Investigation of the effect of physical parameters of seawater on the health of branching corals in Chabahar Bay

Monitoring hard coral health and diversity is essential in assessing their resilience to disturbances such as coral bleaching. This study gathered baseline data on the health and benthic composition of coral reefs in western Calatagan, Batangas, the Philippines. Coral health in two sites – Buntong Gasang and the Quilitisan Marine Protected Area (MPA) – was assessed using the CoralWatch citizen science Coral Health Chart method. The average color score of more than 200 coral colonies was compared between sites and coral growth forms (i.e. branching, boulder, and plate). In addition, benthic composition in both sites was determined using photoquadrats. Buntong Gasang Point and Quilitisan MPA had mean coral scores that are 4.4 (± 1.0 SD) and 3.6 (± 1.0 SD), respectively, thus indicating normal symbiont densities. The analysis also showed little differences in mean color scores among coral growth forms ranging from 3.8–4.3. Both sites had relatively high coral cover (mean = 52.3% ± 4.3% SD in Buntong Gasang, mean = 49.7% ± 8.7% SD in Quilitisan MPA) despite having different benthic compositions [PERMANOVA, F(1,8) = 8.87, p = 0.006]. Branching coral cover was about six times higher in Buntong Gasang Point (17%), whereas encrusting corals dominated at Quilitisan MPA (~ 39%). In addition, algal cover was higher in Quilitisan (45.0%) than in Buntong Gasang (35.5%). Although other studies show that branching corals are less resistant than massive or encrusting forms to coral bleaching, examining coral color suggests that reefs in both Buntong Gasang and Quilitisan MPA appeared to have comparably recovered from the mass bleaching events in 2020–2021. However, regular monitoring is needed to assess the responses of these reefs to future thermal stress. This study shows the potential of monitoring coral color in assessing coral reef health in the Philippines.

Response of phytoplankton assemblages to variations in environmental parameters in a subtropical bay (Chabahar Bay, Iran): Harmful algal blooms and coastal hypoxia

Coral species inventory at War in the Pacific National Historical Park: Final report

Effects of coral-dwelling damselfishes' abundances and diversity on host coral dynamics

Plastic marine debris are a potential threat to the life of marine organisms such as corals. This study aimed to analyze the effect of different plastic waste attachments on the bleaching rate and the health of branching corals at Kelapa Dua Island. Branching coral colonies consisted of 15 fragments of Porites cylidrica at the water depth of 80-90 cm, then treated with plastic waste (control, clear plastic, sack plastic, packaging plastic, and black plastic) for four days. Determination of color changes in corals was determined using Adobe Photoshop CC 2019 and Image j software to obtain the area of the discoloration. The treatment with black plastic became most impactful, with a discoloration area of 5.33 ± 0.48 cm2 and a healthy percentage of 73.62 ± 2.00%. Results of the linear regression between coral discoloration rate and light intensity showed a negative correlation, with r = -0.77 and R2 = 0.59, then between the percentage of coral health and light intensity showed a positive correlation, with r = 0.83 and R2 = 0.69. These results indicated that the decrease in light intensity due to the covered plastic debris affected the discoloration rate and the health percentage of branching coral.

As sequencing techniques have advanced and become cheaper in recent years, there has been a rapid increase in the number of studies conducted into the role of the microbiome in coral health, physiology, and response to environmental change. However, there is substantial variation in the methodological approaches applied. For example, DNA extraction protocols and the types of tissues sampled from the coral meta-organism are known to influence the downstream analyses of the amplified microbial communities and subsequently the interpretation of the microbiome diversity, stability and role. Studies have generally focused on whole organisms, in which the coral sampling steps homogenize the meta-organism microhabitats, however other studies targeting specific microhabitats have identified sources of variation specific to distinct compartments of the coral’s microbial landscape. Here we present a comparative analysis of methodologies optimized for the generation of coral microbiome data from the coral tissues and whole coral fragments of two commonly studied branching coral genera with distinct tissue structure. We investigate the microbiome of the imperforate Pocillopora, where the coral tissue does not penetrate through the calcium carbonate matrix, and the perforate Acropora, where the coral tissues and skeleton are interwoven throughout the coral branch. Through comparing data generated from different DNA extraction protocols using fixed coral tissues isolated from the coral skeletal structure with fixed whole coral fragments, we identify sources of variation inherent to microbial data generated from different sample types, species, and extraction protocols.

Coral reefs and seagrasses are important for biodiversity and liveli­hood but they are fast degrading owing to climatic and non-climatic factors. The impacts of climate change since 1998 and the effects of non-climatic factors, mainly destructive fishing practices, mining, pollution, and coastal development, have altered the community structure and health of corals and seagrasses. Low-tech and low-cost transplantation techniques have been successfully standard­ized and implemented in the Gulf of Mannar, southeast India. A coral rehabilita­tion technique, perfected in 2002, comprising selection of site, identification of suitable native species, precision in fragmentation, choosing fragment size, fix­ing positions, and effective monitoring protocols, resulted in good growth and a survival of 80.1%. The average annual growth was 13.5 cm in fast-growing branching corals and 1.8 cm in massive corals. There was also considerable in­crease in coral cover, recruit density, and population size of fish and associated macrofauna. Likewise, a rehabilitation program for seagrass was started in 2008. Seagrass shoots in the rehabilitated areas showed a good survival rate of 85.04% with increased biodiversity. Rehabilitation of degraded coral and seagrass areas is a viable management practice for the restoration of the ecosys­tem services like fishery, coastal protection, and tourism as well as enhancing ecosystem resilience.

Tide- and rainfall-induced variations of physical and chemical parameters in a mangrove-depleted estuary of East Hainan (South China Sea)

Expression of calcification and metabolism-related genes in response to elevated pCO2 and temperature in the reef-building coral Acropora millepora

Olfactory discrimination in juvenile coral reef fishes: Response to conspecifics and corals

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 438:119-128 (2011) - DOI: https://doi.org/10.3354/meps09271 Biotic and abiotic correlates of tissue quality for common scleractinian corals M. O. Hoogenboom1,*, S. R. Connolly1,2, K. R. N. Anthony3 1ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia 2School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia 3ARC Centre of Excellence for Coral Reef Studies, and School of Biological Sciences, University of Queensland, Brisbane 4072, Australia *Email: mia.hoogenboom@gmail.com ABSTRACT: Reef-building corals provide critical ecosystem functions but are under pressure from a range of stressors, and there is a growing need to understand how environmental factors affect the physiological condition of corals. This study explored the relationships between tissue quality (i.e. energy content per unit surface area) and light intensity, water flow velocity, temperature, colony size and competition for 4 common coral species. A formal model selection procedure revealed that different corals, even species that are closely related and morphologically similar, respond to their local environments in fundamentally different ways. Overall, colony size was the most consistent predictor of tissue quality, and the observed increase in tissue energy content with size may partially explain field observations of reduced mortality for large colonies. However, competitive interactions, light intensity, water flow and temperature also contributed to variation in tissue properties. Warming reduced the tissue quality of massive and foliose corals more than that of branching corals, despite the latter generally being recognised as more susceptible to thermal bleaching. These findings identify species- and habitat-specific responses to baseline environmental variables that can be used to anticipate shifts in coral health under environmental change. KEY WORDS: Light intensity · Water flow · Colony size · Temperature · Competition · Bioenergetics · Statistical modelling · Model-average regression coefficient Full text in pdf format Supplementary material PreviousNextCite this article as: Hoogenboom MO, Connolly SR, Anthony KRN (2011) Biotic and abiotic correlates of tissue quality for common scleractinian corals. Mar Ecol Prog Ser 438:119-128. https://doi.org/10.3354/meps09271 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 438. Online publication date: October 05, 2011 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2011 Inter-Research.

Widespread temperature stress has caused catastrophic coral bleaching events that have been devastating for coral reefs. Here, we evaluate whether coral fluorescence could be utilized as a noninvasive assessment for coral health. We conducted cold and heat stress treatments on the branching coral Acropora yongei, and found that green fluorescent protein (GFP) concentration and fluorescence decreased with declining coral health, prior to initiation of bleaching. Ultimately, cold-treated corals acclimated and GFP concentration and fluorescence recovered. In contrast, heat-treated corals eventually bleached but showed strong fluorescence despite reduced GFP concentration, likely resulting from the large reduction in shading from decreased dinoflagellate density. Consequently, GFP concentration and fluorescence showed distinct correlations in non-bleached and bleached corals. Green fluorescence was positively correlated with dinoflagellate photobiology, but its closest correlation was with coral growth suggesting that green fluorescence could be used as a physiological proxy for health in some corals.

Coral reef health is an important indicator for the assessment of sustainable protected coral reef management and conservation. Indicator will include some community properties namely coral cover and life forms. Coral cover information is basic data in sustainable marine protected area management. This study aims to determine coral cover in the marine protected area of Tidung Island, Seribu Islands. Data retrieval was carried out in the highly protected area with 3 repetitions at a depth of 5 to 10 meters using the Line Intercept Transect (LIT) method. The results showed that the lifeform was dominated by Coral Foliose (62.56%), other than that it was identified as Coral Encrusting, Acropora Branching, Coral Branching, Coral Massive, Coral Mushroom, and Coral Submassive. Observations identified 9 family and 15 genera with excellent hard coral cover percentage (82%). Coral cover percentage others consisting of abiotic (4.11%), algae (0.85%), dead coral with algae (4.41%), soft coral (3.31%), sponge (2.27%), others (3.05%). Marine protected areas are prohibited areas for tourism and fisheries, nevertheless, with a high percentage of coral cover, Tidung Island MPA can be a spawning ground, feeding ground, nursery ground, thus will creating new fishing grounds which indirectly has an impact on improving the community economy from fish catches.

Rapid climate change due to anthropogenic greenhouse gas emissions is pushing corals to and past their physiological limits, while their microbiome is being pressed towards dysbiosis. Microbes greatly influence the health and functioning of corals, but thermal anomalies that cause bleaching can affect certain taxa of the host-associated prokaryote and Symbiodiniaceae communities, leading corals towards a disease-prone state. In some coral species, however, even significant thermal stress may not result in visible signs of bleaching. Whether changes in the coral microbiome occur in these resilient species during temperature anomalies is not well described. In the present study, we tagged, visually assessed and sampled 10 colonies of the branching coral Pocillopora acuta on a fringing reef off Orpheus Island in the central Great Barrier Reef for 1 yr, of which the summer coincided with the 2016 mass-bleaching event. No visible signs of bleaching were observed in any of the 10 colonies throughout the study period, despite experiencing two degree heating weeks of thermal stress and observations of bleaching in other coral species on the same reef. Metabarcoding based on the Symbiodiniaceae ITS2 rDNA spacer and the bacterial 16S rRNA gene provided evidence for stability of the overall microbial community structure, although the bacterial community showed increases in a number of potentially beneficial taxa, such as diazotrophs, during the thermal stress event. These findings suggest some flexibility in the microbiome to adjust to higher than average temperatures without disrupting microbiome stability, perhaps contributing to the thermal resilience of P. acuta.

Photographic application of the Coral Health Chart in turbid environments: The efficiency of image enhancement and restoration methods