scholarly journals Are Coral Clasts from a Turbid Near-Shore Reef Environment a Suitable Material for Radiocarbon Analysis?

Radiocarbon ◽  
2013 ◽  
Vol 55 (2) ◽  
pp. 624-630 ◽  
Author(s):  
Pauline Gulliver ◽  
Suzanne Palmer ◽  
Chris Perry ◽  
Scott Smithers
Keyword(s):  
Coral Cover ◽  
Reef Coral ◽  
High Energy ◽  
Coral Growth ◽  
Live Coral ◽  
Reef Environment ◽  
Suitable Material ◽  
Fine Grained ◽  
Near Shore ◽  
Turbid Zone

Use of coral skeletons to determine growth histories of reefs situated in warm, clear tropical waters is well established. Recently, however, there has been increasing awareness of the significance of reefs occurring in environments that are considered as marginal for coral growth, such as turbid inshore settings characterized by episodes of elevated turbidity, low light penetration, and periodic sediment burial. While these conditions are generally considered as limiting for coral growth, coral reefs in these settings can exhibit high live coral cover and species diversity, and thus can be both ecologically and geologically significant. Turbid-zone reefs are also commonly concentrated along eroding shorelines with many analogues to erosional shorelines developed during the Holocene transgression. A growing number of studies of these previously undocumented reefs reveal that the reef deposits are detrital in nature, comprising a framework dominated by reef rubble and coral clasts and set within a fine-grained terrigenous sediment matrix. In addition to the recognized effects of diagenesis or algal encrustations on the radiocarbon signature of coral samples, episodic high-energy events may rework sediments and can result in age reversals in the same stratigraphic unit. As in other reef settings, the possibility of such reworking can complicate the reconstruction of turbid-zone reef growth chronologies. In order to test the accuracy of dating coral clasts for developing growth histories of these reef deposits, 5 replicate samples from 5 separate coral clasts were taken from 2 sedimentary units in a core collected from Paluma Shoals, an inshore turbid-zone reef located in Halifax Bay, central Great Barrier Reef, Australia. Results show that where care is taken to screen the clasts for skeletal preservation, primary mineralogical structures, and δ13C values indicative of marine carbonate, then reliable 14C dates can be recovered from individual turbid reef coral samples. In addition, the results show that these individual clasts were deposited coevally.

scholarly journals Long-term effects of competition and environmental drivers on the growth of the endangered coral Mussismilia braziliensis (Verril, 1867)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5419 ◽  
Author(s):  
Felipe V. Ribeiro ◽  
João A. Sá ◽  
Giovana O. Fistarol ◽  
Paulo S. Salomon ◽  
Renato C. Pereira ◽  
...  
Keyword(s):  
Coral Growth ◽  
Coralline Algae ◽  
Coral Tissue ◽  
Environmental Drivers ◽  
Stable Phase ◽  
Small Scale ◽  
Live Coral ◽  
Percent Cover ◽  
Study Region ◽  
Turbid Zone

Most coral reefs have recently experienced acute changes in benthic community structure, generally involving dominance shifts from slow-growing hard corals to fast-growing benthic invertebrates and fleshy photosynthesizers. Besides overfishing, increased nutrification and sedimentation are important drivers of this process, which is well documented at landscape scales in the Caribbean and in the Indo-Pacific. However, small-scale processes that occur at the level of individual organisms remain poorly explored. In addition, the generality of coral reef decline models still needs to be verified on the vast realm of turbid-zone reefs. Here, we documented the outcome of interactions between an endangered Brazilian-endemic coral (Mussismilia braziliensis) and its most abundant contacting organisms (turf, cyanobacteria, corals, crustose coralline algae and foliose macroalgae). Our study was based on a long (2006–2016) series of high resolution data (fixed photoquadrats) acquired along a cross-shelf gradient that includes coastal unprotected reefs and offshore protected sites. The study region (Abrolhos Bank) comprises the largest and richest coralline complex in the South Atlantic, and a foremost example of a turbid-zone reef system with low diversity and expressive coral cover. Coral growth was significantly different between reefs. Coral-algae contacts predominated inshore, while cyanobacteria and turf contacts dominated offshore. An overall trend in positive coral growth was detected from 2009 onward in the inshore reef, whereas retraction in live coral tissue was observed offshore during this period. Turbidity (+) and cyanobacteria (−) were the best predictors of coral growth. Complimentary incubation experiments, in which treatments of Symbiodinium spp. from M. braziliensis colonies were subjected to cyanobacterial exudates, showed a negative effect of the exudate on the symbionts, demonstrating that cyanobacteria play an important role in coral tissue necrosis. Negative effects of cyanobacteria on living coral tissue may remain undetected from percent cover estimates gathered at larger spatial scales, as these ephemeral organisms tend to be rapidly replaced by longer-living macroalgae, or complex turf-like consortia. The cross-shelf trend of decreasing turbidity and macroalgae abundance suggests either a direct positive effect of turbidity on coral growth, or an indirect effect related to the higher inshore cover of foliose macroalgae, constraining cyanobacterial abundance. It is unclear whether the higher inshore macroalgal abundance (10–20% of reef cover) is a stable phase related to a long-standing high turbidity background, or a contemporary response to anthropogenic stress. Our results challenge the idea that high macroalgal cover is always associated with compromised coral health, as the baselines for turbid zone reefs may derive sharply from those of coral-dominated reefs that dwell under oligotrophic conditions.

Coral Reefs Damage Assessment due to Oil Pollution in Egyptian Water

2014 ◽  
Vol 522-524 ◽  
pp. 725-728 ◽  
Author(s):  
E. H. Hegazy ◽  
Ahmed Kh. Mehanna ◽  
Mohamed Y. Omar ◽  
Heba Elkilani ◽  
Amr A. Hassan
Keyword(s):  
Coral Reefs ◽  
Damage Assessment ◽  
Oil Spills ◽  
Oil Pollution ◽  
Coral Cover ◽  
Live Coral ◽  
Coastal Tourism ◽  
Reef Environment ◽  
The World ◽  
Ground Damage

Coral reefs are the most biological systems productive and versatile on the surface of the planet earth, which is a source with economic and social, returns great for the country that God-given this natural wealth. Egypt is home to some of the most spectacular coral reefs and associated marine life in the world. Egypt has enacted laws and takes effective measures for the protection and management of coral reefs and associated ecosystems in the Red Sea and its Gulf to characterize these areas of the richness and diversity of coral reef environment is scarce to be repeated elsewhere in the world. The largest sub-sector for the Egyptian tourism market is the coastal tourism. Coastal tourism depends largely on intact reefs, and this is also one of the most important causes of reef degradation in Egypt. Over the last two decades live coral cover has declined in Egypt. Egyptian Environmental Affairs Agency (EEAA) implements its own methodology to estimate the coral reefs impacts as a result of the destruction of coral reefs due to ship aground or anchorage. This paper focuses on and presents the modelling of the destruction of coral reefs as a result of the collision and the ship ground damage assessment in case of oil spills in Egyptian coastal water referring to the EEAA methodology applied in Egypt.

scholarly journals Tutupan Terumbu Karang pada Kedalaman Berbeda di Perairan Pantai Batu Sungu, Desa Les, Kabupaten Buleleng

2021 ◽  
Vol 4 (2) ◽  
pp. 42
Author(s):  
I Putu Dede Charles Dharma Saputra ◽  
IGB Sila Dharma ◽  
Yulianto Suteja ◽  
Widiastuti Widiastuti
Keyword(s):  
Water Quality ◽  
Coral Cover ◽  
Management Plan ◽  
Coral Growth ◽  
Ex Situ ◽  
Live Coral ◽  
Growth Forms ◽  
Significant Difference ◽  
Study Sites

Bali island has many magnificent underwater coral reef gardens that attract tourists. Besides Pemuteran and Menjangan island waters,  Batu Sungu water has also potential to be a new tourist destination. Thus, to determine the potency and management plan in Batu Sungu waters, this research aimed to examine the overall coral cover, coral growth forms, other benthic forms, and each of their components in 5 and 10 m depths.  The overall coral cover, coral growth forms, other benthic forms, and each of their components were counted by using the Line Intercept Transect (LIT) method. Before collecting data, study sites were observed by using the Manta Tow method. Data were collected in 2 depths (5 dan 10 m) with 5 sites each (replicates) that separates within 50 to 150 m. A 25 m LIT was spread parallel to the coastline above the reefs. Live coral colonies, other benthic forms below the transects were measured for the number, length, and growth forms. Water quality was measured in situ (temperature, current, and clarity) and ex situ (pH). Results showed that the category of coral coverage in Batu Sungu water is "good” in 5 m and "moderate” in 10 m whereas there was no significant difference among each component of the overall coral cover. The most dominant coral growth form among the 2 depths was Coral Massive whereas significantly abundant in 5 m. Moreover, the number of Coral Foliose was found significantly high in the same depth. Other coral growth forms were relatively similar in numbers in two depths.  As likewise, the cover of other benthic forms and its component were not significantly different among two depths, except  Dead Coral with Algae which significantly plentiful in 5 m. Sand was dominantly found in two depths with no significant difference. Furthermore, Coraline Alga was only observed in 5 m, however, there were no Macroalga and Alga Assemblages found at this depth. It is assumed that the similarity number of the overall coral cover, coral growth forms, other benthic forms, and each of their components is related to the alikeness of water quality among the two depths. 

scholarly journals Coral Cover and Diversity Life form in Different Geomorpholgy Zone at Kampung Baru Waters, Bintan Island

2021 ◽  
Vol 5 (1) ◽  
pp. 29-36
Author(s):  
Anna Kristine Sigarlaki ◽  
Aditya Hikmat Nugraha ◽  
Dedy Kurniawan
Keyword(s):  
Life Form ◽  
Diversity Index ◽  
Coral Cover ◽  
Coral Growth ◽  
Reef Slope ◽  
Line Transect ◽  
Live Coral ◽  
Dominance Index ◽  
Live Coral Cover

The purpose of this study was to compare the percentage of cover conditions, diversity index, uniformited index and dominance index of  life form coralin the zones reef flate and reef slope in Kampung Baru Lagoi, Bintan Regency. This research was conducted using the method Line Intersept Transect (LIT) with the line transect length used was 30 meters, three replications with a gap of 5 meters. The results showed, at point station 1 in the zone flate Reef the percentage of live coral cover was 36,92% are categorized as moderate. Forms the coral growth Life form were found as many 9 types of Life form hard corals namely ACB, ACT, ACE, ACS, ACD, CB, CM, CE, CS with a diversity index of 2,53 are categorized as moderate, a uniformited index of 0,80 are categorized as high, and a dominance index of 0,22 are categorized as low. At the point station 2 in the zone slope Reef the percentage of live coral cover was 50,44% are categorized as good. Forms of coral growth (Life form) were found as many as 8 types of Life form hard corals namely ACT, ACE, CB, CM, CE, CS, CF and CMR, with a diversity index of 2,13 are categorized as moderate, a uniformited index of 0,71 are categorized as high, and a dominance index of 0,30 are categorized as low.

scholarly journals Species and size diversity in protective services offered by coral guard crabs

2014 ◽  
Author(s):  
C. Seabird McKeon ◽  
Jenna M. Moore
Keyword(s):  
Functional Diversity ◽  
Coral Cover ◽  
Reef Coral ◽  
French Polynesia ◽  
Live Coral ◽  
Protective Services ◽  
Host Coral ◽  
Multiple Predators ◽  
Size Diversity ◽  
Multiple Species

Coral guard crabs in the genus Trapezia are well-documented defenders of their pocilloporid coral hosts against coral predators such as the Crown-of-Thorns seastar (Acanthaster planci complex). The objectives of this study were to examine the protective services of six species of Trapezia against corallivory, and the extent of functional diversity among these Trapezia species. Studies conducted in Mo'orea, French Polynesia showed the Trapezia – coral mutualism protected the host corals from multiple predators through functional diversity in the assemblage of crab symbionts. Species differed in their defensive efficacy, but species within similar size classes shared similar abilities. Smaller Trapezia species, which were previously thought to be ineffective guards, play important defensive roles against small corallivores. We also measured the benefits of this mutualism to nearby coral species in the midst of an Acanthaster outbreak that reduced the live coral cover on the fore reef to less than 4%. The mutualism positively affects the reef coral demography and potential for recovery during adverse predation events through shelter of multiple species of small corals near the host coral. Our results show that some Trapezia species may be functionally equivalent within the same size class, decreasing the threat of gaps in coral protection caused by absence or replacement of any single Trapezia species.

scholarly journals Class Conservation Morfologi Karang berdasarkan Kedalaman pada Struktur Terumbu Karang di Pulau Kemujan dan Pulau Sintok, Karimunjawa, Jawa Tengah Coral Morphology Class Conservation Based on Depth of Coral Reef Structure in Kemujan and Sintok Islands, Karimunjawa, Central Java

2020 ◽  
Vol 9 (2) ◽  
pp. 123-130
Author(s):  
Renanda Nur Erviana ◽  
Pujiono Wahyu Purnomo ◽  
Supriharyono Supriharyono
Keyword(s):  
Water Quality ◽  
Coral Reefs ◽  
Water Depth ◽  
Coral Cover ◽  
Coral Growth ◽  
Live Coral ◽  
Growth Forms ◽  
Point Count ◽  
Effect Of Water ◽  
Coral Morphology

ABSTRAKKemujan dan Sintok merupakan pulau yang termasuk ke dalam zona pemanfaatan sebagai wisata bahari dan memiliki keanekaragaman bentuk pertumbuhan karang yang tinggi. Bentuk pertumbuhan karang dibedakan menjadi karang acropora dan non-acopora dengan perbedaan morfologi seperti tipe branching, massive, encruisting, foliose, dan digitae. Analisis morfologi karang sebagai pendukung status penutupan karang dapat mengetahui kondisi terumbu karang sesuai class conservation. Tujuan penelitian ini mengetahui kualitas perairan, struktur terumbu karang, morfologi karang berdasarkan class conservation dan pengaruh kedalaman terhadap struktur serta morfologi karang di Pulau Kemujan dan Sintok. Pengambilan data dilaksanakan pada bulan November 2019.  Metode penelitian yang digunakan adalah metode Underwater Photo Transect (UPT) dengan menggunakan transek sepanjang 30 meter. Data yang diambil adalah parameter kualitas perairan dan foto underwater karang. Data hasil penelitian diolah menggunakan aplikasi CPCe (Coral Point Count with Excel extensions) dan uji non parametrik dengan SPSS serta dianalisis menggunakan diagram r-K-S. Hasil penelitian menunjukkan bahwa kualitas perairan pada lokasi penelitian masih dalam keadaan normal. Persentase kelimpahan karang hidup termasuk dalam kategori sedang sampai dengan sangat baik yaitu  berkisar 25,56 -76,22%. Persentase morfologi karang berdasarkan Class conservation secara umum memiliki dominasi kelompok kompetitors (K) atau CC=2 yang berkisar 48,72 – 76,5%,  hal ini menunjukkan bahwa pada lokasi penelitian didominasi karang bentuk branching maupun foliose serta tidak ada pengaruh signifikan kedalaman air terhadap morfologi karang. ABSTRACTKemujan and Sintok are islands in the utilization zone as marine tourism and have high diversity of coral growth forms. The coral’s life form can be grouped into acropora and non-acopora corals with morphological differences such as branching, massive, encruisting, foliose, and digitae types. Morphological analysis of corals as supporting the status of coral cover can determine the condition of coral reefs according to class conservation. The purpose of this study are to determine the quality of the waters, the structure of coral reefs, coral morphology based on class conservation and the influence of depth on the structure and morphology of corals in Kemujan and Sintok Islands. Data collection was carried out in November 2019. The research method used was the Underwater Photo Transect (UPT) method using a 30 meter transect. The data collected the parameters of water quality and underwater coral photos. The research data were processed using the CPCe (Coral Point Count with Excel extensions) application and non-parametric tests with SPSS and analyzed using the r-K-S diagram. The results showed that the water quality at the study area was still in a normal condition. However, there was no significant effect of water depth on coral morphology. The percentage of live coral abundance was included in the moderate to very good category, ranging from 25.56 to 76.22%. Percentage of coral morphology based on Class conservation generally has a predominance of competitor groups (K) or CC = 2 ranging from 48.72 - 76.5%. Moreover, the results show that based on the coral growth forms at the study sites were dominated by branching and foliose corals and there was no significant effect of water depth on coral morphology.  

scholarly journals An assessment of small islands coral cover and coral-reef fish diversity at Oba Sub-district, Halmahera Island

2021 ◽  
Vol 890 (1) ◽  
pp. 012060
Author(s):  
F Ismail ◽  
N Akbar ◽  
I Tahir ◽  
R E Paembonan ◽  
I Marus ◽  
...  
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Coral Cover ◽  
Coral Growth ◽  
Systematic Sampling ◽  
Fish Diversity ◽  
Live Coral ◽  
Small Islands ◽  
Study Results ◽  
High Diversity

Abstract Study on the percentage of coral cover four small islands of Oba Sub-district, Halmahera Island of North Maluku Utara Province was carried out in April 2021.The four small islands of Oba Sub-district studied are Woda Island, Raja Island, Tamin Island, and Guratu Island. The study applied systematic sampling method that included collecting coral reef data using UPT (Underwater Photo Transect) method and coral fish data collection using visual census method. Study results showed that live coral coverage of reefs on the four small islands of Oba Sub-district had the highest value of 5.415% and the lowest value of 4.29%. There was positive relationship between coral growth form diversity and fish diversity. High diversity of coral growth forms was significantly related to high diversity of target reef fish.

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

The importance of live coral for small-sized herbivorous reef fishes in physically challenging environments

2012 ◽  
Vol 63 (8) ◽  
pp. 672 ◽  
Author(s):  
C. L. Johansson ◽  
D. R. Bellwood ◽  
M. Depczynski
Keyword(s):  
Coral Cover ◽  
Negative Relationship ◽  
Structural Complexity ◽  
Reef Fishes ◽  
High Energy ◽  
Live Coral ◽  
Herbivorous Fishes ◽  
Live Coral Cover ◽  
Tropical Coral ◽  
The Relationship

Tropical coral reefs are facing increasing levels of disturbance, with predictions of ongoing reductions in live coral cover. The response of herbivorous fishes to loss of coral cover was investigated by analysing the relationship between the abundance of different sized herbivorous fishes and live coral cover, on a high flow reef slope and a sheltered back reef on Ningaloo Reef, Western Australia. We found positive relationships between coral cover and the abundance of small (10–20 cm) excavating and scraping parrotfishes on the slope, but a negative relationship between corals and small (10–15 cm) grazers. These relationships were not evident on back reefs. Generally, the abundance of large individuals were not correlated with live coral in either habitat. We suggest that in physically demanding environments small parrotfishes may utilise the structural complexity of corals to resist strong water flow and/or to reduce predation. Small acanthurid grazers may school to reduce energy costs and minimise predation risk. The loss of coral cover appears to be particularly important for small fishes in high energy habitats, especially non-schooling species.

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