Extensive coral reef decline in Nha Trang Bay, Vietnam: Acanthaster planci outbreak: the final event in a sequence of chronic disturbances

Author(s):  
Konstantin S. Tkachenko ◽  
Nguyen H. Huan ◽  
Nguyen H. Thanh ◽  
Temir A. Britayev
2020 ◽  
Author(s):  
Marina Botana ◽  
Adriano Chaves-Filho ◽  
Alex Inague ◽  
Arthur Guth ◽  
Flavia Saldanha-Corrêa ◽  
...  

Abstract The oxidation of polyunsaturated fatty acids (PUFA) is a common stress response across biomes with potential to trigger impairment of cell growth and reproduction. The oxidative stress theory of coral bleaching induced by global warming has been widely accepted to explain coral reef decline, but its underlying physiological mechanism remains under debate. Here we used lipidomic and population density data to examine cell cultures of three coral reef symbionts after a heat shock (sudden rise of 12 °C for 4 hours). Heat tolerance in S. microadriaticum and C. goreaui was characterized by preservation of thylakoid-derived glycolipids. Conversely, heat sensitivity in B. minutum was linked to elevated concentrations of oxidized PUFA esterified to glycolipids, suggesting that culture growth had ceased due to severe oxidative damage. Our findings provide a basis to further understand the role played by oxidative stress in coral bleaching and reveal novel biomarkers for the monitoring of symbiont-coral health.


2004 ◽  
Vol 38 (15) ◽  
pp. 286A-287A ◽  
Author(s):  
Janet Pelley
Keyword(s):  

2016 ◽  
Vol 67 (5) ◽  
pp. 605 ◽  
Author(s):  
Amy G. Coppock ◽  
Naomi M. Gardiner ◽  
Geoffrey P. Jones

Coral degradation is a major threat towards the biodiversity of coral-reef ecosystems, either through the physical effects of environmental change, or biological agents such as crown-of-thorns (Acanthaster planci). Coral loss is leading to significant declines in reef-fish assemblages, particularly those dependent on live coral as settlement sites. Most reef fishes use olfactory stimuli at settlement; however, their ability to detect chemical stimuli from degraded corals or A. planci is unknown. Here, olfactory responses of juvenile reef fishes to the presence of stressed corals and A. planci were tested. Juveniles of eight common coral-associated species were subjected to a series of pair-wise choice tests, where the period of time spent in two differing water sources was noted. All species demonstrated a significant attraction towards healthy coral (≥76%), avoiding cues emitted by stressed coral colonies. When given the choice between a control water (untreated reef water) and water containing chemical cues from A. planci, most species elicited no response. Finally, when given the choice between chemical cues derived from feeding A. planci or the control, all species avoided A. planci (≥70%). Our results indicated that juvenile reef fish are capable of distinguishing the state of coral health, but not directly from disturbance agents.


2017 ◽  
Vol 44 ◽  
pp. 422.e1-422.e7 ◽  
Author(s):  
Andrea Gaggiano ◽  
Holta Kasemi ◽  
Andrea Monti ◽  
Antonella Laurito ◽  
Mauro Maselli ◽  
...  
Keyword(s):  

2013 ◽  
Vol 1 (1) ◽  
pp. 34
Author(s):  
Patritia Napitupulu ◽  
Hanny Tioho ◽  
Agung Windarto

The information on population structure of Acanthaster planci in Bunaken National Park (BNP) is urgent to be presented in order to be considered in decision making especially on coral reef management in BNP. The objectives of  this study was to examine the  population structure of A. planci, represented by the diameter and weight, number of arms, while the density, distribution and types of coral predation by reef animals in the Southern part of Bunaken Island also observed. Data were collected at the three locations namely, front reef flat (FRF), middle reef flat (MRF) and back reef flat (BRF) with total coverage area of ​​100 x 50 meters. Sixty two individuals (41 at night and 21 at day time) were found with a body diameter ranging between 14 – 28 cm, whereas body weight ranged from 80 – 700 gr, with the number of arms between 9 until 17. The density of A. planci during day time was 0.0042 ind/m2, while the night time was 0.0082 ind/m2, moreover the animal is generally spread aggregated. The results of this study indicated that the population of A. planci in BNP was an adult population with density is still relatively normal, despite an alert sign for the sustainability of coral reef ecosystems in the BNP.


2022 ◽  
Vol 956 (1) ◽  
pp. 012009
Author(s):  
R Z Ningsih ◽  
I Huda ◽  
M A Sarong ◽  
H Fitri

Abstract The crown of thorns starfish is one of the main threats to damage to coral reefs worldwide. Research on Acanthaster coral predator density in the Pulau Dua area, South Aceh district, has been carried out in March 2021, using the Line Intercept Transect (LIT) method. The results showed that the density Acanthaster planci obtained 42 individuals/12.000m2 with natural criteria. Corals fractures can support the life of Acanthaster planci substrate conditions dominated by coral fractures. It can also grow thread algae (Coraline) and encrusting algae, which will then be eaten by Acanthaster planci which are still in the larval stage. This research concludes that the density of Acanthaster planci obtained is still in the natural category with coral reef conditions including good criteria.


2019 ◽  
Vol 19 (2) ◽  
pp. 172
Author(s):  
Noar Muda Satyawan ◽  
Novita Tri Atriningrum

Abstrak : Gangguan eksternal pada ekosistem terumbu karang dapat terjadi secara alami ataupun karena aktifitas manusia yang menimbulkan perubahan fisik maupun ekologis. Perubahan ekologis dapat terlihat dari perubahan komposisi biota yang berasosiasi di dalamnya. Salah satu kelompok biota yang berasosiasi dengan terumbu karang adalah megabenthos. Tujuan dari penelitian ini adalah untk mengetahui kondisi eksisting fauna megabenthos pada ekosistem terumbu karang di perairan Labuhan Pandan Lombok Timur. Pengamatan dilakukan pada 5 stasiun yaitu Gili Bidara (BDR_01), Gili Kondo (KND_01), Gili Petagan 1 (PTG_01), Gili Petagan 2 (PTG_02), dan Gili Petagan 3 (PTG_03). Pengambilan data megabenthos dilakukan dengan metode Benthos Belt Transect (BBT). Hasil penelitian menunjukkan bahwa ditemukan 15 jenis megabenthos yang termasuk dalam 5 Phylum (Mollusca, Echinodermata, Chordata, Annelida, dan Platyhelminthes). Jumlah jenis tertinggi ditemukan pada phylum Echinodermata (10 jenis), kemudian diikuti oleh Mollusca (2 jenis), Chordata (1 jenis), Annelida (1 jenis), dan Platyhelminthes (1 jenis). Kepadatan megabenthos tertinggi ditemukan pada stasiun BDR_01 (10.571 ind/Ha), kemudian diikuti oleh stasiun KND_01 (10.214 ind/Ha), PTG_02 (9.857 ind/Ha), PTG_03 (8.429 ind/Ha) dan PTG_01 (1.714 ind/Ha). Keanekaragaman jenis tertingi ditemukan pada stasiun PTG_01 (H’=1,14), kemudian diikuti oleh BDR_01 (H’=0,76), KND_01 (H’=0,69), PTG_03 (H’=0,17) dan PTG_02 (H’=0,09). Hasil perhitungan indeks dominansi menunjukkan bahwa Didemnum molle (phylum Chordata)  ditemukan dominan pada seluruh stasiun pengamatan. Ditemukan juga jenis megabenthos pemangsa hewan karang yaitu Acanthaster planci pada stasiun PTG_03 serta Drupella sp. pada stasiun BDR_01, KND_01 dan PTG_02. Beberapa jenis megabenthos yang ditemukan dapat dijadikan bioindikator dalam pemantauan kesehatan ekosistem terumbu karang di Perairan Labuhan Pandan, Lombok Timur.Kata Kunci: Kondisi eksisting, Megabenthos, Gempa Bumi, Labuhan Pandan, Lombok TimurAbstract: External disturbance to the coral reef ecosystem occured by naturally or due to human activities that cause physical and ecological changes. Ecological changes could be seen from changes in the composition of the associated biota. One of the biota groups that associated with coral reefs were megabenthos. The purpose of this study were to determine the condition of the megabenthos fauna on coral reef ecosystems in the Labuhan Pandan waters, Eastern Lombok. Observations were made at 5 stations namely Gili Bidara (BDR_01), Gili Kondo (KND_01), Gili Petagan 1 (PTG_01), Gili Petagan 2 (PTG_02), and Gili Petagan 3 (PTG_03). Data of Megabenthos were collected by Benthos Belt Transect (BBT) method. The results showed that found 15 species of megabenthos included in 5 phylum (Mollusca, Echinoderm, Chordata, Annelida, and Platyhelminthes). The highest number of species were found in Echinoderms phylum (10 species), followed by Mollusca (2 species), Chordata (1 species), Annelida (1 species), and Platyhelminthes (1 species). The highest megabenthos density were found at BDR_01 station (10,571 ind / Ha), then followed by stations KND_01 (10,214 ind / Ha), PTG_02 (9,857 ind / Ha), PTG_03 (8,429 ind / Ha) and PTG_01 (1,714 ind / Ha). The highest species diversity were found at stations PTG_01 (H '= 1.14), then followed by BDR_01 (H' = 0.76), KND_01 (H '= 0.69), PTG_03 (H' = 0.17) and PTG_02 (H '= 0.09). The calculation result of dominance index shows that Didemnum molle (phylum Chordata) were found dominant in all observation stations. Also found species of coral predator Acanthaster planci at PTG_03 station and Drupella sp. at stations BDR_01, KND_01 and PTG_02. Several species of megabenthos can be used as bioindicators to monitoring of coral reef health in Labuhan Pandan Waters, East Lombok.Keywords: Existing conditions, megabenthos, earthquake, Labuhan Pandan, Eastern Lombok  


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