scholarly journals Abundance of Herbivorous Fish at Fish Apartment in Tangah Island Coastal Waters of Pariaman City, West Sumatera

2019 ◽  
Vol 6 (1) ◽  
pp. 97
Author(s):  
Suci Frimanozi ◽  
Indra Junaidi Zakaria ◽  
Jabang Nurdin
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Habitat Quality ◽  
Coastal Waters ◽  
Herbivorous Fish ◽  
Coral Recruitment ◽  
Visual Census ◽  
West Sumatra ◽  
And Control ◽  
Reef Condition

Herbivorous fish have an influence on habitat quality and a major factor in determining coral reef community. This herbivorous fish used as indicator of  monitoring refers to reef resilience since of its ability to retain and restore the coral reef condition after disturbance. The presence of herbivores is important in influencing succession of algae, it can reduce and control algae on coral reefs. It’s causes in the availability of space or substrate for corals to recruit. So the research conducted that aims to know the abundance of herbivorous fish in fish apartment as one indicator of monitoring based on endurance. This study had conducted after six months of fish apartment placed in the coastal waters of Tangah Island, Pariaman City, West Sumatra. Then, the observation had done every month for six months in July 2015 - January 2016 at the location of the fish apartment. Observation abundance of herbivorous fish had done by visual census method at fish apartment location. From the results of observations for six months found 10 species of herbivorous fish with total as many as 289 individuals. Zebrasoma scopas is a species with the most individuals than 97 individu. However, to see the effect of herbivorous fish on coral recruitment in fish apartment needs to do further research. Keywords: abundance, herbivorous fish, fish apartment

scholarly journals Assessing the Condition of Coral Reefs and the Indicator Fish (Family: Chaetodontidae) in Coastal Waters of Jayapura City, Papua Province, Indonesia

2019 ◽  
Vol 5 (2) ◽  
pp. 126-132
Author(s):  
Baigo Hamuna ◽  
John Dominggus Kalor ◽  
Adinda Intan Rachmadani
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Fish Species ◽  
Coastal Waters ◽  
Good Condition ◽  
Live Coral ◽  
Visual Census ◽  
Fish Family ◽  
Reef Condition

Abstract The aim of this study was to find out the condition of coral reef coverage and the presence of Chaetodontidae fish in coastal waters of Jayapura City, Indonesia. The observation of coral reef coverage was performed using point intercept transect (PIT) method; meanwhile the observation of the presence of Chaetodontidae fish used visual census method. The result of this study described that coral reef condition in the study site was in severely damage (live coral 0%) in the DOK II site at 6 m depth, moderately damage (live coral 32.00% ± 2.13% to 42.00% ± 13.18%) in Kayu Pulo Island and the DOK II at 3 m depth, and good condition (live coral 56.00% ± 7.48% to 60.00% ± 5.55%) in the Tanjung Kayu Batu. There were 9 Chaetodontidae fish species from Chaetodon genus, Forcipiger genus, and Heniochus genus. The number of Chaetodontidae fish was 95, of which Heniochus acuminatus was the most dominant, as many as 46 individuals.

scholarly journals KONDISI IKAN KARANG FAMILI CHAETODONTIDAE DI DAERAH PERLINDUNGAN LAUT DESA BAHOI KECAMATAN LIKUPANG BARAT KABUPATEN MINAHASA UTARA

2015 ◽  
Vol 2 (3) ◽  
pp. 92
Author(s):  
Jacqline Laikun ◽  
Ari B Rondonuwu ◽  
Unstain N.W.J. Rembet
Keyword(s):  
Spatial Distribution ◽  
Coral Reef ◽  
Coral Reefs ◽  
Protected Areas ◽  
Reef Fish ◽  
Marine Protected Areas ◽  
Visual Census ◽  
Fish Family ◽  
Marine Life ◽  
Reef Condition

The coral reefs are a sundry of marine life. Which one is reef fish in family Chaetodontidae. This fish is  indicator of the coral reef condition. The aim from the research is : discover of spatial distribution of the reef fish family Chaetodontidae and find out of the intercourse of reef fish family Chaetodontidae with the coral reef presence based on growth of coral form. The research was do in the coral reef at Marine Protected Areas in Bahoi Village District of West Likupang North Minahasa Regency, on Tuesday, December 23rd, 2014. The research is using to do the surveying method. The data is collecting distribution of the fish Chaetodontidae (amount from species and individuals to using by technic visual census). The total of reef fish family Chaetodontidae those found in Marina Protected Areas in Bahoi Village is about 20 species, with total of the individuals at a depth of 3 meters and 10 meters is (56,66 and 57,33 individuals/150m2). Keywords : Coral reefs, Chaetodontidae, Bahoi   ABSTRAK Terumbu karang merupakan tempat berbagai macam biota laut. Salah satu Ikan karang adalah ikan famili Chaetodontidae. Ikan ini merupakan ikan indikator terumbu karang. Tujuan dari penelitian ini : mengetahui kelimpahan dari ikan karang famili Chaetodontidae. Penelitian ini dilakukan di Daerah Perlindungan Laut Desa Bahoi Kecamatan Likupang Barat Kabupaten Minahasa Utara, pada hari selasa, tanggal 23 Desember 2014. Penelitian ini menggunakan metode survey. Data yang dikumpulkan adalah kelimpahan ikan Chaetodontidae (Jumlah spesies dan individu dengan menggunakan teknik sensus visual). Jumlah ikan karang famili Chaetodontidae yang di temukan di Daerah Perlindungan Laut Desa Bahoi berjumlah 20 spesies, dengan jumlah individu pada kedalaman 3 meter dan 10 meter berjumlah (56,66 individu/150m2 dan 57,33/150m2 individu). Kata kunci : Terumbu karang, Chaetodontidae, Bahoi 1Bagian dari skripsi 2Mahasiswa Program Studi Manajemen Sumberdaya Perairan FPIK-UNSRAT 3Staf pengajar Fakultas Perikanan dan Ilmu Kelautan Universitas Sam Ratulangi

scholarly journals STATUS TERUMBU KARANG DI PERAIRAN PESISIR NEGERI HUKURILA

2021 ◽  
Vol 17 (1) ◽  
pp. 35-45
Author(s):  
Dicky Sahetapy ◽  
Laura Siahainenia ◽  
Debby A J Selanno ◽  
Johannes M S Tetelepta ◽  
Novianty C Tuhumury
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Coastal Waters ◽  
Coral Species ◽  
Similarity Index ◽  
Ecological Index ◽  
Stony Coral ◽  
The Status ◽  
Coral Communities ◽  
Line Intercept

Coral reef is one of the important coastal ecosystems that have high biodiversity. This study aims to analyze the composition of the taxa and the distribution of coral species, the ecological index of coral communities and the status of coral reefs. The research was conducted from April-May 2019 in the coastal waters of Hukurila Village, South Leitimur District, Ambon City. Collecting coral data by using the Line Intercept Transect (LIT) method. Determination of coral reef condition based on percent data (value) of coral reef cover. During the study, 116 species of stony coral from 49 genera and 16 families were found, which 50 species of them are protected and 23 species of ornamental coral. The similarity index of stony coral species between coral reef locations ranges from 0.52-0.76 or there is the similarity of stony coral species between locations coral reef in the amount of 52-76%. The coral reefs of Hukurila Village have high diversity of coral species, with a low dominance of coral species in the community, and the compatibility of coral species in the community is classified as stable. Acropora corals contributed a low covering percent value (9.98%), while Non-Acropora corals contributed a relatively high percent of covering value (43.56%). The status of coral reefs between locations in the coastal waters of Hukurila Village is in the criteria of good (healthy).   ABSTRAK Terumbu karang merupakan salah satu ekosistem pesisir penting yang emiliki kenanekaragaman hayati tinggi. Penelitian ini bertujuan untuk menganalisis komposisi taksa dan sebaran spesies karang, indeks ekologi kominitas karang dan status terumbu karang. Penelitian dilakukan dari April-Mei 2019 di perairan pesisir Negeri Hukurila Kecamatan Leitimur Selatan Kota Ambon. Pengumpulan data karang menggunakan metode Line Intercept Transect (LIT). Penentuan kondisi terumbu karang berdasarkan data (nilai) persen penutupan karang batu. Selama penelitian ditemukan 116 spesies karang batu dari 49 genera dan 16 famili, dimana 50 spesies diantaranya dilindungi dan 23 spesies karang hias. Indeks similaritas spesies karang batu antar stasiun terumbu karang berkisar antara 0,52-0,76 atau terdapat kesamaan spesies karang batu antar lokasi terumbu karang sebesar 52-76%. Terumbu karang Negeri Hukurila memiliki diversitas spesies karang tinggi, dengan dominansi spesies karang rendah dalam komunitas, dan keserasian spesies karang dalam komunitas tergolong stabil. Karang Acropora memberi kontribusi nilai persen penutupan rendah (9,98%), sementara karang Non-Acropora memberi kontribusi nilai persen penutupan karang batu relatif tinggi (43,56%). Status terumbu karang antar stasiun terumbu perairan pesisir Negeri Hukurila berada dalam kriteria baik (sehat).   Kata kunci: terumbu, karang batu, keragaman spesies, kesamaan, persen penutupan

scholarly journals Grazing Effects of Fish versus Sea Urchins on Turf Algae and Coral Recruits: Possible Implications for Coral Reef Resilience and Restoration

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Leor Korzen ◽  
Alvaro Israel ◽  
Avigdor Abelson
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Sea Urchins ◽  
Benthic Algae ◽  
Herbivorous Fish ◽  
Grazing Impact ◽  
Turf Algae ◽  
Coral Reef Resilience ◽  
Drastic Increase ◽  
The Impact

Herbivory is an important structuring factor in coral reefs, influencing seaweed abundance, competitive interactions between seaweeds and corals, and coral reef resilience. Despite reports of a drastic increase in the cover of benthic algae and turf dominancy in the coral reefs of Eilat, Red Sea, very little is known about the factors responsible for this phenomenon or the possible effects of herbivory on turf algae and coral recruits. Here, we examine the effects of herbivory by experimentally exposing turf algae and coral recruits to grazing activities of herbivorous fish and sea urchins. Using remote video cameras to document removal of algae and coral spats, we show that the main grazing impact is due to daily grazing by fishes, whereas the significant impact of sea urchins is mainly expressed in their adverse effect on the survival of coral recruits, with a relatively low effect on algal biomass. These findings contribute to our understanding of the factors influencing turf algae establishment and proliferation, and the survival of coral recruits on the coral reefs of Eilat. The clear differences between the impact of herbivorous fish and that of sea urchins, on the Eilat reefs, have critical implications for reef resilience and restoration measures.

scholarly journals Spatial and Temporal Variation of Scleractinian Coral Recruitment in Balok Coastal Waters and Bidong Island, Malaysia

2021 ◽  
Vol 6 (1) ◽  
pp. 1-14
Author(s):  
Fikri Akmal Khodzori ◽  
Shahbudin Saad ◽  
Husaini Rani
Keyword(s):  
Coral Reef ◽  
Temporal Variation ◽  
Environmental Conditions ◽  
Coastal Waters ◽  
Scleractinian Coral ◽  
Larval Settlement ◽  
Artificial Reef ◽  
Spatial And Temporal Variation ◽  
Coral Recruitment ◽  
Recruitment Patterns

Understanding coral recruitment is important as increasing of regional decline of coral reef worldwide. This study aimed to investigate the spatial and temporal coral recruitment patterns around reef sites in Balok coastal waters and Bidong Island, Malaysia. Recruitment density was determined by quantifying number of coral recruits settled on the terra-cotta tiles and artificial reef settlement plates. In Balok coastal waters, a total of 159 coral recruits were counted with 0.09 ± 0.03 n/m2 mean recruitment density per plate, while in Bidong Island, a total of 319 coral recruits were counted with 0.19 ± 0.02 n/m2 mean recruitment density per plate. Coral recruits were dominated by genus Pocillopora followed by Stylopora and Seriatopora in Bidong. Meanwhile in Balok, genus Platygyra was dominant coral recruits followed by Porites and Fungia. Additionally, minor spawning event was predicted in Balok coastal waters in September due to increase number of Platygyra coral. Recruitment density varied significantly between locations, types of settlement plates and plate’s orientation at both study areas. Current findings highlighted the significant use of artificial reef plates to increase the chances of larval settlement. This research also provides important information in assessing coral resilience towards different environmental conditions between coastal and sheltered reef areas.

Factors Affecting Coral Recruitment and Calcium Carbonate Accretion Rates on a Central Pacific Coral Reef

2021 ◽  
Author(s):  
◽  
Franziska Elmer
Keyword(s):  
Coral Reef ◽  
Calcium Carbonate ◽  
Coral Reefs ◽  
Benthic Community ◽  
Coral Cover ◽  
Coralline Algae ◽  
Benthic Organisms ◽  
Coral Recruitment ◽  
Central Pacific ◽  
Accretion Rates

<p>Coral recruitment and calcium carbonate (CaCO₃) accretion are fundamental processes that help maintain coral reefs. Many reefs worldwide have experienced degradation, including a decrease in coral cover and biodiversity. Successful coral recruitment helps degraded reefs to recover, while CaCO₃ accretion by early successional benthic organisms maintains the topographic complexity of a coral reef system. It is therefore important to understand the processes that affect coral recruitment and CaCO₃ accretion rates in order to understand how coral reefs recover from disturbances.  The aim of this thesis was to determine how biophysical forcing factors affect coral recruitment, calcification and bioerosion on a pristine coral reef. I used artificial settlement tiles to measure coral recruitment and CaCO₃ accretion at ten sites (four on the fore reef, four on the Western Reef Terrace and two at the Entrance Channel) at Palmyra Atoll. Fungia skeletons and pieces of dead coral rock were used to measure bioerosion rates, which were combined with the CaCO₃ accretion rates to obtain a net CaCO₃ budget of the reef substratum. Interactions between coral recruits and other benthic organisms on the settlement tiles were recorded to determine the settlement preferences and competitive strength of coral recruits. The settlement preference of Pocillopora damicornis for divots shaped like steephead and bumphead parrotfish bites marks was determined by adding P. damicornis larvae to a container with a settlement tile with the aforementioned divots.  I found that coral recruitment and CaCO₃ accretion are influenced by biophysical forcing factors. Most pocilloporids likely recruit close to their parents while the origin of poritid larvae is much more distant. Pocilloporid recruitment rates were also significantly correlated with the successional stage of the benthic community on the settlement tiles, especially the cover of biofilm and bryozoa. Biofilm and crustose coralline algae (CCA) were preferred as settlement substrata by coral larvae, however both pocilloporids and poritids settled on a large number of different benthic substrata. P. damicornis larvae showed a significant settlement preference for divots shaped like parrotfish bite marks over a flat settlement surface. Coral recruits were good competitors against encrusting algae but were often outcompeted by filamentous and upright algae. Settlement tiles were almost entirely colonised by benthic organisms within three to twelve months of deployment. The mass of CaCO₃ deposited onto the settlement tiles negatively correlated with herbivore grazing pressure on the benthic community. Bioerosion rates within pieces of coral (internal bioerosion) increased over time but overall bioerosion rates (internal and external) rarely exceeded CaCO₃ deposition by CCA.  My results show how variability in biophysical forcing factors leads to natural variation in coral recruitment and CaCO₃ accretion. This thesis highlights the importance of measuring herbivore grazing, CCA and turf algae cover to gain a better understanding of reef resilience. I conclude that models constructed for Caribbean reefs may not be suited to predict resilience in Pacific reefs and that within the Pacific, two different kinds of resilience models need to be constructed, one for human-inhabited coral reefs and one for uninhabited coral reefs.</p>

scholarly journals Coral reef condition in the coastal waters of Kei Besar Island, Southeast Maluku-Indonesia

2021 ◽  
Vol 805 (1) ◽  
pp. 012002
Author(s):  
D Sahetapy ◽  
G V Limon ◽  
J M S Tetelepta ◽  
J A Pattikawa ◽  
F Rijoly ◽  
...  
Keyword(s):  
Coral Reef ◽  
Coastal Waters ◽  
Reef Condition

scholarly journals HUBUNGAN PERSENTASE TUTUPAN KARANG DENGAN KELIMPAHAN IKAN KARANG DI PULAU MENJANGAN KECIL, KEPULAUAN KARIMUNJAWA, KABUPATEN JEPARA,JAWA TENGAH (Relationship of Coral Cover Percentage with Reef Fishes Abundance in Menjangan Kecil Island, Karimunjawa Island, Jepara)

2018 ◽  
Vol 6 (4) ◽  
pp. 333-338
Author(s):  
Fahmi Fahmi ◽  
Supriharyono Supriharyono ◽  
Abdul Ghofar
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Reef Fish ◽  
Coral Cover ◽  
Reef Fishes ◽  
Line Transect ◽  
Live Coral ◽  
East Side ◽  
Visual Census ◽  
West Side

Ekosistem terumbu karang merupakan kekayaan sumberdaya laut yang memiliki peranan penting dalam mendukung kehidupan berbagai organisme perairan. Salah satu organisme yang memiliki ketergantungan hidup pada terumbu karang adalah ikan karang. Hal ini dikarenakan ikan karang melalui fase hidup sebagian atau seluruhnya di terumbu karang, sehingga terumbu karang menjadi tempat tinggal, tempat mencari makan, tempat berlindung dan tempat berkembang biak.  Penelitian dilaksanakan pada bulan Mei 2017, dengan tujuan untuk mengetahui persentase tutupan karang hidup dan kelimpahan ikan. Serta hubungan persentase tutupan karang dengan kelimpahan ikan karang pada sisi Barat dan Timur Pulau Menjangan Kecil kedalaman 1 dan 3 meter. Metode yang digunakan adalah metode observasi lapangan, dengan metode sampling menggunakan transek garis (line transect) pada data karang dan visual census untuk data ikan sepanjang 25m. Hasil dari penelitian ini menunjukkan bahwa Persentase rata-rata tutupan karang yang diperoleh pada kedalaman 1 meter sisi Barat adalah 73,39%, sedangkan pada kedalaman 3 meter adalah 85,97%. Persentase tutupan karang pada kedalaman 1 meter sisi Timur adalah 63,73%, sedangkan pada kedalaman 3 meter adalah 77,61%. Secara keseluruhan kondisi terumbu karang masih tergolong baik. Kelimpahan rata-rata ikan pada sisi Barat kedalaman 1 meter adalah 70 individu/125 m2, sedangkan pada kedalaman 3 meter adalah 232 individu/125 m2. Kelimpahan ikan sisi Timur kedalaman 1 dan 3 meter masing-masing adalah 49 dan 138 individu/125 m2. Hasil perhitungan indeks korelasi secara keseluruhan menghasilkan nilai 0,8415 dengan koefesien determinasi sebesar 0,7081. Hal ini menunjukkan bahwa pola hubungan persentase tutupan karang dengan kelimpahan ikan karang kuat (signifikan) dan positif (searah). Coral reef ecosystem is a wealth of marine resources that have an important role in supporting the life of various aquatic organisms. One of the organisms that has a living dependence on coral reefs is reef fish. This is because coral fish through a partial or complete life phase on the coral reef, so that coral reefs become a place to live, a place to find food, shelter and breeding ground. The study was conducted in May 2017, with the objective of knowing the percentage of live coral cover and fish abundance. And the correlation of percentage of coral cover with abundance of reef fish on West and East side of Menjangan Kecil Island depth of 1 and 3 meters. The method used is field observation method, with sampling method using line transect on coral data and visual census for fish data along 25m. The results of this study indicate that the average percentage of coral cover obtained at a depth of 1 meter west side is 73.39%, while at a depth of 3 meters is 85.97%. The percentage of coral cover at depth of 1 meter East side is 63,73%, while at depth 3 meter is 77,61%. Overall the condition of coral reefs is still quite good. The average abundance of fish on the west side of 1 meter depth is 70 individuals / 125 m2, while at 3 meters depth is 232 individuals / 125 m2. The abundance of fish on Eastern side, depth of 1 and 3 meters respectively were 49 and 138 individu / 125 m2. Result of calculation of correlation index as a whole yield value 0,8415 with coefficient of determination equal to 0,7081. This shows that the pattern of correlation of percentage of coral cover with abundance of reef fish is strong (significant) and positive (unidirectional).

scholarly journals Kondisi Terumbu Karang Di Pantai Empu Rancak Kabupaten Jepara

2018 ◽  
Vol 21 (1) ◽  
pp. 49 ◽  
Author(s):  
Suryono Suryono ◽  
Edi Wibowo ◽  
Raden Ario ◽  
Nur Taufiq SPJ ◽  
Ria Azizah
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Coastal Waters ◽  
Coral Cover ◽  
Good Condition ◽  
Ecological Impacts ◽  
Marine Tourism ◽  
Run Off ◽  
Index Value ◽  
Line Intercept

Abstract Coral Reef Condition In Coastal Waters of Empu Rancak, Mlonggo, Regency of Jepara Empu Rancak coastal  waters in Karanggondang village, Mlonggo District is one of the coral reef ecosystem location in coastal area of  Jepara Regency. Following the growth of culinary and Marine  tourism bring the need for monitoring the condition of coral reefs so that such activity does not provide ecological impacts against the condition of coral reefs. The method used to assess the condition of coral reefs  is Line Intercept Transect which done by percentage calculation of living coral coverage. The research results shows that the condition of the coral reefs in a depth of 3 metres found coral cover percentage of 4.5%, while at a depth of 6 meters found coral cover percentage of 9.7%. From this result indicates the coral reefs in critical condition，however the high biodiversity and dominance index value is presumed that these coral reefs was in good condition. It`s showed by the high percentage of coral die either at a depth of 3 metres (95.54%) or at a depth of 6 meters(90.30%). The diversity of species of coral were found at a depth of 3 meters consist of 6 genus, they are: Goniastrea sp., Favia sp., Galaxea sp., Porites, Acropora sp. and Montipora sp., whereas at a depth of 6 meters were found more species of coral diversity for at least 11 genus, they are: Acropora sp., Favites sp., Echinopora sp., Goniastrea sp. Symphyllia agaricia sp, Favia sp., Goniopora sp., Porites sp., Montipora sp., Platygyra sp., and Montastrea sp. The condition of coral reefs cover which relatively critical are caused by decreasing the quality of waters ecology that caused by sedimentation rate and runoff processes of land activity, high waves in northwest monsoon and the growth of culinary tourism as well as marine  tourism in Empu Rancak coastal  waters gradually worsen the condition of coral reefs. Keywords : Coral reef, tourism, Line Intercept Transect, AbstrakPerairan pantai Empu Rancak desa Karanggondang, Kecamatan Mlonggo merupakan salah satu lokasi ekosistem  terumbu karang yang berada pesisir di kabupaten Jepara. Dengan berkembangnya aktivitas wisata kuliner serta wisata  bahari, maka perlu dilakukan pemantauan kondisi terumbu karang agar kegiatan tersebut tidak tidak memberikan dampak ekologi terhadap kondisi terumbu karang. Metode yang dipergunakan untuk menilai kondisi terumbu karang adalah  dengan metode perhitungan persentase penutupan karang hidup menggunakan Line Intercept Transect. Hasil penelitian menunjukan bahwa Kondisi terumbu karang di kedalaman 3 meter ditemukan prosentasi tutupan karang sebesar 4,5 %, sedangkan pada kedalaman 6 meter ditemukan prosentase tutupan karang sebesar 9,7 %, maka kondisi terumbu karang di perairan pantai empu rancak Mlonggo, dalam kondisi buruk sekali, namun tingginya keanekaragaman dan nilai indeks dominasi, maka diduga bahwa terumbu karang dilokasi penelitian pernah dalam kondisi baik sebelumnya. Hal ini ditunjukan dengan tingginya prosentase karang mati baik pada kedalaman 3 meter (95,54 %) maupun pada kedalaman 6 meter (90,30 %). Keanekaragaman jenis karang yang ditemukan pada kedalaman 3 meter terdiri atas 6 genus yaitu : GoniastreaSp., Favia Sp., Galaxea Sp., Porites Sp., Acropora Sp.,dan Montipora Sp.,sedangkan pada kedalaman 6 meter ditemukan keanekaraamanan jenis karang yang lebih banyak (11 genus), yaitu : Acropora sp., Favites sp., Echinopora sp., Goniastrea sp., Symphyllia agaricia, Favia sp., Goniopora sp., Porites sp., Montipora sp., Platygyra sp. ,dan Montastrea sp. Kondisi tutupan terumbu karang yang relatif buruk sekali  diduga  diakibatkan oleh menurunnya kualitas ekologi perairan yang diakibatkan oleh oleh tekanan  laju  sedimentasi serta proses  run off dari aktivitas didaratan, tingginya paparan  gelombang pada saat musim barat serta  berkembangnya  wisata kuliner serta wisata bahari  di perairan Pantai Empu rancak yang  memperburuk kondisi terumbu karang.  Kata Kunci : Terumbu Karang, pariwisata, Line Intercept Transect

Factors Affecting Coral Recruitment and Calcium Carbonate Accretion Rates on a Central Pacific Coral Reef

2021 ◽  
Author(s):  
◽  
Franziska Elmer
Keyword(s):  
Coral Reef ◽  
Calcium Carbonate ◽  
Coral Reefs ◽  
Benthic Community ◽  
Coral Cover ◽  
Coralline Algae ◽  
Benthic Organisms ◽  
Coral Recruitment ◽  
Central Pacific ◽  
Accretion Rates

<p>Coral recruitment and calcium carbonate (CaCO₃) accretion are fundamental processes that help maintain coral reefs. Many reefs worldwide have experienced degradation, including a decrease in coral cover and biodiversity. Successful coral recruitment helps degraded reefs to recover, while CaCO₃ accretion by early successional benthic organisms maintains the topographic complexity of a coral reef system. It is therefore important to understand the processes that affect coral recruitment and CaCO₃ accretion rates in order to understand how coral reefs recover from disturbances.  The aim of this thesis was to determine how biophysical forcing factors affect coral recruitment, calcification and bioerosion on a pristine coral reef. I used artificial settlement tiles to measure coral recruitment and CaCO₃ accretion at ten sites (four on the fore reef, four on the Western Reef Terrace and two at the Entrance Channel) at Palmyra Atoll. Fungia skeletons and pieces of dead coral rock were used to measure bioerosion rates, which were combined with the CaCO₃ accretion rates to obtain a net CaCO₃ budget of the reef substratum. Interactions between coral recruits and other benthic organisms on the settlement tiles were recorded to determine the settlement preferences and competitive strength of coral recruits. The settlement preference of Pocillopora damicornis for divots shaped like steephead and bumphead parrotfish bites marks was determined by adding P. damicornis larvae to a container with a settlement tile with the aforementioned divots.  I found that coral recruitment and CaCO₃ accretion are influenced by biophysical forcing factors. Most pocilloporids likely recruit close to their parents while the origin of poritid larvae is much more distant. Pocilloporid recruitment rates were also significantly correlated with the successional stage of the benthic community on the settlement tiles, especially the cover of biofilm and bryozoa. Biofilm and crustose coralline algae (CCA) were preferred as settlement substrata by coral larvae, however both pocilloporids and poritids settled on a large number of different benthic substrata. P. damicornis larvae showed a significant settlement preference for divots shaped like parrotfish bite marks over a flat settlement surface. Coral recruits were good competitors against encrusting algae but were often outcompeted by filamentous and upright algae. Settlement tiles were almost entirely colonised by benthic organisms within three to twelve months of deployment. The mass of CaCO₃ deposited onto the settlement tiles negatively correlated with herbivore grazing pressure on the benthic community. Bioerosion rates within pieces of coral (internal bioerosion) increased over time but overall bioerosion rates (internal and external) rarely exceeded CaCO₃ deposition by CCA.  My results show how variability in biophysical forcing factors leads to natural variation in coral recruitment and CaCO₃ accretion. This thesis highlights the importance of measuring herbivore grazing, CCA and turf algae cover to gain a better understanding of reef resilience. I conclude that models constructed for Caribbean reefs may not be suited to predict resilience in Pacific reefs and that within the Pacific, two different kinds of resilience models need to be constructed, one for human-inhabited coral reefs and one for uninhabited coral reefs.</p>

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