Prominence of environmental and anthropogenic agents on the occurrence of coral reef bleaching syndrome and coral diseases

2024 ◽  
Vol 74 (10) ◽  
pp. 6139-2024
Author(s):  
MICHAŁ SCHULZ ◽  
ALEKSANDRA ŁOŚ ◽  
PATRYCJA SKOWRONEK ◽  
ANETA STRACHECKA

Coral reefs are the most productive ecosystems on Earth. They ensure the conservation of biodiversity and are a live habitat for 25% of all marine organisms. The main relationship on the coral reef is the symbiosis between corals and algae from the genus Symbiodinium (commonly called zooxanthellae). The authors of this publication have characterized and described the factors limiting the occurrence of coral reefs, including: water temperature, salinity, access to sunlight, contamination, physicochemical and hydromechanical parameters of water. Moreover anthropogenic threats to coral reefs have been specified, including diving tourism, ecological disasters (e.g. oil spills) and the development of marine aquaristics. Rapid changes in the basic living conditions are dangerous for corals and their symbionts and may cause the unsuitability of the new environment resulting in diseases such as coral bleaching. Corals bleaching is a disease associated with the break of the coral and algae relationship which results in a coral reef death on a global scale. Awareness of these negative factors, often related to human activity, may allow us to better understand the ecological processes that are the basis of reef functioning and might enable us to prevent and oppose to the changes and ecological recessions of coral reefs.

2021 ◽  
Vol 118 (21) ◽  
pp. e2015265118
Author(s):  
Christopher E. Cornwall ◽  
Steeve Comeau ◽  
Niklas A. Kornder ◽  
Chris T. Perry ◽  
Ruben van Hooidonk ◽  
...  

Ocean warming and acidification threaten the future growth of coral reefs. This is because the calcifying coral reef taxa that construct the calcium carbonate frameworks and cement the reef together are highly sensitive to ocean warming and acidification. However, the global-scale effects of ocean warming and acidification on rates of coral reef net carbonate production remain poorly constrained despite a wealth of studies assessing their effects on the calcification of individual organisms. Here, we present global estimates of projected future changes in coral reef net carbonate production under ocean warming and acidification. We apply a meta-analysis of responses of coral reef taxa calcification and bioerosion rates to predicted changes in coral cover driven by climate change to estimate the net carbonate production rates of 183 reefs worldwide by 2050 and 2100. We forecast mean global reef net carbonate production under representative concentration pathways (RCP) 2.6, 4.5, and 8.5 will decline by 76, 149, and 156%, respectively, by 2100. While 63% of reefs are projected to continue to accrete by 2100 under RCP2.6, 94% will be eroding by 2050 under RCP8.5, and no reefs will continue to accrete at rates matching projected sea level rise under RCP4.5 or 8.5 by 2100. Projected reduced coral cover due to bleaching events predominately drives these declines rather than the direct physiological impacts of ocean warming and acidification on calcification or bioerosion. Presently degraded reefs were also more sensitive in our analysis. These findings highlight the low likelihood that the world’s coral reefs will maintain their functional roles without near-term stabilization of atmospheric CO2 emissions.


2013 ◽  
Vol 10 (10) ◽  
pp. 6747-6758 ◽  
Author(s):  
R. Albright ◽  
C. Langdon ◽  
K. R. N. Anthony

Abstract. Ocean acidification is projected to shift coral reefs from a state of net accretion to one of net dissolution this century. Presently, our ability to predict global-scale changes to coral reef calcification is limited by insufficient data relating seawater carbonate chemistry parameters to in situ rates of reef calcification. Here, we investigate diel and seasonal trends in carbonate chemistry of the Davies Reef flat in the central Great Barrier Reef and relate these trends to benthic carbon fluxes by quantifying net ecosystem calcification (nec) and net community production (ncp). Results show that seawater carbonate chemistry of the Davies Reef flat is highly variable over both diel and seasonal cycles. pH (total scale) ranged from 7.92 to 8.17, pCO2 ranged from 272 to 542 μatm, and aragonite saturation state (Ωarag) ranged from 2.9 to 4.1. Diel cycles in carbonate chemistry were primarily driven by ncp, and warming explained 35% and 47% of the seasonal shifts in pCO2 and pH, respectively. Daytime ncp averaged 37 ± 19 mmol C m−2 h−1 in summer and 33 ± 13 mmol C m−2 h−1 in winter; nighttime ncp averaged −30 ± 25 and −7 ± 6 mmol C m−2 h−1 in summer and winter, respectively. Daytime nec averaged 11 ± 4 mmol CaCO3 m−2 h−1 in summer and 8 ± 3 mmol CaCO3 m−2 h−1 in winter, whereas nighttime nec averaged 2 ± 4 mmol and −1 ± 3 mmol CaCO3 m−2 h−1 in summer and winter, respectively. Net ecosystem calcification was highly sensitive to changes in Ωarag for both seasons, indicating that relatively small shifts in Ωarag may drive measurable shifts in calcification rates, and hence carbon budgets, of coral reefs throughout the year.


DEPIK ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 69-75
Author(s):  
Muhammad Akhyar Maududi ◽  
Oktiyas Muzaky Luthfi

The interaction between algae and coral is one of the most important of ecological processes in coral reef ecosystems. They are one of the main food sources in a large number of herbivorous animals in coral reef ecosystems. Makroalgae is also a major competitor in degrading coral reefs at a time when macroalgae gains dominate the coral reefs. Algae growth is relatively very fast, so it can be used as an indicator in the initial study to determine the processes that affect populations and coral reef communities. The purpose of this study is to determine the distribution of macroalgae cover on coral reefs in the Nusa Penida, Bali using the transect quadrant (1x1m2)x 100m method. This study shows that the lowest macroalgae cover at Crystal Bay and the highest in Buyuk can be concluded that the high macroalgae cover is made possible by the large supply of nutrients from the land which becomes the supplier of organic materials that increases the fertility of waters, meanwhile in the waters close to the high seas obtain additional nutrients derived from the lifting of the water mass (upwelling). Data and information are needed for the interest of regional planning towards the future related to the management and utilization of marine resources potential in the coastal area in Nusa Penida, Bali.Interaksi antara alga dan karang merupakan hal terpenting dari proses ekologi pada ekosistem terumbu karang. Mereka merupakan salah satu sumber produsen primer pada sejumlah besar hewan herbivora pada ekosistem terumbu karang. Makroalga juga menjadi pesaing utama dalam mendegradasi terumbu karang pada saat kelimpahaan makroalga mendominasi terhadap terumbu karang. Pertumbuhan alga tergolong sangat cepat, sehingga dapat digunakan sebagai indikator dalam studi awal untuk mengetahui proses yang mempengaruhi populasi dan komunitas terumbu karang. Tujuan dari penelitian ini adalah mengetahui sebaran tutupan makroalga pada terumbu karang di daerah utama wisata penyelaman Nusa Penida, Bali dengan menggunakan metode transek kuadran dengan ukuran (1x1m2) x 100 m. Penelitian ini menunjukan bahwa tutupan makroalga terendah pada Crystal Bay dan tertinggi di Buyuk dapat ditarik kesimpulan jika tingginya tutupan makroalga dimungkinkan oleh besarnya suplai nutrien daratan yang menjadi pensuplai bahan organik yang meningkatkan kesuburan perairan. Sedangkan pada  perairan yang dekat dengan laut lepas mendapat tambahan nutrien yang berasal dari pengangkatan massa air (upwelling). Data dan informasi ini diperlukan untuk kepentingan perencanaan pengembangan wilayah ke depannya yang terkait dengan pengelolaan dan pemanfaatan potensi sumberdaya laut di wilayah pesisir di Nusa Penida, Bali.


2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Caroline S. Rogers

Irrefutable evidence of coral reef degradation worldwide and increasing pressure from rising seawater temperatures and ocean acidification associated with climate change have led to a focus on reef resilience and a call to “manage” coral reefs for resilience. Ideally, global action to reduce emission of carbon dioxide and other greenhouse gases will be accompanied by local action. Effective management requires reduction of local stressors, identification of the characteristics of resilient reefs, and design of marine protected area networks that include potentially resilient reefs. Future research is needed on how stressors interact, on how climate change will affect corals, fish, and other reef organisms as well as overall biodiversity, and on basic ecological processes such as connectivity. Not all reef species and reefs will respond similarly to local and global stressors. Because reef-building corals and other organisms have some potential to adapt to environmental changes, coral reefs will likely persist in spite of the unprecedented combination of stressors currently affecting them. The biodiversity of coral reefs is the basis for their remarkable beauty and for the benefits they provide to society. The extraordinary complexity of these ecosystems makes it both more difficult to predict their future and more likely they will have a future.


2017 ◽  
Vol 3 (2) ◽  
pp. 107 ◽  
Author(s):  
Nadia Aldyza ◽  
Afkar ,

This study aims to determine the genus of coral and coral diseases in the coral reef ecosystem of Tuan Island Peukan Bada, Aceh Besar District. The data of coral genera were gathered by using point intercept transect method, whereas, the data of coral diseases were gathered by using survey method. The data were identified by using handbook and then analyzed descriptively. The results showed that there were 5 coral genera found in Tuan Island Pekan Bada namely: Acropora, Montipora, Pocillopora, Porites, and Goniastrea. Meanwhile, coral diseases that are found in Tuan Island were ulcerative white spots, growth anomalies of an unknown cause, sediment damage, alga overgrowth, pink line disease dan pigmentation responses. The conclusion of this study were (1) the coral reefs that were found in Tuan Island Peukan Bada, Aceh Besar District consisted of 5 genera, and (2) coral diseases in Tuan Island consisted of 6 types of diseases.


2018 ◽  
Vol 5 (1) ◽  
pp. 29
Author(s):  
Ni Luh Putu Febbi Mellani ◽  
I Gede Hendrawan ◽  
Widiastuti Karim

This research was conducted to determine the coral health condition of genus Porites at Jemeluk beach and Penuktukan beach with the different of reef geomorphology. Coral reef data was collected  for two days in Jemeluk beach (reef flats) in March 2017 and in Penuktukan beach (reef slope) in April 2017. Each observation location consisted of 3 stations parallel to the coastline. Observation of coral health data using belt transect method size 2 x 25 m with width of 1 meter each to left and right side. Photo documentation was performed on coral reefs of Porites and subsequently identified the types of diseases and forms of health problems using Coral Disease Handbook, Guidelines for Assessment, Monitoring and Management. The types of coral diseases found in both beaches are ulcerative white spot and white plague. The number of dominant colonies that infected with the disease was found on Jemeluk beach which has coastal morphology of coral reefs. The coral health conditions of the genus Porites found on Jemeluk and Penuktukan beaches are in an unhealthy condition. Compromised health is dominant in Jemeluk beach, this is estimated to be caused by the presence of river flow at observation sites which  is relatively high. In addition, the coral reef morphology in Jemeluk beach is reef flat causing the reefs in this area to be more susceptible to damage.


2012 ◽  
Vol 8 (6) ◽  
pp. 1016-1018 ◽  
Author(s):  
Christopher H. R. Goatley ◽  
David R. Bellwood

Sediments are a ubiquitous feature of all coral reefs, yet our understanding of how they affect complex ecological processes on coral reefs is limited. Sediment in algal turfs has been shown to suppress herbivory by coral reef fishes on high-sediment, low-herbivory reef flats. Here, we investigate the role of sediment in suppressing herbivory across a depth gradient (reef base, crest and flat) by observing fish feeding following benthic sediment reductions. We found that sediment suppresses herbivory across all reef zones. Even slight reductions on the reef crest, which has 35 times less sediment than the reef flat, resulted in over 1800 more herbivore bites (h −1 m −2 ). The Acanthuridae (surgeonfishes) were responsible for over 80 per cent of all bites observed, and on the reef crest and flat took over 1500 more bites (h −1 m −2 ) when sediment load was reduced. These findings highlight the role of natural sediment loads in shaping coral reef herbivory and suggest that changes in benthic sediment loads could directly impair reef resilience.


2021 ◽  
Vol 8 ◽  
Author(s):  
Alberto Candela ◽  
Kevin Edelson ◽  
Michelle M. Gierach ◽  
David R. Thompson ◽  
Gail Woodward ◽  
...  

Coral reefs are of undeniable importance to the environment, yet little is known of them on a global scale. Assessments rely on laborious, local in-water surveys. In recent years remote sensing has been useful on larger scales for certain aspects of reef science such as benthic functional type discrimination. However, remote sensing only gives indirect information about reef condition. Only through combination of remote sensing and in situ data can we achieve coverage to understand reef condition and monitor worldwide condition. This work presents an approach to global mapping of coral reef condition that intelligently selects local, in situ measurements that refine the accuracy and resolution of global remote sensing. To this end, we apply new techniques in remote sensing analysis, probabilistic modeling for coral reef mapping, and decision theory for sample selection. Our strategy represents a fundamental change in how we study coral reefs and assess their condition on a global scale. We demonstrate feasibility and performance of our approach in a proof of concept using spaceborne remote sensing together with high-quality airborne data from the NASA Earth Venture Suborbital-2 (EVS-2) Coral Reef Airborne Laboratory (CORAL) mission as a proxy for in situ samples. Results indicate that our method is capable of extrapolating in situ features and refining information from remote sensing with increasing accuracy. Furthermore, the results confirm that decision theory is a powerful tool for sample selection.


Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 251
Author(s):  
Adi Zweifler (Zvifler) ◽  
Michael O’Leary ◽  
Kyle Morgan ◽  
Nicola K. Browne

Increasing evidence suggests that coral reefs exposed to elevated turbidity may be more resilient to climate change impacts and serve as an important conservation hotspot. However, logistical difficulties in studying turbid environments have led to poor representation of these reef types within the scientific literature, with studies using different methods and definitions to characterize turbid reefs. Here we review the geological origins and growth histories of turbid reefs from the Holocene (past), their current ecological and environmental states (present), and their potential responses and resilience to increasing local and global pressures (future). We classify turbid reefs using new descriptors based on their turbidity regime (persistent, fluctuating, transitional) and sources of sediment input (natural versus anthropogenic). Further, by comparing the composition, function and resilience of two of the most studied turbid reefs, Paluma Shoals Reef Complex, Australia (natural turbidity) and Singapore reefs (anthropogenic turbidity), we found them to be two distinct types of turbid reefs with different conservation status. As the geographic range of turbid reefs is expected to increase due to local and global stressors, improving our understanding of their responses to environmental change will be central to global coral reef conservation efforts.


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