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Globally, coral reefs are under pressure from climate change, with concerning declines in coral abundance observed due to increasing cumulative impacts. Active intervention measures that mitigate the declines are increasingly being applied to buy time for coral reefs as the world transitions to a low-carbon economy. One such mitigation strategy is coral restoration based on large-scale coral aquaculture to provide stock for reseeding reefs, with the added potential of selecting corals that better tolerate environmental stress. Application of probiotics during production and deployment, to modulate the naturally occurring bacteria associated with corals, may confer health benefits such as disease resistance, increased environmental tolerance or improved coral nutrition. Here, we briefly describe coral associated bacteria and their role in the coral holobiont, identify probiotics traits potentially beneficial to coral, and discuss current research directions required to develop, test and verify the feasibility for probiotics to improve coral aquaculture at industrial scales.

As many degrading shallow reefs suffer from recruitment failure, mesophotic coral ecosystems have been suggested as a potential source of coral propagules promoting the recolonization of these reefs. However, whether mesophotic coral populations can repopulate shallower reefs is currently debatable. Here, we compared the response of corals settled on mesophotic (50 m) tiles and transplanted to the shallow reef (10 m), at a Nature Reserve and an unprotected site in the northern Gulf of Eilat/Aqaba, Red Sea. Mortality was substantially higher for the transplanted corals, as compared with their shallow counterparts living on the tiles, with over half of the transplanted juveniles dying 1 yr post-transplantation. Transplanted corals exhibited a 24% higher survivorship at the MPA site. We further explored the survival and growth rates of the 4 most common transplanted coral genera (Cyphastrea, Porites, Psammocora, and Stylophora). An inverse relationship between survival and growth was evident among the transplanted coral genera; Porites and Stylophora demonstrated similar net growth rates to those of their shallow-water counterparts but lower post-transplantation survivorship, while Cyphastrea and Psammocora showed the opposite trend. Although this study demonstrates the reduced plasticity of mesophotic coral juveniles to cope with shallow-water conditions, it nonetheless offers some potential to facilitate shallow-reef recovery.

It has been widely shown that oyster reefs enhance local biodiversity and fisheries production. To determine the importance of intertidal remnant estuarine oyster reefs compared to unstructured sandy habitats over small spatial scales (

Metal stable isotopes in marine carbonates have been widely used as novel proxies for metal cycling through the geological past. Amongst these metals, copper (Cu) and zinc (Zn) have received great attention owing to their vital roles in metabolic processes. However, whether modern marine biogenic carbonates record the seawater isotope signatures of Cu (δ65Cu) and Zn (δ66Zn) and mechanisms and factors controlling isotope fractionation of these metals remain unclear, hindering applications of both isotope systems in paleoceanography. Here we present annually-resolved records of δ65Cu and δ66Zn in seven coral (Porites) cores sampled from different marine settings in the South China Sea and the Luzon Strait, western Pacific. We find that the aragonitic skeletons of corals are enriched in light Cu but heavy Zn isotopes relative to surface seawaters, with δ65Cu and δ66Zn in the range of −0.16 ± 0.06‰ to 0.40 ± 0.05‰ and 0.06 ± 0.04‰ to 0.46 ± 0.08‰ (2SD), respectively. The coral δ65Cu exhibits significant inter- and intra-colony variations, which are most likely controlled by Rayleigh-type fractionation in the calcifying fluids of corals rather than by changes in environmental factors or seawater δ65Cu. We thus suggest that δ65Cu in ancient carbonates may not be a direct record of Cu isotope compositions in coeval seawaters. In contrast, coral δ66Zn shows insignificant temporal variation, and the Zn isotope fractionation between individual corals and seawaters are relatively small and constant (0.10 ± 0.05‰, n = 33, 2SD). This limited Zn isotope fractionation is much lower than that determined during inorganic precipitation of calcite, which is likely due to pH up-regulation by the coral that changes aqueous Zn speciation, and preferential organic complexation of the heavy Zn isotopes in the calcifying fluids. Therefore, Porites corals are promising archives for tracking historical changes of surface seawater δ66Zn. Our new datasets of reef carbonates, particularly the coral δ65Cu values which are measured for the first time, could provide a better constrain on marine Cu and Zn geochemistry and their modern oceanic mass and isotope budgets.

Cutting-edge DNA methylation-based epigenetic aging techniques were applied to Gulf of Mexico northern red snapper (Lutjanus campechanus; n = 10; 1–26 years old) and red grouper (Epinephelus morio; n = 10; 2–14 years old). Bisulfite-converted restriction site-associated DNA sequencing was used to identify CpG sites (cytosines followed by guanines) that exhibit age-correlated DNA methylation, and species-specific epigenetic clocks developed from hundreds of CpG sites in each species showed strong agreement between predicted and otolith-derived age (r2 > 0.99 for both species). Results suggest epigenetic age estimation could provide an accurate and efficient approach to mass-aging fishes in a non-invasive manner.

Kelp forests cover ~30% of the world’s coastline and are the largest biogenic marine habitat on earth. Across their distribution, kelp forests are essential for the healthy functioning of marine ecosystems and consequently underpin many of the benefits coastal societies receive from the ocean. Concurrently, rising sea temperatures, overgrazing by marine herbivores, sedimentation, and water pollution have caused kelp forests populations to decline in most regions across the world. Effectively managing the response to these declines will be pivotal to maintaining healthy marine ecosystems and ensuring the benefits they provide are equitably distributed to coastal societies. In Chapter 1, I review how the marine management paradigm has shifted from protection to restoration as well as the consequences of this shift. Chapter 2 introduces the field of kelp forest restoration and provides a quantitative and qualitative review of 300 years of kelp forest restoration, exploring the genesis of restoration efforts, the lessons we have learned about restoration, and how we can develop the field for the future. Chapter 3 is a direct answer to the question faced while completing Chapter 2. This chapter details the need for a standardized marine restoration reporting framework, the benefits that it would provide, the challenges presented by creating one, and the solutions to these problems. Similarly, Chapter 4 is a response to the gaps discovered in Chapter 2. Chapter 4 explores how we can use naturally occurring positive species interactions and synergies with human activities to not only increase the benefits from ecosystem restoration but increase the probability that restoration is successful. The decision to restore an ecosystem or not is informed by the values and priorities of the society living in or managing that ecosystem. Chapter 5 quantifies the fisheries production, nutrient cycling, and carbon sequestration potential of five key genera of globally distributed kelp forests. I conclude the thesis by reviewing the lessons learned and the steps required to advance the field kelp forest restoration and conservation.

This paper is a literature review on marine hardbottom environments (MHE) that emerge in coastal regions in the Brazilian state of Ceará. This stretch of the Brazilian coast houses several rock formations, which are widely distributed in the intertidal zone. These formations have various origins and composition, ranging from crystalline rocks to biogenic structures, but most are composed by sandstones. These substrates support biodiverse ecosystems that produce valuable environmental goods and services, which have historical and socioeconomic relevance for the state. Despite their importance, they are currently threatened by various types of local and global stressors, and a consistent government effort to protect them is still lacking. There are many knowledge gaps regarding these formations and new studies are needed to support conservation actions involving these ecosystems. Este artigo é uma revisão da literatura sobre ambientes marinhos rochosos que surgem em regiões costeiras do estado brasileiro do Ceará. Esse trecho da costa brasileira abriga diversas formações rochosas, que estão amplamente distribuídas na zona entremarés. Essas formações possuem origens e composições diversas, que vão desde rochas cristalinas até estruturas biogênicas, mas a maioria é composta por arenitos. Esses substratos sustentam ecossistemas biodiversos que produzem bens e serviços ambientais valiosos, que têm relevância histórica e socioeconômica para o estado. Apesar de sua importância, eles estão atualmente ameaçados por vários tipos de estressores locais e globais e ainda falta um esforço consistente do governo para protegê-los. Existem muitas lacunas de conhecimento a respeito dessas formações e novos estudos são necessários para subsidiar ações de conservação envolvendo tais ecossistemas

Crown-of-thorns sea stars (Acanthaster sp.) are among the most studied coral reef organisms, owing to their propensity to undergo major population irruptions, which contribute to significant coral loss and reef degradation throughout the Indo-Pacific. However, there are still important knowledge gaps pertaining to the biology, ecology, and management of Acanthaster sp. Renewed efforts to advance understanding and management of Pacific crown-of-thorns sea stars (Acanthaster sp.) on Australia’s Great Barrier Reef require explicit consideration of relevant and tractable knowledge gaps. Drawing on established horizon scanning methodologies, this study identified contemporary knowledge gaps by asking active and/or established crown-of-thorns sea star researchers to pose critical research questions that they believe should be addressed to improve the understanding and management of crown-of-thorns sea stars on the Great Barrier Reef. A total of 38 participants proposed 246 independent research questions, organized into 7 themes: feeding ecology, demography, distribution and abundance, predation, settlement, management, and environmental change. Questions were further assigned to 48 specific topics nested within the 7 themes. During this process, redundant questions were removed, which reduced the total number of distinct research questions to 172. Research questions posed were mostly related to themes of demography (46 questions) and management (48 questions). The dominant topics, meanwhile, were the incidence of population irruptions (16 questions), feeding ecology of larval sea stars (15 questions), effects of elevated water temperature on crown-of-thorns sea stars (13 questions), and predation on juveniles (12 questions). While the breadth of questions suggests that there is considerable research needed to improve understanding and management of crown-of-thorns sea stars on the Great Barrier Reef, the predominance of certain themes and topics suggests a major focus for new research while also providing a roadmap to guide future research efforts.

[ES] El continuo cambio de la sociedad está provocando e interactuando con el medio ambiente de una manera que, en muchas ocasiones, es negativa. Por ello hemos de concienciarnos del problema que está ocasionando y empezar a diseñar y construir espacios que contrarresten estos problemas. Es necesario regenerar esos espacios y recursos medioambientales de una manera rápida y eficaz. Así, se ha querido diseñar un módulo básico prefabricado de hormigón para la realización de colmenas para la generación de biodiversidad marina. El problema actual de los arrecifes artificiales es el escaso diseño y artificialidad de estos espacios que se han construido. Por otro lado, los objetivos que se han querido desarrollar, o no se han cumplido, o se han establecido a muy largo plazo. Por ello se va a diseñar este módulo de hormigón para que presente un grado alto de adaptación al medio y generar, por acumulación de los mismos, un espacio que se mimetice con el entorno de una manera rápida y eficaz. Tendremos en cuenta la intención de, junto con la construcción del módulo, crear unos paneles interiores que, junto con el uso del hormigón, proporcionen microorganismos que influyan a potenciar los primeros eslabones de la cadena trófica que se puede llegar a instalar para desarrollarse un alto grado de eficacia los objetivos buscados., [EN] The continuous change of society is provoking and interacting with the environment in a negative way. Therefore, we have to become aware of the problem it is causing and begin to design and build spaces that counteract these problems. Therefore, it is necessary to regenerate these spaces and environmental resources in a fast and effective way. Therefore, we wanted to create and design a prefabricated concrete module for the realization of hives for the generation of marine biodiversity. The current problem of artificial reefs is the poor design and artificiality of these spaces that have been built. On the other hand, the objectives that have been developed, or have not been met, or have been established in the very long term. Therefore, this concrete module will be designed to present a high degree of adaptation to the environment and generate a space that blends in with the environment quickly and effectively. This design, together with the manufacturing and transportation process will be influenced by the previous study we make and, in itself, of the necessary considerations. Therefore, we will determine the shape to be placed on the seabed. We will take into account the intention, together with the construction of the module, to create interior panels that, together with the use of concrete, will provide microorganisms that influence to enhance the first links of the trophic chain that can be installed to develop a high degree of effectiveness of the objectives sought.

An obituary for the Great Barrier Reef (the Reef) by travel and food writer Rowan Jacobsen (2016) commemorated its ‘lifetime accomplishments’ in Outside, the US outdoor recreational magazine. ‘News’ of the Reef's demise went viral and the economic and political furore that followed was immense. Tourism industries, especially reliant on international arrivals, were impacted as potential visitors accepted the Reef's passing as fact. Politicians scampered to reassure Australians and the globe that the Reef was indeed still alive and beautiful. In the Australian public sphere, climate science deniers, alongside those advocating for climate action, collided over the impacts of global warming to Reef health. Subsequent mass coral bleaching events in 2016, 2017 and 2020 sustained at the very least, the idea that the Reef was, or was soon to be, dead. Our paper follows the idea of a ‘dead Reef’ in the context of historical and recent debates about Reef protection. Using Google Trends, we identify Jacobsen's article as the source of increased Australian and global ideation of a ‘dead Reef’. As a site of local and global environmental communication – where human relations to nature are expressed and understood - the Reef holds extraordinary story telling power. At the current junction then, the way we communicate the Reef is critical to public understanding and political action on climate change. We conclude Jacobsen's article is an example of the problems of satirical communication, serving to amplify existing conflicts and undermine efforts to foster to climate action.

Up to one-third of all described marine species inhabit coral reefs, but the future of these hyperdiverse ecosystems is insecure due to local and global threats, such as overfishing, eutrophication, ocean warming, and acidification. Although these impacts are expected to have a net detrimental effect on reefs, it has been shown that some organisms like octocorals may remain unaffected, or benefit from, anthropogenically induced environmental change, and may replace stony corals in future reefs. Despite their potential importance in future shallow-water coastal environments, the molecular mechanisms leading to the resilience to anthropogenic-induced stress observed in octocorals remain unknown. Here, we use manipulative experiments, proteomics, and transcriptomics to show that the molecular toolkit used by Pinnigorgia flava, a common Indo-Pacific gorgonian octocoral, to deposit its calcium-carbonate skeleton is resilient to heat and seawater acidification stress. Sublethal heat stress triggered a stress response in P. flava but did not affect the expression of 27 transcripts encoding Skeletal Organic Matrix (SOM) proteins. Exposure to seawater acidification did not cause a stress response but triggered the downregulation of many transcripts, including an osteonidogen homolog present in the SOM. The observed transcriptional decoupling of the skeletogenic and stress-response toolkits provides insights into the mechanisms of resilience to anthropogenically-driven environmental change observed in octocorals.

The well-cataloged marine fish fauna of the Galapagos Islands includes eight of the 12 species of snappers (Lutjanidae) found in the Tropical Eastern Pacific. A recent recreational scuba dive in the Galapagos produced photographs of an additional snapper species, Lutjanus inermis (Peters, 1869), which was sufficiently common as to likely have a recently established resident population.

Mesophotic coral ecosystems (30–150 m depth) present a high oceanic biodiversity, but remain one of the most understudied reef habitats, especially below 60 m depth. Here, we have assessed the rates of photosynthesis and dissolved inorganic carbon (DIC) and nitrogen (DIN) assimilation by Symbiodiniaceae associated with four soft coral species of the genus Sinularia and two stony coral species of the genus Leptoseris collected respectively at 65 and 80–90 m depth in the Gulf of Eilat. Our study demonstrates that both Leptoseris and Sinularia species have limited autotrophic capacities at mid-lower mesophotic depths. DIC and DIN assimilation rates were overall ~ 10 times lower compared to shallow corals from 10 m depth in the same reef. While Leptoseris symbionts transferred at least 50% of the acquired nitrogen to their host after 8-h incubation, most of the nitrogen was retained in the symbionts of Sinularia. In addition, the host tissue of Sinularia species presented a very high structural carbon to nitrogen ratio (C : N) compared to Leptoseris or to the shallow coral species, suggesting nitrogen limitation in these mesophotic soft corals. The limited capacity of soft coral symbionts to acquire DIN and transfer it to the coral animal, as well as the high C : N ratios, might explain the scarcity of symbiotic soft corals at mid-lower mesophotic depths compared to their prevalence in the shallower reef. Overall, this study highlights the significance of DIN for the distribution of the Cnidarian- Symbiodiniaceae association at mesophotic depth.

Urbanized coral reefs are often chronically affected by sedimentation and reduced light levels, yet many species of corals appear to be able to thrive under these highly disturbed conditions. Recently, these marginal ecosystems have gained attention as potential climate change refugia due to the shading effect of suspended sediment, as well as potential reservoirs for stress-tolerant species. However, little research exists on the impact of sedimentation on coral physiology, particularly at the molecular level. Here, we investigated the transcriptomic response to sediment stress in corals of the family Merulinidae from a chronically turbid reef (one genet each of Goniastrea pectinata and Mycedium elephantotus from Singapore) and a clear-water reef (multiple genets of G. pectinata from the Gulf of Aqaba/Eilat). In two ex-situ experiments, we exposed corals to either natural sediment or artificial sediment enriched with organic matter and used whole-transcriptome sequencing (RNA sequencing) to quantify gene expression. Analysis revealed a shared basis for the coral transcriptomic response to sediment stress, which involves the expression of genes broadly related to energy metabolism and immune response. In particular, sediment exposure induced upregulation of anaerobic glycolysis and glyoxylate bypass enzymes, as well as genes involved in hydrogen sulphide metabolism and in pathogen pattern recognition. Our results point towards hypoxia as a probable driver of this transcriptomic response, providing a molecular basis to previous work that identified hypoxia as a primary cause of tissue necrosis in sediment-stressed corals. Potential metabolic and immunity trade-offs of corals living under chronic sedimentation should be considered in future studies on the ecology and conservation of turbid reefs.

Coral reefs are increasingly threatened by heat stress events leading to coral bleaching. In 2016, a mass bleaching event affected large parts of the Great Barrier Reef (GBR). Whilst bleaching severity and coral mortality are usually monitored throughout major bleaching events, other health indicators, such as changes in microbial partners, are rarely assessed. We examined the impact of the 2016 bleaching event on the composition of the microbial communities in the coral Pocillopora acuta at Havannah Island Pandora reef, separated by 12 km on the inshore central GBR. Corals experienced moderate heat stress (3.6 and 5.3 degree heating weeks), inducing major bleaching (30–60%) at the coral community level. Samples were partitioned according to Symbiodiniaceae densities into three bleaching severity categories (mild, moderate, and severe). Whilst Symbiodiniaceae densities were similar at both reef locations, sequencing of the Symbiodiniaceae ITS2 and prokaryotic 16S rRNA genes revealed that microbial communities were significantly different between reefs, but not according to bleaching severity. Symbiodiniaceae composition was dominated by the genus Cladocopium with low abundances of Durusdinium detected in moderately and severely bleached colonies at both sites, despite site-specific ITS2 profiles. Bacterial communities were dominated by Proteobacteria and were almost entirely lacking the common Pocilloporid associate Endozoicomonas regardless of bleaching severity. Strikingly, only 11.2% of the bacterial Amplicon Sequencing Variants (ASVs) were shared between sites. This reef specificity was driven by 165 ASVs, mainly from the family Rhodobacteraceae. Comparison with previous studies suggests that the moderate heat stress experienced on the central GBR in 2016 caused the near-complete absence of Endozoicomonas. Symbiodiniaceae and bacteria (particularly Rhodobacteraceae) can be vertically transmitted in P. acuta, and larval propagation can be spatially restricted for this brooding species. Our results demonstrate that, unlike bleaching severity, location-specific factors and species-specific life history traits might have been paramount in shaping the P. acuta microbiome.

The highfin blenny, Lupinoblennius nicholsi, is a marine fish species reported in reef and rocky inshore habitats with a disjunct distribution in the southern Gulf of Mexico. Overall, there are very few studies on this species and there is a scarcity of molecular resources for genetic comparisons. We set out to report the first mitochondrial genome for L. nicholsi and report a range expansion for the species. An individual of L. nicholsi was collected from the coast of Dauphin Island, Alabama. The mitochondrial genome was sequenced, assembled, and annotated. The fragment corresponding to cytochrome oxidase I (COI) was used to compare this sample to other cryptobenthic species of the Atlantic. Finding a mature individual in the coast of Alabama implies this species has a continuous distribution throughout the northern Gulf of Mexico. The mitochondrial genome of L. nicholsi is 16,416 bp in length and comprised of 13 protein coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a non-coding D-loop. Comparisons using COI support the species is L. nicholsi and separate it from other cryptobenthic fishes found in the area. This study represents the first mitochondrial genome for this L. nicholsi, serving as a reference for future comparative studies with marine fishes. By reporting the range expansion of this species, this study provides insights on the fish diversity of the Gulf of Mexico.

Oxygen concentrations in coastal waters have declined globally by 10% since the mid-twentieth century, and ocean warming will further reduce the solubility of oxygen in coastal habitats. Some nearshore reefs experience periodic hypoxic conditions due to eutrophication, especially during the wet season. Here, we determined the combined impacts of hypoxia and elevated temperature on the reef-building coral, Orbicella faveolata, by exposing corals to normoxic or hypoxic conditions and ambient or elevated temperatures. Oxygen consumption was monitored using closed-system respirometry. Corals within hypoxic conditions consumed 34% less oxygen relative to corals in normoxic conditions. Corals in the elevated temperature normoxic treatment experienced a 10% increase in oxygen consumption relative to the control. Corals exposed to both stressors simultaneously experienced a 62% reduction in oxygen consumption. These results suggest that increased temperature may exacerbate the negative effects of hypoxia on O. faveolata.

Environmental conditions have a strong influence on sea turtle population dynamics. Sea turtles spend most of their lives in foraging areas; however, there is a lack of information on how oceanographic and biological parameters determine habitat use and density. Here, we estimated density of green turtles Chelonia mydas and hawksbill turtles Eretmochelys imbricata in a South Atlantic foraging area (Arraial do Cabo, Brazil). We also investigated the influence of environmental variables (wind fetch, temperature, depth, and visibility) and benthic composition on the distribution of turtles. Surveyed sites were split between a colder, more wave-exposed location (western), and a warmer, more sheltered location (eastern). To ensure that these mobile and sparsely distributed species were adequately surveyed, underwater visual censuses (timed transects) were conducted. Sea turtle densities were significantly different between warm/sheltered and cold/wave-exposed locations. C. mydas were almost 10 times more frequently sighted than E. imbricata. The local distribution of E. imbricata mirrored large-scale latitudinal patterns, where this tropical species is dominant on warmer reefs (similar to habitat conditions found at the eastern location). It was not possible to assess the environmental influence on E. imbricata sightings due to their low density. C. mydas were frequently sighted in the cold/exposed sites and negatively correlated with depth. Overall, the density of E. imbricata and C. mydas suggests that Arraial do Cabo is an important feeding ground in the western Atlantic Ocean. This study highlights that visual census can produce reliable density estimates of sea turtles in foraging areas.

Coral reef ecosystem is one of the most complex, rich and productive environments. In Visakhapatnam coast a patch of coral reef bed is found (in between Santapalli to Kalingapatnam). This environment provides a rich coral reef fish biodiversity in the region. Also the shipwrecks found in the area work as an artificial reef and the growth of algae and other organisms and attracting reef fish communites in the area. During the study period 127 species of coral reef inhabiting fishes were recorded in Visakhapatnam fishing harbour. The present paper describes the report of six reef-associated fishes which are new records in Visakhapatnam coastal waters viz. Lepidotrigla bispinosa Steindachner, 1898, Stethojulis trilineata (Bloch & Schneider, 1801), Pristigenys refulgens (Valenciennes, 1862), Apogonichthyoides sialis (Jordan & Thompson, 1914), Pseudanthias marcia Randall & Hoover, 1993 and Acanthocepola indica (Day, 1888) out of which two are new to the Bay of Bengal coast of Indian mainland and another four are new distributional record to Bay of Bengal.

Small-scale reef fisheries are important commercial and subsistence activities that support the livelihoods of millions of people in tropical regions. Tropical marine fisheries typically target a diversity of species caught with a matching diversity of fishing gears and practices. Here, we explored how multiple fishing gears select for distinct functional traits of fish assemblages inside a large multiple use marine environmental protected area off northeastern Brazil. In 1833 landing interviews with local fishers, we identified 101 species, which were categorized according to six traits: body size, schooling behavior, mobility, position in the water column, diet and period of activity. Our research is the first to explore the broad patterns of gear selectivity with regards to fish functional traits for different habitat types. While gears used in reef habitats were highly selective of sedentary and benthic species that form schools with few individuals, gears used in coastal lagoons were selective of highly mobile pelagic species that form large schools. We found a low competitive interaction between different gear types, meaning there was a low overlap in trait selectivity between fishing gears. We also found direct associations between gears and fish functional traits: hooks and line targeted species that exhibit limited mobility capabilities, making these species more vulnerable to local levels of fishing effort. In contrast, nets and fish corrals targeted mobile species that exhibited a greater diversity of functional traits. Some of our results contrasted with the current literature on the topic, with differences highlighting the need for more research to clarify global patterns of trait selectivity by gear type. Our results have implications for fisheries management in northeastern Brazil: gear bans and effort caps are commonly used management measures that can foster fisheries sustainability by minimizing impacts to fish assemblage functions.

The Guana-Tolomato-Matanzas (GTM) system is a well-flushed estuary in Northeastern Florida, USA, and characterized as having an extraordinarily high abundance of oysters that resembles the populations described by Euro-American settlers. Historically, dense populations of oysters, such as those found in GTM, are believed to play an important role in water filtration; however, most research teams seeking to simulate this role have not had access to such robust populations to parametrize their models. To quantify the filtration service (FS) of Eastern oysters (Crassostrea virginica) in GTM at several spatial scales (i.e., reef, watershed, estuary), we implemented a model that solves for the hydrodynamics and depletion of particulate matter passing over model oyster populations, the latter of which were derived from detailed bay-wide surveys. The model results suggested that oyster reefs populating the GTM play an important role in water quality by filtering ~60% of the estuary’s volume within its residence time. Our approach teases apart the role of reef size, residence time, particle concentration, and other physical factors on the generation of FS at different spatial scales. Downstream effects were found to be very important for estuary FS, which depend on the spatial distribution of the reefs in the GTM and local and estuarine-scale hydrodynamics. Therefore, the difference between “realized” FS and the “potential” FS of a given reef may be substantial when considering the complex hydrodynamic and connectivity among populations at several scales. Our model results provide clear and actionable information for management of these oyster populations and conservation of their ecosystem services.

Species identification is key for coral reef conservation and restoration. Recent coral molecular-morphological studies have indicated the existence of many cryptic species. Coelastrea aspera (Verrill, 1866) is a zooxanthellate scleractinian coral that is widely distributed in the Indo-Pacific. In Japan, this species is distributed from the subtropical reef region to the high-latitudinal non-reef region. Previous studies have reported that C. aspera colonies in the non-reef region release egg-sperm bundles (bundle type), whereas those in the reef region release eggs and sperm separately (non-bundle type) and release planula larvae after spawning. This difference in reproduction might be relevant to species differences. To clarify the species delimitation of C. aspera, the reproduction, morphology and molecular phylogeny of C. aspera samples collected from reef and non-reef regions in Japan were analysed, along with additional morphological and molecular data of samples from northern Taiwan. The results show that C. aspera is genetically and morphologically separated into two main groups. The first group is the non-bundle type, distributed only in reef regions, whereas the second group is the bundle type, widely distributed throughout the reef and non-reef regions. Examination of type specimens of the taxon’s synonyms leads us to conclude that the first group represents the true C. aspera, whereas the second is Coelastrea incrustans comb. nov., herein re-established, that was originally described as Goniastrea incrustans Duncan, 1886, and had been treated as a junior synonym of C. aspera.

Carbonate strata are a vital and favorable reservoir for global oil and gas exploration, and carbonate sedimentary systems record ancient oceanic and paleoclimatic conditions, including paleoenvironmental variations throughout geologic periods. Carbonate platforms are widely distributed among the Xisha Islands in the South China Sea and contain large amounts of oil and gas resources. Biogenic reefs are the dominant parts of the carbonate platforms in the Xisha Islands; however, research on the factors that control and affect biogenic reef development is lacking. In this study, a core from well XK-1, which is located on Yongxing Island in the Xisha Islands, a sedimentary noise model, and time-series analyses were used to determine the effects of sea-level fluctuations from 5.3 Ma to present. The results show that coral reefs in the Xisha Islands are sensitive to eustatic fluctuations and that a decrease in sea level essentially corresponds to an increase in sedimentation rate. Indexes of the East Asian monsoon and other environmental indexes show that the Pleistocene and Holocene were suitable for coral growth; however, the trends shown by these indexes and the sea-level variation indicate that the future growth of coral reefs will be at a disadvantage. Research on the controlling factors of biogenic reefs is of significance for understanding reef growth, performing global reef comparisons, and encouraging the future protection of coral reefs.

The Great Barrier Reef World Heritage Area (GBRWHA) in north eastern Australia spans 2500 km of coastline and covers an area of ~ 350,000 km2. It includes one of the world’s largest seagrass resources. To provide a foundation to monitor, establish trends and manage the protection of seagrass meadows in the GBRWHA we quantified potential seagrass community extent using six random forest models that include environmental data and seagrass sampling history. We identified 88,331 km2 of potential seagrass habitat in intertidal and subtidal areas: 1111 km2 in estuaries, 16,276 km2 in coastal areas, and 70,934 km2 in reef areas. Thirty-six seagrass community types were defined by species assemblages within these habitat types using multivariate regression tree models. We show that the structure, location and distribution of the seagrass communities is the result of complex environmental interactions. These environmental conditions include depth, tidal exposure, latitude, current speed, benthic light, proportion of mud in the sediment, water type, water temperature, salinity, and wind speed. Our analysis will underpin spatial planning, can be used in the design of monitoring programs to represent the diversity of seagrass communities and will facilitate our understanding of environmental risk to these habitats.

Coral reef fish perform numerous important functional roles on coral reefs. Of these, carbonate sediment production, as a by‐product of parrotfish feeding, is especially important for contributing to reef framework construction and reef‐associated landform development. However, only limited data exist on: (i) how production rates vary among reef habitats as a function of parrotfish assemblages, (ii) the relative importance of sediment produced from eroded, reworked, and endogenous sources, or (iii) the size fractions of sediment generated by different parrotfish species and size classes. These parameters influence not only overall reef‐derived sediment supply, but also influence the transport potential and depositional fate of this sedimentary material. Here, we show that parrotfish sediment production varies significantly between reef‐platform habitats on an atoll‐margin Maldivian reef. Highest rates of production (over 0.8 kg m−2 year−1) were calculated in three of the eight platform habitats; a rubble‐dominated zone, an Acropora spp. dominated zone, and a patch reef zone. Habitat spatial extent and differences in associated parrotfish assemblages strongly influenced the total quantities of sediment generated within each habitat. Nearly half of total parrotfish sediment production occurred in the rubble habitat, which comprised only 8% of the total platform area. Over 90% of this sedimentary material originated from eroded reef framework as opposed to being reworked existing or endogenously produced sediment, and comprised predominantly coral sands (predominantly 125–1000 µm in diameter). This is comparable to the dominant sand types and size fractions found on Maldivian reef islands. By contrast, nearly half of the sediment egested by parrotfish in the Acropora spp. dominated and patch reef habitats resulted from reworked existing sediments. These differences between habitats are a result of the different parrotfish assemblages supported. Endogenous carbonate production was found to be insignificant compared to the quantity of eroded and reworked material. Our findings have important implications for identifying key habitats and species which act as major sources of sediment for reef‐island systems., Our findings show that parrotfish sediment production varies between reef habitat types as a function of the species assemblages and fish sizes supported. The origins of this material (i.e., bioerosion of reef substrate, sediment reworking, or endogenous production) also varies between habitat types because of the species and sizes of parrotfish present. In addition, we show that all species studied produce sediment size fractions suitable for shoreline maintenance.

The apparent ability of corals to acquire and maintain enhanced stress tolerance through a dose-dependent environmental memory, which may persist for multiple years, has critical implications for coral reef conservation research. Such responses are variable across coral species and environmental stressors, with primed corals exhibiting a modified response to secondary stress exposures. While the mechanisms underlying coral memory responses are poorly understood, they likely involve both the coral host and microbiome. With advances in molecular technologies, it is now possible to investigate potential memory mechanisms in non-model organisms, including transcriptional regulation through epigenetic modifications. We integrate evidence of coral environmental memory and suggest future research directions to evaluate the potential for this process to enhance coral resilience under climate change.

Giant clam shell mining (GCSM), a unique phenomenon occurring at remote coral reefs in the southern South China Sea (SCS), forms striking scars on the reef flats and damages the reef flat substrate. Through image analyses at three times (2004.02.02, 2014.02.26, and 2019.04.10) and in situ surveys at Ximen Reef, a representative site that has experienced GCSM, we quantified the GCSM-generated substrate damage and the corresponding recovery. GCSM was estimated to have occurred sometime between 2012 and 2014, causing reduction in live coral subarea and formation of micro-relief as trenches and mounds. GCSM-generated damage was restricted to the reef flat. After GCSM, coral and algae subarea increased, and the trenches and mounds tended to be filled and eroded, representing a natural recovery of the substrate. The legal prohibition on human disturbances at the coral reefs contributed to substrate recovery at Ximen Reef. This case also implied that recovery of the other coral reefs that suffered from GCSM is possible.

Economic valuation plays an important role as a comprehensive instrument to assess prices (price tags) on the existence of goods and services of an ecosystem. This research aims to analyze utilization conditions including utilization value, non-utilization value and total economic value of coral reef resources and formulate a strategy for managing the reef ecosystem of Warbal Island and surrounding waters. The research on the economic valuation of warbal island coral reef ecosystem and surrounding waters was conducted in July-November 2019. Primary data collection was done through field observations and interviews, while secondary data was obtained through references from the Village Government, Southeast Maluku Fisheries Service, WWF Indonesia and scientific publications. Data was analyzed using methods of analysis of total economic value from use valueand non-use value. Based on the results of the study obtained the total economic value of the utilization and non-utilization of coral reef resources in Warbal Island and surrounding waters reached IDR. 7.275.603.819/year. The value of utilization of coral reef resources of Warbal Island and surrounding waters amounted to IDR. 7.257.318.819/year, while the non-utilization value of coral reef resources amounted to IDR. 18.250.000/year. At least, there are 11 strategies and 22 management directives recommended for the management of Warbal Island coral reef resources and surrounding waters. ABSTRAK Valuasi ekonomi berperan penting sebagai instrument yang komperhensif untuk memberi penilaian harga (price tag) terhadap keberadaan barang dan jasa suatu ekosistem. Penelitian ini bertujuan untuk menganalisisnilai pemanfaatan, nilai non pemanfaatan dan nilai ekonomi total sumberdaya terumbu karang serta merumuskan strategi pengelolaan ekosistem terumbu kawasan Pulau Warbal dan perairan sekitarnya. Penelitian tentang valuasi ekonomi ekosistem terumbu karang Pulau Warbal dan perairan sekitarnya dilakukan pada Juli-Nopember 2019. Pengumpulan data primer dilakukan melalui pengamatan lapangan dan wawancara, sedangkan data sekunder diperoleh melalui referensi dari Pemerintah Desa, Dinas Perikanan Maluku Tenggara, WWF Indonesia dan publikasi ilmiah. Data dianalisis menggunakan metode analisis nilai ekonomi total dari use value dan non use value. Berdasarkan hasil penelitian diperoleh nilai ekonomi total dari pemanfaatan dan non pemanfaatan sumberdaya terumbu karang kawasan Pulau Warbal dan perairan sekitarnya mencapai Rp. 7.275.603.819/tahun. Nilai pemanfaatan sumberdaya terumbu karang Pulau Warbal dan perairan di sekitarnya sebesar Rp. 7.257.318.819/tahun, sedangkan nilai non pemanfaatan sumberdaya terumbu karang sebesar Rp. 18.250.000/tahun. Terdapat 11 strategi dan 22 arahan pengelolaan yang direkomendasikan untuk pengelolaan sumberdaya terumbu karang Pulau Warbal dan perairan di sekitarnya. Kata kunci: valuasi ekonomi, ekonomi total, nilai pemanfaatan, terumbu karang, Maluku Tenggara

The tourism activities linked to artificial provisioning of blacktip reef sharks (Carcharhinus melanopterus) and pink whiprays (Pateobatis fai) on a specific site in French Polynesia were suddenly and completely stopped due to a COVID-19 lockdown that lasted 6 weeks from March 20 until April 30, 2020. Using both drone footage and underwater counting, we were able to track the abundance of those two species before, during, and after reopening and thus investigate the impact of provisioning on wild shark populations. The absence of any stimulus during this long period resulted in almost total desertion of the site by the elasmobranchs. However, 1 day prior to reopening, some individuals of both species positively reacted to the single acoustic stimulus of an engine boat, showing the resilience of conditioning, and some elasmobranchs reacted to acoustic and olfactive stimuli linked to the provisioning practice from the first day after reopening. During the first 2 weeks after reopening, the abundance of both species remained at reduced levels comparable to those observed between 2008 and 2010 for sharks;i.e., around 9 animals in the presence of local tourists. Pre-lockdown abundance levels, reaching approximatively 15 individuals for sharks and 10 for rays, were considered restored 1 and 2 months after reopening for blacktip reef sharks and pink whiprays, respectively. These findings improve our capacity to better understand the potential effects of artificial provisioning tourism on the abundance of elasmobranchs by showing that conditioning is resilient for several weeks, suggesting that intermittent interruption of elasmobranchs feeding would not really help to decrease its impact on animal welfare.

The world's coral reefs are under threat as climate change causes increases in frequency and severity of acute thermal stress. This is compounded by chronic pressures including rises in sea surface temperature, overfishing and decline in water quality. Monitoring to understand the recovery dynamics of corals is paramount to enable effective management of coral reefs. While detailed mechanistic models provide insight into reef recovery patterns, colony scale monitoring is not viable for reefs over a large geographical extent, such as the Great Barrier Reef (GBR). Consequently, aggregated coral cover data are utilised in practice and phenomenological analysis directly applicable to these monitoring programmes is essential for reef health reporting. These analyses are especially challenging for assessment of recovery potential of reefs reduced to very low coral cover (