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Artificial transplantation of corals is a common method used to restore damaged or unhealthy coral assemblages. Though a number of studies have successfully transplanted coral fragments, there is no general consensus on the type of substratum to be used. The present study focused on the growth and survivorship of Montipora capitata (rice coral) and Porites lobata (lobe coral) fragments, which were transplanted onto different natural and synthetic substrata. No significant differences in coenosarc tissue growth or survivorship were observed between the species. Measurements after 184 days of growth, found transplant growth to be significantly higher on rhyolite breccia and amorphous coral skeletons than on black ʻAʻā lava. Nevertheless, no significant differences were observed between any of the other substrata. After 365 days of growth, survivorship was also observed to not be significantly different between substrata; with the only exception of being lower on glass substratum. It is hypothesized that success in a coral reef restoration project is largely determined by the actual coral fragmentation and transplantation process; as no distinct substratum affinity was observed for M. capitata and P. lobata transplants. [ABSTRACT FROM AUTHOR]

Hermatypic corals are an important sessile group in the benthic structure of tropical coral reef communities. Many organisms, in response to the environmental conditions, have developed different strategies of growth by modifying their morphologies and reproduction mode, as is the case of free-living colonies called coralliths. So far, important parameters such as calcification, growth rates and their relation with biotic and abiotic factors on coralliths have not been described. This study represents the first record of a corallith form of Porites lobata and provides information on its sclerochronology. Coral growth parameters of different coralliths were compared by measuring extension rate (cm y − 1 ), skeletal density (g cm − 3 ), calcification rate (g cm − 2 y − 1 ), average age (yr) and sphericity (S). The influence of the environment on corallith growth was assessed using water temperature as an abiotic factor and bioturbation by fish as a biotic factor. Analysis of annual density bands using X-ray densitometry provided a mean extension rate of 0.47 ± 0.23 cm y − 1 , skeletal density of 1.08 ± 0.14 g cm − 3 , and calcification rate of 0.51 ± 0.26 g cm − 2 y − 1 . The results reveal differences in growth parameters between coralliths including a strong relationship of calcification rate with seawater temperature. In addition, direct and indirect bioturbations promoted the colony rotation resulting in a hemispherical form. Hence, the evidence suggests that scleractinian corals have developed an important growth strategy that allows the species to form new colonies and maintain successful coral reef communities through free-living corallith growth. [ABSTRACT FROM AUTHOR]

Sewage pollution threatens the health of coastal populations and ecosystems, including coral reefs. We investigated spatial patterns of sewage pollution in Puako, Hawaii using enterococci concentrations and δ 15 N Ulva fasciata macroalgal bioassays to assess relationships with the coral disease Porites lobata growth anomalies (PGAs). PGA severity and enterococci concentrations were high, spatially variable, and positively related. Bioassay algal δ 15 N showed low sewage pollution at the reef edge while high values of resident algae indicated sewage pollution nearshore. Neither δ 15 N metric predicted PGA measures, though bioassay δ 15 N was negatively related to coral cover. Furthermore, PGA prevalence was much higher than previously recorded in Hawaii and the greater Indo-Pacific, highlighting Puako as an area of concern. Although further work is needed to resolve the relationship between sewage pollution and coral cover and disease, these results implicate sewage pollution as a contributor to diminished reef health. [ABSTRACT FROM AUTHOR]

Dietary specialists tend to be less susceptible to the effects of chemical defenses produced by their prey compared to generalist predators that feed upon a broader range of prey species. While many researchers have investigated the ability of insects to detoxify dietary allelochemicals, little research has been conducted in marine ecosystems. We investigated metabolic detoxification pathways in three species of butterflyfishes: the hard coral specialist feeder, Chaetodon multicinctus , and two generalist feeders, Chaetodon auriga and Chaetodon kleinii . Each species was fed tissue homogenate of the hard coral Porites lobata or the feeding deterrent compound homarine (found in the coral extract), and the expression and catalytic activity of cytochrome P450 (CYP) 3A-like and CYP2-like enzymes were examined after one-week of treatment. The P. lobata homogenate significantly induced content and catalytic activity of CYP2-like and CYP3A-like forms, by 2–3 fold and by 3–9 fold, respectively, in C. multicinctus . Homarine caused a significant decrease of CYP2-like and CYP3A-like proteins at the high dose in C. kleinii and 60–80% mortality in that species. Homarine also induced CYP3A-like content by 3-fold and catalytic activity by 2-fold in C. auriga , while causing non-monotonic increases in CYP2-like and CYP3A-like catalytic activity in C. multicinctus . Our results indicate that dietary exposure to coral homogenates and the feeding deterrent constituent within these homogenates caused species-specific modulation of detoxification enzymes consistent with the prey selection strategies of generalist and specialist butterflyfishes. [ABSTRACT FROM AUTHOR]

Sub-seasonally resolved and replicated coral Sr/Ca time series at Clipperton Atoll (10°18′N, 109°13′W) in the eastern Pacific are assessed as a sea surface temperature (SST) proxy in this region with small seasonal SST variability. The composite coral Sr/Ca time series is a partially replicated record of three live and one sub-modern colony of Porites lobata extending back to 1874. Large inter-colony coral Sr/Ca offsets equate to relative SST differences of 0.6 to 4.3 °C and limit the ability to reconstruct absolute SST changes. Moreover, the replication method revealed a 12-year section of growth in one colony where mean Sr/Ca was anomalously low (~ 1 °C higher SST) relative to the other colonies without evidence of diagenesis or other significant skeletal alterations. The presence of this anomalous interval supports the need for multi-coral Sr/Ca replication in specific sites or regions. The Clipperton Composite Sr/Ca anomaly record is significantly coherent (r = 0.71–0.76, p < 0.001) with gridded instrumental SSTs but with larger amplitude decadal variance that appears to more accurately represent actual SST variability at Clipperton. The amplitude of the secular warming trend during the last century at Clipperton is 0.3 to 0.6 °C larger (~ twice as large) than the trend in the poorly “ground-truthed” instrumental SST records for the region. The interannual and decadal variability in Clipperton coral Sr/Ca demonstrates strong coherence to the Pacific Decadal Oscillation and the El Niño/Southern Oscillation (ENSO) with reduced ENSO variability from 1920 to late 1930s and enhanced variability in the late twentieth century. [ABSTRACT FROM AUTHOR]

Abstract: Cadmium (Cd) concentrations in coral skeleton track oceanic upwelling, which brings Cd-rich deep water to the surface. In this study we report sub-monthly measurements of [Cd]coral measured via laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) in three species of coral (Porites lobata, Pavona gigantea, and Pavona clavus) from an upwelling site in the Gulf of Panama. Although single LA tracks in all species yielded variable results, the average of multiple tracks mirrored changes in in situ seawater Cd ([Cd]sw), with an offset between peaks. In addition, [Cd]coral determined by LA-ICP-MS and isotope dilution (ID)-ICP-MS was compared in P. clavus and found to be highly correlated, despite consistently lower concentrations measured using the ID method. Two 5.5-month long high-resolution P. clavus [Cd]coral records revealed that the maximum [Cd]coral values occurred after the sea surface temperature minimum, at the same time as the seawater phosphate concentration and coral P/Ca maximum, and approximately one month before peak [Cd]sw. Based on these findings we hypothesize that corals are actively taking up Cd and incorporating it into their skeleton, and that [Cd]sw only increases once Cd is no longer being rapidly removed from the water column via biological processes. After accounting for a 1-month offset between the coral and seawater [Cd] maxima, both LA- and ID-derived [Cd]coral values were significantly correlated to [Cd]sw, providing a calibration for this [Cd]sw proxy in P. clavus. A three year high-resolution P. clavus LA-[Cd]coral record demonstrated the potential of [Cd]coral to generate a high-resolution [Cd]sw record. However, due to the natural variability in high-resolution LA-ICPMS [Cd]coral values within and among coral colonies, three laser tracks per colony and at least three colonies of P. clavus need to be analyzed to produce a reliable coral [Cd]coral record. [Copyright &y& Elsevier]

Abstract: δ13C was determined at a high spatial resolution by secondary ion mass spectrometry (SIMS) across a 1year section of a modern Porites lobata coral skeleton from Hawaii. Skeletal δ13C is dominated by large oscillations of 5–7‰ that typically cover skeletal distances equivalent to periods of ∼14–40days. These variations do not reflect seawater temperature and it is unlikely that they reflect variations in the δ13C of local seawater. We observe no correlation between skeletal δ13C and the pH of the calcification fluid (estimated from previous measurements of skeletal δ11B). We conclude that either the proportion of skeletal carbon derived from metabolic CO2 is not reflected by estimated ECF pH (as the [CO2] in the overlying coral tissue varies) and/or the δ13C composition of the metabolic CO2 is highly variable. We also observe no correlation between skeletal δ13C and previous δ18O SIMS measurements. Variations in skeletal δ13C and δ18O do not have a common timing, providing no evidence that skeletal δ13C and δ18O vary in response to a single factor. This suggests that skeletal δ13C is principally driven by variations in the δ13C composition of metabolic CO2 rather than by the abundance of metabolic CO2, which would also affect skeletal δ18O. The δ13C composition of metabolic CO2 reflects the processes of photosynthesis, heterotrophic feeding and respiration in the overlying coral tissue. Corals catabolise stored lipid reserves to meet energetic demands when photosynthesis conditions are sub-optimal. Variations in the amounts and types of reserves utilised could induce changes in the δ13C composition of metabolic CO2 and the resultant skeleton which are temporally offset from skeletal δ18O records. [Copyright &y& Elsevier]

Abstract: The Pu isotopes, 239Pu and 240Pu, were determined in annually-banded skeletons of an accurately dated (1943–1999) modern coral (Porites lobata) from Guam Island to identify historical Pu sources to the tropical Northwest Pacific Ocean. Activity concentrations of 239+240Pu and 240Pu/239Pu atom ratios were determined in the dated coral bands using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). Close-in fallout from the former US Pacific Proving Grounds (PPG) in the Marshall Islands and global fallout were identified as the two main sources. The Guam site was dominated by PPG close-in fallout in the 1950s, with an average 240Pu/239Pu atom ratio of 0.315±0.005. In addition, a higher 240Pu/239Pu atom ratio (0.456±0.020) was observed that could be attributed to fallout from the “Ivy Mike” thermonuclear detonation in 1952. The atom ratio decreased in the 1960s and 1970s due to increase in the global fallout with a low 240Pu/239Pu atom ratio (∼0.18). Recent coral bands (1981–1999) are dominated by the transport of remobilised Pu, with high 240Pu/239Pu atom ratios, from the Marshall Islands to Guam Island along the North Equatorial Current (NEC). This remobilised Pu was estimated to comprise 69% of the total Pu in the recent coral bands, although its contribution was variable over time. [Copyright &y& Elsevier]

Abstract: Sr/Ca, B/Ca, Mg/Ca and δ11B were determined at high spatial resolution across ∼1year of a modern Hawaiian Porites lobata coral by secondary ion mass spectrometry (SIMS). We observe significant variations in B/Ca, Mg/Ca, Sr/Ca and δ11B over short skeletal distances (nominally equivalent to periods of <20days). This heterogeneity probably reflects variations in the composition of the extracellular calcifying fluid (ECF) from which the skeleton precipitates. Calcification site pH (total scale) was estimated from skeletal δ11B and ranged from 8.3 to 8.8 (±∼0.1) with a mean of ∼8.6. Sr/Ca and B/Ca heterogeneity is not simply correlated with calcification site pH, as might be expected if Ca-ATPase activity increases the pH and decreases the Sr/Ca and B(OH)4 −/CO3 2− ratios of the ECF. We produced a simple model of the ECF composition and the skeleton deposited from it, over a range of calcium transport and carbonate scenarios, which can account for these observed geochemical variations. The relationship between the pH and Sr/Ca of the ECF is dependent on the concentration of DIC at the calcification site. At higher DIC concentrations the ECF has a high capacity to buffer the [H+] changes induced by Ca-ATPase pumping. Conversely, at low DIC concentrations, this buffering capacity is reduced and ECF pH changes more rapidly in response to Ca-ATPase pumping. The absence of a simple correlation between ECF pH and skeletal Sr/Ca implies that calcification occurred under a range of DIC concentrations, reflecting variations in the respiration and photosynthesis of the coral and symbiotic zooxanthellate in the overlying coral tissues. Our observations have important implications for the use of coral skeletons as indicators of palaeo-ocean pH. [Copyright &y& Elsevier]

Abstract: Bleached and non-bleached fragments of three species of Hawaiian corals were exposed to enhanced and ambient concentrations of zooplankton at 1 and 6 m depth to determine the contribution of zooplankton to the coral''s daily carbon budget. The size and taxonomic grouping were recorded for every zooplankton captured and the relative input of zooplankton of different size classes was determined. The contribution of heterotrophy to animal respiration (CHAR) was calculated using an improved method that included the proportionate contribution of zooplankton from all size classes. Results show that the proportionate effects of species, depth and bleaching treatments on coral feeding rates were not significantly different between ambient and enhanced zooplankton concentrations. Corals captured the same size and assemblage of zooplankton under all evaluated conditions, and preferentially captured plankters smaller than 400 µm. Feeding rates of Porites lobata increased with depth regardless of bleaching status. Feeding rates of Porites compressa increased with depth in non-bleached corals, but not in bleached corals. Within depth, feeding rates of bleached Montipora capitata increased, P. compressa decreased and P. lobata remained unchanged relative to non-bleached fragments. Therefore, the feeding response of corals to the same disturbance may vary considerably. Calculated CHAR values show that heterotrophic carbon from zooplankton plays a much larger role in the daily carbon budget of corals than previously estimated, accounting for 46% of some coral species'' daily metabolic carbon requirements when healthy and 147% when bleached. Thus, heterotrophically acquired carbon made an important contribution to the daily carbon budget of corals under all experimental conditions. These results suggest that the relative importance of autotrophic and heterotrophic carbon to a coral''s energetic needs is mediated by a coral''s bleaching status and environment, and should be considered on a continuum, from 100% photoautotrophy to 100% heterotrophy. [Copyright &y& Elsevier]

Shallow marine sediments and fringing coral reefs of the Buyat-Ratototok district of North Sulawesi, Indonesia, are affected by submarine disposal of tailings from industrial gold mining and by small-scale gold mining using mercury amalgamation. Between-site variation in heavy metal concentrations in shallow marine sediments was partially reflected by trace element concentrations in reef coral skeletons from adjacent reefs. Corals skeletons recorded silicon, manganese, iron, copper, chromium, cobalt, antimony, thallium, and lead in different concentrations according to proximity to sources, but arsenic concentrations in corals were not significantly different among sites. Temporal analysis found that peak concentrations of arsenic and chromium generally coincided with peak concentrations of silica and/or copper, suggesting that most trace elements in the coral skeleton were incorporated into detrital siliciclastic sediments, rather than impurities within skeletal aragonite. [Copyright &y& Elsevier]

This study used non-invasive pulse-amplitude modulated (PAM) fluorometry to measure the maximum fluorescence yield (F v/F m) of two Hawaiian scleractinian coral species exposed to short-term sedimentation stress. Beach sand or harbor mud was applied to coral fragments in a flow-through aquarium system for 0–45h, and changes in F v/F m were measured as a function of sediment type and length of exposure. Corals were monitored for up to 90h to document recovery after sediment removal. Sediment deposition significantly decreased F v/F m in both species and was a function of sediment type and time. Corals that received sediment for 30h or more had the greatest reduction in yield and exhibited little recovery over the course of the experiment. Harbor mud caused a greater reduction in Porites lobata yield than beach sand, whereas both sediment types had equally deleterious effects on Montipora capitata. Colony morphology and sediment type were important factors in determining yield reduction—P. lobata minimized damage from coarse sand grains by passive sediment rejection or accumulation in depressions in the skeleton, and fluorescence yield decreased most in corals exposed to sticky harbor mud or in colonies with flattened morphologies. Species-specific differences could not be tested due to differences in colony morphology and surface area. [Copyright &y& Elsevier]

From September to November 1997, most of Indonesia was covered by a dense blanket of haze, originating from fires on Sumatra and Borneo. Specimens of Porites lobata were collected from two locations, i.e. the Riau Archipelago, south of Singapore, where the haze was most dense, and the Karimunjawa Islands, north of Central Java, where the effects were less severe. All corals exhibited strong Kinetic Isotope Effects (KIE). On plots of δ18O vs. δ13C, shifts in coral metabolism associated with the haze event could be estimated from the distance individual values are positioned from the theoretical KIE line. Skeletons of corals affected by the haze showed decreased δ13C values, perhaps produced by a shift to a more heterotrophic mode of feeding. These results suggest that wildfires and major forest fire events on tropical coastlines may be recorded in nearby corals, as could temporal variation in frequency of major fires. Moreover, information on coral metabolism may be determined by examining shifts of coral skeletal values in C–O space. [Copyright &y& Elsevier]

Competition between corals and macroalgae is frequently observed on reefs with the outcome of these interactions affecting the relative abundance of reef organisms and therefore reef health. Anthropogenic activities have resulted in increased atmospheric CO 2 levels and a subsequent rise in ocean temperatures. In addition to increasing water temperature, elevated CO 2 levels are leading to a decrease in oceanic pH (ocean acidification). These two changes have the potential to alter ecological processes within the oceans, including the outcome of competitive coral-macroalgal interactions. In our study, we explored the combined effect of temperature increase and ocean acidification on the competition between the coral Porites lobata and on the Great Barrier Reef abundant macroalga Chlorodesmis fastigiata. A temperature increase of +1 °C above present temperatures and CO 2 increase of +85 ppm were used to simulate a low end emission scenario for the mid- to late 21st century, according to the Representative Concentration Pathway 2.6 (RCP2.6). Our results revealed that the net photosynthesis of P. lobata decreased when it was in contact with C. fastigiata under ambient conditions, and that dark respiration increased under RCP2.6 conditions. The Photosynthesis to Respiration (P:R) ratios of corals as they interacted with macroalgal competitors were not significantly different between scenarios. Dark calcification rates of corals under RCP2.6 conditions, however, were negative and significantly decreased compared to ambient conditions. Light calcification rates were negatively affected by the interaction of macroalgal contact in the RCP2.6 scenario, compared to algal mimics and to coral under ambient conditions. Chlorophyll a , and protein content increased in the RCP2.6 scenario, but were not influenced by contact with the macroalga. We conclude that the coral host was negatively affected by RCP2.6 conditions, whereas the productivity of its symbionts (zooxanthellae) was enhanced. While a negative effect of the macroalga (C. fastigiata) on the coral (P. lobata) was observed for the P:R ratio under control conditions, it was not enhanced under RCP2.6 conditions. • Study investigates a common coral-macroalgal interaction under a low end emission scenario. • Light calcification is negatively influenced by an interaction of macroalgal contact and scenario. • Protein content, zooxanthellae density and Chlorophyll a were enhanced under scenario conditions. • Negative impacts of macroalgae on corals were observed, but not enhanced by scenario conditions. • More research on the impacts of climate change on the dynamics of coral-algal interactions is needed. [ABSTRACT FROM AUTHOR]