More than a decade ago, a new mitochondrial Open Reading Frame (mtORF) was discovered in corals of the family Pocilloporidae, which turn out to be an effective barcode gene for these corals. However, its function remains unknown. Recently, this gene revealed the existence of a hybrid Stylophora lineage (RS_LinA) inhabiting in sympatry along the environmental gradient of the Red Sea (18.5°C to 33.9°C) with its parental species (RS_LinB). Furthermore, in RS_LinB, the mtORF uncovered phylogeographic patterns that were strongly correlated with environmental variations. This was similar to the patterns unraveled by hsp70, suggesting that mtORF too might be involved in thermal adaptation. Here we used computational approaches to characterize the mtORF and to identify its potential role. Results showed that this gene encodes a transmembrane protein (0.97<P< 1.00) involved in transport (0.80<P< 0.87), regulation of metabolic processes (0.70<P<0.85), and likely in the cell-surface receptor signaling pathway (0.56<P<0.80). Predicted protein functions differed among Stylophora lineages and interestingly, in RS_LinB only, the protein was intrinsically disordered and displayed domains involved in cellular complexes and stress response (0.0001< P <0.001). These characteristics, exclusive of an endemic lineage adapted to extreme environmental fluctuations, support a role of the mtORF in stress response, speciation and adaptation.

Coral reefs are one of the most productive yet vulnerable ecosystems on Earth. An important step in understanding the functioning of coral communities is studying the environmental impact on the state of reefs. The present study aimed to assess the impacts of the water temperature, precipitation, wave action and population density on the seasonal bleaching, partial and complete mortality of shallow-water branching corals of Pocillopora verrucosa species complex. The present study was conducted at the Dam Bay research station (Nha Trang Bay) from 26 April 2020 to 2 April 2021. Throughout the study the percentage of bleached coral colonies varied from 1 to 41.5% with two peaks, in autumn (October) and spring (April). Rates of the development of partial mortality varied from 0 to 10%, with a pronounced peak in December. At the end of the experiment, the percentage of coral colonies suffering from partial mortality reached 47%. Only 4,5% of experimental colonies died by the end of the study. Analysis revealed that water temperature and partial mortality are the drivers of bleaching, while wave action, temperature and bleaching are the factors with a significant impact on partial mortality. In the present study, the main cause of coral death was the development of algal fouling at the sites of colony lesions, which gradually spread over the entire surface of the colony. We showed also that the impact of individual stress on mortality prevailed over the impact of seasonal bleaching and partial mortality events.

Temperature and pH can expedite the ability of pathogens to cause diseases in cold-water corals (CWCs). The present study employed a combination of histology and polymerase chain reaction diagnostic techniques to investigate potential pathogens present in the CWCs Lophelia pertusa and Madrepora oculata in the Porcupine Bank Canyon (PBC), NE Atlantic. No pathogen was observed in the Madrepora samples. Neither histology nor standard PCR detected Vibrio spp. in the corals, although using Illumina technology, V. shilonii was observed in some L. pertusa samples in low abundances (0.22%). A Rickettsiales-like organisms (RLOs) occurred at a prevalence of 8.0% and at a low infection intensity of 1 - 4. Lophelia showed a few RLOs infection from the PBC canyon head (2.7%) and high infections in the south branch (5.3%). Similarly, unidentified cells observed in L. pertusa from the south branch (4.0%) were more common than those found in the canyon head (1.3%) with a prevalence of 5.3%. Although the route of pathogen infection is unclear, a likely mode of entry could be associated with particulate availability and the feeding strategies of the scleractinian corals. This suggest that L. pertusa invests energy into an enhanced immune function and reduced susceptibility to global pathogens despite a changing ocean environment.

Coastal resources in Lian, Batangas, have undergone significant degradation due to a combination of human activities and natural factors, including sea-level rise, changes in sea-surface temperature, fluctuations in rainfall, increased storm frequency, and sedimentation. This has led to adverse effects on key ecosystems such as corals, mangroves, and seagrasses. To assess the extent of climate change hazards on these coastal resources, a Vulnerability Assessment was conducted in the municipality of Lian, Batangas. The assessment employed a combination of the Coastal Integrity Vulnerability Assessment Toolkit (CIVAT) and Integrated Coastal Sensitivity, Exposure, and Adaptive Capacity to Climate Change (ICSEA-C) guidelines. Additionally, the analysis incorporated detailed mapping using Light Detection and Ranging (LiDAR) data for mangroves and LandSat 8 imagery for corals and seagrasses. The findings at the municipal scale revealed that a staggering 90% of mangroves in Lian, Batangas, were highly vulnerable. This vulnerability was attributed to a high score in intrinsic characteristics and a low adaptive capacity. Similarly, a majority of seagrasses in the area were classified as medium and highly vulnerable at the municipal level. Only 10–20% of seagrasses received low to medium vulnerability scores. Shockingly, almost 100% of the coral reefs in Lian, Batangas, were deemed highly vulnerable, indicating a critical threat to this crucial marine ecosystem.