Suitability of the manta tow technique for estimating relative and absolute abundances of crown-of-thorns starfish (Acanthaster planci L. ) and corals

1992 ◽  
Vol 43 (2) ◽  
pp. 357 ◽  
Author(s):  
PJ Moran ◽  
G De'ath
Keyword(s):  
Coral Cover ◽  
Cost Effective ◽  
Live Coral ◽  
Statistical Relationship ◽  
Acanthaster Planci ◽  
Dead Coral ◽  
Effective Option ◽  
Fixed Area ◽  
Large Coral ◽  
Broad Scale

The manta tow technique has been used mainly for broad-scale surveys of large coral reef systems. The present study comprised two separate investigations of the technique. One involved investigating its repeatability by comparing the performance of three observers towed together along a reef. The other compared the counts of crown-of-thorns starfish from manta tow and SCUBA swim surveys undertaken within 30 large areas on eight reefs. Overall, the technique was found to be highly repeatable, particularly for crown-of-thorns starfish and live coral cover. It was less repeatable for assessing the cover of dead coral, although this was still within acceptable limits. A strong statistical relationship (r2adj = 0.91) was found between the starfish counts obtained from manta tows and those obtained from SCUBA swim surveys. Consequently, the former can be calibrated to predict the latter. The crown-of-thorns starfish is known to be cryptic and to have an aggregated distribution. However, the present study showed that the manta tow technique is a reasonably accurate and cost-effective option for determining relative changes in the distribution and abundance of noncryptic starfish where the unit of interest is a whole reef (or a large part thereof). As a comparison, approximately 14 manta tows (each lasting 2 min) will give the same level of accuracy as 10 SCUBA swim surveys of the same fixed area. The sensitivity of the manta tow technique in detecting relative changes in abundance will depend on the number of tows that are conducted. As a guide, however, a typical manta tow survey (involving approximately 50-60 tows) is capable of detecting a 20% change in the abundance of an out-breaking population of crown-of-thorns starfish. Given these findings, the manta tow technique also may be useful for assessing relative changes in the distribution and abundance of other organisms.

Effects of training on observer performance in assessing benthic cover by means of the manta tow technique

1996 ◽  
Vol 47 (1) ◽  
pp. 19 ◽  
Author(s):  
IR Miller ◽  
G De'ath
Keyword(s):  
Field Experiment ◽  
Great Barrier Reef ◽  
Coral Cover ◽  
Observer Performance ◽  
Live Coral ◽  
Barrier Reef ◽  
Acanthaster Planci ◽  
Dead Coral ◽  
And Training

The manta tow technique is used to obtain broadscale information on the distribution of Acanthaster planci and corals on the Great Barrier Reef. A field experiment was used to investigate how experience and training affects visual estimates of benthic cover made by observers using the manta tow technique. For live coral and sandlrubble cover, experienced observers obtained significantly higher levels of precision in their estimates than inexperienced observers; training increased the precision of these estimates for both experienced and inexperienced observers. Dead coral cover was sparse (<5%), making it difficult to assess the performance of the manta tow technique for this form of benthic cover. For both live and dead coral, and for sandlrubble, the levels of agreement between observers exceeded that expected by chance by between 5 to 1 and 10 to 1.

Acanthaster planci impact on coral communities at permanent transect sites on Bruneian reefs, with a regional overview and a critique on outbreak causes

2011 ◽  
Vol 92 (4) ◽  
pp. 803-809 ◽  
Author(s):  
David J.W. Lane
Keyword(s):  
Coral Cover ◽  
Food Limitation ◽  
Past Century ◽  
Live Coral ◽  
Sea Star ◽  
Acanthaster Planci ◽  
The Past ◽  
Live Coral Cover ◽  
Coral Communities ◽  
High Precipitation

The submerged coral reefs of Brunei, little-impacted by human activity and characterized by high live coral cover, have no recorded history in recent decades of the presence of the crown-of-thorns (COT), Acanthaster planci. This sea star, first recorded on Brunei reefs in 2008, attained outbreak densities in 2010. At Littledale Shoal its impact on corals at permanent transect sites has been quantified; mean live coral cover reduced by half from 2006 to 2010 due predominantly to predation. Line intersect transect data confirm a predisposition for tabular Acropora species, a prominent feature at this site, although other scleractinian taxa were also predated. Other regional outbreaks are reviewed, including episodes, and their timing, within the neighbouring Coral Triangle (CT). Mounting evidence implicates nutrient-enhanced increases in primary production as a primary cause of COT outbreaks. However, this stands in contrast with a report of global oceanic phytoplankton decline in the past century, and there is little evidence of such a link in the CT, even though this region is characterized by high precipitation, erosional plumes and seasonal upwelling-associated phytoplankton blooms. Furthermore, until survivorship and competency for a wider spectrum of mass-spawned invertebrate planktotrophs in relation to elevated phytoplankton densities is better understood, such evidence, suggesting release from food limitation as the principal cause of enhanced COT recruitment, should be interpreted with caution.

scholarly journals KONDISI EKOSISTEM TERUMBU KARANG DI PERAIRAN KRUENG RAYA, KABUPATEN ACEH BESAR

2021 ◽  
Vol 8 (1) ◽  
pp. 11
Author(s):  
Nurul Najmi ◽  
M Rizki Fazillah ◽  
Muhammad Agustiar
Keyword(s):  
Coral Reef ◽  
Coral Cover ◽  
Live Coral ◽  
Coral Mortality ◽  
Coral Reef Ecosystem ◽  
Dead Coral ◽  
High Increase ◽  
Mortality Index ◽  
Malacca Strait ◽  
Reef Ecosystem

This study aims to analyze the condition of the coral reef ecosystem including the substrate, genus composition, and the level of coral mortality in the waters of the Malacca Strait, Masjid Raya District, Aceh Besar District. The research was conducted from October 2016 to October 2019 in the waters of the Malacca Strait, Masjid Raya District, Aceh Besar District. The research site is divided into three stations consisting of Lhok Mee Station, Ahmad Rhang Manyang and Benteng Inong Balee Station. Data were collected using the Point Intercept Transect method. The results showed that the condition of coral reefs at Lhok Mee Station was in the damaged category with coral cover ranging from 6.56% - 13.44%. Ahmad Rhang Manyang Station is included in the moderate to good category with coral cover ranging from 38.75% - 67.19%. Meanwhile, Benteng Inong Balee Station is included in the medium category with coral cover ranging from 45.94% - 56.88%. The monitoring results found that 30 coral genera with the highest composition of the coral genera came from the Porites genus, while other coral genera were unevenly distributed. The value of the mortality index for Lhok Mee Station shows a high increase in mortality of live coral to dead coral. Meanwhile, Ahmad Rhang Manyang and Benteng Inong Balee stations have low coral mortality index values.

scholarly journals KOMPARASI POLA SPASIAL KONDISI TERUMBU KARANG TAMAN NASIONAL KARIMUNJAWA

2021 ◽  
Vol 14 (2) ◽  
pp. 175-184
Author(s):  
M Munasik ◽  
Andy Ahmad Romadhoni ◽  
Muhammad Helmi
Keyword(s):  
Coral Reef ◽  
Spatial Pattern ◽  
National Park ◽  
Coral Cover ◽  
Assessment Method ◽  
Live Coral ◽  
Dead Coral ◽  
Coral Rubble ◽  
Management Zones ◽  
Protection Zone

ABSTRACTComparative studies on the percentage of coral reef substrate cover have been carried out in 3 (three) management zones (protection zone, utilization and Non-MPA) Karimunjawa National Park (KNP). The Manta Tow broadscale coral reef assessment method was applied to the north side of Bengkoang Island and the south side of Cemara Besar Island (protection zone), southern side of Bengkoang Island and northern side of Cemara Besar Island (utilization zone) and Non-MPA (Seruni Island) to observe live coral cover, dead coral, coral rubble and soft coral. Substrate cover variations from 10-12 towing (track length 200m) from each side of the island have formed a spatial pattern of coral reef conditions. Furthermore, the condition of the coral reefs was confirmed using the UPT (Underwater Photo Transect) detailed assessment method with one station on each side of the island. The results showed that there were differences in the spatial pattern of coral reef conditions as indicated by significant differences in the percentage of live coral cover, dead coral, rubble and coral lifeform among management zones of the KNP. The condition of coral reefs of the MPA is better and has a higher diversity of coral species than Non-MPA of the Karimunjawa National Park. The spatial pattern of coral reef conditions can be used as an indicator of disturbances in the coral reef ecosystem and can be used for periodic analysis of coral reef monitoring data in conservation areas.Keywords: spatial pattern, coral reef condition, manta tow, underwater photo transect, Karimunjawa National Park.ABSTRAKStudi perbandingan persentase tutupan substrat terumbu karang telah di lakukan pada 3 (tiga) zona pengelolaan (zona perlindungan, pemanfaatan dan luar kawasan) Taman Nasional Karimunjawa. Metode penilaian terumbu karang skala luas Manta Tow diaplikasikan di sisi utara P. Bengkoang dan sisi selatan P. Cemara Besar (zona perlindungan), sisi selatan P. Bengkoang dan sisi utara P. Cemara Besar (zona pemanfaatan) dan luar kawasan (P. Seruni) untuk mengamati tutupan karang hidup, karang mati, pecahan karang dan karang lunak. Variasi persentase tutupan substrat dari 10-12 tarikan Manta Tow (panjang lintasan 200m) dari masing-masing sisi pulau telah membentuk pola spasial kondisi terumbu karang. Selanjutnya penilaian kondisi terumbu karang dikonfirmasi dengan menggunakan metode penilaian rinci UPT (Underwater Photo Transect) dengan satu stasiun setiap sisi pulau. Hasil menunjukkan terdapat perbedaan pola spasial kondisi terumbu karang yang ditunjukkan oleh perbedaan yang signifikan persentase tutupan karang hidup, karang mati, pecahan karang dan lifeform karang antar zona pengelolaan.  Kondisi terumbu karang di dalam kawasan lebih baik dan memiliki keragaman jenis karang lebih tinggi daripada di luar kawasan Taman Nasional Karimunjawa. Pola spasial kondisi terumbu karang dapat dijadikan indikator terjadinya gangguan pada ekosistem terumbu karang di suatu kawasan dan dapat digunakan untuk analisis data pemantauan terumbu karang secara berkala di kawasan konservasi.Kata Kunci: pola pasial, kondisi terumbu karang, manta tow, underwater photo transect, Taman Nasional Karimunjawa,

scholarly journals Measuring coral reef decline through meta-analyses

2005 ◽  
Vol 360 (1454) ◽  
pp. 385-395 ◽  
Author(s):  
I.M Côté ◽  
J.A Gill ◽  
T.A Gardner ◽  
A.R Watkinson
Keyword(s):  
Coral Reef ◽  
Large Scale ◽  
Coral Cover ◽  
Meta Analysis ◽  
Cost Effective ◽  
Data Availability ◽  
Small Scale ◽  
Ecological Change ◽  
Live Coral ◽  
Scale Estimate

Coral reef ecosystems are in decline worldwide, owing to a variety of anthropogenic and natural causes. One of the most obvious signals of reef degradation is a reduction in live coral cover. Past and current rates of loss of coral are known for many individual reefs; however, until recently, no large-scale estimate was available. In this paper, we show how meta-analysis can be used to integrate existing small-scale estimates of change in coral and macroalgal cover, derived from in situ surveys of reefs, to generate a robust assessment of long-term patterns of large-scale ecological change. Using a large dataset from Caribbean reefs, we examine the possible biases inherent in meta-analytical studies and the sensitivity of the method to patchiness in data availability. Despite the fact that our meta-analysis included studies that used a variety of sampling methods, the regional estimate of change in coral cover we obtained is similar to that generated by a standardized survey programme that was implemented in 1991 in the Caribbean. We argue that for habitat types that are regularly and reasonably well surveyed in the course of ecological or conservation research, meta-analysis offers a cost-effective and rapid method for generating robust estimates of past and current states.

scholarly journals Comparison of Live Coral Cover in Central and South Bangka

2018 ◽  
Vol 21 (1) ◽  
pp. 37
Author(s):  
Mu'alimah Hudatwi ◽  
Umroh Umroh
Keyword(s):  
Coral Reef ◽  
Coral Cover ◽  
Reef Coral ◽  
Live Coral ◽  
Dead Coral ◽  
Live Coral Cover ◽  
Anthropogenic Stressor ◽  
High Turbidity ◽  
The Universe ◽  
Runoff And Sedimentation

Abstract Coral reef ecosystem has many biological, ecological, and economical functions to the universe. This ecosystem provides shelter, food, and home for many marine organisms and together they perform diverse and rich ecosystem. However, this diverse ecosystem is very susceptible to environmental change, such as climate change, ocean acidification, and other anthropogenic impact. When reef-building coral could not stand with harsh condition they will eventually die. We assume that anthropogenic stressor such as turbidity, terrestrial runoff, and sedimentation is the main problem here, because of high number of tin mining activities. Bangka and Belitung Islands are huge tin producer and has been exploited heavily by the legal and illegal miner company. The purpose of this study is to investigate the live coral cover in Central and South Bangka by using the line intercept transect to calculate the live coral, died coral, and algae in each stations. The results showed that the coral cover in Central Bangka and South Bangka has fair condition (25-40% of live stony coral). Value of live and dead coral cover was 40% with Semujur and Ketawai represent the coral cover in Central Bangka. While South Bangka has slight (1-2%) difference of live coral, dead coral, and algae cover. High number of dead coral mainly composed by dead coral overgrown by algae, allegedly caused by high turbidity and sedimentation from the anthropogenic stressor. Keywords: coral reef, coral cover, died coral, sedimentation Abstrak Perbandingan Tutupan Karang Hidup di Bangka Tengah dan SelatanEkosistem terumbu karang mempunyai fungsi biologi, ekologi, dan ekonomi yang bermanfaat bagi manusia. Ekosistem ini menyediakan tempat berlindung, makanan, dan rumah bagi organisme laut dan membentuk suatu ekosistem yang kaya dan beragam. Namun, ekosistem ini sangat rentan terhadap perubahan lingkungan, sepertiiklim, asidifikasi, dan dampak lain yang dilakukan manusia. Ketika terumbu karang tidak mampu bertahan dengan perubahan lingkungan yang ekstrim mereka akan mati. Kami menduga bahwa dampak antropogenik seperti turbiditas, runoff dari darat, dan sedimentasi merupakan penyebab utama kerusakan terumbu karang, karena banyaknya aktivitas penambangan. Kepulauan Bangka belitung adalah penghasil timah terbesar dan telah dieksploitasi oleh penambang timah legal maupun ilegal. Tujuan dari penelitian ini adalah untuk mengetahui tutupan karang hidup di Provinsi Bangka Tengah dan Bangka Selatan dengan menggunakan metode traksek garis. Hasil menunjukkan bahwa terumbu karang di Bangka Tengah dan Selatan termasuk kategori sedang (25- 40% tutupan karang). Tutupan karang hidup dan karang mati di Bnagka Tengah sebesar 40% dari hasill pengamatan di Semujur dan Ketawai. Sedangkan nilai tutupan karang hidup, karang mati, dan alga di Bangka Selatan mempunyai angka perbedaan yang rendah (1-2%). Tingginya tutupan karang mati tersusun oleh karang mati yyang ditumbuhi alga yang disebabkan oleh turbiditas dan sedimentasi.Kata Kunci: karang mati, terumbu karang, tutupan karang, sedimentasi

scholarly journals KELIMPAHAN Acanthaster planci DAN TUTUPAN KARANG HIDUP DI PERAIRAN PULAU SAPARUA, PROVINSI MALUKU

2020 ◽  
Vol 26 (2) ◽  
pp. 125
Author(s):  
Fismatman Ruli ◽  
Robert Alik ◽  
Dominggus Polnaya ◽  
Nurjirana Nurjirana ◽  
Sufardin Sufardin ◽  
...  
Keyword(s):  
Coral Cover ◽  
Live Coral ◽  
Growth Forms ◽  
Acanthaster Planci ◽  
Live Coral Cover ◽  
Observation Area ◽  
Coral Reef Ecosystems ◽  
Belt Transect ◽  
Almost All ◽  
Line Intercept

Achantaster planci atau Crown-of-thorns starfish merupakan hewan pemangsa karang yang secara langsung dapat menyebabkan degradasi pada ekosistem terumbu karang. Penelitian ini bertujuan untuk mengetahui kelimpahan dari A. planci dan kondisi karang di Pulau Saparua. Jumlah lokasi pengamatan sebanyak lima stasiun. Penelitian ini dilaksanakan pada November 2018 di Pulau Saparua, Kabupaten Maluku Tengah, Provinsi Maluku. Pengamatan tutupan karang hidup dan kelimpahan Achantaster planci dilakukan dengan menggunakan metode Line Intercept Transect (LIT), pengamatan Acanthaster planci menggunakan metode sabuk (Belt Transect) yang mengikuti garis LIT dengan panjang 70 meter dan lebar 2 meter sehingga luasan area pengamatan sebesar 140 m2. Hasil penelitian menunjukkan kondisi tutupan karang hidup tergolong kedalam kriteria sedang hingga sangat baik (26,5%-89,54%) dan terdapat sepuluh bentuk pertumbuhan yang ditemukan pada lokasi ini. Indeks mortalitas karang tertinggi pada Stasiun (Stn) 2, daerah dimana tidak ditemukan A. planci. Keberadaan A. planci hanya ditemukan pada Stn 1, Stn 4 dan Stn 5, dengan kelimpahan A. planci tertinggi ditemukan pada Stn 1 sebanyak 0,036 ind/m2. Bentuk pertumbuhan karang Acropora mendominasi hampir pada seluruh stasiun dan A. planci ditemukan pada stasiun yang memiliki tutupan karang hidup yang didominasi oleh bentuk pertumbuhan Acropora branching dan coral branching. Korelasi baik tutupan karang dan kelimpahan A. planci maupun karang mati dan A. planci tergolong cukup dan tidak signifikan. Achantaster planci or Crown-of-thorns starfish are coral predators that can directly cause degradation of coral reef ecosystems. This study aims to determine the abundance of A. planci, live coral cover on Saparua Island. The number of observation stations was five locations. This research was conducted in November 2018 on Saparua Island, Central Maluku Regency, Maluku Province. Observations of live coral cover and Achantaster planci abundance were carried out using the Line Intercept Transect (LIT) method, Acanthaster planci observations using the Belt Transect method which followed the LIT with a length of 70 meters and a width of 2 meters so that the area of   the observation area was 140 m2. The results showed the condition of live coral cover was classified as moderate to very good criteria (26.5% -89.54%) and there were ten of coral lifeforms found at this location. The highest coral mortality index was determined in St 2 areas where A. planci was not found. The presence of A. planci was only found in St 1, St 4 and St 5, where the highest abundance of A. planci was found in St 1 by 0.036 ind / m2. Acropora coral growth forms dominate almost all stations and A. planci is found in stations that have live coral cover dominated by Acropora branching and coral branching growth forms. Correlation of both coral cover and abundance of A. planci and dead coral and A. planci is classified as sufficient and not significant.

scholarly journals KONDISI TERUMBU KARANG DI KAWASAN WISATA PULAU BOKORI, KENDARI, PROVINSI SULAWESI TENGGARA

OSEANA ◽  
2021 ◽  
Vol 46 (1) ◽  
pp. 23-29
Author(s):  
Ofri Johan ◽  
Jupri Jupri ◽  
Fella Pritian Cera ◽  
Ahmad Rezza Dzumalex ◽  
Ratna Diyah Palupi ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Coral Cover ◽  
Live Coral ◽  
Percent Cover ◽  
City Center ◽  
Tourist Destination ◽  
Dead Coral ◽  
Dominant Type ◽  
Mushroom Coral ◽  
The City

Bokori Island has been a tourist destination managed by the Tourism Office of the Southeast Sulawesi Provincial since 2014. The location is close to the city center, making this island visited by many tourists. In addition to the beauty of the island, it is also necessary to maintain the beauty of coral reefs as objects for underwater recreation. The study was conducted on 24–25 July 2019 at three sites of observation. The research purpose was to determine the condition of coral reefs of the island, which is used as a tourist destination. The result indicates that the condition of coral reefs is categorized good by having coral cover about 50.67%. The dominant coral at the island is the foliose coral (CF) group with percent cover about 22%, followed by coral branching (CB) 10%, Acropora tabulate (ACT) 8.57%, mushroom coral (CMR) 6%, encrusting coral (CE) 2% and massive coral (CM) 1.33%. The dominant type of substrate was dead coral with algae (DCA) about 37.3%, and the damage due to explosion could still be seen in the location. The current condition of coral needs to be maintained and improved supervision so that live coral can improve so that the function to support underwater tourism can be achieved.

scholarly journals Field measurements of a massive Porites coral at Goolboodi (Orpheus Island), Great Barrier Reef

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam Smith ◽  
Nathan Cook ◽  
Kailash Cook ◽  
Rachelle Brown ◽  
Richard Woodgett ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Growth Models ◽  
Coral Cover ◽  
Field Measurements ◽  
Science Research ◽  
Live Coral ◽  
Barrier Reef ◽  
Language And Culture ◽  
Large Coral ◽  
Massive Porites

AbstractAn exceptionally large coral Porites sp. has been identified and measured at Goolboodi (Orpheus Island), Great Barrier Reef (GBR). This coral was measured in March 2021 during citizen science research of coral reefs in the Palm Islands group. We conducted a literature review and consulted scientists to compare the size, age and health of the Porites with others in the GBR and internationally. This is the largest diameter Porites coral measured by scientists and the sixth highest coral measured in the GBR. The health of the Porites was assessed as very good with over 70% live coral cover and minor percentages of sponge, live coral rock and macroalgae. An estimated age of 421–438 years was calculated based on linear growth models. Manbarra Traditional Owners were consulted and suggested that the Porites be named Muga dhambi (big coral) to communicate traditional knowledge, language and culture to indigenous, tourists, scientists and students.

scholarly journals Severe Heat Stress Resulted in High Coral Mortality on Maldivian Reefs following the 2015–2016 El Niño Event

Oceans ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 233-245
Author(s):  
Pia Bessell-Browne ◽  
Hannah E. Epstein ◽  
Nora Hall ◽  
Patrick Buerger ◽  
Kathryn Berry
Keyword(s):  
Heat Stress ◽  
Coral Bleaching ◽  
El Niño ◽  
El Nino ◽  
Coral Cover ◽  
Small Island ◽  
Live Coral ◽  
Dead Coral ◽  
Coral Assemblage ◽  
Severe Heat Stress

Coral cover worldwide has been declining due to heat stress caused by climate change. Here we report the impacts of the 2015–2016 El Niño mass coral bleaching event on the coral cover of reefs located on central and northern atolls of the Maldives. We surveyed six reef sites in the Alifu Alifu (Ari) and Baa (South Maalhosmadulu) Atolls using replicate 20 m benthic photo transects at two depths per reef site. Live and recently dead coral cover identified from images differed between reef sites and depth. Recently dead corals on average made up 33% of the coral assemblage at shallow sites and 24% at deep sites. This mortality was significantly lower in massive corals than in branching corals, reaching an average of only 6% compared to 41%, respectively. The best predictors of live coral cover were depth and morphology, with a greater percentage of live coral at deep sites and in massive corals. The same predictors best described the prevalence of recently dead coral, but showed inverse trends to live coral. However, there was high variability among reef sites, which could be attributed to additional local stressors. Coral bleaching and resulting coral mortalities, such as the ones reported here, are of particular concern for small island nations like the Maldives, which are reliant on coral reefs.

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