C < 0,25 adalah tergolong rendah. Asosiasi spesis gastropoda di ekosistem lamun ditemukan tiga ciri, (1) klasifikasi golongan asosiasi positif adalahCypraea tigris dan Monetaria annulus,Cypraea tigris dan Cymbiola nivosa, Strombus labiatus dan Cyclope pellucida, Strombus labiatus dan Cymbiola nivosa, Monetaria annulus dan Cerithiun nodulosum, Cymbiola nivosa dan Cerithiun nodulosum; Cerithiu nodulosum dan Angaria dephinus dan Faunus ater. Klasifikasi golongan tidak berasosiasi (2) Angaria dephinus dan asosiasi mendekati zero (0,04) yaitu Monetaria annulus dan Cymbiola nivosa. Dan klasifikasi golongan asosiasi negatif, hasil penelitian sebagian besar menunjukkan asosiasi negatif pasangan spesis gastropoda di ekosistem lamun.Kata kunci : Gastropoda, Kepadatan, Diversitas, Dominansi, Asosiasi.
Food Habits of Lencam Lethrinu Food Habits of Lencam Lethrinus rubrioperculatus Sato, 1978 (Fish: Lethrinidae) Tampi, Aprillia A.; Bataragoa, Nego E.; Rangan, Jety K.; Rembet, Unstain N. W. J.; Mandagi, Stephanus V.; Boneka, Farnis B.
Jurnal Ilmiah Platax Vol. 11 No. 1 (2023): ISSUE JANUARY-JUNE 2023
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v11i1.43931

Abstract

This study was conducted to determine the type and composition of food contained in the stomach of the Spotchheek emperor Lethrinus rubrioperculatus in Napo Keluar Nain Likupang waters based on sex and body size. Samples were taken from the catch of fishermen and then the fish samples were then taken to the laboratory for data collection. The method used to determine the composition of fish food used the Index of preponderance (IP). The results showed that the food habits of Spotchheek emperor in Napo Luar Nain Likupang waters with the types of food contained in the stomach of Spotchheek emperor, namely fish, shrimp, gastropods, Polychaeta, crabs (megalopa), and octopus where the main food of Spotchheek emperor is IP fish (94,16%). While the main food based on sex and length of body size is fish, with male IP 96.98% and female 91.15% respectively, while based on body length of Spotchheek emperor where small IP 91.06%, medium IP 98.45% and large IP 82.22%. Keywords: Food, Likupang, preponderance Abstrak Penelitian ini dilakukan untuk mengetahui jenis dan komposisi makanan yang terdapat dalam lambung ikan lencam Lethrinus rubrioperculatus di Napo Keluar Nain Perairan Likupang berdasarkan jenis kelamin dan ukuran tubuh. Sampel diambil dari hasil tangkapan nelayan kemudian sampel ikan selanjutnya dibawah ke Labolatorium untuk pengambilan data. Metode yang digunakan untuk mengetahui  komposisi makanan ikan digunakan indeks bagian terbesar (IBT). Metode ini  digunakan untuk menilai bermacam-macam jenis makanan ikan. Hasil penelitian menunjukan bahwa kebiasaan makanan ikan lencam di Napo Keluar Nain Perairan Likupang dengan jenis makanan yang terdapat dalam lambung ikan lencam yaitu ikan, udang, gastropoda, polychaeta, kepiting (megalopa) dan octopus di mana makanan utama dari ikan lencam adalah ikan IBT (94,16%). Sedangkan makanan utama berdasarkan jenis kelamin dan panjang ukuran tubuh yaitu ikan, dengan masing-masing IBT  jantan 96,07% dan betina 91,15% sedangkan berdasarkan panjang ukuran tubuh ikan lencam IBT kecil 91,98%, sedang 98,45% dan besar 82,22%. Kata kunci: Makanan, Likupang, Indeks Bagian Terbesar.
Coral Covers and the Abundance of Reef Fish in Community Base Management Marine Protected Area (CBM-MPA) Bahoi Village North Sulawesi, Indonesia Siahaan, Dedy Octavian; Mandagi, Stephanus V.; Wagey, Billy T.; Sumilat, Deiske A.
Jurnal Ilmiah Platax Vol. 11 No. 1 (2023): ISSUE JANUARY-JUNE 2023
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v11i1.43944

Abstract

In the last few decades, coral reef ecosystem has been under significant pressure due to anthropogenic impacts and naturally driven factors. The coral reef ecosystem is unique because it has very high biodiversity and many organisms depend on its existence. Every organism in a coral reef ecosystem uniquely contributes to how coral reef communities survive and function. However, coral reef ecosystems are also vulnerable to pressures that cause degradation, interfering with the ecosystem balance. This study aims to monitor the ecological condition of coral reefs and the abundance of reef fish to see how the MPA program in Bahoi village helps the coral reef ecosystem from degradation. The data was collected using Line Intercept Transect (LIT) method, which was drawn 70 meters transect line horizontally at a depth of 3-5 meters. The same transect line was also used to collect data about reef fish by using a Visual Census. The observation distance length is 2.5 meters to the left and right of the transect line. Results of the study showed that the coral cover of MPA Bahoi Village is in the Fair category and the abundance of reef fish in the MPA area is in the Moderate category.  Keywords: Coral Cover; Coral Reef; Marine Protected Area (MPA); Monitoring; Reef Fish  
Morphometric and Meristic Yellowstrip Scad Selaroides leptolepis (Cuvier, 1833) Landed at TPI Tumumpa and PPI Kema Fajar Vafry; Manginsela, Fransine B.; Wantasen, Adnan S.; Mandagi, Stephanus V.; Tilaar, Ferdinand F.; Rimper, Joice R.T.S.L
Jurnal Ilmiah Platax Vol. 11 No. 1 (2023): ISSUE JANUARY-JUNE 2023
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v11i1.44335

Abstract

This research about morphometric and meristic character of yellow stripscad. Fish samples were selected from various sizes in order to represent the various sizes of yellow stripscad that existin nature. Samples of yellow stripscad were taken from fish landed at TPI Tumumpa as many as 60 tail and PPI Kema as many as 60 tail. The purpose of this study was to determine how the morphometric and meristic character of yellow stripscad landed in TPI Tumumpa and PPI Kema. Data analysis with K-mean cluster method using SPSS 25 and Ms. Excel 2019. Yellow stripscad landed in TPI Tumumpa and PPI Kema have different morphometric character with percentage difference of 95%. For meristic character have a fairly small lavel of difference with a difference of 29%. Keywords : yellow stripscad, morphometric, meristic, TPI Tumumpa, PPI Kema. Abstrak Penelitian ini mengenai karakter morfometrik dan meristik ikan selar kuning. Penelitian ini menggunakan metode deskriptif kuantitatif. Sampel ikan akan dipilih dari berbagai macam ukuran agar dapat mewakili berbagai macam ukuran ikan selar kuning yang ada di alam. Sampel ikan selar kuning diambil dari ikan yang didaratkan di TPI Tumumpa sebanyak 60 ekor dan di PPI Kema sebanyak 60 ekor. Tujuan dari penelitian ini untuk mengetahui bagaimana karakter morfometrik dan meristik ikan selar kuning yang didaratkan di TPI Tumumpa dan PPI Kema. Analisis data dengan metode K-mean cluster menggunakan program SPSS 25 dan Ms. Excel 2019. Ikan selar kuning yang didaratkan di TPI Tumumpa dan PPI Kema memiliki karakter morfometrik yang berbeda dengan persentase perbedaan sebesar 95%. Untuk  karakter meristiknya memiliki tingkat perbedaan yang cukup kecil dengan tingkat perbedaan sebesar 29%.  Kata- kata kunci : ikan selar kuning, morfometrik, meristik, TPI  Tumumpa, PPI Kema.  
Macroalgae Communities In The Waters Of Tateli Village, Mandolang, And Mokupa Village Waters, Tombariri, Minahasa District, North Sulawesi Province Turangan, Septiara; Kepel, Rene Charles; Mandagi, Stephanus V.; Mantiri, Rose O. S. E.; Menajang, Febry S. I.; Kambey, Alex D.
Jurnal Ilmiah Platax Vol. 12 No. 1 (2024): ISSUE JANUARY-JUNE 2024
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v12i1.49441

Abstract

On the coast of Beton Panjang and Tasik Ria, there are tidal flats with white sand substrates and some seagrass beds (seagrass) and macroalgae. Until now, there is still limited research on macroalgae in Beton Panjang and Tasik Ria. However, studies on macroalgae, especially aspects of their anatomical characteristics, have not been carried out. Therefore, it is necessary to study the anatomical characteristics and structure of the community. Sampling was carried out at the lowest ebb with the help of an application (to find out the lowest ebb time). They are laying transects at each location for macroalgae data collection as many as 3 transect lines 50 m long drawn perpendicularly from the coast towards the sea with the assumption that the community is evenly distributed. The distance between transects is 30 m with a squared distance of 5 m. Each square is used for data collection measuring 1 x 1 m². Analysis of the density index and relative density in Beton Panjang coastal waters yielded a density value of 0.06 ind.m2 – 0,43 ind./m2. The lowest density value is in the speciesLaurencia papillosa and the highest is in speciesPadina australis With a total density of individuals per species of 0.43 ind./m2. In the coastal waters of Tasik Ria, the highest density index is for species Neomeris  annulled with a value of 0.63 ind./m2. The highest diversity index value is in the coastal waters of Tasik Ria with a value of H' = 2.33, while the highest dominance index is in the coastal waters of Beton Panjang with a dominance value of D = 0.16. The highest wealth and equity values ​​are in the coastal waters of Tasik Ria with a value of d = 2.27 and E = 0.94. Keywords: macroalgae, Beton Panjang, Tasik Ria, anatomical characteristics   Abstrak Di pesisir Beton Panjang dan Tasik Ria terdapat rataan pasang surut dengan substrat pasir putih dan beberapa hamparan lamun (seagrass) serta makroalga. Sampai saat ini, masih terbatas penelitian tentang makroalga di Beton Panjang dan Tasik Ria. Namun, kajian mengenai makroalga khususnya aspek karakteristik anatomi belum dilakukan. Oleh sebab itu, perlu dilakukan kajian karakteristik anatomi dan juga struktur komunitasnya.Pengambilan sampel dilakukan pada saat surut terrendah dengan bantuan aplikasi Tides (untuk mengetahui waktu surut terrendah). Peletakan transek pada masing-masing lokasi untuk pengambilan data makroalga sebanyak 3 garis transek sepanjang 50 m yang ditarik tegak lurus dari pantai ke arah laut dengan asumsi bahwa penyebaran komunitas merata. Jarak antar transek yaitu 30 m dengan jarak kuadrat yaitu 5 m. Setiap kuadrat dipakai untuk pengambilan data berukuran 1 x 1 m². Analisi indeks kepadatan dan kepadatan relatif di perairan pesisir Beton Panjang di dapat nilai kepadatan 0,06 ind.m2 – 0,43 ind./m2. Nilai kepadatan terendah ada pada spesies Laurencia papillosa dan yang tertinggi ada pada spesies Padina australis Dengan jumlah kepadatan individu perjenis 0,43 ind./m2. Pada perairan pesisir Tasik Ria, indeks kepadatan tertinggi ada pada spesies Neomeris annulata dengan nilai 0,63 ind./m2 . Nilai indeks keanekaragaman tertinggi ada pada pada perairan pesisir Tasik Ria dengan nilai H’= 2,33, sedangkan untuk indeks dominasi tertinggi ada pada perairan pesisir Beton Panjang dengan nillai dominasi D=0,16. Untuk nilai kekayaan dan kemerataan tertinggi ada pada perairan pesisir Tasik Ria dengan nilai d= 2,27 dan E= 0,94. Katakunci: makroalga, Beton Panjang, Tasik Ria, karakteristik anatomi.
Direct Benefit Value Of Coral Reefs Ecosystem in Bahoi Village West Likupang District North Minahasa Regency Kindangen, Rezky G. T. L; Sangari, Joudy R. R.; Wantasen, Adnan S.; Rembet, Unstain N. W. J.; Mandagi, Stephanus V.; Kambey, Alex D.
Jurnal Ilmiah Platax Vol. 12 No. 1 (2024): ISSUE JANUARY-JUNE 2024
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v12i1.50086

Abstract

The high use of coastal resources especially coral reefs by the people of Bahoi Village can affect the existing ecosystem. This research was conducted in July 2021 in Bahoi Village, West Likupang District, North Minahasa Regency designed to determine the value of direct benefits of the coral reefs ecosystem at the location. The data collected in this study were primary and secondary data. Primary data were obtained by conducting interviews among the fishermen as respondents. The interview was conducted using the purposive sampling method by taking a sample of 30 respondents from fishermen's households in the community. As for secondary data, namely the ecological condition of coral reefs (coral cover), the general condition and population of Bahoi Village were based on YAPEKA 2015 data. The data collected were then tabulated and analyzed using the effect on production (EOP) model to determine the value of the direct benefits of coral reefs. The main livelihood of the people of Bahoi Village is fishermen, which is comprised of 107 people (60% of the total number of households in Bahoi Village. The results show that the community of Bahoi is very dependent on the coastal resources. Based on the result of the EOP analysis technique used the value of direct use benefits obtained from coral reef fisheries is Rp. 379,746,378,-/ha/year. Keywords: Direct benefits, ecosystem value, Coral reefs Abstrak Tingginya pemanfaatan pesisir khususnya terumbu karang oleh masyarakat Desa Bahoi dapat mempengaruhi sumber daya ekosistem yang ada. Penelitian ini dilaksanakan pada bulan Juli 2021 di Desa Bahoi, Kecamatan Likupang Barat, Kabupaten Minahasa Utara dengan tujuan untuk mengetahui nilai manfaat langsung ekosistem terumbu karang di lokasi tersebut. Sumber data yang dikumpulkan dalam penelitian ini menggunakan data primer dan data sekunder. Data primer didapatkan dari hasil wawancara. Wawancara yang dilakukan menggunakan metode purposive sampling dengan mengambil sampel responden sebanyak 30 orang. Sedangkan untuk data sekunder yaitu kondisi ekologi terumbu karang (tutupan karang) Desa Bahoi, Gambaran umum Desa Bahoi dan jumlah penduduk Desa Bahoi. Data yang dikumpulkan selanjutnya dibuat tabulasi dan dilakukan analisis untuk menentukan nilai manfaat langsung dari terumbu karang yang ada di Desa Bahoi. Mata pencaharian utama masyarakat Desa Bahoi adalah nelayan yaitu sebanyak 107 orang (60% dari total jumlah kepala keluarga Desa Bahoi). Dimana menunjukkan bahwa masyarakat Desa Bahoi sangat bergantung pada hasil perairan di Desa Bahoi. Berdasarkan hasil analisis dengan pendekatan EOP, diperoleh nilai manfaat langsung yang didapatkan dari pemanfaatan terumbu karang sebagai perikanan tangkap di Desa Bahoi yaitu sebesar  Rp. 379.746.378,-/ha/tahun. Kata kunci: Manfaat langsung, Nilai, Terumbu karang
Seagrass Community Structure in Mangket Beach Water, Kema District, North Minahasa Regency Wakkary, Paramitha G.; Mandagi, Stephanus V.; Kondoy, Khristin I. F.; Kepel, Rene Ch.; Menajang, Febry S. I.; Rangan, Jety
Jurnal Ilmiah Platax Vol. 12 No. 1 (2024): ISSUE JANUARY-JUNE 2024
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v12i1.50365

Abstract

The purpose of this study was to determine the types of seagrasses, density, relative density, frequency, diversity index, dominance index, and environmental factors in Mangket coastal waters. This research method is the quadratic and line transect. This research was conducted in the waters of Mangket Beach, Kema District, North Minahasa Regency on November 27, 2022. There were 3 species of seagrass found in Mangket Beach waters, namely, Cymodocea rotundata, Cymodocea serrullata, and Enhalus acoroides. The number of seagrass species stands at the study site ranged from 105-814 individuals, species density (4.38-33.92 individuals/m2), relative density (6.54-50.72%), frequency of presence (1.67-4 .00), relative frequency (17.24-41.38%), diversity index H'= (0.38) and dominance index (0.004-0.26). The environmental conditions in the waters are temperature 29.5°C, salinity 32‰, and sandy and sandy mud substrates. Keywords: Mangket Beach, seagrasses, community structures. Abstrak Tujuan penelitian ini adalah untuk mengetahui Struktur Komunitas Lamun meliputi jenis-jenis lamun, kepadatan, kepadatan relatif, frekuensi, frekuensi relatif, indeks keanekaragaman, indeks dominasi dan faktor lingkungan perairan pantai Mangket. Metode penelitian ini adalah kuadrat dan line transek. Penelitian ini dilaksanakan di perairan Pantai Mangket Kecamatan Kema Kabupaten Minahasa Utara pada tanggal 27 November 2022. Spesies lamun yang ditemukan di perairan Pantai Mangket berjumlah 3 yaitu, Cymodocea rotundata, Cymodocea serrullata dan Enhalus acoroides. Jumlah tegakan spesies lamun di lokasi penelitian berkisar dari 105-814 individu, kepadatan spesies (4,38-33,92 individu/m2), kepadatan relatif (6,54-50,72%), frekuensi kehadiran (1,67-4,00), frekuensi relatif (17,24-41,38%), indeks keanekaragaman H’= (0,38) dan indeks dominasi (0,004-0,26). Kondisi lingkungan di perairan yakni suhu 29,5°C, salinitas 32‰, substrat lumpur berpasir dan berpasir. Kata Kunci: Pantai Mangket, lamun, struktur komunitas.
Condition Factors and Length-Weight Relationships of Fifteen Important Fish Species in the Estuary of Manado Bay Indonesia Manu, Gaspar; Bataragoa, Nego E.; Mandagi, Stephanus V.; Dauhan, Dulce Maria; Sampe, Ayumi Angraini
Jurnal Ilmiah Platax Vol. 11 No. 2 (2023): ISSUE JULY-DECEMBER 2023
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35800/jip.v11i2.51491

Abstract

This research aims to analyze condition factors and growth patterns of estuary fish in Manado Bay. Sampling was carried out at the river estuary in Manado Bay, the Pineleng River in Bahu, the Sario River estuary in Sario, the Tondano River estuary in Sindulang, and the Bailang River estuary in Tumumpa. Sampling was carried out in June and July 2023 in the new moon and full moon phases at each river mouth. The fishing gear uses a beach seine 20 m long with a net height of 2 m. Analysis of condition factors and growth patterns using a length-weight relationship approach. Fulton's Condition Factor: K=100W/L3 Where K is the condition factor, W is the weight of the fish and L is the length of the fish (total length). Relative condition factor: Kn=W/Ŵ, where W is the weight of the fish and Ŵ is the estimated weight of the fish from the analysis of the length-weight relationship. Allometric and isometric growth patterns with length-weight relationship analysis: W=aLb where W is the weight of the fish (g), L is the length of the fish (cm), a and b are constants. During the research, 43 fish species were obtained and 15 of them were classified as important species whose presence was ≥1% relative abundance. Fulton's K obtained ranged from 0.69-1.76, the lowest species was 0.69 Stolephorus commersonnii and the highest was 1.76 Neovespicula depressifrons. The Kn value obtained for almost all species was ≈ 1.0, except for Sillago sihama, which was much smaller, namely 0.77. The value of the constant b relationship between length and weight varied between 2.22 in Caranx ignobilis and 3.9 in Ambassis gymnocephalus. The growth pattern is isometric for six species, negative allometric for four species, and positive allometric for five species. Keywords: Species, condition, allomotric, isomatric. Abstrak Penelitian ini bertujuan untuk manganalisis factor kondisi dan pola pertumbuhan ikan muara sungai di Teluk Manado. Pengambilan sampel dilakukan pada muara sungai di teluk Manado, Sungai Pineleng di Bahu, muara Sungai Sario di Sario, muara Sungai Tondano di Sindulang dan muara Sungai Bailang di Tumumpa. Sampling dilakukan pada bulan Juni dan Juli fase bulan baru dan bulan purnama pada masing-masing muara sungai. Alat tangkap menggunakan pukat pantai panjang 20 m dengan tinggi jaring 2 m. Analisis faktor kondisi dan pola pertumbuhan dengan pendekatan hubungan panjang-berat. Fulton’s Condition Factor: K=100W/L3 Di mana K adalah fator kondisi, W berat ikan dan L panjang ikan (panjang total). Faktor kondisi relative: Kn=W/Ŵ, di mana W adalah berat ikan dan Ŵ adalah berat ikan yang diduga dari analisis hubungan panjang-berat. Pola pertumbuhan allometrik dan isometrik dengan analisis hubungan panjang-berat: W=aLb dimana W adalah berat ikan (g), L panjang ikan (cm), a dan b adalah konstanta. Selama penelitian diperoleh 43 speses ikan dan 15 diantaranya tergolong speses penting yang kehadirannya ≥1% kelimpahan relatif. Fulton’s K diperoleh berkisar antara 0,69-1,76 spesies terendah 0,69 Stolephorus commersonnii dan tertinggi 1,76 Neovespicula depressifrons. Kn diperoleh hampir seluruh spesies nilai ≈ 1,0 kecuali Sillago sihama jauh lebih kecil yakni 0,77. Nilai konstatnta b hubungan panjang berat berfariasi antara 2,22 pada Caranx ignobilis dan 3,9 pada Ambassis gymnocephalus. Pola pertumbuhan isometrik enam spesies, allometrik negatif empat spesies dan allometrik positif lima spesies. Kata Kunci: Spesies, kondisi, almotrik, isomatrik.
Co-Authors Adnan Wantasen Alex D. Kambey Anneke V. Lohoo Billy Theodorus Wagey Dauhan, Dulce Maria Dedy Octavian Siahaan, Dedy Octavian Deiske Adeliene Sumilat, Deiske Adeliene Edwin D Ngangi Fajar Vafry Farnis B. Boneka Ferdinand Frans Tilaar Fransine B. Manginsela Gaspar Manu John L. Tombokan Joice R.T.S.L Rimper Kaseger, Cindy Kepel, Rene Ch. Khristin I. F. Kondoy, Khristin I. F. Kindangen, Rezky G. T. L Kondoy, Khristin F I. Lalita, Jans Djoike Mamuaja, Jane M. Markus T. Lasut Menajang, Febry S. I. Nego E. Bataragoa, Nego E. Puasa, Rio N. Rafii, Keken Angliyana Rangan, Jety Rangan, Jety K. Rene Charles Kepel, Rene Charles Rose O. S. E. Mantiri, Rose O. S. E. Sampe, Ayumi Angraini Sangari, Joudy R. R. Tampi, Aprillia A. Tilaar, Ferdinand F. Turangan, Septiara Unstain N. W. J. Rembet, Unstain N. W. J. Wakkary, Paramitha G.