Coral Growth Research Articles

Diversity analysis of moray eel (muraenidae) on artificial reef structure in mengiat beach, Nusa Dua, Bali

Optimal coral growth has a positive impact on increasing biodiversity. This can be observed through the increase in the number of marine species as the transplanted coral reefs age. One natural indicator in coastal ecosystems is the presence of moray eels. Within the coral reef ecosystem, the diversity of moray eels as natural predators belonging to the category of reef fish can serve as an indication of a healthy and balanced ecosystem. The method used in this research is visual counting or visual observation of several species of marine eels on three different major installed reef star media, as part of coral reef restoration efforts. The data collection locations include three points of reef star media installation: BTN, Coral Garden, and Cluster 5. The water conditions in these locations, such as salinity, temperature, pH, and conductivity, indicate the adequate quality to support coral reef restoration efforts. In this study, five species of marine eels frequently encountered in the three data collection locations identified as: Echidna nebulosa, Gymnothorax thyrsoideus, Gymnothorax fimbriatus, Gymnothorax pictus, and Gymnothorax richardsonii. The highest abundance and diversity were found in Coral Garden, followed by Cluster 5, with BTN being the lowest.

Study of the sea urchins (echinoidea) influence on the coral reef communities in the Nusa Dua Bali conservation area

Coral reef ecosystems are crucial for marine ecosystems as they support various other marine organisms. Sea urchins, such as Diadema setosum and Echinometra mathaei influence the coral reef communities by consuming algae that disrupt coral growth. This study aims to determine reef star coral media quantity, identify the dominant coral species at three points (BTN, Coral Garden, and Cluster 5) in Nusa Dua Beach, and assess the influence of sea urchins on coral reefs. The sampling method used was Purposive sampling, and visual observations which were conducted from June 27 to June 30, 2022. Results showed the varying sea urchin populations, with Acropora sp. and Pocillopora sp. dominating at BTN, Acropora sp. and Pectinia sp. at Coral Garden, and Acropora sp. at Cluster 5. The findings suggest that sea urchins play a key role in maintaining coral reefs by consuming macroalgae and supporting coral survival.

Effective Techniques for the Feeding and <em>Ex Situ</em> Culture of a Brooding Scleractinian Coral, <em>Pocillopora acuta</em>

Climate change is affecting the survival, growth, and recruitment of corals globally, with large-scale shifts in abundance and community composition expected in reef ecosystems over the next several decades. Recognition of this reef degradation has prompted a range of novel research- and restoration-based active interventions. Ex situ aquaculture can play a supporting role through the establishment of robust coral culture protocols (e.g., to improve health and reproduction in long-term experiments) and through the provision of a consistent broodstock supply (e.g., for use in restoration projects). Here, simple techniques for the feeding and ex situ culture of brooding scleractinian corals are outlined using the common and well-studied coral, Pocillopora acuta, as an example. To demonstrate this approach, coral colonies were exposed to different temperatures (24 °C vs. 28 °C) and feeding treatments (fed vs. unfed) and the reproductive output and timing, as well as the feasibility of feeding Artemia nauplii to corals at both temperatures, was compared. Reproductive output showed high variation across colonies, with differing trends observed between the temperature treatments; at 24 °C, fed colonies produced more larvae than unfed colonies, but the opposite was found in colonies cultured at 28 °C. All colonies reproduced before the full moon, and differences in reproductive timing were only found between unfed colonies in the 28 °C treatment and fed colonies in the 24 °C treatment (mean lunar day of reproduction ± standard deviation: 6.5 ± 2.5 and 11.1 ± 2.6, respectively). The coral colonies fed efficiently on Artemia nauplii at both treatment temperatures. These proposed feeding and culture techniques focus on the reduction of coral stress and the promotion of reproductive longevity in a cost-effective and customizable manner, with versatile applicability in both flow-through and recirculating aquaculture systems.

Use of predator exclusion cages to enhance Orbicella faveolata micro-fragment survivorship and growth during restoration

As coral reefs face increasing threats from a variety of stressors, coral restoration has become an important tool to aid coral populations. A novel strategy for restoring boulder corals is microfragmentation, which may enhance coral growth by at least five times, depending on species and conditions. However, mortality rates are still significant during the early weeks after transplanting microfragments to impacted areas. We examined the effects of predation after transplanting fragments by caging Orbicella faveolata microfragments and testing if field survival rates would increase after an acclimation period. We tracked the health and growth of ten genotypes across different acclimation periods from a control group of no acclimation (0 months) to full acclimation (4 months). After four months, we presented a mix of acclimated and unacclimated corals to reef predators. Coral survivorship was highest in acclimation cages (near 100%) compared to the field (p < 0.001), with significant growth differences across genotypes (p < 0.001). Microfragments also grew more in acclimation cages (p < 0.001), with rates slowing down in the first two months after being planted into the substrate. Microfragments that had been acclimated for longer than one month also showed comparatively higher survival rates, further supporting the importance of acclimation during restoration. These results suggest caging fragments boost coral survival during initial stages of restoration by > 50% and increase the persistence of transplanted fragments. Results also highlight the importance of identifying and prioritizing genotypes with high survival and growth rates. Beyond coral restoration, results demonstrate the possible negative ecological effects of corallivores, particularly parrotfishes, on recent transplants of fragments.

The success of ornamental coral propagation in Banyuwangi East Java, Indonesia: observation of different depths and species

Ornamental corals have become the main attention objects for many hobbyists and have already become a source for foreign exchange in developing countries. Through ornamental coral propagation, the continuity of ornamental coral trade can be guaranteed and the level of damage is very limited. The propagation technique has been developed by ornamental coral exporters in several locations in Indonesia. This paper has two main objectives: a) to determine the site suitability of ornamental coral propagation locations and b) to provide a detailed description of the development and progress of ornamental coral propagation in Indonesia with first-hand information from 14 companies. The present study showed that the highest growth rate was found on branched specimens of E. glabrescens (2.50 cm) after 5 months, and the lowest growth rate was found on branched specimens of E. paraancora (0.42 cm). Corals with larger branches or with two or three branches of E. glabrescens and E. paraancora have a low mortality and increased the number of branches to three to four branches after 5 months. Small colonies also survive with a mortality of 20%. The cultured corals can grow optimally and have exotic colors when placed at different depths. Best coral growth was obtained from fast-growing coral species at a shallow depth (<10 m). While medium depth (10–15 m) was suitable for corals with moderate growth rates, the deeper depths (> 15 m) were characterized by bright-colored corals with slow-growing rates. Color quality and growth of corals are closely related to some supporting factors such as the suitability of locations that have different physical, biological, and chemical factors in different depths and thus follow different requirements among coral species. Location choices determine the success of coral cultivation both for ornamental and restoration purposes. These results are valuable background information for traded ornamental corals that can be utilized by propagators.

Integrative taxonomy, larval biology and functional morphology of the little known gall-forming coral endoparasite Petrarca (Thecostraca: Ascothoracida)

Abstract Petrarca is an ascothoracidan endoparasite in scleratinian dendrophyllid corals. Petrarca can stimulate coral growth, forming a gall chamber to house itself inside the coral skeleton. The diversity, molecular phylogeny and feeding ecology of Petrarca are understudied. This is the first study of Petrarca to be based on light and scanning electron microscopy to document the fine-scale external and functional morphology of its trophi and other structures. A combined molecular and morphological approach revealed at least four closely related species of Petrarca, P. goanna, P. morula, Petrarca nozawai sp. nov. and Petrarca rubus sp. nov. in Turbinaria and Astreopora corals in Asia. Carapace shape and fine morphology, ultrastructure of the antennular aesthetasc, morphological characteristics of the trophi and the shape and size of the penis rami are diagnostic characters. Several morphological characters, which are all probably synapomorphies, have been proposed to distinguish the genus Petrarca from other Ascothoracida. Mouthparts morphology of Petrarca are developed for cutting and chewing, rather than for piercing and sucking as in many other Ascothoracida. The external surface of the carapace of Petrarca is ornamented with densely packed secretory papillae used putatively for the chemical dissolution of the substrate necessary for the formation of the gall chamber.

Testing the effectiveness of natural and artificial substrates for coral reef restoration at Isla Isabel National Park, Mexico

Introduction: The branching coral Pocillopora is the main reef-building species in the Eastern Tropical Pacific (ETP) region. However, their populations have been threatened due to the intense effect of thermal-stress events in the last three decades. As a mitigating response, active restoration strategies have been developed. However, it has not been possible to establish specific protocols along the ETP’s reefs.
 Objective: To evaluate the efficiency of two different substrates (natural vs. artificial), through coral growth comparison (extension rate and tissue area) in three Pocillopora coral morphospecies within a year.
 Methods: Coral growth was estimated by two techniques: extension rate and tissue area of P. cf. verrucosa, P. cf. capitata, and P. cf. damicornis every three months during a year.
 Results: The extension rate and superficial area growth vary among the coral morphospecies P. cf. verrucosa (16.33 mm yr-1 and 168.49 mm2 yr-1), P. cf. capitata (16.25 mm yr-1 and 176.83 mm2 yr-1), and P. cf. damicornis (12.38 mm yr-1 and 87.62 mm2 yr-1). The data reveals that substrate type did not affect Pocillopora growth, yet there was an effect caused by seasonal changes.
 Conclusions: This study demonstrates that coral restoration can be implemented using both natural and artificial substrata, with no differences in coral growth. We recommend the implementation of coral reef restoration programs, highlighting the importance of initiate during the warm season due to optimal growth performance of P. cf. verrucosa and P. cf capitata species, which improves the effectiveness of management actions in Isla Isabel National Park.

Spatio-temporal variation in the growth of coral fragments of opportunity in the Eastern Tropical Pacific: implications for coral reef restoration

Introduction: Coral- reef communities are considered one of the most biodiverse, but also most threatened, marine ecosystems, and the accelerating loss of habitat over the past decades warrants active intervention. 
 Objective: The present study demonstrates the successful implementation of a low-impact restoration technique in three Central Mexican Pacific degraded coral communities, using a protocol based on natural fragmentation (“fragments of opportunity”) of the branching coral Pocillopora spp., considered the most abundant and primary carbonate-producing coral species of the Eastern Tropical Pacific. 
 Methods: The restoration program was implemented in two offshore and one inshore coraline areas. The relationships between seawater temperature and coral survival, growth, and attachment rate were assessed over one year, with 183 fragments monitored each month. 
 Results: The mean coral growth rate was 3.3 ± 0.1 mm mo-1, with annual growth rates in length and width of 39.9 ± 14.2 and 36.5 ± 19.5 mm yr-1, respectively. Self-attachment efficiency was 78 % and the survival rate was high (84 %). The growth rate differed significantly among reefs. 
 Conclusions: Upon monitoring directly fragmented corals over a year, growth rates were deemed high enough to merit active restoration in the region. However, our data show that structural and abiotic differences and seasonal variability must be considered overall in successful long-term coral community restoration initiatives in the eastern Pacific region.

Demographic and population response of the threatened coral Acropora cervicornis (Scleractinia, Acroporidae) to fireworm corallivory

Introduction: The fireworm Hermodice carunculata is a widespread polychaete that can prey upon many coral species. However, few studies have examined the effect of fireworm predation on coral demographics during non-outbreak periods. 
 Objective: To determine whether predation by H. carunculata compromised the growth, survival, and population performance of the threatened coral Acropora cervicornis. 
 Methods: Nursery-reared coral fragments (n = 99) were fixed to the bottom of Punta Melones reef in the Island Municipality of Culebra, Puerto Rico. Predation activity and its demographic consequences on coral outplants were assessed from December 2020 to August 2022. Susceptibility to predation was compared between colonies collected directly from the reef and those originating from outside sources (e.g., coral nurseries). With the demographic data, simple size-based population matrix models were developed to 1) examine whether fireworm predation led to a significant decline in population growth rate (λ), 2) determine the demographic transition(s) that contribute the most to λ, and 3) determining the demographic transition(s) that accounted for differences in λ when comparing scenarios that considered either only predated colonies or both predated and non-predated outplants. 
 Results: Predation increased over time, being more frequently observed in the area with the highest topographic relief and on colonies foreign to the study site. Outplants that were partially consumed grew significantly slower than non-predated colonies; however, predation did not threaten their survival. The likelihood of being attacked by the fireworm increased with branching complexity. The estimated λ for a scenario considering only those predated colonies was 0.99, whereas, for a scenario where both predated and non-predated colonies were considered, λ was 0.91. Population growth, under both scenarios, was mainly influenced by the probability of a large colony surviving and remaining at the largest size. 
 Conclusions: Although predation can negatively impact coral growth, the relatively high survival rate of predated colonies compensates for the adverse effects. Since survival is the demographic transition that contributes most to population growth, it could be concluded that under a non-outbreak scenario, fireworm predation may not be the primary cause of A. cervicornis population decline.

Change in the composition of fauna associated with Pocillopora spp. (Scleractinia, Pocilloporidae) following transplantation

Introduction: Associated fauna comprises most of the diversity of a coral reef and performs ecological functions essential to the reef’s survival. Since Pocillopora corals harbor an important associated fauna, reef restoration efforts are underway in Golfo Dulce, Costa Rica, to preserve them. 
 Objective: To describe changes in cryptofauna and fish communities associated with Pocillopora colonies to better understand the succession of associated fauna following transplantation. 
 Methods: An experimental patch of 30 nursery-grown Pocillopora colonies and a control patch containing no colonies were monitored for 8 months following transplantation in Golfo Dulce. Cryptofauna within each colony and fish within each patch were observed using SCUBA to quantify temporal changes in the abundance, diversity, and community structure of the colonies. 
 Results: The abundance and diversity of cryptofauna increased throughout the experiment. Obligate symbiont decapods were the most abundant. The composition of the community of cryptofauna differed between periods with fish in the genus Scarus as the main contributor to any differences. The increase in abundance and diversity of cryptofauna and fish may reflect coral growth and the corresponding availability of space and environmental complexity in the experimental patch. The composition of the cryptofauna communities was generally consistent with other studies. However, a high density of decapod symbionts could suggest that without other Pocillopora colonies to move to, they may crowd together despite their aggressive tendencies. 
 Conclusions: Pocillopora colonies will experience an increase in symbionts that could positively contribute to the health and survival of the coral following transplantation.

Active restoration efforts in the Central Mexican Pacific as a strategy for coral reef recovery

Introduction: The 1997-98 El Niño event caused massive coral bleaching and mortality in the Central Mexican Pacific (CMP). Punta de Mita alone used to harbor more than 30 % of the coral coverage in this region, with a mono-specific Pocillopora coverage. The 1997-1998 ENSO event caused massive coral mortality reducing live coral coverage to < 5 %. Despite being considered a coral region unlikely to recover, recent restoration efforts have been implemented to rehabilitate the coral community.
 Objective: To assess coral recovery by analyzing the coral growth and survival rates of branching Pocillopora species at Punta de Mita.
 Methods: Healthy coral fragments of opportunity were re-attached to the natural substrata using zip ties and measured considering their growth in terms of maximum length and width (cm) to determine their annual extension rates.
 Results: After 50 weeks, corals duplicated their size, with a mean growth of ~ 4 cm year-1. After 100 weeks (2 years), corals triplicated their size, increasing on average 8–9 cm in each diameter.
 Conclusions: Successful coral reef restoration activities in the Central Mexican Pacific are the result of Pocillopora’s physiological processes, such as fast growth rates, and recent life-history traits, like the ability to cope with thermal anomalies, which enable them to thrive in a dynamic region severely affected by natural and anthropogenic perturbations. Indeed, a region considered unlikely to recover has regained its live coral cover from < 5 % in 1998 up to 15 % in 20 years. This demonstrates the importance of assisting natural coral recovery with restoration efforts, especially in coral locations that, despite environmental perturbations, have proven to be resilient and may become coral refugia areas under the current climate change scenario.

Coral growth over the past 550 years in the central South China Sea linked to monsoon- and seabird-induced nutrient stress

Coral growth over the past 550 years in the central South China Sea linked to monsoon- and seabird-induced nutrient stress

Lessons learned implementing mineral accretion and coral gardening at Agincourt Reef, Great Barrier Reef

SummaryThe health and diversity of coral reefs are critically important to the stability and value of the marine tourism industry. Declines in coral reef health through climate change impacts and cyclones, and associated media coverage, have impacted tourism visitation. In January 2018, a major change in Australian Government policy included a Reef Restoration and Adaptation Program to investigate the best science and technology options for helping the Great Barrier Reef recover and adapt to the changing environment. We report on a trial of two intervention methods, mineral accretion and coral gardening, to improve hard coral recovery at a popular site on the Great Barrier Reef. We installed six artificial reef substrates onto which an equal number of coral fragments of seven species were transplanted over the course of two years. During this time, three of the six treatments were connected to a low‐voltage power source to encourage mineral accretion and enhance coral growth. Electrolysis resulted in substantial mineral accretion on the steel substrate, however, the technology had no positive effect on the survival or growth of transplanted coral colonies. After 13 months, a second round of transplanted coral fragments was undertaken, and the electrolysis was discontinued. Over a four‐year period, mean live coral cover increased significantly in both treatment locations, from 1.7% and 0% to 80.8% and 75.8%, respectively. Control locations increased insignificantly from a mean of 5% to 14.2%. The mineral accretion technology proved technically challenging and did not support the growth or health of transplanted corals, providing no evidence to support the use of mineral accretion technology for this purpose. The technology may, however, have applications in the creation of new, solid substrates and for initial rubble stabilisation efforts. These results demonstrate the effective use of artificial substrates in conjunction with coral gardening techniques for the recovery of hard coral at degraded tourism sites.

Light limitation and coral mortality in urbanised reef communities due to sea-level rise

Sea-level rise (SLR) is expected to elevate the depth of seawater above shallow coral reefs, reducing light availability to the benthic environment, and impacting the survival and growth of corals especially on turbid reefs. However, the extent of impact at the deepest reef zones remains unknown. Coral growth could continue to keep pace above light thresholds as sea level rises, but mortality due to light limitation could vary between localities and local conditions. Here, we examine possible outcomes of corals inhabiting Singapore's turbid reefs in the years 2050 and 2100 by characterising their depth distributions and predicting potential mortality rates based on SLR projections. Our results reveal that in 2050, under both RCP4.5 and RCP8.5 sea level projections, up to 6.24% of colonies could face mortality if their growth is not considered. In 2100, up to 7.68% mortality under RCP4.5 and up to 10.7% mortality under RCP8.5 are predicted. When coral linear extension is considered, in 2050, under both RCP4.5 and RCP8.5 sea level projections, up to 1.03% of colonies could face mortality. In 2100, up to 0.87% mortality under RCP4.5 and up to 1.84% mortality under RCP8.5 are predicted. Species-specific losses could amount to 20% of colonies primarily at the deepest zones. The most vulnerable species exhibit a depth distribution with most colonies situated at the deeper parts of their depth ranges. Our findings suggest that sea-level rise may potentially result in the loss of coral cover for some species, but overall mortality could be low.

Title: Fungal Language-Based Interface Between a Wire Wound Resistor in a Biocrete Marine Fungus-Based Substrate With All Species of Fungus, Interfaced to a PSoC MCU and Network for Study of Fungal Language-Based Ca Deposition and Electric Field Induced Coral Growth

Title: Fungal Language-Based Interface Between a Wire Wound Resistor in a Biocrete Marine Fungus-Based Substrate With All Species of Fungus, Interfaced to a PSoC MCU and Network for Study of Fungal Language-Based Ca Deposition and Electric Field Induced Coral Growth

Carbonate budgets in Lakshadweep Archipelago bear the signature of local impacts and global climate disturbances

Predicted sea-level rise and increased storm frequency caused by climate change drastically threaten low-lying inhabited coral atolls. Coral reef frameworks are the atolls’ primary defence from these changes. The growth and integrity of these frameworks is reflected in their carbonate budgets, a dynamic balance between biogenic accretion through coral growth and erosional forces, both of which are affected by factors acting at different spatial scales. We explored how carbonate budgets, estimated using the ReefBudget methodology, vary between three inhabited atolls that face differing anthropogenic stressors in the Lakshadweep Archipelago in the Northern Indian Ocean. We surveyed ten reefs, at two depths each, across the three islands. Overall, net carbonate budgets of reefs across all atolls were below optimal production rates needed to continue protecting shorelines (5 G measured on healthy reefs). This was a result of repeated mass bleaching events as well as local impacts. Carbonate production was influenced by a recent mass bleaching event in 2016 and a cyclone in 2018, and varied between depths and exposures, potentially due to differential recovery and mortality dynamics. Erosional processes were locally mediated with both urchin and parrotfish density showing large differences between islands, possibly linked to nutrient outflow and fishing intensity. We also find that by the year 2100, a large proportion of shallow sites will experience an increase in water depth above half a metre under moderate and high emissions scenarios, but none will breach this threshold under a low emissions scenario. Our results show that patterns of carbonate production were largely mediated by the history of global/regional disturbances, while erosional rates were much more dependent on local factors.

Meso-mechanical anisotropy and fracture evolution of reef limestones from the Maldives Islands and the South China Sea

Reef limestone is a biogenic sedimentary rock widely distributed in coral reef areas, acting as an important foundation for coast construction. Due to its special biogenic origin, reef limestone is different from conventional rocks both in terms of rock structure and mechanical properties. In this study, mesoscale uniaxial compression experiments with five different loading directions were conducted on two kinds of reef limestones from the Maldives Islands and the South China Sea, respectively. The real-time high-resolution videos and images of failure processes were recorded simultaneously to investigate the fracture evolution and fracture surface roughness of reef limestones. It demonstrated that the reef limestones belonged to extremely soft to soft rocks, and their uniaxial compressive strength (UCS) values fluctuated with high discreteness. The mesoscale mechanical properties of reef limestones were highly anisotropic and mainly controlled by pore structure. The occurrence of dissolution pores in reef limestone tended to intensify mechanical anisotropy. With the integration of the fracture initiation and propagation features of reef limestones, it is supposed that the intrinsic mechanism of anisotropy was probably attributed to the differences in coral growth direction and dissolution. Furthermore, the quantified fracture surface roughness was revealed to have a good consistency with density and UCS for the reef limestones from the South China Sea. The findings are helpful for providing theoretical and experimental references for engineering construction in coral reef areas.

Taxonomical and functional analyses of epifaunal polychaetes associated with Mussismilia spp.: the effects of coral growth morphology.

The increasing habitat heterogeneity and complexity shows positive effects over different communities, leading to environmental diversity, access to resources and reducing the effectiveness of predation. In the present study we evaluate the structural and functional patterns of polychaete assemblages of three Mussismilia species with different coral morphology. Mussismilia hispida has a massive growth pattern; M. braziliensis also is a massive coral but forms a crevice in the corallum base; and M. harttii has a meandroid pattern. Ten individuals of the three Mussismilia species were sampled in two reefs in the Todos-os-Santos Bay, and we analyzed the differences in richness and abundance of polychaete species and the functional diversity metrics: Rao's quadratic entropy, functional dispersion, functional evenness, number of functional groups and functional richness, among Mussismilia species. Two-way ANOVA with permutations showed significant differences for polychaete abundances and richness among Mussismilia species (higher values for M. harttii), but no differences were recorded when compared between the two coral reef areas studied. There was no statistical difference among coral species or between reefs in relation to the functional diversity components influenced by abundance, such as Rao quadratic entropy, functional dispersion, and functional evenness. Some individual polychaete functional traits presented differences among Mussismilia species, and that also helped us to build a picture about the effect of different growth structures over functional aspects of polychaete assemblages. Thus, the taxonomical approach, the analysis of individual functional traits and the functional diversity metrics are fundamental tools to characterize the assemblage of organisms associated with corals.

Multiple Factors Driving Carbonate System in Subtropical Coral Community Environments along Dapeng Peninsula, South China Sea

Coral reef ecosystems have extremely high primary productivity and play an important role in the marine carbon cycle. However, due to the high carbon metabolism efficiency of coral communities, little is known about the carbon sink–source properties of coral reefs. In November 2022, in situ field investigations coupled with incubation experiments were conducted in typical subtropical coral reef waters, i.e., Yangmeikeng Sea Area (Area I) and Dalu Bay (Area Ⅱ), to explore the dynamics of the carbonate system and its controlling factors. The results revealed that the carbonate parameters had high variability, comprehensively forced by various physical and biochemical processes. Overall, Areas I and Ⅱ were net sinks of atmospheric CO2, with net uptake fluxes of 1.66 ± 0.40 and 0.99 ± 0.08 mmol C m−2 day−1, respectively. The aragonite saturation state (ΩA), 3.04–3.87, was within the range adequate for growth of tropical shallow-water scleractinian corals. Inorganic carbon budget results indicated that photosynthesis and microbial respiration were the main factors affecting the dynamics of carbonate systems in the whole study area. However, focusing on the reef areas, coral metabolism was also a key factor affecting the carbonate system in seawater (especially in Area I) and its contribution accounted for 28.9–153.3% of the microbial respiration. This study highlighted that metabolism of coral communities could significantly affect the seawater carbonate system, which is of great significance in the context of the current process of ocean acidification.

Pertumbuhan Dan Laju Pertumbuhan Karang Stylophora pistillata Dengan Jenis Substrat Berbeda Yang Ditanam Pada Tiga Kedalaman Di Pantai Serangan

ABSTRACT
 Coral transplantation is the activity of cultivating/breeding coral colonies using the fragmentation method. This activity is carried out as an effort to prevent damage to the coral reef ecosystem so the existence of coral reefs and the species that live around them can be maintained. Several techniques have been used in transplant activities, but knowledge of the right transplantation technique is needed so the activities can run well. This research aims to determine the effect of different types of substrates used on the growth and growth rate of coral Stylophora pistillata transplanted at three depths at Serangan Beach, so the transplantation activities run effectively and efficiently. The research was carried out for four months from November 2021 to March 2022 through field research using the Randomized Block Design method with two factors, namely the type of substrate used (cement and sand; bricks) and different depths (1 m, 3 m and 5 m). This study used 90 fragments of Stylophora pistillata. The results of the analysis showed that the different types of substrate gave significantly different effects on growth and growth rate at a depth of 1 m. However, at the other two depths, the effect of different substrate types were not differed significantly. The best coral growth and growth rate was seen in corals using cement and sand substrates transplanted at a depth of 1 m with growth of 3,29 cm (height) and 3,93 cm (width), while the highest growth rate was 0,82 cm/ month. (height) and 0,98 cm/month (width).