A conceptual framework to help choose appropriate blue nature-based solutions.

Biodiversity loss and climate change have severely impacted ecosystems and livelihoods worldwide, compromising access to food and water, increasing disaster risk, and affecting human health globally. Nature-based Solutions (NbS) have gained interest in addressing these global societal challenges. Although much effort has been directed to NbS in urban and terrestrial environments, the implementation of NbS in marine and coastal environments (blue NbS) lags. The lack of a framework to guide decision-makers and practitioners through the initial planning stages appears to be one of the main obstacles to the slow implementation of blue NbS. To address this, we propose an integrated conceptual framework, built from expert knowledge, to inform the selection of the most appropriate blue NbS based on desired intervention objectives and social-ecological context. Our conceptual framework follows a four incremental steps structure: Step 1 aims to identify the societal challenge(s) to address; Step 2 highlights ecosystem services and the underlying biodiversity and ecological functions that could contribute to confronting the societal challenge(s); Step 3 identify the specific environmental context the intervention needs to be set within (e.g. the spatial scale the intervention will operate within, the ecosystem's vulnerability to stressors, and its ecological condition); and Step 4 provides a selection of potential blue NbS interventions that would help address the targeted societal challenge(s) considering the context defined through Step 3. Designed to maintain, enhance, recover, rehabilitate, or create ecosystem services by supporting biodiversity, the blue NbS intervention portfolio includes marine protection (i.e., fully, highly, lightly, and minimally protected areas), restorative activities (i.e., active, passive, and partial restoration; rehabilitation of ecological function and ecosystem creation), and other management measures (i.e., implementation and enforcement of regulation). Ultimately, our conceptual framework guides decision-makers toward a versatile portfolio of interventions that cater to the specific needs of each ecosystem rather than imposing a rigid, one-size-fits-all model. In the future, this framework needs to integrate socio-economic considerations more comprehensively and be kept up-to-date by including the latest scientific information.

Selection of parameters for seagrass management: Towards the development of integrated indicators for French Antilles.

Seagrass beds are increasingly impacted by human activities in coastal areas, particularly in tropical regions. The objective of this research program was to study seagrass beds characteristics under various environmental conditions in the French Antilles (FA, Caribbean Sea). A total of 61 parameters, from plant physiology to seagrass ecosystem, were tested along a gradient of anthropogenic conditions, distributed across 11 sites and 3 islands of the FA. A selection of 7 parameters was identified as relevant for the monitoring of seagrass meadows in the framework of public policies. They combined "early warning indicators" (e.g. nutrients and some trace metals) and long-term responding parameters (e.g. shoot density) adapted to management time scales. The ecological status of seagrass meadows was evaluated using a PCA. This work is a first step towards monitoring and management of seagrass meadows in the FA.

Combining agent-based, trait-based and demographic approaches to model coral-community dynamics.

The complexity of coral-reef ecosystems makes it challenging to predict their dynamics and resilience under future disturbance regimes. Models for coral-reef dynamics do not adequately account for the high functional diversity exhibited by corals. Models that are ecologically and mechanistically detailed are therefore required to simulate the ecological processes driving coral reef dynamics. Here, we describe a novel model that includes processes at different spatial scales, and the contribution of species' functional diversity to benthic-community dynamics. We calibrated and validated the model to reproduce observed dynamics using empirical data from Caribbean reefs. The model exhibits realistic community dynamics, and individual population dynamics are ecologically plausible. A global sensitivity analysis revealed that the number of larvae produced locally, and interaction-induced reductions in growth rate are the parameters with the largest influence on community dynamics. The model provides a platform for virtual experiments to explore diversity-functioning relationships in coral reefs.

How a collaborative integrated taxonomic effort has trained new spongiologists and improved knowledge of Martinique Island (French Antilles, eastern Caribbean Sea) marine biodiversity.

Although sponges are important components of benthic ecosystems of the Caribbean Sea, their diversity remained poorly investigated in the Lesser Antilles. By organizing a training course in Martinique, we wanted both to promote taxonomy and to provide a first inventory of the sponge diversity on this island. The course was like a naturalist expedition, with a field laboratory and a classroom nearby. Early-career scientists and environmental managers were trained in sponge taxonomy. We gathered unpublished data and conducted an inventory at 13 coastal sites. We explored only shallow water habitats (0-30 m), such as mangroves, reefs or rocky bottoms and underwater caves. According to this study, the sponge fauna of Martinique is currently represented by a minimum of 191 species, 134 of which we could assign species names. One third of the remaining non-identified sponge species we consider to be new to science. Martinique appears very remarkable because of its littoral marine fauna harboring sponge aggregations with high biomass and species diversity dominating over coral species. In mangroves, sponges cover about 10% of the surface of subtidal roots. Several submarine caves are true reservoirs of hidden and insufficiently described sponge diversity. Thanks to this new collaborative effort, the Eastern Caribbean has gained a significant increase of knowledge, with sponge diversity of this area potentially representing 40% of the total in the Caribbean Sea. We thus demonstrated the importance of developing exploratory and educational research in areas historically devoid of biodiversity inventories and systematics studies. Finally, we believe in the necessity to consider not only the number of species but their distribution in space to evaluate their putative contribution to ecosystem services and our willingness to preserve them.

Cystophloroketals A-E, Unusual Phloroglucinol-Meroterpenoid Hybrids from the Brown Alga Cystoseira tamariscifolia.

Cystophloroketals A-E (1-5), five new phloroglucinol-meroditerpenoid hybrids, have been isolated together with their putative biosynthetic precursor, the monocyclic meroditerpenoid 6, from the Mediterranean brown alga Cystoseira tamariscifolia. They represent the first examples of meroditerpenoids linked to a phloroglucinol through a 2,7-dioxabicyclo[3.2.1]octane moiety. The chemical structures, including absolute configurations, were elucidated on the basis of extensive spectroscopic analysis (HR-ESIMS, 1D and 2D NMR, and ECD) and TDDFT ECD calculations. Compounds 1-6 were tested for their antifouling activity against several marine colonizing species (bacteria, fungi, invertebrates, micro- and macroalgae). Compound 6 showed high potency for the inhibition of macrofoulers (invertebrates and macroalgae), while cystophloroketals B (2) and D (4) displayed strong inhibition of the germination of the two macroalgae tested and moderate antimicrobial activities (bacteria, microalgae, and fungi).

Antifouling bastadin congeners target mussel phenoloxidase and complex copper(II) ions.

Synthetically prepared congeners of sponge-derived bastadin derivatives such as 5,5'-dibromohemibastadin-1 (DBHB) that suppress the settling of barnacle larvae were identified in this study as strong inhibitors of blue mussel phenoloxidase that is involved in the firm attachment of mussels to a given substrate. The IC50 value of DBHB as the most active enzyme inhibitor encountered in this study amounts to 0.84 µM. Inhibition of phenoloxidase by DBHB is likely due to complexation of copper(II) ions from the catalytic centre of the enzyme by the α-oxo-oxime moiety of the compound as shown here for the first time by structure activity studies and by X-ray structure determination of a copper(II) complex of DBHB.

Caribbean corals in crisis: record thermal stress, bleaching, and mortality in 2005.

BACKGROUND: The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. METHODOLOGY/PRINCIPAL FINDINGS: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. CONCLUSIONS/SIGNIFICANCE: Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.

Challenges for the development of new non-toxic antifouling solutions.

Marine biofouling is of major economic concern to all marine industries. The shipping trade is particularly alert to the development of new antifouling (AF) strategies, especially green AF paint as international regulations regarding the environmental impact of the compounds actually incorporated into the formulations are becoming more and more strict. It is also recognised that vessels play an extensive role in invasive species propagation as ballast waters transport potentially threatening larvae. It is then crucial to develop new AF solutions combining advances in marine chemistry and topography, in addition to a knowledge of marine biofoulers, with respect to the marine environment. This review presents the recent research progress made in the field of new non-toxic AF solutions (new microtexturing of surfaces, foul-release coatings, and with a special emphasis on marine natural antifoulants) as well as the perspectives for future research directions.

Meroditerpenoids and derivatives from the brown alga Cystoseira baccata and their antifouling properties.

The brown alga Cystoseira baccata harvested along the Atlantic coasts of Morocco yielded seven new meroditerpenoids (1-4) and derivatives (5-7), whose chemical structures were elucidated mainly by 2D NMR and mass spectrometry. Surprisingly, for all these compounds, which possess a bicyclo[4.3.0]nonane ring system, a trans fusion of the bicyclic system was deduced by stereochemical studies even though such compounds isolated from Cystoseira species are known to have a typical cis orientation for the bridgehead methyls. The antifouling and antibacterial activities of compounds 1-5 and 7 were evaluated, as well as their toxicity toward nontarget species. Compounds 4, 5, and 7 showed antifouling activities against growth of microalgae, macroalgal settlement, and mussel phenoloxidase activity, while being nontoxic to larvae of sea urchins and oysters.

Evaluation of the activity of the sponge metabolites avarol and avarone and their synthetic derivatives against fouling micro- and macroorganisms.

The sesquiterpene hydroquinone avarol (1) was isolated from the marine sponge Dysidea avara, whereas the corresponding quinone, avarone (2), was obtained by oxidation of avarol, and the significantly more lipophilic compounds [3'-(p-chloro-phenyl)avarone (3), 3',4'-ethylenedithioavarone (4), 4'-isopropylthioavarone (5), 4'-tert-butylthioavarone (6), 4'-propylthioavarone (7), 4'-octylthioavarone (8)] were obtained by nucleophilic addition of thiols or p-chloroaniline to avarone. All these compounds were tested, at concentrations ranging from 0.5 to 50 microg/mL, for their effect on the settlement of the cyprid stage of Balanus amphitrite, for toxicity to both nauplii and cyprids and for their growth inhibitory activity on marine bacteria (Cobetia marina, Marinobacterium stanieri, Vibrio fischeri and Pseudoalteromonas haloplanktis) and marine fungi (Halosphaeriopsis mediosetigera, Asteromyces cruciatus, Lulworthia uniseptata and Monodictys pelagica).

Inhibitory effects of mediterranean sponge extracts and metabolites on larval settlement of the barnacle Balanus amphitrite.

One of the most promising alternative technologies to antifouling paints based on heavy metals is the development of coatings whose active ingredients are compounds naturally occurring in marine organisms. This approach is based on the problem of epibiosis faced by all marine organisms and the fact that a great number of them cope with it successfully. The present study investigated the antifouling activity of a series of extracts and secondary metabolites from the epibiont-free Mediterranean sponges Ircinia oros, I. spinosula, Cacospongia scalaris, Dysidea sp., and Hippospongia communis. Antifouling efficacy was evaluated by the settlement inhibition of laboratory-reared Balanus amphitrite Darwin cyprids. The most promising activity was exhibited by the metabolites 2-[24-acetoxy]-octaprenyl-1-4-hydroquinone (8a), dihydrofurospongin II (10), and the alcoholic extract of Dysidea sp.

Settlement behaviour of marine invertebrate larvae measured by EthoVision 3.0.

Submerged marine surfaces are rapidly colonized by fouling organisms. Current research is aimed at finding new, non-toxic, or at least environmentally benign, solutions to this problem. Barnacles are a major target organism for such control as they constitute a key component of the hard fouling community. A range of standard settlement assays is available for screening test compounds against barnacle cypris larvae, but they generally provide little information on mechanism(s) of action. Towards this end, a quick and reliable video-tracking protocol has been developed to study the behaviour of the cypris larvae of the barnacle, Balanus amphitrite, at settlement. EthoVision 3.0 was used to track individual cyprids in 30-mm Petri dishes. Experiments were run to determine the optimal conditions vis-a-vis acclimation time, tracking duration, number of replicates, temperature and lighting. A protocol was arrived at involving a two Petri dish system with backlighting, and tracking over a 5-min period after first acclimating the cyprids to test conditions for 2 min. A minimum of twenty replicates was required to account for individual variability in cyprid behaviour from the same batch of larvae. This methodology should be widely applicable to both fundamental and applied studies of larval settlement and with further refinements, to that of smaller fouling organisms such as microalgae and bacteria.

Seasonal variation of antifouling activities of marine algae from the Brittany coast (France).

The antifouling activity of extracts (aqueous, ethanol, and dichloromethane) of 9 marine macroalgae against bacteria, fungi, diatoms, macroalgal spores, mussel phenoloxidase activity, and barnacle cypris larvae has been investigated in relation to season in bimonthly samples from the Bay of Concarneau (France). Of the extracts tested, 48.2% were active against at least one of the fouling organisms, and of these extracts, 31.2% were seasonally active with a peak of activity in summer corresponding to maximal values for water temperature, light intensity, and fouling pressure, and 17% were active throughout the year. This seasonal activity may be adaptive as it coincides with maximal fouling pressure in the Bay of Concarneau. Dichloromethane extracts of Rhodophyceae were the most active in the antifouling assays.