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Papers by Jansen Dkirk

Research paper thumbnail of Mangrove Community Structure On The Coast Of Tanjung Kelapa, Tombariri Districts, Bunaken National Park

Jurnal Ilmiah Platax (edisi elektronik), Jan 4, 2023

Research paper thumbnail of インドネシア浅海域に於ける棘皮動物相(ヒトデ類、ウニ類、ナマコ類)

Research paper thumbnail of 北スラウェシ州の国立自然公園(Bunaken及びTangkoko)における観光現状とエコツーリズムに関する意向調査

日本観光研究学会全国大会学術論文集, Dec 1, 2011

Research paper thumbnail of Estimasi penyerapan karbon hutan mangrove Bahowo Kelurahan Tongkaina Kecamatan Bunaken

Jurnal Pesisir dan Laut Tropis (Tropical Coastal and Marine Research), Jul 17, 2018

Research paper thumbnail of Meristic And Morfometric Characteristics Of Scad Mackerel Decapterus macarellus (Cuvier, 1833)

Jurnal Ilmiah PLATAX

Fish are cold-blooded vertebrates, whose body movements and balance are mainly using fins, breath... more Fish are cold-blooded vertebrates, whose body movements and balance are mainly using fins, breathing through gills, and living in an aquatic environment. Most vertebrates in the world are fish covering 48.1%, mammals (10.8%), reptiles (14.4%), amphibians (6.0%), and birds (20.7%). One of the fish consumed in North Sulawesi is scad mackerel locally called malalugis. This research focused on the meristic and morphometric characteristics of blue scad. The samples were caught in Makalehi waters and then landed in Manado Bay. Meristic observations (related to the number) included the number of spines and soft dorsal fin, pectoral fin, pelvic fin, anal fin (anal), and caudal fin. There were 9 spines on the first dorsal (D1), 2 spines and 30-37 soft rays on the second dorsal (D2), 3 spines and 24-31 soft rays on the anal fin (A), and 1,327 linea lateralis (LL). The morphometric observations cover total length, standard length, fork length, head length, tail stem length, eye width, body wid...

Research paper thumbnail of (Editor- in-chief)

Pesisir dan Lautan Indonesia ” kembali hadir dengan perubahan judul, yakni “Pesisir & Lautan”, me... more Pesisir dan Lautan Indonesia ” kembali hadir dengan perubahan judul, yakni “Pesisir & Lautan”, menyusul edisi pertama yang terbit bulan Maret 1998 dengan desain yang lebih menarik. Judul baru tersebut diharapkan akan lebih atraktif dan mudah diingat pembaca. Perubahan judul jurnal ini tidak mengubah tema dan tujuan jurnal, dimana masih membicarakan masalah-masalah yang berkaitan dengan pengelolaan sumberdaya pesisir dan lautan di Indonesia. Penerbitan edisi kedua ini diharapkan akan lebih bermanfaat dan dapat membantu semua kalangan, terutama para pemerhati serta pihak-pihak yang peduli terhadap pelestarian serta pengelolaan sumberdaya pesisir dan lautan, sekaligus dapat berperan sebagai media informasi dalam mengulas permasalahan pengelolaan sumberdaya pesisir dan lautan. Akhirnya saya ucapkan selamat membaca dan kontribusi serta saran-saran anda kami tunggu selalu.

Research paper thumbnail of Protogynous hermaphroditism in the sand diver Trichonotus filamentosus

NIPPON SUISAN GAKKAISHI, 1991

Sexual patterns of the sand diver Trichonotus filamentosus were studied using specimens collected... more Sexual patterns of the sand diver Trichonotus filamentosus were studied using specimens collected at Hakata Bay, Kyushu, Japan, between 1986-1989. The species was found to be a protogynous hermaphrodite for the following reasons: (1) The males are not only larger in body size than females, but also have a different body form and color, with intermediate types occurring within a range where the male and female sizes overlap. (2) Differences in annuli in otoliths between the sexes suggest that males are older than females. (3) Bisexual gonads occur in 4.58% of the specimens examined histologically. (4) Bisexual gonads and mature testes exhibit secondary structure. The size frequency distributions of the males and females, and the occurrence of specimens with bisexual gonads indicate that the sand diver of Hakata Bay undertakes protogynous sex change at 80-120mm SL, after the spawning season in summer. It has also been found that the present species is monandric, because all males have secondary testes.

Research paper thumbnail of Struktur Komunitas Ikan Family Chaetodontidae Sebagai Indikator Kondisi Kesehatan Lingkungan Ekosistem Terumbu Karang DI Zona Tradisional Pulau Bunaken Taman Nasional Bunaken

Jurnal Pesisir dan Laut Tropis (Tropical Coastal and Marine Research), Oct 4, 2021

The presence of coral reef fishes, especially family Chaetodontidae is one of bioindicators to en... more The presence of coral reef fishes, especially family Chaetodontidae is one of bioindicators to environment health condition of coral reef. Fish indicator research in Bunaken Island waters aims to find out the community structure, such as the composition, abundance, density, equality, diversity and dominance. Data collection was conducted at 5 (five) locations in the Bunaken Island Traditional Zone where there are 5 (five) observation points respectively, namely TP-1 Mandolin, TP-2 Alung Banua, TP-3 Sachiko, TP-4 Muka Kampung, and TP-5 Bunaken Timur. Data collection by underwater visual census (UVC) techniques using SCUBA. The results showed there were 23 species of indicator fish from family Chaetodontidae, total individuals number of each species in 5 research sites as many as 97 individuals. The highest fish density is 0.06 at TP-5 while the lowest value in TP-2 with density value 0.02. Through indicator fish community structure indicates that the coral reef quality conditions is stable indicated by diversity values (H') in all locations were moderate category and inversely proportional by low dominance values, high leveling values (E). The similarity rate (IS) of indicator fish species in all locations differs from each other indicating the condition of coral reefs in each location grows independently without being influenced by other locations.

Research paper thumbnail of Studies on the Sexual Patterns in Ten Species of Japanese Marine Fishes

Research paper thumbnail of Acanthuridae in Bitunuris Waters Talaud Islands

Jurnal Ilmiah PLATAX

This study aims to determine the species of fish from the Acanthuridae family in Bitunuris Villa... more This study aims to determine the species of fish from the Acanthuridae family in Bitunuris Village, Salibabu Island, Talaud Islands Regency. Fish samples were caught using monofilament gill nets with a mesh size of 1.5 inches, net length of 15 m, and net height of 2 m. Sampling was carried out in April and May 2021. A total of 63 individuals were caught consisting of nine species. Acanthurus nigrofuscus 40 individuals, 10.0-17.0 cm in length and 18-77 g in weight. Acanthurus lineatus three individuals, 9.4-17.7 cm in length and 17-96 g in weight. Acanthurus triostegus is seven individuals, 9.3-12.4 cm in length, and weighs 21-55 g. Acanthurus nigricans two individuals each measuring 13.9-13.9 cm in length and weighing 67-70 g each. One individual Ctenochaetus cyanocheilus, a total length of 10.3 cm, and weight of 29 g. Naso lituratus four individuals, length 15.1-17.7 cm and weight ranging from 68-115 g. Naso brevirostris one individual measuring 23.0 cm in length and weighing 186 ...

Research paper thumbnail of Vertical distribution and effect of the depth on growth form and genus of hard coral on coral reef in Bunaken Island, North Sulawesi, Indonesia

AQUATIC SCIENCE & MANAGEMENT

Bunaken Island generally has a 90° slope and it forms like an underwater wall. However, there are... more Bunaken Island generally has a 90° slope and it forms like an underwater wall. However, there are several locations in Bunaken Island that have a more gradually inclined slope. This study was aimed to identify the effect of depth and slope gradient toward vertical distribution on growth forms and genera of hard coral at three stations in Bunaken Island. The data was collected using Line Intercept Transect (LIT) method which was dragged vertically at 3-15 meters depth. The results of study showed two different types of slopes, steep and gentle slopes. Stations 1 and 2 were categorized as steep slope (90° and 55°, respectively) and station 3 was gentle slope (43°). Encrusting growth forms dominated at 90° slope, while at 55° and 43° slope was dominated by massive growth forms. Vertical distribution of the corals shows change in size and numbers of colonies along with increasing depth.

Research paper thumbnail of Composition and Condition Of Coral Reefs In Dudepo Cape, South Bolaang Mongondow Regency, North Sulawesi

Jurnal Ilmiah PLATAX

This study aims to determine the composition and condition of coral reefs in Dudepo Cape, South B... more This study aims to determine the composition and condition of coral reefs in Dudepo Cape, South Bolaang Mongondow Regency. The method used is Line Intercept Transect (LIT). Data were collected by SCUBA diving at 3 meters and 10 meters depths. In 3 meters depth was found biotic components such as Acropora and non-Acropora with 6 growth forms, and five other biotic components, while abiotic components were only found in coral rubbles (R). In 10 meter depth was found biotic components live coral with 7 growth forms, and five other biotic components, while the abiotic components as sand and coral rubbles. In two depths, the coral reef component dominant were Acropora digitate (ACD) and Acropora branching (ACB). The condition of coral reefs at 3-meter depth and 10 meters were “Fair” with the percent cover of live corals being 35.59% and 37.30%.Keywords: Coral; Coral Reef; ConditionAbstrakPenelitian ini bertujuan untuk mengetahui komposisi dan kondisi terumbu karang di Tanjung Dudepo Ka...

Research paper thumbnail of 北スラウェシ州の国立自然公園(Bunaken及びTangkoko)における観光現状とエコツーリズムに関する意向調査

日本観光研究学会全国大会学術論文集, Dec 1, 2011

Research paper thumbnail of Community structure of mangrove in Mantehage Island and Paniki Island, North Sulawesi, Indonesia

Aacl Bioflux, 2019

The determination of mangrove community structure was conducted in Mantehage Island and Paniki Is... more The determination of mangrove community structure was conducted in Mantehage Island and Paniki Island, North Sulawesi, Indonesia. The continous quadrant method was used. This method uses a 10x10 m quadrant as the observation base, an auxiliary line set cut (perpendicular to the coastline) on one part of the mangrove ecosystem as an observation track. A total of 8 different species of mangroves were identified in the study area belonging to Malpighiales (Rhizophoraceae), Myrtales (Lythraceae, Combretaceae) and Sapindales (Meliaceae). The most abundant mangrove species across the thirteen stations is Ceriops tagal with a density of 3,020 individuals per hectare. Species richness index, diversity index, evenness index and dominance index were calculated to determine the diversity of mangroves along the study area. Station 3 obtained the highest species richness and station 6 obtained the lowest species richness. Station 2 recorded the highest diversity and station 6 recorded the lowest...

Research paper thumbnail of Struktur Komunitas Dan Zonasi Vegetasi Mangrove Desa Darunu Kecamatan Wori Kabupaten Minahasa Utara

JURNAL PESISIR DAN LAUT TROPIS, 2021

Mangrove ecosystem is a collection of distinctive plant types that contained in tropical and subt... more Mangrove ecosystem is a collection of distinctive plant types that contained in tropical and subtropical coastal region. The purpose of research was to find out the community structure and mangrove zonation at Darunu Village, Wori District, North Minahasa Regency. The research was conducted by the quadrant transect line method. It was done by pulling a straight line, perpendicular from the outermost mangrove area to the land direction, along 100 m by determining three data retrieval Station. To determine the condition of mangrove then density, species frequency, species coverage, important value index, diversity index and equality types were analyzed. The result found 5 mangroves species, namely: Rhizophora apiculata, R. mucronata, Sonneratia alba, Bruguiera gymnorrhiza and Avicennia officinalis. The highest density value was R.apiculata, as well as species frequency, while the species coverage value found in S. alba. The diversity value found at Station 2. The zonation of mangro...

Research paper thumbnail of Struktur Komunitas Mangroce di Kelurahan Tongkaina Manado

JURNAL PESISIR DAN LAUT TROPIS, 2017

Mangrove merupakan tumbuhan yang unik dan khas karena mampu bertahan hidup pada daerah yang ekstr... more Mangrove merupakan tumbuhan yang unik dan khas karena mampu bertahan hidup pada daerah yang ekstrim dengan kadar salinitas yang tinggi. Mangrove juga sering disebut dengan tumbuhan pasang-surut karena pertumbuhanya dipengaruhi oleh pasang-surut. Penelitian dilakukan dengan menggunakan metode line transek kuadran dengan menentukan tiga titik pengamatan (stasiun) pengambilan sampel, dan untuk mengetahui kondisi mangrove maka dilakukan perhitungan kerapatan jenis, frekuensi jenis, penutupan jenis, dominasi, indeks nilai penting dan keanekaragaman. Untuk fariabel lingkungan dilakukan beberapa pengukuran yaitu pengukuran suhu, salinitas dan juga melihat tipe substrat yang ada di Kampung Bahowo. Dari hasil penelitian, diketahui bahwa jenis mangrove yang memiliki nilai kerapatan tertinggi yaitu Rhizophora apiculata, dan untuk nilai frekuensi tertinggi juga yaitu jenis Rhizophora apiculata, sedangkan untuk nilai dominasi tertinggi dimiliki oleh jenis Sonneratia alba. Dan untuk keanekaragama...

Research paper thumbnail of The present status of coral reef condition in Bunaken National Park and Manado Bay, North Sulawesi, Indonesia

Galaxea, Journal of Coral Reef Studies, 2009

Manado Bay fronts Manado City, North Sulawesi with its total population of ca. 500,000 people. In... more Manado Bay fronts Manado City, North Sulawesi with its total population of ca. 500,000 people. In 1992, the governmetn established a National Park in the bay to protect coral reef ecosystems on five particular islands facing Manado Bay. Life Form Category by Linear In tercept Transect in 2 sites has good conditions (ca. 55%), 2 sites have moderate (ca. 30%), and the other 2 (two) sites are in a poor condition (＜20%). In comparison to studies from the early 1990s the present coral condition seems to have decreased. Anthropogenic activities from the city and the increasing number of foreign and domes tic visitors who dive in the park are probably the cause of the park's coral deterioration in Manado Bay. Since 1996, new construction and coastal reclamation in the city have also used the hard substrates for new coral re cruitment. However, the excellent grade of water quality in the bay is an important factor in which the new coral colonies have successfully settled on the new hard sub strate.

Research paper thumbnail of Protogynous hermaphroditism in the wrasse Choerodon azurio

NIPPON SUISAN GAKKAISHI, 1991

Research paper thumbnail of Distribusi Vertikal Karang Batu (Scleractinia) Di Perairan Desa Kalasey, Kabupaten Minahasa

JURNAL PESISIR DAN LAUT TROPIS, 2015

Penelitian ini dilaksanakan dengan tujuan untuk mengetahui struktur komunitas dan distribusi vert... more Penelitian ini dilaksanakan dengan tujuan untuk mengetahui struktur komunitas dan distribusi vertikal karang scleractinia di perairan Desa Kalasey.Jumlah spesies yang ditemukan pada lereng terumbu berjumlah 48 dan pada rataan terumbu 38.Jumlah koloni pada lereng terumbu berjumlah 190 dan pada rataan terumbu 133.Spesies Porites lobata memiliki kepadatan relatif tertinggi pada lereng terumbu dan Favites halicora pada rataan terumbu, masing-masing dengan nilai 20%. Nilai indeks keanekaragaman menunjukkan keanekaragaman tinggi pada lereng terumbu (3,12) dan keanekaragaman sedang pada rataan terumbu (2,95). Secara umum, kedua loaksi tersebut memiliki pola penyebaran seragam. Hasil indeks kemerataan pada lereng terumbu 0,80 dan rataan terumbu 0,81. Kedua nilai tersebut digolongkan pada komunitas yang stabil.

Research paper thumbnail of Study Of Hard Coral (Scleractinia) Recruitment In The Molas Waters, Manado City

Jurnal Ilmiah PLATAX, 2022

Coral recruitment is the entry of new coral individuals into coral reef populations due to reprod... more Coral recruitment is the entry of new coral individuals into coral reef populations due to reproduction or migration. Juvenile coral is the result of metamorphosis and growth of coral planula measuring 5 cm and attached to certain substrates. There are two types of substrates in the waters, stable substrates and unstable substrates such as rubble. The purpose of this study was to study hard coral recruitment, both in terms of density, the composition of juvenile coral colony types, size, and the type of substrate occupied by juvenile corals. This research was conducted in August 2021 in the waters of Molas, Bunaken District, Manado City. The method used for site selection is the purposive sampling method and data collection using a sampling method with quadrant transects. The results showed that the density of coral recruitment at the study site was 8,43 colonies/m2. The percentage of juvenile coral attachment on stable substrates is 90% and 10% on unstable substrates. The average s...

Research paper thumbnail of Mangrove Community Structure On The Coast Of Tanjung Kelapa, Tombariri Districts, Bunaken National Park

Jurnal Ilmiah Platax (edisi elektronik), Jan 4, 2023

Research paper thumbnail of インドネシア浅海域に於ける棘皮動物相(ヒトデ類、ウニ類、ナマコ類)

Research paper thumbnail of 北スラウェシ州の国立自然公園(Bunaken及びTangkoko)における観光現状とエコツーリズムに関する意向調査

日本観光研究学会全国大会学術論文集, Dec 1, 2011

Research paper thumbnail of Estimasi penyerapan karbon hutan mangrove Bahowo Kelurahan Tongkaina Kecamatan Bunaken

Jurnal Pesisir dan Laut Tropis (Tropical Coastal and Marine Research), Jul 17, 2018

Research paper thumbnail of Meristic And Morfometric Characteristics Of Scad Mackerel Decapterus macarellus (Cuvier, 1833)

Jurnal Ilmiah PLATAX

Fish are cold-blooded vertebrates, whose body movements and balance are mainly using fins, breath... more Fish are cold-blooded vertebrates, whose body movements and balance are mainly using fins, breathing through gills, and living in an aquatic environment. Most vertebrates in the world are fish covering 48.1%, mammals (10.8%), reptiles (14.4%), amphibians (6.0%), and birds (20.7%). One of the fish consumed in North Sulawesi is scad mackerel locally called malalugis. This research focused on the meristic and morphometric characteristics of blue scad. The samples were caught in Makalehi waters and then landed in Manado Bay. Meristic observations (related to the number) included the number of spines and soft dorsal fin, pectoral fin, pelvic fin, anal fin (anal), and caudal fin. There were 9 spines on the first dorsal (D1), 2 spines and 30-37 soft rays on the second dorsal (D2), 3 spines and 24-31 soft rays on the anal fin (A), and 1,327 linea lateralis (LL). The morphometric observations cover total length, standard length, fork length, head length, tail stem length, eye width, body wid...

Research paper thumbnail of (Editor- in-chief)

Pesisir dan Lautan Indonesia ” kembali hadir dengan perubahan judul, yakni “Pesisir & Lautan”, me... more Pesisir dan Lautan Indonesia ” kembali hadir dengan perubahan judul, yakni “Pesisir & Lautan”, menyusul edisi pertama yang terbit bulan Maret 1998 dengan desain yang lebih menarik. Judul baru tersebut diharapkan akan lebih atraktif dan mudah diingat pembaca. Perubahan judul jurnal ini tidak mengubah tema dan tujuan jurnal, dimana masih membicarakan masalah-masalah yang berkaitan dengan pengelolaan sumberdaya pesisir dan lautan di Indonesia. Penerbitan edisi kedua ini diharapkan akan lebih bermanfaat dan dapat membantu semua kalangan, terutama para pemerhati serta pihak-pihak yang peduli terhadap pelestarian serta pengelolaan sumberdaya pesisir dan lautan, sekaligus dapat berperan sebagai media informasi dalam mengulas permasalahan pengelolaan sumberdaya pesisir dan lautan. Akhirnya saya ucapkan selamat membaca dan kontribusi serta saran-saran anda kami tunggu selalu.

Research paper thumbnail of Protogynous hermaphroditism in the sand diver Trichonotus filamentosus

NIPPON SUISAN GAKKAISHI, 1991

Sexual patterns of the sand diver Trichonotus filamentosus were studied using specimens collected... more Sexual patterns of the sand diver Trichonotus filamentosus were studied using specimens collected at Hakata Bay, Kyushu, Japan, between 1986-1989. The species was found to be a protogynous hermaphrodite for the following reasons: (1) The males are not only larger in body size than females, but also have a different body form and color, with intermediate types occurring within a range where the male and female sizes overlap. (2) Differences in annuli in otoliths between the sexes suggest that males are older than females. (3) Bisexual gonads occur in 4.58% of the specimens examined histologically. (4) Bisexual gonads and mature testes exhibit secondary structure. The size frequency distributions of the males and females, and the occurrence of specimens with bisexual gonads indicate that the sand diver of Hakata Bay undertakes protogynous sex change at 80-120mm SL, after the spawning season in summer. It has also been found that the present species is monandric, because all males have secondary testes.

Research paper thumbnail of Struktur Komunitas Ikan Family Chaetodontidae Sebagai Indikator Kondisi Kesehatan Lingkungan Ekosistem Terumbu Karang DI Zona Tradisional Pulau Bunaken Taman Nasional Bunaken

Jurnal Pesisir dan Laut Tropis (Tropical Coastal and Marine Research), Oct 4, 2021

The presence of coral reef fishes, especially family Chaetodontidae is one of bioindicators to en... more The presence of coral reef fishes, especially family Chaetodontidae is one of bioindicators to environment health condition of coral reef. Fish indicator research in Bunaken Island waters aims to find out the community structure, such as the composition, abundance, density, equality, diversity and dominance. Data collection was conducted at 5 (five) locations in the Bunaken Island Traditional Zone where there are 5 (five) observation points respectively, namely TP-1 Mandolin, TP-2 Alung Banua, TP-3 Sachiko, TP-4 Muka Kampung, and TP-5 Bunaken Timur. Data collection by underwater visual census (UVC) techniques using SCUBA. The results showed there were 23 species of indicator fish from family Chaetodontidae, total individuals number of each species in 5 research sites as many as 97 individuals. The highest fish density is 0.06 at TP-5 while the lowest value in TP-2 with density value 0.02. Through indicator fish community structure indicates that the coral reef quality conditions is stable indicated by diversity values (H') in all locations were moderate category and inversely proportional by low dominance values, high leveling values (E). The similarity rate (IS) of indicator fish species in all locations differs from each other indicating the condition of coral reefs in each location grows independently without being influenced by other locations.

Research paper thumbnail of Studies on the Sexual Patterns in Ten Species of Japanese Marine Fishes

Research paper thumbnail of Acanthuridae in Bitunuris Waters Talaud Islands

Jurnal Ilmiah PLATAX

This study aims to determine the species of fish from the Acanthuridae family in Bitunuris Villa... more This study aims to determine the species of fish from the Acanthuridae family in Bitunuris Village, Salibabu Island, Talaud Islands Regency. Fish samples were caught using monofilament gill nets with a mesh size of 1.5 inches, net length of 15 m, and net height of 2 m. Sampling was carried out in April and May 2021. A total of 63 individuals were caught consisting of nine species. Acanthurus nigrofuscus 40 individuals, 10.0-17.0 cm in length and 18-77 g in weight. Acanthurus lineatus three individuals, 9.4-17.7 cm in length and 17-96 g in weight. Acanthurus triostegus is seven individuals, 9.3-12.4 cm in length, and weighs 21-55 g. Acanthurus nigricans two individuals each measuring 13.9-13.9 cm in length and weighing 67-70 g each. One individual Ctenochaetus cyanocheilus, a total length of 10.3 cm, and weight of 29 g. Naso lituratus four individuals, length 15.1-17.7 cm and weight ranging from 68-115 g. Naso brevirostris one individual measuring 23.0 cm in length and weighing 186 ...

Research paper thumbnail of Vertical distribution and effect of the depth on growth form and genus of hard coral on coral reef in Bunaken Island, North Sulawesi, Indonesia

AQUATIC SCIENCE & MANAGEMENT

Bunaken Island generally has a 90° slope and it forms like an underwater wall. However, there are... more Bunaken Island generally has a 90° slope and it forms like an underwater wall. However, there are several locations in Bunaken Island that have a more gradually inclined slope. This study was aimed to identify the effect of depth and slope gradient toward vertical distribution on growth forms and genera of hard coral at three stations in Bunaken Island. The data was collected using Line Intercept Transect (LIT) method which was dragged vertically at 3-15 meters depth. The results of study showed two different types of slopes, steep and gentle slopes. Stations 1 and 2 were categorized as steep slope (90° and 55°, respectively) and station 3 was gentle slope (43°). Encrusting growth forms dominated at 90° slope, while at 55° and 43° slope was dominated by massive growth forms. Vertical distribution of the corals shows change in size and numbers of colonies along with increasing depth.

Research paper thumbnail of Composition and Condition Of Coral Reefs In Dudepo Cape, South Bolaang Mongondow Regency, North Sulawesi

Jurnal Ilmiah PLATAX

This study aims to determine the composition and condition of coral reefs in Dudepo Cape, South B... more This study aims to determine the composition and condition of coral reefs in Dudepo Cape, South Bolaang Mongondow Regency. The method used is Line Intercept Transect (LIT). Data were collected by SCUBA diving at 3 meters and 10 meters depths. In 3 meters depth was found biotic components such as Acropora and non-Acropora with 6 growth forms, and five other biotic components, while abiotic components were only found in coral rubbles (R). In 10 meter depth was found biotic components live coral with 7 growth forms, and five other biotic components, while the abiotic components as sand and coral rubbles. In two depths, the coral reef component dominant were Acropora digitate (ACD) and Acropora branching (ACB). The condition of coral reefs at 3-meter depth and 10 meters were “Fair” with the percent cover of live corals being 35.59% and 37.30%.Keywords: Coral; Coral Reef; ConditionAbstrakPenelitian ini bertujuan untuk mengetahui komposisi dan kondisi terumbu karang di Tanjung Dudepo Ka...

Research paper thumbnail of 北スラウェシ州の国立自然公園(Bunaken及びTangkoko)における観光現状とエコツーリズムに関する意向調査

日本観光研究学会全国大会学術論文集, Dec 1, 2011

Research paper thumbnail of Community structure of mangrove in Mantehage Island and Paniki Island, North Sulawesi, Indonesia

Aacl Bioflux, 2019

The determination of mangrove community structure was conducted in Mantehage Island and Paniki Is... more The determination of mangrove community structure was conducted in Mantehage Island and Paniki Island, North Sulawesi, Indonesia. The continous quadrant method was used. This method uses a 10x10 m quadrant as the observation base, an auxiliary line set cut (perpendicular to the coastline) on one part of the mangrove ecosystem as an observation track. A total of 8 different species of mangroves were identified in the study area belonging to Malpighiales (Rhizophoraceae), Myrtales (Lythraceae, Combretaceae) and Sapindales (Meliaceae). The most abundant mangrove species across the thirteen stations is Ceriops tagal with a density of 3,020 individuals per hectare. Species richness index, diversity index, evenness index and dominance index were calculated to determine the diversity of mangroves along the study area. Station 3 obtained the highest species richness and station 6 obtained the lowest species richness. Station 2 recorded the highest diversity and station 6 recorded the lowest...

Research paper thumbnail of Struktur Komunitas Dan Zonasi Vegetasi Mangrove Desa Darunu Kecamatan Wori Kabupaten Minahasa Utara

JURNAL PESISIR DAN LAUT TROPIS, 2021

Mangrove ecosystem is a collection of distinctive plant types that contained in tropical and subt... more Mangrove ecosystem is a collection of distinctive plant types that contained in tropical and subtropical coastal region. The purpose of research was to find out the community structure and mangrove zonation at Darunu Village, Wori District, North Minahasa Regency. The research was conducted by the quadrant transect line method. It was done by pulling a straight line, perpendicular from the outermost mangrove area to the land direction, along 100 m by determining three data retrieval Station. To determine the condition of mangrove then density, species frequency, species coverage, important value index, diversity index and equality types were analyzed. The result found 5 mangroves species, namely: Rhizophora apiculata, R. mucronata, Sonneratia alba, Bruguiera gymnorrhiza and Avicennia officinalis. The highest density value was R.apiculata, as well as species frequency, while the species coverage value found in S. alba. The diversity value found at Station 2. The zonation of mangro...

Research paper thumbnail of Struktur Komunitas Mangroce di Kelurahan Tongkaina Manado

JURNAL PESISIR DAN LAUT TROPIS, 2017

Mangrove merupakan tumbuhan yang unik dan khas karena mampu bertahan hidup pada daerah yang ekstr... more Mangrove merupakan tumbuhan yang unik dan khas karena mampu bertahan hidup pada daerah yang ekstrim dengan kadar salinitas yang tinggi. Mangrove juga sering disebut dengan tumbuhan pasang-surut karena pertumbuhanya dipengaruhi oleh pasang-surut. Penelitian dilakukan dengan menggunakan metode line transek kuadran dengan menentukan tiga titik pengamatan (stasiun) pengambilan sampel, dan untuk mengetahui kondisi mangrove maka dilakukan perhitungan kerapatan jenis, frekuensi jenis, penutupan jenis, dominasi, indeks nilai penting dan keanekaragaman. Untuk fariabel lingkungan dilakukan beberapa pengukuran yaitu pengukuran suhu, salinitas dan juga melihat tipe substrat yang ada di Kampung Bahowo. Dari hasil penelitian, diketahui bahwa jenis mangrove yang memiliki nilai kerapatan tertinggi yaitu Rhizophora apiculata, dan untuk nilai frekuensi tertinggi juga yaitu jenis Rhizophora apiculata, sedangkan untuk nilai dominasi tertinggi dimiliki oleh jenis Sonneratia alba. Dan untuk keanekaragama...

Research paper thumbnail of The present status of coral reef condition in Bunaken National Park and Manado Bay, North Sulawesi, Indonesia

Galaxea, Journal of Coral Reef Studies, 2009

Manado Bay fronts Manado City, North Sulawesi with its total population of ca. 500,000 people. In... more Manado Bay fronts Manado City, North Sulawesi with its total population of ca. 500,000 people. In 1992, the governmetn established a National Park in the bay to protect coral reef ecosystems on five particular islands facing Manado Bay. Life Form Category by Linear In tercept Transect in 2 sites has good conditions (ca. 55%), 2 sites have moderate (ca. 30%), and the other 2 (two) sites are in a poor condition (＜20%). In comparison to studies from the early 1990s the present coral condition seems to have decreased. Anthropogenic activities from the city and the increasing number of foreign and domes tic visitors who dive in the park are probably the cause of the park's coral deterioration in Manado Bay. Since 1996, new construction and coastal reclamation in the city have also used the hard substrates for new coral re cruitment. However, the excellent grade of water quality in the bay is an important factor in which the new coral colonies have successfully settled on the new hard sub strate.

Research paper thumbnail of Protogynous hermaphroditism in the wrasse Choerodon azurio

NIPPON SUISAN GAKKAISHI, 1991

Research paper thumbnail of Distribusi Vertikal Karang Batu (Scleractinia) Di Perairan Desa Kalasey, Kabupaten Minahasa

JURNAL PESISIR DAN LAUT TROPIS, 2015

Penelitian ini dilaksanakan dengan tujuan untuk mengetahui struktur komunitas dan distribusi vert... more Penelitian ini dilaksanakan dengan tujuan untuk mengetahui struktur komunitas dan distribusi vertikal karang scleractinia di perairan Desa Kalasey.Jumlah spesies yang ditemukan pada lereng terumbu berjumlah 48 dan pada rataan terumbu 38.Jumlah koloni pada lereng terumbu berjumlah 190 dan pada rataan terumbu 133.Spesies Porites lobata memiliki kepadatan relatif tertinggi pada lereng terumbu dan Favites halicora pada rataan terumbu, masing-masing dengan nilai 20%. Nilai indeks keanekaragaman menunjukkan keanekaragaman tinggi pada lereng terumbu (3,12) dan keanekaragaman sedang pada rataan terumbu (2,95). Secara umum, kedua loaksi tersebut memiliki pola penyebaran seragam. Hasil indeks kemerataan pada lereng terumbu 0,80 dan rataan terumbu 0,81. Kedua nilai tersebut digolongkan pada komunitas yang stabil.

Research paper thumbnail of Study Of Hard Coral (Scleractinia) Recruitment In The Molas Waters, Manado City

Jurnal Ilmiah PLATAX, 2022

Coral recruitment is the entry of new coral individuals into coral reef populations due to reprod... more Coral recruitment is the entry of new coral individuals into coral reef populations due to reproduction or migration. Juvenile coral is the result of metamorphosis and growth of coral planula measuring 5 cm and attached to certain substrates. There are two types of substrates in the waters, stable substrates and unstable substrates such as rubble. The purpose of this study was to study hard coral recruitment, both in terms of density, the composition of juvenile coral colony types, size, and the type of substrate occupied by juvenile corals. This research was conducted in August 2021 in the waters of Molas, Bunaken District, Manado City. The method used for site selection is the purposive sampling method and data collection using a sampling method with quadrant transects. The results showed that the density of coral recruitment at the study site was 8,43 colonies/m2. The percentage of juvenile coral attachment on stable substrates is 90% and 10% on unstable substrates. The average s...