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The biodiversity of the Mediterranean Sea is under severe threat from climate change and anthropic pressure, in particular pollution. Plastic and emerging contaminants (ECs) ever-growing abundance and widespread distribution are raising concerns as one of the most important threats to the marine environment. Indeed, several studies have been conducted in recent years, however, there remains a significant scarcity of studies, especially concerning anthozoan in the Mediterranean region. This study aimed to investigate for the first time the occurrence of emerging contaminants (ECs) in five key anthozoan species in the Mediterranean (Cladocora caespitosa, Eunicella cavolini, Madracis pharensis, Parazoanthus axinellae, and Paramuricea clavata). Specifically, we focused on phthalic acid esters (PAEs), active pharmaceutical ingredients (APIs), and UV-filters molecules, analyzing coral tissues by solid phase microextraction (SPME) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) to detect contamination. Our investigation revealed variable capacities for bioaccumulation among the species, indicating complexity in the absorption dynamics of these contaminants. We discussed inter and intra-specific variability and their potential explanations in relation to growth form and life stage of the colonies, as well as the environmental conditions such as currents and habitat where they are usually found. It is important to notice that even low concentrations of these contaminants may have significant adverse effects due to continuous exposition. Therefore, we examined the potential sublethal impacts, including reduced energy production and photosynthetic activity, growth inhibition, compromised detoxification, and excessive immune system responses. Further research is needed to fully understand the dynamics of accumulation and the biological consequences of these contaminants, especially considering the additional threats posed by climate change. This is impo

Coral reefs are threatened by climate change and the effects of human activity on the marine environment. Researchers are attempting to rescue this fragile ecosystem through coral restoration actions, and a common step in these procedures is transplanting the new coral colonies into coral reefs. To do that, commercial concrete or epoxy resins, also called putty, are utilized, highlighting different concerns about their mechanical and hardening performances and their impact and fate once released into the environment. Hence, this study presents a new biodegradable epoxidized soybean oil acrylate (ESOA)/zein-based coral putty capable of quick hardening underwater as an ecofriendly alternative for transplantation of new coral colonies in the reef. Coral putty is composed of two components, containing one a radical initiator and the other a radical accelerator. Once the two components are mixed, coral putty becomes hard underwater in 20–25 min, showing a hardening timescale much faster than other commercial products. The coral putty is biocompatible when applied to the coral Stylophora pistillata in aquaria and Acropora tenuis corals are out-planted on the reef in the Maldives, demonstrating how this new class of vegetable-oil-based materials can be a more sustainable alternative to epoxy resins commonly used in coral restoration procedures.

Coral reefs are suffering from both natural and anthropogenic stressors which are posing threats to the survival of countries that completely rely on them for their ecosystem services, such as the Republic of Maldives. In the last years, Maldivian reefs have undergone severe mass bleaching such as the 2016 event which impacted 73% of the corals. This couples with threats posed by corallivore outbreaks, coral diseases, human activities, and pollution. In this context, billions of coral colonies, potentially including the most enigmatic, resistant, and ancient ones—colonies over 5m, likely centennial—such as the giant corals, are at risk. These individuals hold unique information from biological, genetic, and paleoclimatic perspectives, having withstood environmental perturbations. They might hold the key to coral reef resilience. We present preliminary findings of giant coral colonies in the Maldives, located with the assistance of citizen scientists. The data provided was collected based on two levels of complexity, dependent on participants' level of expertise. Colonies have been identified across multiple atolls, with a seemingly higher abundance in the southern part of the archipelago. As expected, Porites sp. is the most common genus identified, with colonies exhibiting various growth forms, often found on slopes of channels and reaching lengths of over 10 m. The objective of this work is to raise awareness about the importance and fragility of these organisms, moreover to provide the Maldivian government with a map of potentially sensitive areas worthy of protection. Additionally, the data serve as the foundation for future studies by experts in different fields.

Phthalates are widely employed plasticizers blended to plastic polymers that, during plastic aging and weathering are prone to leach in the surrounding environment. Thus, phthalates were proposed to indirectly evaluate MPs contamination in marine environments, with still uncertain and scarce data, particularly for wildlife. This study investigates simultaneously microplastics (MPs) and phthalates (PAEs) occurrence in wild Actinia equina and Anemonia viridis, two common and edible sea anemone species. Both species had a 100 % frequency of MPs occurrence, with similar average concentrations. PAEs were detected in 70 % of samples, with concentrations up to 150 ng/g in A. equina and 144.3 ng/g for A. viridis. MPs and PAEs present in sea anemone tissues appear to reflect seawater plastic contamination conditions in the study area. Given the rapid biodegradation of PAEs, occurrence and concentrations of both these additives and their metabolites could be useful tracers of short-term plastic debris-biota interactions.

Coral reefs worldwide are declining due to high sea surface temperatures, causing coral bleaching and the endosymbiosis rupture between the coral polyps and the unicellular algae Symbiodinaceae. Bleached corals will likely die because Symbiodinaceae algae provide most of the energy coral colonies need. Among the newly developed strategies to prevent coral bleaching is thermal preconditioning, i.e., applying sub-lethal temperature on corals before heat stress, which has shown promising results in slowing coral bleaching. However, the cellular mechanisms that increase heat tolerance by thermal preconditioning are still unknown. This study showed that thermal preconditioning on the coral species Pocillopora damicornis postponed the adverse effects of heat stress-inducing bleaching. Thermal preconditioning was performed by exposing the coral colonies to the sub-lethal temperature of 28°C for one week, after which thermal stress was applied at 31°C for another seven days. We assessed coral bleaching by analyzing the Symbiodinaceae density, taxonomical identification, and chlorophyll concentration (Chl). Moreover, we compared the expression of Heat shock protein 70 (Hsp70), a molecular chaperone involved in cell protein protection, the activity of three antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase and the lipid peroxidation in preconditioned, non-preconditioned and control colonies. Our results showed that Chl concentration and symbiont density were higher in preconditioned corals than in non-preconditioned corals. In addition, no difference in Symbiodinaceae identity was observed. Then, preconditioned colonies had higher antioxidant enzyme activity and higher expression of Hsp70 compared to non-preconditioned colonies. According to our findings, thermal preconditioning can potentially delay coral bleaching by reducing oxidative stress and ensuring cellular homeostasis. This indicates that thermal preconditioning could be a helpfu

Coral reefs worldwide are declining due to high sea surface temperatures, causing coral bleaching and the endosymbiosis rupture between the coral polyps and the unicellular algae Symbiodinaceae. Bleached corals will likely die because Symbiodinaceae algae provide most of the energy coral colonies need. Among the newly developed strategies to prevent coral bleaching is thermal preconditioning, i.e. applying sub-lethal temperature on corals before heat stress which has shown promising results in slowing coral bleaching. However, the cellular mechanisms that increase heat tolerance by thermal preconditioning are still unknown. This study showed that thermal preconditioning on the two coral species, namely Pocillopora damicornis and Stylophora pistillata, postponed the adverse effects of heat stress-inducing bleaching. Thermal preconditioning was performed by exposing the coral colonies to the sub-lethal temperature of 28°C for one week, after which thermal stress was applied at 31°C for another seven days. We assessed coral bleaching by analyzing the Symbiodinaceae density, taxonomical identification, and chlorophyll concentration (Chl). Moreover, we compared the expression of Heat shock protein 70 (Hsp70), a molecular chaperone involved in cell protein protection, the activity of three antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase and the lipid peroxidation in preconditioned, non-preconditioned and control colonies. Our results showed that Chl concentration and symbiont density were higher in preconditioned corals than non-preconditioned corals in both coral species. In addition, no difference in Symbiodinaceae identity was observed. Then, preconditioned S. pistillata and P. damicornis had higher antioxidant enzymes activity and higher expression of Hsp70 compared to non-preconditioned colonies. Therefore, our results suggest that thermal preconditioning delayed coral bleaching in both S. pistillata and P. damicornis by mitigat

The Mediterranean Sea's biodiversity is declining due to climate change and human activities, with plastics and emerging contaminants (ECs) posing significant threats. This study assessed phthalic acid esters (PAEs) and active pharmaceutical ingredients (APIs) occurrence in four anthozoan species (Cladocora caespitosa, Eunicella cavolini, Madracis pharensis, Parazoanthus axinellae) using solid phase microextraction (SPME) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). All specimens were contaminated with at least one contaminant, reaching maximum values of 57.3 ng/g for the ∑PAEs and 64.2 ng/g (wet weight) for ∑APIs, with dibutyl phthalate and Ketoprofen being the most abundant. P. axinellae was the most contaminated species, indicating higher susceptibility to bioaccumulation, while the other three species showed two-fold lower concentrations. Moreover, the potential adverse effects of these contaminants on anthozoans have been discussed. Investigating the impact of PAEs and APIs on these species is crucial, given their key role in the Mediterranean benthic communities.

Microplastic pollution is an increasing threat to coral reefs, which are already strongly challenged by climate change -related heat stress. Although it is known that scleractinian corals can ingest microplastic, little is known about their egestion and how microplastic exposure may impair corals at physiological and cellular levels. In addition, the effects of microplastic pollution at current environmental concentration have been little investigated to date, particularly in corals already impacted by heat stress. In this study, the combined effects of these environmental threats on Pocillopora damicornis were investigated from a physical and cellular perspective. Colonies were exposed to three concentrations of polyethylene microplastic beads (no microplastic beads: [No MP], 1 mg/L: [Low MP]; 10 mg/L: [High MP]), and two different temperatures (25 degrees C and 30 degrees C) for 72 h. No visual signs of stress in corals, such as abnormal mucus production and polyp extroflection, were recorded. At [Low MP], beads adhered to colonies were ingested but were also egested. Moreover, thermally stressed colonies showed a lower adhesion and higher egestion of microplastic beads. Coral bleaching was observed with an increase in temperature and microplastic bead concentration, as indicated by a general decrease in chlorophyll concentration and Symbiodiniaceae density. An increase in lipid peroxidation was measured in colonies exposed to [Low MP] and [High MP] and an up -regulation of stress response gene hsp70 was observed due to the synergistic interaction of both stressors. Overall, our findings showed that heat stress still represents the main threat to P. damicornis, while the effect of microplastics on coral health and physiology may be minor, especially at control temperature. However, microplastics could exacerbate the effect of thermal stress on cellular homeostasis, even at [Low MP]. While reducing ocean warming is critical for preserving coral reefs, effective man

Outbreaks of coral diseases have recently emerged as a significant threat for the fitness and survival of corals, exacerbated by climate change effects. Factors like ocean warming and acidification are identified as significant environmental stressors that may heighten the susceptibility of corals to diseases. In recent times, attention is rising towards a particular type of coral lesion, growth anomalies (GAs) or skeletal tissue anomalies. The etiology of such lesions is still under investigation and poorly known, with potential links to anthropogenic stressors and extreme temperature conditions. GAs are recognized as true tumors that not only impact the morphology of the polyps but also disrupt biological functioning, compromising the reproductive capabilities, feeding abilities and the capacity of defending against external agents. Although they are becoming more common and are observed worldwide, there is still a lack of comprehensive understanding regarding their presence in the Maldivian area. Here, we present the first evidence of four distinct GAs across three coral species, Acropora sp., Montipora sp., and Pachyseris speciosa, observed across multiple locations within the Maldivian Archipelago. Moreover, we analyzed samples of tumoral and healthy skeleton samples of two genera, Acropora and Pachyseris, throughout Scanning Electron Microscope (SEM) imagery. We investigated morphometrical parameters such as corallite dimensions and general structure, such as presence of columella and septa apperance. Although the results must be implemented by additional analysis, the outcomes of our study gave a first insight on differences in the morphology of growth anomalies and possible implications on coral survival.

At present the information regarding the occurrence of human pharmaceuticals (PhaCs) in coral reefs and their potential impacts on the associated fauna is limited. To optimize the collection of data in these delicate environments, we employed a solid-phase microextraction (bioSPME) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) procedure that enabled in vivo determinations in soft corals. Specifically, we researched the antibiotics Ofloxacin Sulfamethoxazole and Clarithromycin, the anti-inflammatory Diclofenac Propyphenazone Ketoprofen and Amisulpride, the neuroactive compounds Gabapentin-lactam, the beta-blocker Metoprolol and the antiepileptic Carbamazepine. Reproducibility was between 2.1% and 9.9% and method detection limits LODs) were between 0.2 and 1.6 ng/g and LOQs between 0.8 and 5.4 mg/g. The method was then applied to establish a baseline for the occurrence of these compounds in the Maldivian archipelago. Colonies of Sarcophyton sp. and Sinularia sp. were sampled along an inner-outer reef transect. Five of the ten targeted PhaCs were identified, and 40% of the surveyed coral colonies showed the occurrence of at least one of the selected compounds. The highest concentrations were found inside the atoll rim. Oxoflacin (9.5 ± 3.9 ng/g) and Ketoprofen (4.5 ± 2.3 ng/g) were the compounds with the highest average concentrations. Outside the atoll rim, only one sample showed contamination levels above the detection limit. No significant differences were highlighted among the two surveyed soft coral species, both in terms of average concentrations and bioconcentration factors (BCFs).

Maldives are recognized as one of the most attractive countries for scuba divers and shark enthusiasts thanks to the biodiverse coral reef systems and the great abundance of megafauna. Consequently, the development of shark-related and eco-tourism activities emerged as a valuable and effective alternative to the fishing industry, becoming an important socio-economic source of income, not only within Maldives but also in many other countries. This richness in diversity and abundance of sharks, make this region the ideal area for studying shark bahavior and interspecific relations among different species sharing the same habitat. Advances in underwater video technology and involvement of people in citizen science have expanded our ability to investigate several aspects of the mysterios shark ecology and biology. One of them is shark behavior, primarily due to the challenges associated with observing, studying, and comprehending it. Among various intriguing behaviours observed, the phenomenon of sharks rubbing against ocean floor or rocks is common, whereas instances of interspecific sharks chafing behavior are much less frequent. This behavior, where a smaller shark rubbing against a larger species, utilizing dermal denticles to rid itself of parasites or dead skin cells, has garnered scientific interest in recent years. However, the full implications of this behavior, including its costs and benefits, remain yet not fully understood. In this context, we present new evidences of grey reef sharks (Carcharhinus amblyrhynchos; Bleeker, 1856) engaging in chafing behavior against whale shark (Rhincodon typus, Smith 1828) in the Maldives. These observations suggest that grey reef sharks may engage in chasing and chafing behavior for cleaning purposes or take advantage of larger sharks as an anti-predation tactic. These findings contribute to shed light on previously unexplored aspects of interspecies interactions among elasmobranch and highlights the need for further resear

In the last 15 years, coral associated microbiome emerged as an extremely important research field for its key role in the health-status of corals and their potential response to diseases and environmental changes. Despite these evidences, nowadays our knowledge of microbial communities associated with corals remains remarkably scarce, especially in the Mediterranean and Maldivian area, due to the novelty of this topic and the difficulties related to the analysis protocols. In this context, this study aimed to describe and compare for the first time the microbiomes associated with three species of scleractinian corals: two from the Mediterranean Sea (Cladocora caespitosa and Madracis pharensis) and one from the Maldives (Herpolitha limax). Taxonomic analyses were conducted by Illumina sequencing of the V5-V6 16S rRNA hypervariable regions. From the analysis of beta diversity, calculated on the relative abundance of the 19 most abundant families, it was possible to infer the existence of two distinct microbiomes, one on the Mediterranean coral specimens (mainly unclassified Rhodospirillales and unclassified Poribacteria) and the other one on Herpolitha limax individuals (mainly Burkholderiaceae and Nocardiaceae). Moreover, the microbiome of healthy and diseased (Brown Band Disease) individuals of Acropora tenuis collected in the Maldives was analysed, revealing the presence of families as Nocardiaceae and especially Moraxellaceae (Acinetobacter sp.), already cited in another work as the main trigger of BBD in Acropora sp. Further studies are needed to better understand how the different biotic and abiotic factors shape microbiome composition; this information could be crucial to define the microbiome role in coral survival, especially in the modern context of global climate change. Furthermore, these findings could also be used to improve the main mitigation tools currently used to cope with the problem, such as coral restoration.

Coral reefs are the most spectacular and diverse ecosystems of tropical oceans. Corals rely on the mutualistic relationship between scleractinian corals and photosynthetic dinoflagellates of the family Symbiodiniaceae (zooxanthellae) which are crucial to the health of the host cnidarian. To better understand zooxanthellae, laboratory culture model systems are one valuable tool allowing for experimental manipulation. However, the maintenance of algal cultures is expensive and labor-intensive. Cryopreservation offers a solution for long-term storage of cultures, but a system is needed to reliably assess cell viability after thawing. Multiple methods to assess the viability of zooxanthellae exist, but many of these are tested on dead zooxanthellae killed with heat which is of little use when trying to assess the viability of cells killed by freezing. Therefore, we evaluated the utility of existing viability methods to assess live vs frozen-killed Breviolum sp. (formerly Clade B) isolated from the sea anemone Aiptasia spp. Of 38 dyes tested on zooxanthellae maintained in culture, none could distinguish live from frozen-dead cells despite replicating exactly published methods or varying concentrations and staining times. For cultured cells, live vs frozen-dead cells could easily be differentiated by a shift in autofluorescence from red to bright green for the latter. In contrast, freshly isolated live vs frozen-dead zooxanthellae could be differentiated using Acridine Orange and DAPI. These could be a promising method for evaluating the viability of cryopreserved zooxanthellae.

The Mediterranean is known for its marine biodiversity, especially gorgonian forests. Unfortunately, these are experiencing rapid declines due to climate change, manifested by repeated marine heat waves resulting in mass mortality events since the early 1990 s. To better understand why gorgonians are declining, more systematic approaches to investigate the exact causes are needed, and pathology may aid in this goal. We described gross and microscopic pathology of tissue loss in three key gorgonian species in the Mediterranean region, Paramuricea clavata, Eunicella cavolini, and Leptogorgia sarmentosa, that were all experiencing various degrees of acute to subacute tissue loss characterized by exposed axial skeleton sometimes partly colonized by epibionts and thinning of adjacent tissues. The most significant variety of lesions was seen in P. clavata followed by L. sarmentosa and E. cavolini. For all species, dissociation of gastrodermal cells was the dominant microscopic lesion followed by necrosis of the gastrodermis. Ciliates invading gastrodermis and associated with necrosis of polyps were seen only in E. cavolini. Epidermal tissue loss was seen only in L. sarmentosa, while P. clavata was distinguished by a prominent inflammatory response and unidentified dark round structures within the tentacle epidermis and gastrodermis with no host response. Further work to understand the cause of death in gorgonians is needed, particularly to elucidate the role of ciliates and environmental co-factors or infectious agents not visible on light microscopy, as well as applications of additional tools such as cytology.

Outbreaks of coral diseases have recently emerged as a significant threat for the fitness and survival of corals, exacerbated by climate change effects. Factors like ocean warming and acidification are identified as significant environmental stressors that may heighten the susceptibility of corals to diseases. In recent times, attention is rising towards a particular type of coral lesion, growth anomalies (GAs) or skeletal tissue anomalies. The etiology of such lesions is still under investigation and poorly known, with potential links to anthropogenic stressors and extreme temperature conditions. GAs are recognized as true tumors that not only impact the morphology of the polyps but also disrupt biological functioning, compromising the reproductive capabilities, feeding abilities and the capacity of defending against external agents. Although they are becoming more common and are observed worldwide, there is still a lack of comprehensive understanding regarding their presence in the Maldivian area. Here, we present the first evidence of four distinct GAs across three coral species, Acropora sp., Montipora sp., and Pachyseris speciosa, observed across multiple locations within the Maldivian Archipelago. Moreover, we analyzed samples of tumoral and healthy skeleton samples of two genera, Acropora and Pachyseris, throughout Scanning Electron Microscope (SEM) imagery. We investigated morphometrical parameters such as corallite dimensions and general structure, such as presence of columella and septa apperance. Although the results must be implemented by additional analysis, the outcomes of our study gave a first insight on differences in the morphology of growth anomalies and possible implications on coral survival.

In the last decades, there has been a concerning increase in the frequency and severity of coral disease outbreaks on a global scale, resulting in significant damage to the coral reef ecosystem and biodiversity. Growth anomalies (GAs) have been increasingly observed, with significantly higher occurrences in larger and older coral colonies compared to their smaller counterparts. However, there is a notable lack of knowledge and reports regarding growth anomalies in the Maldivian region. Here, we provide the first evidence of four distinct growth anomalies on three coral species, respectively on Acropora sp., Montipora sp., and Pachyseris speciosa, observed across four different locations across three atolls within the Maldivian Archipelago.

Sharks are particularly susceptible to bioaccumulation due to their life history characteristics and trophic position within marine ecosystems. Despite this, studies of bioaccumulation cover only a small proportion of extant species. In this study we report concentrations of trace elements and heavy metals in blood samples of Sphyrna lewini for the first time. We report high concentrations of several trace elements and heavy metals, with concentrations of some elements exceeding the limit determined safe for human consumption. High elemental concentrations may reflect biochemical differences between blood plasma and other tissues; however, they may also be symptomatic of high levels of exposure triggered by anthropogenic activities. We also provide evidence of elemental accumulation through ontogeny, the nature of which differs from that previously reported. Ultimately, this baseline study increases our understanding of interspecific and intraspecific variation in bioaccumulation and ecotoxicology in elasmobranchs which may prove important in ensuring adequate management.

The family Euphylliidae consists of reef-building zooxanthellate scleractinian corals distributed across the Indo-Pacific. Seven extant genera comprising a total of 22 valid species are currently recognised. Recent studies have re-organised the taxonomy of the family at the genus level based on molecular and morphological data, including a comprehensive revision of Euphyllia and the resurrection of Fimbriaphyllia. Here, three mitochondrial loci (coi, 12S rRNA, and 16S rRNA) were sequenced and morphological examinations were conducted at three scales (macro/micromorphology and microstructure of the skeleton, and polyp morphology) to study the phylogeny and taxonomy of Euphylliidae. We analysed a total of 11 valid species collected from seven Indo-Pacific localities. The monotypic genus Coeloseris, currently in Agariciidae, was also investigated since previous molecular data suggested a close relationship with the Euphylliidae. Molecular and morphological phylogenetic trees were broadly concordant in the definition of genus-level clades. All analysed genera, i.e., Ctenella, Euphyllia, Fimbriaphyllia, Galaxea, and Gyrosmilia, were reciprocally monophyletic based on molecular results. Coeloseris was nested within the family and, therefore, is formally moved into Euphylliidae. Updated morphological diagnoses are provided for each investigated genus. This study further demonstrated that a phylogenetic classification of scleractinian corals can be achieved by applying a combined morpho-molecular approach. Finally, we encourage phylogenetic and taxonomic studies of the euphylliid taxa not yet analysed molecularly, such as the monotypic genera Montigyra and Simplastrea.

As coral reefs continue to degrade at an alarming rate, coral restoration efforts are increasing worldwide in an attempt to keep up with the global challenge of preserving these iconic ecosystems and the many services they provide. Coral gardening, the farming and outplanting of coral fragments, is a commonly applied practice; however, regional validation is required before upscaling can be considered. This study follows up from the successful farming of fragments in mid-water rope nurseries, by reporting on the successive outplanting of these corals. Specifically, 60 Pocillopora verrucosa colonies were outplanted to a degraded reef at different depths (1–12 m), applying three arrangement patterns (equal, clustered, random). After 1 year, 72% were considered successfully outplanted (alive and still attached), with detachment being the main challenge at wave-impacted shallow depths, while loose coral rubble caused more partial mortality at depth. Outplanting stress was observed at 1–6 m depth, but had no impact on survival or growth. Drupella sp. predation was most common at 3 m and 79% of colonies hosted mutualistic fauna after 1 year. Outplanting significantly benefitted the reef environment with a higher fish abundance and diversity along with a higher increase in natural coral cover (H = 2.7; 6.2% increase) in comparison with the control sites. These are promising results, considering that the restoration site has shown little natural recovery in the last few years (coral cover <4%). We hope that our findings provide useful initial insights and help to guide effective restoration practices in the Maldives.

Over the last decades, the biodiversity of the Mediterranean Sea has experienced rapid decline due to climate change and human activities. Marine heat waves, mass mortality events, and increasing pollution in coastal areas, particularly from plastics and emerging contaminants (ECs) are among the most significant threats, problem that has become even more pronounced in the aftermath of the recent pandemic. In this context, the present work aimed to assess, for the first time, the occurrence of phthalic acid esters (PAEs) and pharmaceutical and personal care products (PPCPs) in four key species of Mediterranean benthic community: Cladocora caespitosa, Eunicella cavolini, Madracis pharensis, and Parazoanthus axinellae. For PAEs and PPCPs determination in the coral tissue solid phase microextraction (SPME) and liquid chromatography couple to tandem mass spectrometry (LC- MS/MS) were performed. All the specimens were found to be contaminated with at least one type of ECs over the quantification limit. The PAEs displayed an average concentration of 17.23 ± 11.39 ng/g with a maximum value of 44.17 ng/g, while the PPCPs average concentration was 25.89 ± 16.99 ng/g with a maximum value of 57.49 ng/g. The most abundant were DBP (10.35 ± 5.59 ng/g) and ketoprofen (16.97 ± 17.05 ng/g) respectively. Interestingly, they were found in higher concentrations in the same species, P. axinellae, suggesting a higher susceptibility to adsorb both contaminants. Furthermore, the other three species demonstrated an adsorption capacity two-fold lower, possibly due to varying environmental conditions related to depth, currents, and shelter, which exposed them differently to the contaminants. Given the crucial role of these species in forming the habitat of benthic communities along the Mediterranean coastal environment, it is important to investigate the potential human impact in the form of PAEs and PPCPs more thoroughly.

Nudibranchs have a mostly carnivorous diet, and they prey on a wide variety of other animal taxa. Many species, mainly belonging to the Cladobranchia suborder, feed on cnidarians, including member of the class Hydrozoa. Several hydrozoan species display a symbiotic lifestyle, being associated with other benthic invertebrates, including for instance bryozoans, corals, octocorals, and sponges. In our knowledge, no record of nudibranch predation on symbiotic hydrozoans has been reported so far, possibly thanks to the protective action by the host towards its symbiotic hydrozoan. Here, we show the unexpected case of a nudibranch belonging to the recently described species Sakuraeolis marhe (Fernández-Simón and Moles, 2023) feeding on Zanclea sp. 2, a hydrozoan associated with the cheilostome bryozoan Celleporaria sp. This trophic association is confirmed by the presence and storage of the nematocysts into the nudibranch cnidosacs. Moreover, the nudibranch appears to selectively store mostly a single type of nematocyst, that is large size stenotele. The observation here reported represents the first well-documented record of a nudibranch feeding on a symbiotic hydrozoan and the first confirmed case of predation on Zanclea polyps. Moreover, we provide additional genetic information and the first description of the internal anatomy of S. marhe.

Coral reefs in the Caribbean are known to be affected by many coral diseases, yet the ecology and etiology of most diseases remain understudied. The Caribbean ciliate infection (CCI) caused by ciliates belonging to the genus Halofolliculina is a common disease on Caribbean reefs, with direct contact considered the most likely way through which the ciliates can be transmitted between infected and healthy colonies. Here we report an observation regarding a Coralliophila sp. snail feeding in proximity to a cluster of ciliates forming the typical disease band of CCI. The result of this observation is twofold. The feeding behavior of the snail may allow the passive attachment of ciliates on the body or shell of the snail resulting in indirect transport of the ciliates among colo-nies, which makes it eligible as a possible disease vector. Alternatively, the lesions created from snail feeding may enhance the progression of the ciliates already present on the coral as well as promoting additional infections allowing pathogens to enter through the feeding scar.

The hydrozoan family Cladocorynidae inhabits tropical to temperate waters and comprises the two genera Pteroclava and Cladocoryne. Pteroclava lives in association with some octocorals and hydrozoans, whereas Cladocoryne is more generalist in terms of substrate choice. This work provides a thorough morpho-molecular reassessment of the Cladocorynidae by presenting the first well-supported phylogeny of the family based on the analyses of three mitochondrial and four nuclear markers. Notably, the two nominal genera were confirmed to be monophyletic and both morphological and genetic data led to the formal description of a new genus exclusively associated with octocorals, Pseudozanclea gen. nov. Maggioni & Montano. Accordingly, the diagnosis of the family was updated. The ancestral state reconstruction of selected characters revealed that the symbiosis with octocorals likely appeared in the most recent common ancestor of Pteroclava and Pseudozanclea. Additionally, the presence of euryteles aggregation in the polyp stage and the exumbrellar nematocyst pouches with euryteles represent synapomorphies of all cladocorynid taxa and probably emerged in their most recent common ancestor. The analysis of several Pteroclava krempfi colonies from Indo-Pacific and Caribbean localities associated with several host octocorals revealed a high intra-specific genetic variability. Single- and multi-locus species delimitations resulted in three to five species hypotheses, but the statistical analysis of morphometric data showed only limited distinction among the clades of P. krempfi. However, P. krempfi clades showed differences in both host specificity, mostly at the octocoral family level, and geographic distribution, with one clade found exclusively in the Caribbean Sea and the others found in the Indo-Pacific.

Coral restoration initiatives are gaining significant momentum in a global effort to enhance the recovery of degraded coral reefs. However, the implementation and upkeep of coral nurseries are particularly demanding, so that unforeseen breaks in maintenance operations might jeopardize well-established projects. In the last 2 years, the COVID-19 pandemic has resulted in a temporary yet prolonged abandonment of several coral gardening infrastructures worldwide, including remote localities. Here we provide a first assessment of the potential impacts of monitoring and maintenance breakdown in a suite of coral restoration projects (based on floating rope nurseries) in Colombia, Seychelles, and Maldives. Our study comprises nine nurseries from six locations, hosting a total of 3,554 fragments belonging to three coral genera, that were left unsupervised for a period spanning from 29 to 61 weeks. Floating nursery structures experienced various levels of damage, and total fragment survival spanned from 40 to 95% among projects, with Pocillopora showing the highest survival rate in all locations present. Overall, our study shows that, under certain conditions, abandoned coral nurseries can remain functional for several months without suffering critical failure from biofouling and hydrodynamism. Still, even where gardening infrastructures were only marginally affected, the unavoidable interruptions in data collection have slowed down ongoing project progress, diminishing previous investments and reducing future funding opportunities. These results highlight the need to increase the resilience and self-sufficiency of coral restoration projects, so that the next global lockdown will not further shrink the increasing efforts to prevent coral reefs from disappearing.

Coral reefs are known to be among the most diverse marine ecosystems and one of the richest in terms of associations and species interactions, especially involving invertebrates such as corals and sponges. The study of cryptofauna diversity associated with coral reefs is recently gaining momentum. There is an ever-growing body of scientific literature supporting the ecological importance that cryptofauna play in the survival and resilience of the reef ecosystem. Unfortunately, in the last decades, these associations have been threatened by climate change and anthropic pressure. Despite that, our knowledge about cryptic fauna remains remarkably scarce, therefore this study aimed to address this gap by defining for the first time the spatial ecology of the association between the epibiont hydrozoan Nemalecium lighti and the Porifera community of shallow coral reef systems at Bonaire. In particular, the host range, prevalence, and distribution of the association were examined in relation to different sites, depths, and dimensions of the sponge hosts. Nemalecium lighti has been found in association with 9 out 16 genera of sponges and 15 out 16 of the dive sites examined. The prevalence of the hydroid – sponge association in Bonaire reef was 6.55%, with maximum value of over 30%. This hydrozoan has been found to be a generalist symbiont, with a strong preference for sponges of the genus Aplysina and no significant preference in relation to depth. On the contrary, the size of the host resulted to influence the prevalence of association with large tubular sponges found to be the preferred host. Although further studies are needed to better explain the main biological and ecological reason for these results, this study improved our understanding about the cryptofauna diversity of coral reefs associations in Bonaire.

The need for comprehensive and effective coral restoration projects, as part of a broader conservation management strategy, is accelerating in the face of coral reef ecosystem decline. This study aims to expand the currently limited knowledge base for restoration techniques in the Maldives by testing the performance of mid-water rope nurseries in a lagoon and a reef habitat. We examined whether different coral farming habitats impacted fragment survival, health and growth of two coral genera and how the occurrence of mutualistic fauna, predation and disease influenced coral rearing success. Two nurseries were stocked with a total of 448 Pocillopora verrucosa and 96 Acropora spp. fragments, divided into different groups (four Pocillopora groups: lagoon nursery at 5 m; reef nursery at 5, 10 and 15 m; two Acropora groups: lagoon nursery at 5 m and reef nursery at 5 m). Eight fragment replicates from the same donor colony (Pocillopora genets: N = 14, Acropora genets N = 6) were used in each group and monitored for one year. Our results show that fragment survival was high in both farming habitats (>90%), with P. verrucosa surviving significantly better in the lagoon and Acropora spp. surviving and growing significantly faster in the reef nursery. P. verrucosa growth rates were similar between reef and lagoon habitat. Different rearing depths in the reef nursery had no impact on the survival of P. verrucosa but coral growth decreased considerably with depth, reducing fragments’ ecological volume augmentation and growth rates by almost half from 5 to 15 m depth. Further, higher fish predation rates on fragments were recorded on the reef, which did not impact overall nursery performance. Mutualistic fauna, which correlated positively with fragment survival, was more frequently observed in the lagoon nursery. The occurrence of disease was noted in both habitats, even though implications for fragment health were more severe in the lagoon. Overall, our study demonstrates t

Small island nations like the Maldives are highly dependent on healthy coral reefs and the ecosystem services they provide. Lately, Maldivian reefs have experienced considerable degradation as a result of severe mass bleaching events and accumulating threats posed by pollution, human development, coral diseases, and outbreaks of corallivores. Coral restoration can be a useful mitigation tool in assisting natural recovery, especially when economically important reef areas such as resort reefs are in poor health with slow natural recovery. This study assesses the performance efficiency of lagoon mid-water rope nurseries for coral gardening in two different atolls in the Maldives for the first time. Three different coral genera, namely Acropora, Pocillopora, and Porites, were assessed applying a common monitoring protocol. Fragment survival was generally very high, exceeding 90% survivorship for the genus Acropora and Pocillopora, while nursing success for Porites was significantly lower (66%). We further report benchmark growth rates for these genera in mid-water rope nurseries in the Maldives. The study also identifies potential threats to coral nursing success, namely disease occurrence and predation, as we report the corallivorous nudibranch Phestilla on in situ nursing stock for the first time. Overall, our results suggest that the use of mid-water rope nurseries in lagoons is an efficient and widely applicable technique for rearing corals in the Maldives. We aim to provide useful insight into best practices for applying this coral gardening technique on a wider scale in the archipelago and highlight future research requirements.

The bioconcentration of dimethyl phthalate (DMP) diethyl phthalate (DEP) dibutyl phthalate (DBP) butyl benzyl phthalate (BBzP), di-(2-ethy hexyl) phthalates (DEHP), mono-butyl phthalate (MBP), mono-benzyl phthalate (MBzP), mono-(2-ethy hexyl) phthalate (MEHP) in the soft corals Coelogorgia palmosa, Sinularia sp., Sarcophyton glaucum, and Lobophytum sp. was investigated. Specimens were cultured in a microcosm environment built-up at the Genova Aquarium and analyses were carried out by in vivo SPME-LC-MS/MS. The distributions of the phthalates among the four surveyed species resulted significantly different. Calculated bioconcentration factors (BCFs) showed values spanning over two orders of magnitude, from a minimum of log10 BCFDEP = 1.0 in Sarcophyton glaucum to a maximum of log10 BCFDBP = 3,9 calculated for Coelogorgia palmosa. Moreover, the calculated BCFs of the long chain phthalates resulted up to three orders of magnitude lower than theoretically predicted (from logKow), whereas BCF of short chain phthalates resulted higher. This, together with the detection of phthalic acid monoesters, suggests the presence of species-specific different metabolic transformation among the surveyed soft coral species that involve DEHP.

Capitate hydrozoans are a morphologically and ecologically diverse hydrozoan suborder, currently including about 200 species. Being grouped in two clades, Corynida and Zancleida, these hydrozoans still show a number of taxonomic uncertainties at the species, genus and family levels. Many Capitata species established symbiotic relationships with other benthic organisms, including bryozoans, other cnidarians, molluscs and poriferans, as well as with planktonic dinoflagellates for mixotrophic relationships and with bacteria for thiotrophic ectosymbioses. Our study aimed at providing an updated and comprehensive phylogeny reconstruction of the suborder, at modelling the evolution of selected morphological and ecological characters, and at testing evolutionary relationships between the symbiotic lifestyle and the other characters, by integrating taxonomic, ecological and evolutionary data. The phylogenetic hypotheses here presented shed light on the evolutionary relationships within Capitata, with most families and genera being recovered as monophyletic. The genus Zanclea and family Zancleidae, however, were divided into four divergent clades, requiring the establishment of the new genus Apatizanclea and the new combinations for species in Zanclea and Halocoryne genera. The ancestral state reconstructions revealed that symbiosis arose multiple times in the evolutionary history of the Capitata, and that homoplasy is a common phenomenon in the group. Correlations were found between the evolution of symbiosis and morphological characters, such as the perisarc. Overall, our results highlighted that the use of genetic data and a complete knowledge of the life cycles are strongly needed to disentangle taxonomic and systematic issues in capitate hydrozoans. Finally, the colonization of tropical habitat appears to have influenced the evolution of a symbiotic lifestyle, playing important roles in the evolution of the group.

Verified records of the bull shark Carcharhinus leucas are lacking in the Maldives. This study provides the first confirmed evidence of 23 sightings observed from 2013 to 2023 in the central and southern atolls of this archipelago. Most of the sightings occurred in close proximity to inhabited areas, where food waste is often discarded into the water, or in several dive sites, suggesting the presence of this species in different locations around central and southern atolls. Although further research is required to fully investigate the C. leucas population in the Maldives, this report documents and confirms its presence in this region.

The invention describes a biocompatible and biodegradable composite material for the underwater delivery of active agent curcumin to reduce the effects of high seawater temperature on marine organisms such as corals. The antioxidant action of curcumin allows to mitigate the effect of climate change and improve the survival of ecosystems that are fragile, unique, biodiverse, and important for thousands of people worldwide like coral reefs.

Massive coral bleachingepisodes induced by thermal stress areone of the first causes of coral death worldwide. Overproduction ofreactive oxygen species (ROS) has been identified as one of the potentialcauses of symbiosis breakdown between polyps and algae in corals duringextreme heat wave events. Here, we propose a new strategy for mitigatingheat effects by delivering underwater an antioxidant to the corals.We fabricated zein/polyvinylpyrrolidone (PVP)-based biocomposite filmsladen with the strong and natural antioxidant curcumin as an advancedcoral bleaching remediation tool. Biocomposites' mechanical,water contact angle (WCA), swelling, and release properties can betuned thanks to different supramolecular rearrangements that occurby varying the zein/PVP weight ratio. Following immersion in seawater,the biocomposites became soft hydrogels that did not affect the coral'shealth in the short (24 h) and long periods (15 days). Laboratorybleaching experiments at 29 and 33 & DEG;C showed that coral coloniesof Stylophora pistillata coated withthe biocomposites had ameliorated conditions in terms of morphologicalaspects, chlorophyll content, and enzymatic activity compared to untreatedcolonies and did not bleach. Finally, biochemical oxygen demand (BOD)confirmed the full biodegradability of the biocomposites, showinga low potential environmental impact in the case of open-field application.These insights may pave the way for new frontiers in mitigating extremecoral bleaching events by combining natural antioxidants and biocomposites.

The red gorgonian Paramuricea clavata is a fundamental ecosystem engineer of coralligenous biocenosis in the Mediterranean Sea, where it plays crucial ecological functions and enhances the habitat biodiversity. However, this species is strongly endangered due to climate change-related stressors such as mucilage events, which have increased in recent decades causing extensive damage and mortality, but whose impacts at the molecular and cellular levels are still unexplored. In this study, different cellular stress biomarkers were analyzed in mucilage-colonized P. clavata specimens living in the Portofino Marine Protected Area (Ligurian Sea, Italy), in order to elucidate the cellular pathways affected by mucilage and the cellular defense mechanisms adopted. Within these colonies, portions of healthy tissue located at different distances from mucilage-induced necrosis were considered. Our results showed that mucilage affected the cellular oxidative status and impaired lipid cell membranes of the whole P. clavata colony. Indeed, an increase in the superoxide dismutase (SOD) and glutathione reductase (GR) enzymatic activity and in the level of lipid peroxidation (LPO) was detected in colonies showing mucilage-induced necrotic tissues compared to healthy ones. In particular, fragments sampled just next to the necrotic tissue displayed the highest levels of SOD and LPO, indicating that harmful oxidative damage was in progress, especially in portions neighboring the mucilage colonization. In this context, the up-regulation of the antioxidant mechanisms might represent a defense and a barrier from hypoxic or anoxic conditions created by mucilage overgrowth or by the invasion of toxic organisms embedded in the mucilaginous aggregates. On the contrary, the cellular protein homeostasis, analyzed by the expression of the 60-kDa Heat shock protein (Hsp60), was not altered by the mucilage. This analysis contributes to provide new insights into the cellular and molecular response of

Coral reefs are among the most diverse ecosystems in the world. The diversity of life found in the habitats created by corals is so large that the reefs are known as the “rainforests of the sea.” Unfortunately, severe natural and anthropogenic changes such as ocean warming, acidification, coral diseases, and plastic pollution are extremely detrimental to this ecosystem. To enrich the ambient conditions of the corals and boost their growth, the potential of two biocomposites is evaluated based on biodegradable polyurethane and silicone matrices as scaffolds for the growth of oceanic organisms. Furthermore, their degradation is investigated within the coral reefs of Faafu Atoll, Republic of Maldives. The observations indicate that there are a significant number of organisms that settle and grow on these biocomposites in the Maldivian lagoon, both of an animal and photosynthetic nature. The biocomposites have the potential to become suitable scaffolds for diverse hard bottom fouling organisms. Moreover, the presence of coral larvae on the biocomposites suggests that during their biodegradation, these biocomposites can support the growth of organisms, generating a suitable environment for triggering the birth of new corals.

Reef fishes are a treasured part of marine biodiversity, and also provide needed protein for many millions of people. Although most reef fishes might survive projected increases in ocean temperatures, corals are less tolerant. A few fish species strictly depend on corals for food and shelter, suggesting that coral extinctions could lead to some secondary fish extinctions. However, secondary extinctions could extend far beyond those few coral-dependent species. Furthermore, it is yet unknown how such fish declines might vary around the world. Current coral mass mortalities led us to ask how fish communities would respond to coral loss within and across oceans. We mapped 6964 coral-reef-fish species and 119 coral genera, and then regressed reef-fish species richness against coral generic richness at the 1° scale (after controlling for biogeographic factors that drive species diversification). Consistent with small-scale studies, statistical extrapolations suggested that local fish richness across the globe would be around half its current value in a hypothetical world without coral, leading to more areas with low or intermediate fish species richness and fewer fish diversity hotspots.

The hydrozoan species Nemalecium lighti (Hargitt, 1924) is widely distributed in tropical marine waters around the world. Here we report the complete linear mitochondrial genome of N. lighti from Sint Eustatius (Lesser Antilles). The mitochondrial genome with a length of 14,320 bp encodes for 13 protein-coding genes, two tRNA genes, and two rRNA genes. Gene arrangement differs from that found in other species of the same taxonomic order and a phylogenetic analysis shows that based on mitochondrial genes, N. lighti clusters outside of the Leptothecata, rendering the order paraphyletic.

Corallivory causes considerable damage to coral reefs and can exacerbate other disturbances. Among coral predators, Drupella spp. are considered as delayer of coral recovery in the Republic of Maldives, although little information is available on their ecology. Thus, we aimed to assess their population structure, feeding behaviour and spatial distribution around 2 years after a coral bleaching event in 2016. Biological and environmental data were collected using belt and line intercept transects in six shallow reefs in Maldives. The snails occurred in aggregations with a maximum of 62 individuals and exhibited a preference for branching corals. Yet, the gastropods showed a high plasticity in adapting feeding preferences to prey availability. Drupella spp. were homogenously distributed in the study area with an average of 9.04 ± 19.72 ind/200 m2. However, their occurrence was significantly different at the reef scale with the highest densities found in locations with higher coral cover. The impact of Drupella spp. appeared to be minimal with the population suffering from the loss of coral cover. We suggest that monitoring programs collect temporal- and spatial-scale data on non-outbreaking populations or non-aggregating populations to understand the dynamics of predation related to the co-occurrence of anthropogenic and natural impacts.