Large Coral Research Articles

Marine Reservoir Corrections for the Brazilian Northern Coast Using Modern Corals

ABSTRACTThe Abrolhos bank, in southern Bahia State (BA), is the largest coral reef system in the southwestern Atlantic. It is highly influenced by the Brazil Current (BC), since it is located in the continental shelf. By contrast, Todos os Santos Bay (TSB), in Salvador, capital of Bahia State (BA) has an important coral biodiversity, located in a bay inlet with restricted water circulation. Coral cores were collected in those sites and were analyzed for density band counting and by Th/U dating to estimate growth rates and age. In this work, we present14C ages of some of these bands in order to evaluate the marine reservoir effect (MRE) to which the colonies were subjected during growth. It is the first study making use of coral skeleton samples for MRE determination for the Brazilian coast. ΔR was calculated to be –151±2314C yr, while that for the TSB was –107±5114C yr.

Potential feedback between coral presence and farmerfish collective behavior promotes coral recovery

Stable between‐group differences in collective behavior have been documented in a variety of social taxa. Here we evaluate the effects of such variation, often termed collective or colony‐level personality, on coral recovery in a tropical marine farmerfish system. Groups of the farmerfish Stegastes nigricans cultivate and defend gardens of palatable algae on coral reefs in the Indo‐Pacific. These gardens can promote the recruitment, growth, and survival of corals by providing a refuge from coral predation. Here we experimentally evaluate whether the collective response of farmerfish colonies is correlated across intruder feeding guilds – herbivores, corallivores and egg‐eating predators. Further, we evaluate if overall colony responsiveness or situation‐specific responsiveness (i.e. towards herbivores, corallivores, or egg‐eaters in particular) best predicts the growth of outplanted corals. Finally, we experimentally manipulated communities within S. nigricans gardens, adding either macroalgae or large colonies of coral, to assess if farmerfish behavior changes in response to the communities they occupy. Between‐group differences in collective responsiveness were repeatable across intruder guilds. Despite this consistency, responsiveness towards corallivores (porcupinefish and ornate butterflyfish) was a better predictor of outplanted coral growth than responsiveness towards herbivores or egg‐eaters. Adding large corals to farmerfish gardens increased farmerfish attacks towards intruders, pointing to possible positive feedback loops between their aggression towards intruders and the presence of corals whose growth they facilitate. These data provide evidence that among‐group behavioral variation could strongly influence the ecological properties of whole communities.

Large‐scale coral reef rehabilitation after blast fishing in Indonesia

The severely degraded condition of many coral reefs worldwide calls for active interventions to rehabilitate their physical and biological structure and function, in addition to effective management of fisheries and no‐take reserves. Rehabilitation efforts to stabilize reef substratum sufficiently to support coral growth have been limited in size. We documented a large coral reef rehabilitation in Indonesia aiming to restore ecosystem functions by increasing live coral cover on a reef severely damaged by blast fishing and coral mining. The project deployed small, modular, open structures to stabilize rubble and to support transplanted coral fragments. Between 2013 to 2015, approximately 11,000 structures covering 7,000 m2 were deployed over 2 ha of a reef at a cost of US$174,000. Live coral cover on the structures increased from less than 10% initially to greater than 60% depending on depth, deployment date and location, and disturbances. The mean live coral cover in the rehabilitation area in October 2017 was higher than reported for reefs in many other areas in the Coral Triangle, including marine protected areas, but lower than in the no‐take reference reef. At least 42 coral species were observed growing on the structures. Surprisingly, during the massive coral bleaching in other regions during the 2014–2016 El Niño–Southern Oscillation event, bleaching in the rehabilitation area was less than 5% cover despite warm water (≥30°C). This project demonstrates that coral rehabilitation is achievable over large scales where coral reefs have been severely damaged and are under continuous anthropogenic disturbances in warming waters.

Population collapse dynamics in Acropora downingi, an Arabian/Persian Gulf ecosystem-engineering coral, linked to rising temperature.

As in the tropical Atlantic, Acropora populations in the southern Persian/Arabian Gulf plummeted within two decades after having been ecosystem engineers on most wave-exposed reefs since the Pleistocene. Since 1996/1998 live coral cover in the Gulf declined by over 90% in many areas, primarily due to bleaching and diseases caused by rising temperatures. In the formerly dominant table-coral species A.downingi, population dynamics corresponding to disturbance regimes was quantified in three transition matrices (lower disturbance pre-1996; moderate disturbance from 1998 to 2010 and 2013 to 2017, disturbed in 1996/1998, 2010/11/12, 2017). Increased disturbance frequency and severity caused progressive reduction in coral size, cover, and population fecundity. Small size-classes were bolstered more by partial colony mortality than sexual recruitment. Some large corals had a size refuge and resisted die-back but were also lost with increasing disturbance. Matrix and biophysical larval flow models suggested one metapopulation. Southern, Arabian, populations could be connected to northern, Iranian, populations but this connectivity was lost under assumptions of pelagic larval duration at rising temperatures shortened to a third. Then, the metapopulation disintegrated into isolated populations. Connectivity required to avoid extinctions increased exponentially with disturbance frequency and correlation of disturbances across the metapopulation. Populations became unsustainable at eight disturbances in 15years, when even highest theoretical recruitment no longer compensated mortality. This lethal disturbance frequency was 3-fold that of the moderately disturbed monitoring period and 4-fold of the preceding low-disturbance period-suggesting ongoing shortening of the disturbance-free period. Observed population collapse and environmental changes in the Gulf suggest that A.downingi is heading toward at least functional extinction mainly due to increasingly frequent temperature-induced mortality events, clearly linked to climate change.

Species richness and spatial distribution of benthic amphipods (Crustacea: Peracarida) in the Alacranes Reef National Park, Gulf of Mexico

The diversity and distribution of benthic amphipods has been explored in the Alacranes Reef, which is the largest coral reef ecosystem in the Gulf of Mexico. New insights into species richness, spatial distribution and extension of geographical ranges are presented by using data from published records and field surveys. A total of 117 species have been recorded, 9 of which are potentially new to science, 39 of which have new geographical records, and 7 are non-indigenous and previously reported in the literature as potentially invasive. Based on the use of a species-richness indicator (Chao 2), the expected species number is 40% higher, up to 200 spp., when compared to the observed species richness. The spatial distribution of amphipods varied significantly as a function of habitat type, showing the highest richness values on coral patches and the major abundances on man-made structures, such as navigation buoys and fishing traps. Multivariate analyses suggested the distinction between three taxonomically diverse species assemblages that showed similar ecological affinities, i.e. those on: (1) soft-bottom environments, grouping bare substrata and seagrass beds habitats; (2) hard-bottom environments, grouping coral patch and reef wall habitats; and (3) artificial substrata. The results highlight the importance of this reef ecosystem for a high amphipod diversity, but it is susceptible to future modifications in the presence of non-indigenous species, potentially invasive, on artificial substrata.

A large predatory reef fish species moderates feeding and activity patterns in response to seasonal and latitudinal temperature variation

Climate-driven increases in ocean temperatures are expected to affect the metabolic requirements of marine species substantially. To mitigate the impacts of increasing temperatures in the short-term, it may be necessary for ectothermic organisms to alter their foraging behaviour and activity. Herein, we investigate seasonal variation in foraging behaviour and activity of latitudinally distinct populations of a large coral reef predator, the common coral trout, Plectropomus leopardus, from the Great Barrier Reef, Australia. P. leopardus exhibited increased foraging frequency in summer versus winter time, irrespective of latitude, however, foraging frequency substantially declined at water temperatures >30 °C. Foraging frequency also decreased with body size but there was no interaction with temperature. Activity patterns were directly correlated with water temperature; during summer, the low-latitude population of P. leopardus spent up to 62% of their time inactive, compared with 43% for the high-latitude population. The impact of water temperature on activity patterns was greatest for larger individuals. These results show that P. leopardus moderate their foraging behaviour and activity according to changes in ambient temperatures. It seems likely that increasing ocean temperatures may impose significant constraints on the capacity of large-bodied fishes to obtain sufficient prey resources while simultaneously conserving energy.

Predation by feeding aggregations of Drupella spp. inhibits the recovery of reefs damaged by a mass bleaching event

High densities of two corallivorous gastropods, Drupella cornus and D. rugosa, may delay the recovery of coral reefs impacted by mass bleaching events by aggregating on the remaining corals. Following severe bleaching in April/May 2016 that resulted in the loss of up to 80% of the living coral cover from reefs in South Male, Maldives, aggregations of up to 250 Drupella per coral were recorded on surviving colonies. The distribution of snails was not random; larger aggregations were seen on reefs with fewer remaining live corals and also on the largest corals. Branching, digitate and tabular corals, especially species of Acropora and Pocillopora, sustained the highest mortality from the bleaching. Remaining colonies of these taxa exhibited the highest occurrence of snails and the most extensive snail predation, although less-preferred taxa such as Montipora, Porites, Astreopora, Cyphastrea and Pachyseris were also targeted. Drupella also concentrated on broken Acropora branches and overturned colonies; on some reefs, these were the only surviving acroporids, and many of them did not bleach. Continued predation pressure from Drupella may eliminate formerly dominant corals, including genets that are resistant to higher sea water temperatures.

Effects of temperature, salinity and composition of the dinoflagellate assemblage on the growth of Gambierdiscus carpenteri isolated from the Great Barrier Reef

Increases in reported incidence of ciguatera fish poisoning (hereafter ciguatera) have been linked to warmer sea temperatures that are known to trigger coral bleaching events. The drivers that trigger blooms of ciguatera-causing dinoflagellates on the Great Barrier Reef (GBR) are poorly understood. This study investigated the effects of increased temperatures and lowered salinities, often associated with environmental disturbance events, on the population growth of two strains of the potentially ciguatera-causing dinoflagellate, Gambierdiscus carpenteri (NQAIF116 and NQAIF380). Both strains were isolated from the central GBR with NQAIF116 being an inshore strain and NQAIF380 an isolate from a stable environment of a large coral reef aquarium exhibit in ReefHQ, Townsville, Australia. Species of Gambierdiscus are often found as part of a mixed assemblage of benthic toxic dinoflagellates on macroalgal substrates. The effect of assemblage structure of dinoflagellates on the growth of Gambierdiscus populations has, however, not been explored. The study, therefore investigated the growth of G. carpenteri within mixed assemblages of benthic dinoflagellates. Population growth was monitored over a period of 28days under three salinities (16, 26 and 36) and three temperature (24, 28 and 34°C) conditions in a fully crossed experimental design. Temperature and salinity had a significant effect on population growth. Strain NQAIF380 exhibited significantly higher growth at 28°C compared to strain NQAIF116, which had highest growth at 24°C. When strain NQAIF116 was co-cultured with the benthic dinoflagellates, Prorocentrum lima and Ostreopsis sp., inhibitory effects on population growth were observed at a salinity of 36. In contrast, growth stimulation of G. carpenteri (strain NQAIF116) was observed at a salinity of 26 and particularly at 16 when co-cultured with Ostreopsis-dominated assemblages. Range expansion of ciguatera-causing dinoflagellates could lead to higher frequency of reported ciguatera illness in populated temperate Australian regions, outside the tropical range of the GBR. Therefore, the findings on salinity and temperature tolerance of two strains of G. carpenteri indicates potential adaptability to different local environmental conditions. These are baseline data for future investigations into the potential southward range expansion of ciguatera-causing dinoflagellates originating from the GBR.

Discovery of a new species of hermit crab of the genus Pylopaguropsis Alcock, 1905 from the Caribbean: "den commensal" or "cleaner"? (Crustacea, Anomura, Paguridae).

A new secretive, yet brightly colored hermit crab species of the family Paguridae, Pylopaguropsis mollymullerae sp. n., is fully described based on specimens from the reefs of Bonaire, Lesser Antilles, southern Caribbean Sea. Populations of this new species were discovered and photographed in the Bonaire National Marine Park under a large coral ledge, at a depth of 13.7 m, living in crevices known by scuba divers to serve as den to a pair of “flaming reef lobsters” Enoplometopus antillensis, or a “broad banded moray” Channomuraena vittata. This new species is only the second species of Pylopaguropsis Alcock, 1905 known from the western Atlantic, the 20th named worldwide, and belongs in the teevana group of species of the genus. It is remarkably similar, and herein considered geminate, to the tropical eastern Pacific congener, Pylopaguropsis teevana (Boone, 1932), the two being characterized and uniquely different from all other species of the genus, by the striking and deeply excavated, scoop-like ventral surface of the chela of the right cheliped. Minor differences separate this new species from Pylopaguropsis teevana in the relative length of the antennal acicles (exceeding the corneas versus not exceeding the corneas in Pylopaguropsis teevana); dorsal armature of the right chela (smooth or with scattered minute tubercles versus with numerous small tubercles in Pylopaguropsis teevana); surface shape of the lateral face of the dactyl of right pereopod 3 (evenly convex versus flattened in Pylopaguropsis teevana); and coloration (red bright red stripes versus brown stripes in Pylopaguropsis teevana). The highly visible color pattern of bright red stripes on white background typical of decapods known to have cleaning symbioses with fish, dense setation on the flagella of the antennae, and preference for a crevicular habitat, combined with brief in situ nocturnal observations, suggests the possibility that Pylopaguropsis mollymullerae sp. n. engages in “cleaner” activities or functions as a “den commensal” with moray eels. The morphology and possible meaning of the observed behavior is discussed. A tabular summary of the distribution, habitat, and published information on all species of Pylopaguropsis is presented. Supplemental photographs and a video of live Pylopaguropsis mollymullerae sp. n. are included.

<i>Drupella</i> outbreak in a large coral community off the coast of Cape Toi, Miyazaki, Japan

<i>Drupella</i> outbreak in a large coral community off the coast of Cape Toi, Miyazaki, Japan

Effects of terrestrial runoff on the coral communities in Santiago Bay, Colima, Mexican Pacific Coast.

Coral reef ecosystems are under stress of different origins, from factors including sedimentation, fragmentation, overfishing, and tourism, depending on their geographical location, depth, and proximity to recreation areas. In this study of Juluapan Lagoon, we examined the relationship between various water-quality attributes and the status indicators of the coral community at La Boquita reef. During 2011 (12 months of sampling), six monitoring stations in the Juluapan lagoon were established in order to observe the gradient of the distribution of the physicochemical parameters: three stations on the upper part, or BI, (S4 to S6) and three more in the lower part, or BII, (S1 to S3). A control station (CS) was located in the coral reef close to the lagoon channel, and where dissolved inorganic nutrients and cellular carbon content were determined. Additionally, we considered the monitoring of three of the eight largest coral structures/headlands of this community: the first was the station closest to the channel communicating with Juluapan lagoon (C1), the second was in the intermediate region with respect to that lagoon (C2), and the third was farthest from the channel (C3). Three line intercept transects (LIT) 30 m in length and perpendicular to the coast provenance were established in each station, and the parameters indicative of the status of corals were evaluated in an area of 60 m2 on each transect (180 m2 by the station). Turbidity, evidence of fishing, signs of settling, algal coverage, abundance of fish, rate of sediment, and coral health records (as for CoralWach chart) were determined in situ and from digital photographs and videos. Considering various community status indicators used in the reef area, we could recognize a state of general deterioration, which was reflected in the loss of 17 % of coral coverage. The main anthropogenic disturbances in adjacent areas to La Boquita reef included wastewater discharges into the lagoon, tourist developments in the coastal zone, deforestation and erosion resulting from inappropriate development, and the runoff of nutrients from agricultural lands nearby the lagoon. All these significantly contributed to the nutrient-enriched waters of the lagoon, especially in summer, with negative effects on the coral community. Continued exposure to these factors, coupled with the lack of control over other anthropogenic components, has promoted the maintenance of a chronic stress state in the studied coral community. Our findings highlight the need for the development of appropriate coastal management and conservation policies for the coral reefs of the Mexican Pacific Coast.

Restricted grouper reproductive migrations support community-based management.

Conservation commonly requires trade-offs between social and ecological goals. For tropical small-scale fisheries, spatial scales of socially appropriate management are generally small—the median no-take locally managed marine area (LMMA) area throughout the Pacific is less than 1 km2. This is of particular concern for large coral reef fishes, such as many species of grouper, which migrate to aggregations to spawn. Current data suggest that the catchment areas (i.e. total area from which individuals are drawn) of such aggregations are at spatial scales that preclude effective community-based management with no-take LMMAs. We used acoustic telemetry and tag-returns to examine reproductive migrations and catchment areas of the grouper Epinephelus fuscoguttatus at a spawning aggregation in Papua New Guinea. Protection of the resultant catchment area of approximately 16 km2 using a no-take LMMA is socially untenable here and throughout much of the Pacific region. However, we found that spawning migrations were skewed towards shorter distances. Consequently, expanding the current 0.2 km2 no-take LMMA to 1–2 km2 would protect approximately 30–50% of the spawning population throughout the non-spawning season. Contrasting with current knowledge, our results demonstrate that species with moderate reproductive migrations can be managed at scales congruous with spatially restricted management tools.

Microbial domes and megaoncoids in Miocene reefs in the Mahakam Delta in East Kalimantan, Indonesia

Coral patch reefs in the Miocene Mahakam delta in East Kalimantan (Borneo, Indonesia) developed in shallow marine turbid waters. These reefs grew in delta front to prodelta environments under fluctuating siliciclastic input. Langhian patch reefs are well exposed in limestone quarries of the Air Putih area, near the city of Samarinda and include two different types of microbial carbonates in two sections, 2km apart. In the northern section, microbialites occur as low-relief domes, up to 2m wide and 0.5m high. The domes show internal lamination and coralline algae and encrusting foraminifers interlayered with microbial micrite. They developed around large coral fragments at the transition from reef deposits to fine-grained siliciclastics. Microbialites in the southern section formed decimetre- to metre-scale nodules (here termed “megaoncoids”) around nuclei of large coral fragments. Microbial micrite with laminated to digitate fabrics intergrew with coralline algae and encrusting foraminifers to form the thick covers of megaoncoids. Small nodules were bound together in larger ones, which are usually strongly asymmetric internally. Megaoncoids accumulated in a carbonate breccia laterally changing into coral boundstones. In both sections, microbialites grew on the flanks of shallow-water, low-relief patch reefs in poorly illuminated, low-energy conditions. Flat-domed microbialites formed on a nearly horizontal, stable seafloor seawards of the patch reef. The megaoncoids in the southern section formed as a result of downslope displacement of coral fragments coated by microbialite/coralline algal/encrusting foraminifer crusts. The slope of the patch reef's flank favoured the falling and rolling of encrusted corals, with the continued growth of microbial crusts on all sides of nodules. In contrast to Quaternary and recent occurrences of microbialites in Indo-Pacific and Caribbean reefs, the Samarinda microbialites are not components of the reef framework nor formed in deep water. Instead, they developed in shallow, turbid waters of the Miocene Mahakam delta in periods of arrested siliciclastic input.

Mass occurrence of the large solitary rugose coral Phaulactis angusta at the boundary Lower/Upper Visby Formation in the Silurian of Gotland, Sweden: palaeoecology and depositional implications

The boundary between the Lower and Upper Visby formations on Gotland (Sweden), which roughly correlates with the Llandovery–Wenlock boundary, is characterised by a mass occurrence of the large solitary rugose coral Phaulactis angusta. This coral-rich layer can be followed for some 50 km along the north-west coast of Gotland. The mass occurrence coincides with the onset of a pronounced, globally recognised δ13C and δ18O excursions in the lower Sheinwoodian. Altogether 31 specimens of P. angusta from eight localities were examined. We demonstrate that the corals preferred to grow in an upright position. Attachment structures were not observed, and therefore a liberosessile life strategy is suggested. Some corallites show an abrupt change in growth direction accompanied by a decrease in diameter. These features mostly occur in later growth stages and may be explained by disturbances in the growth due to toppling or tilting of the corals. Many specimens were able to change their growth axes, but finally died after such an event. Most specimens in the outcrops show a flattened upper surface, which is interpreted as a result of post-mortem abrasion. Epibiontic bryozoan encrustation took place mostly while the corals where alive, whereas stromatoporoid encrustation and Trypanites borings occurred post-mortem. The repeated growth, tilting and erosion of the corallites of P. angusta demonstrate that the Phaulactis layer represents a condensed interval, characterised by multiple pulses of sediment accumulation and erosion.

Size-dependent physiological responses of the branching coral Pocillopora verrucosa to elevated temperature and PCO2.

Body size has large effects on organism physiology, but these effects remain poorly understood in modular animals with complex morphologies. Using two trials of a ∼24 day experiment conducted in 2014 and 2015, we tested the hypothesis that colony size of the coral Pocillopora verrucosa affects the response of calcification, aerobic respiration and gross photosynthesis to temperature (∼26.5 and ∼29.7°C) and PCO2 (∼40 and ∼1000 µatm). Large corals calcified more than small corals, but at a slower size-specific rate; area-normalized calcification declined with size. Whole-colony and area-normalized calcification were unaffected by temperature, PCO2 , or the interaction between the two. Whole-colony respiration increased with colony size, but the slopes of these relationships differed between treatments. Area-normalized gross photosynthesis declined with colony size, but whole-colony photosynthesis was unaffected by PCO2 , and showed a weak response to temperature. When scaled up to predict the response of large corals, area-normalized metrics of physiological performance measured using small corals provide inaccurate estimates of the physiological performance of large colonies. Together, these results demonstrate the importance of colony size in modulating the response of branching corals to elevated temperature and high PCO2.

Cardiac Depressant Activity of Erythrina variegata Linn on Isolated Frog- Heart

Objective: Erythrina variegata Linn of the family leguminaceae is a medium sized deciduous small tree with prickly stems and branches, leaves with triangular leaflets and large coral red flowers and grows all over Bangladesh. Different parts of E. variegata have used in traditional medicine as nervine sedative, febrifuge, anti-asthmatic and antiepileptics.It is having the d-tubacurarine like activity. The present study was under taken to evaluate the cardiac depressant activity of Erythrina variegata in experimental animal model. Materials and method: Aqueous extract of E. variegata was tested for cardiac depressant action by using frog isolated heart model. Different concentration of atropine sulphate is used along with plant water extract. Results: The water extract shows the significant cardiac depressant activity. Conclusion: The present study shows that E. variegata has significant cardiac depressant activity.

Dietary isotope patterns and their social implications in a prehistoric human population from Sigatoka, Fiji

The late-1980s excavation of a well organized cairn-burial cemetery at the Sigatoka Sand Dunes site on Viti Levu, Fiji, recovered a population that is closely grouped in time with individuals coming from a nearby Fijian Plainware Phase village (1435–1300cal BP). Analysis of carbon (δ13C) and nitrogen (δ15N) stable isotopes from a sample of 22 of these individuals provides insight into village-level diet and its variation across the population. Results indicate a mixed diet high in C3 plant resources but with a key marine component. Variation in diet based on sex does not occur. Differential treatment of the dead through interment in large coral rock cairns versus pit burials in the cemetery, speaks to rank in Fijian antiquity. Individuals interred in cairns trend toward elevated carbon values, suggesting access to marine proteins as a potential correlate for status in the burial population. Isotopic measurements for a late prehistoric individual from Sigatoka and measurements from nine faunal samples also are presented. The latter, with other faunal measurements from Fiji, provides a food web for comparative interpretation of human diet.

Coral population dynamics across consecutive mass mortality events.

Annual coral mortality events due to increased atmospheric heat may occur regularly from the middle of the century and are considered apocalyptic for coral reefs. In the Arabian/Persian Gulf, this situation has already occurred and population dynamics of four widespread corals (Acropora downingi, Porites harrisoni, Dipsastrea pallida, Cyphastrea micropthalma) were examined across the first-ever occurrence of four back-to-back mass mortality events (2009-2012). Mortality was driven by diseases in 2009, bleaching and subsequent diseases in 2010/2011/2012. 2009 reduced P.harrisoni cover and size, the other events increasingly reduced overall cover (2009: -10%; 2010: -20%; 2011: -20%; 2012: -15%) and affected all examined species. Regeneration was only observed after the first disturbance. P.harrisoni and A.downingi severely declined from 2010 due to bleaching and subsequent white syndromes, while D.pallida and P.daedalea declined from 2011 due to bleaching and black-band disease. C.microphthalma cover was not affected. In all species, most large corals were lost while fission due to partial tissue mortality bolstered small size classes. This general shrinkage led to a decrease of coral cover and a dramatic reduction of fecundity. Transition matrices for disturbed and undisturbed conditions were evaluated as Life TableResponse Experiment and showed that C.microphthalma changed the least in size-class dynamics and fecundity, suggesting they were 'winners'. In an ordered 'degradation cascade', impacts decreased from the most common to the least common species, leading to step-wise removal of previously dominant species. A potentially permanent shift from high- to low-coral cover with different coral community and size structure can be expected due to the demographic dynamics resultant from the disturbances. Similarities to degradation of other Caribbean and Pacific reefs are discussed. As comparable environmental conditions and mortality patterns must be expected worldwide, demographic collapse of many other coral populations may soon be widespread.

Reef flattening effects on total richness and species responses in the Caribbean.

There has been ongoing flattening of Caribbean coral reefs with the loss of habitat having severe implications for these systems. Complexity and its structural components are important to fish species richness and community composition, but little is known about its role for other taxa or species-specific responses. This study reveals the importance of reef habitat complexity and structural components to different taxa of macrofauna, total species richness, and individual coral and fish species in the Caribbean. Species presence and richness of different taxa were visually quantified in one hundred 25-m(2) plots in three marine reserves in the Caribbean. Sampling was evenly distributed across five levels of visually estimated reef complexity, with five structural components also recorded: the number of corals, number of large corals, slope angle, maximum sponge and maximum octocoral height. Taking advantage of natural heterogeneity in structural complexity within a particular coral reef habitat (Orbicella reefs) and discrete environmental envelope, thus minimizing other sources of variability, the relative importance of reef complexity and structural components was quantified for different taxa and individual fish and coral species on Caribbean coral reefs using boosted regression trees (BRTs). Boosted regression tree models performed very well when explaining variability in total (82·3%), coral (80·6%) and fish species richness (77·3%), for which the greatest declines in richness occurred below intermediate reef complexity levels. Complexity accounted for very little of the variability in octocorals, sponges, arthropods, annelids or anemones. BRTs revealed species-specific variability and importance for reef complexity and structural components. Coral and fish species occupancy generally declined at low complexity levels, with the exception of two coral species (Pseudodiploria strigosa and Porites divaricata) and four fish species (Halichoeres bivittatus, H. maculipinna, Malacoctenus triangulatus and Stegastes partitus) more common at lower reef complexity levels. A significant interaction between country and reef complexity revealed a non-additive decline in species richness in areas of low complexity and the reserve in Puerto Rico. Flattening of Caribbean coral reefs will result in substantial species losses, with few winners. Individual structural components have considerable value to different species, and their loss may have profound impacts on population responses of coral and fish due to identity effects of key species, which underpin population richness and resilience and may affect essential ecosystem processes and services.

Outbreak of white syndrome in Acropora spp., temperate region of Japan

Coral diseases are a growing concern worldwide, posing another threat to a system already plagued by bleaching and predation. White syndromes (WS) are tissue loss diseases causing mortality on corals globally (e.g., Willis et al. 2004). In Japan,WSwas initially reported in the nation’s largest coral reef area around the Ishigaki-Iriomote Islands (Nature Conservation Bureau 2004) and has since been observed sporadically in northern Japan. This study describes an outbreak of WS in the temperate region of Japan. Hermatypic corals are distributed around Ohshima Island (31°31′N, 131°24′E) (southeast of the main island of Kyushu, Japan), where there is no coral reef development. Conspicuous signs of WS were recognized around this island in July 2014, primarily spreading to the dominant species of the area, Acropora solitaryensis (Fig. 1) and A. japonica, which form large colonies. Almost 25 % of the colonies (41 of 164 colonies examined) of Acropora spp. from shallow to deep water (7–14 m depth) were affected by WS in November 2014. For A. japonica, 50 % colonies were affected. Even in winter (February 2015), when water temperatures dropped to 15 °C, WS-infected corals were still observed. Turbinaria peltata, another dominant coral in this area, has been affected bywhite spot syndrome (Yamashiro and Fukuda 2009), but no WS infections have been observed in this species to date. The water temperature in July and August 2014 was 27 °C, which was lower compared to 2013; however, two strong typhoons hit this region in July (on 10th and 28th), causing heavy turbidity (observation by M.F.). Four typhoons landed on Kyushu in 2014, the most in a decade (mean 2.2 per year; data from Japan Meteorological Agency). Although there is no direct evidence of a causal agent for WS in this area, sedimentation/ turbidity appears to be one possible driver of coral disease, as recently observed in Australia (Pollock et al. 2014).