Climate change, coral reef ecosystems, and management options for marine protected areas

Hydrothermally treated coral scaffold promotes proliferation of mesenchymal stem cells and enhances segmental bone defect healing

Introduction: Synthetic hydroxyapatite (HAp) scaffolds have shown promising therapeutic outcomes in both animals and patients. In this study, we aim to evaluate the chemical and physical phenotype, biocompatibility, and bone repair effects of hydrothermally treated coral with natural coral and synthetic HAp. Methods: The phase composition, surface pattern, 3D structures, and porosity of the scaffolds were characterized, and cell viability, proliferation, and osteogenic differentiation of mesenchymal stem cells (MSCs) after seeding onto the scaffold were determined. The scaffolds were implanted into rats to assess their bone repair effects using micro-CT analysis, mechanical testing, and histological staining. Results: The results showed that the phase composition, porous structure, and porosity of hydrothermally treated coral were comparable to pure HAp scaffold. While only the natural coral happens to be dominantly calcium carbonate. Higher cell proliferation and osteogenic differentiation potential were observed in the hydrothermally treated coral scaffold compared to natural coral and pure HAp. Histological results also showed increased new bone formation in the hydrothermally treated coral group. Discussion: Overall, our study suggests that hydrothermal modification enhances the cytocompatibility and therapeutic capacity of coral without altering its physical properties, showing superior effectiveness in bone repair to synthetic HAp.

Siting MPAs for multiple protecting purposes by co-consideration of ecological importance and anthropogenic impacts

The global marine ecosystem has been significantly altered by the combined effects of multiple anthropogenic impacts. Systematic planning of marine protected areas (MPAs) is of paramount importance in alleviating conflicts between humans and the sea. Existing approaches, however, merely integrate both ecological and anthropogenic factors for multiple conservation purposes. By combining the three main anthropogenic impact factors with two main ecological importance factors, this study used a GIS-based AHP-OWA method to identify different levels of priority protection for MPAs in Zhejiang, China. Our results proved that: 1) the multi-objective MPA siting issues can be addressed by the GIS-based AHP-OWA method through scenario simulation; 2) the best locations for MPAs are in the northeast, central, and southern marine areas of Zhejiang; 3) considering the trade-off degree, spatial conservation efficiency, and spatial heterogeneity, an optimized MPA siting scheme can be developed for decision-makers. The proposed MPA siting method and case study may provide an effective technical reference for solving regional marine spatial planning (MSP) issues in the future.

The Use of a Production Function to Evaluate Caribbean Ocean Health Conflicts and Economic Development: Policy Implications

Central American and Caribbean (CAC) countries enjoy diverse marine environments. The oceans that enclose these coastlines contribute significantly to their economic growth. Industrial expansion and tourism place pressure on the marine ecosystems causing a decline in ocean health. To evaluate the cause of ocean health changes we investigated the factors influencing CAC ocean health using a health production function. Using Rank-Based Regression and the set of extractive, cultural and human well-being and services goals measuring Ocean Health Index (OHI), data from the World Bank, and the Human Development Index we developed a production function for CAC countries ocean health. Results show that all regional OHI scores, but Tourism and Recreation, the main income earning industry for most of the CAC countries, are less than the global score with four of the goals less than 40. The production function shows that all the goals, but the biodiversity sub-goal species, positively influencing OHI. Two climatic related variables, Nitrous Oxide and Carbon Dioxide negatively influenced OHI. The results are important to policy makers as they decide on the need to make greater effort towards improving sustainable contribution of CAC ocean resources to the blue economy.

Cascading effects of climate change on recreational marine flats fishes and fisheries

Tropical and subtropical coastal flats are shallow regions of the marine environment at the intersection of land and sea. These regions provide myriad ecological goods and services, including recreational fisheries focused on flats-inhabiting fishes such as bonefish, tarpon, and permit. The cascading effects of climate change have the potential to negatively impact coastal flats around the globe and to reduce their ecological and economic value. In this paper, we consider how the combined effects of climate change, including extremes in temperature and precipitation regimes, sea level rise, and changes in nutrient dynamics, are causing rapid and potentially permanent changes to the structure and function of tropical and subtropical flats ecosystems. We then apply the available science on recreationally targeted fishes to reveal how these changes can cascade through layers of biological organization-from individuals, to populations, to communities-and ultimately impact the coastal systems that depend on them. We identify critical gaps in knowledge related to the extent and severity of these effects, and how such gaps influence the effectiveness of conservation, management, policy, and grassroots stewardship efforts.

Modeling demersal fish and benthic invertebrate assemblages in support of marine conservation planning

Marine classification schemes based on abiotic surrogates often inform regional marine conservation planning in lieu of detailed biological data. However, these schemes may poorly represent ecologically relevant biological patterns required for effective design and management strategies. We used a community-level modeling approach to characterize and delineate representative mesoscale (tens to thousands of kilometers) assemblages of demersal fish and benthic invertebrates in the Northwest Atlantic. Hierarchical clustering of species occurrence data from four regional annual multispecies trawl surveys revealed three to six groupings (predominant assemblage types) in each survey region, broadly associated with geomorphic and oceanographic features. Indicator analyses identified 3-34 emblematic taxa of each assemblage type. Random forest classifications accurately predicted assemblage distributions from environmental covariates (AUC > 0.95) and identified thermal limits (annual minimum and maximum bottom temperatures) as important predictors of distribution in each region. Using forecasted oceanographic conditions for the year 2075 and a regional classification model, we projected assemblage distributions in the southernmost bioregion (Scotian Shelf-Bay of Fundy) under a high emissions climate scenario (RCP 8.5). Range expansions to the northeast are projected for assemblages associated with warmer and shallower waters of the Western Scotian Shelf over the 21st century as thermal habitat on the relatively cooler Eastern Scotian Shelf becomes more favorable. Community-level modeling provides a biotic-informed approach for identifying broadscale ecological structure required for the design and management of ecologically coherent, representative, well-connected networks of Marine Protected Areas. When combined with oceanographic forecasts, this modeling approach provides a spatial tool for assessing sensitivity and resilience to climate change, which can improve conservation planning, monitoring, and adaptive management.

The Effects of Depth-Related Environmental Factors on Traits in Acropora cervicornis Raised in Nurseries

Populations of Acropora cervicornis, one of the most important reef-building corals in the Caribbean, have been declining due to human activities and global climate change. This has prompted the development of strategies such as coral farms, aimed at improving the long-term viability of this coral across its geographical range. This study focuses on comprehending how seawater temperature (ST), and light levels (LL) affect the survival and growth of A. cervicornis fragments collected from three reefs in Culebra, Puerto Rico. These individuals were fragmented into three pieces of the similar sizes and placed in farms at 5, 8, and 12 m depth. The fragments, ST and LL were monitored for 11 months. Results show that fragments from shallow farms exhibit significantly higher mortalities when compared to the other two depths. Yet, growth at shallow farms was nearly 24% higher than at the other two depths. Corals grew fastest during winter, when temperature and LL were lowest, regardless of the water depth. Fragment mortality and growth origin were also influenced by reef origin. We conclude that under the current conditions, shallow farms may offer a slight advantage over deep ones provided the higher growth rate at shallow farms and the high fragment survival at all depths.

Acute acidification stress weakens the head kidney immune function of juvenile Lates calcarifer

Acidized water environment can impact many physiological processes of aquatic animals. The response of the head kidney to acidification, especially the immune response, is of great significance to health. This study analyzed the histological and transcriptional changes under different acidification levels (C group, pH 8.1; P group, pH 7.4; E group, pH 3.5) in the short term (12 h, 36 h and 60 h) in the head kidney of juvenile L. calcarifer. The results showed that the acidification of the water environment caused tissue damage to the head kidney of L. calcarifer, and the damage appeared earlier and was stronger in the extreme pH group. The transcriptional response of L. calcarifer head kidney increased with the increase of acidification level. The two treatments transcriptional responses showed different trends in terms of time. After KEGG function enrichment, with the increase of stimulation time, the proportion of down-regulated pathways was increasing, and the types of pathway enrichment at different acidification levels were quite different at the initial stage. At 12 h, the first category in the P group with the most significant number of pathways was 'Metabolism', and the first category in the E group with the largest number of pathways was 'Human Diseases'. At 60 h, the enrichment pathways of the two groups were highly overlapping in immune-related pathways, which contained 26 common DEGs. They had a dominant expression pattern. In the P group, the expression level decreased with time. In the E group, the down-regulation degree of expression level at 12 h reached the level of the P group at 60 h, and the expression level remained low until 60 h. Through the correlation network, interferon regulatory factor 7 (IRF7), Tripartite motif containing-21 (TRIM21), Signal transducer and activator of transcription 1 (STAT1) and Signal transducer and activator of transcription 3 (STAT3) were found to have the most correlation with other genes. In this study, juvenile L. calcarifer showed different coping strategies to different levels of acute acidification stress, but all of them resulted in the extensive weakening of head kidney immune function.

Coupling high-resolution coral bleaching modeling with management practices to identify areas for conservation in a warming climate: Keramashoto National Park (Okinawa Prefecture, Japan)

Increases in sea-surface temperature due to global warming are a major threat to tropical and subtropical corals as exposure to high water temperatures is the primary cause of coral bleaching. To continue receiving high ecosystem services from coral reef ecosystems in the future, it is important to predict the growth conditions of corals and take appropriate countermeasures to protect them at both global and local scales. The Kerama Islands (part of the Nansei Islands, Japan) were selected as the study area. The islands have been designated as a national park and attract substantial tourism, which utilizes the coral reef ecosystem. The selected study site is significant as it is known to act as a source of coral larvae for the surrounding area. In this study, coral bleaching and mortality rates under present and +1.5 °C/+2.0 °C water temperature conditions were estimated using a 1) three-dimensional hydrodynamic model with a spatial resolution of 100 m and 2) statistical model describing the relationship between various environmental parameters and coral bleaching and mortality rates. Applying a local hydrodynamic model enabled us to obtain high-resolution spatial and temporal variations in water temperature and current speed, and these data were used to obtain statistical model data. Coral conservation sites were prioritized based on 1) projections of the spatial distribution of bleaching and mortality rates under global warming conditions and 2) locations of the main diving and conservation points, with the intention of continuing the present use and management locations. The results of this study are expected to contribute to the management of coral reef ecosystems through conservation and adaptation strategies at local scales.

Identifying mangrove-coral habitats in the Florida Keys

Coral reefs are degrading due to many synergistic stressors. Recently there have been a number of global reports of corals occupying mangrove habitats that provide a supportive environment or refugium for corals, sheltering them by reducing stressors such as oxidative light stress and low pH. This study used satellite imagery and manual ground-truthing surveys to search for mangrove-coral habitats in the Florida Keys National Marine Sanctuary and then collected basic environmental parameters (temperature, salinity, dissolved oxygen, pH_NBS, turbidity) at identified sites using a multi-parameter water quality sonde. Two kinds of mangrove-coral habitats were found in both the Upper and Lower Florida Keys: (1) prop-root corals, where coral colonies were growing directly on (and around) mangrove prop roots, and (2) channel corals, where coral colonies were growing in mangrove channels under the shade of the mangrove canopy, at deeper depths and not in as close proximity to the mangroves. Coral species found growing on and directly adjacent to prop roots included Porites porites (multiple morphs, including P. divaricata and P. furcata), Siderastrea radians, and Favia fragum. Channel coral habitats predominantly hosted S. radians and a few S. siderea, although single colonies of Solenastrea bournoni and Stephanocoenia intersepta were observed. Although clear, low-turbidity water was a consistent feature of these mangrove-coral habitats, the specific combination of environmental factors that determine which mangrove habitats are favorable for coral recruitment remains to be defined. Circumstantial evidence suggests additional coral communities existed on mangrove shorelines of oceanside and backcountry islands until destroyed, likely by Hurricane Irma. These mangrove-coral habitats may be climate refugia for corals and could be included in ecosystem management plans and considered for their applications in coral restoration.

Incorporating climate change adaptation into marine protected area planning

Climate change is increasingly impacting marine protected areas (MPAs) and MPA networks, yet adaptation strategies are rarely incorporated into MPA design and management plans according to the primary scientific literature. Here we review the state of knowledge for adapting existing and future MPAs to climate change and synthesize case studies (n = 27) of how marine conservation planning can respond to shifting environmental conditions. First, we derive a generalized conservation planning framework based on five published frameworks that incorporate climate change adaptation to inform MPA design. We then summarize examples from the scientific literature to assess how conservation goals were defined, vulnerability assessments performed and adaptation strategies incorporated into the design and management of existing or new MPAs. Our analysis revealed that 82% of real-world examples of climate change adaptation in MPA planning derive from tropical reefs, highlighting the need for research in other ecosystems and habitat types. We found contrasting recommendations for adaptation strategies at the planning stage, either focusing only on climate refugia, or aiming for representative protection of areas encompassing the full range of expected climate change impacts. Recommendations for MPA management were more unified and focused on adaptative management approaches. Lastly, we evaluate common barriers to adopting climate change adaptation strategies based on reviewing studies which conducted interviews with MPA managers and other conservation practitioners. This highlights a lack of scientific studies evaluating different adaptation strategies and shortcomings in current governance structures as two major barriers, and we discuss how these could be overcome. Our review provides a comprehensive synthesis of planning frameworks, case studies, adaptation strategies and management actions which can inform a more coordinated global effort to adapt existing and future MPA networks to continued climate change.

Progress towards a representative network of Southern Ocean protected areas

Global threats to ocean biodiversity have generated a worldwide movement to take actions to improve conservation and management. Several international initiatives have recommended the adoption of marine protected areas (MPAs) in national and international waters. National governments and the Commission for the Conservation of Antarctic Marine Living Resources have successfully adopted multiple MPAs in the Southern Ocean despite the challenging nature of establishing MPAs in international waters. But are these MPAs representative of Southern Ocean biodiversity? Here we answer this question for both existing and proposed Antarctic MPAs, using benthic and pelagic regionalizations as a proxy for biodiversity. Currently about 11.98% of the Southern Ocean is protected in MPAs, with 4.61% being encompassed by no-take areas. While this is a relatively large proportion of protection when compared to other international waters, current Antarctic MPAs are not representative of the full range of benthic and pelagic ecoregions. Implementing additional protected areas, including those currently under negotiation, would encompass almost 22% of the Southern Ocean. It would also substantially improve representation with 17 benthic and pelagic ecoregions (out of 23 and 19, respectively) achieving at least 10% representation.

Integrating climate adaptation and biodiversity conservation in the global ocean

The impacts of climate change and the socioecological challenges they present are ubiquitous and increasingly severe. Practical efforts to operationalize climate-responsive design and management in the global network of marine protected areas (MPAs) are required to ensure long-term effectiveness for safeguarding marine biodiversity and ecosystem services. Here, we review progress in integrating climate change adaptation into MPA design and management and provide eight recommendations to expedite this process. Climate-smart management objectives should become the default for all protected areas, and made into an explicit international policy target. Furthermore, incentives to use more dynamic management tools would increase the climate change responsiveness of the MPA network as a whole. Given ongoing negotiations on international conservation targets, now is the ideal time to proactively reform management of the global seascape for the dynamic climate-biodiversity reality.

Management strategies for coral reefs and people under global environmental change: 25 years of scientific research

Coral reef ecosystems and the people who depend on them are increasingly exposed to the adverse effects of global environmental change (GEC), including increases in sea-surface temperature and ocean acidification. Managers and decision-makers need a better understanding of the options available for action in the face of these changes. We refine a typology of actions developed by Gattuso et al. (2015) that could serve in prioritizing strategies to deal with the impacts of GEC on reefs and people. Using the typology we refined, we investigate the scientific effort devoted to four types of management strategies: mitigate, protect, repair, adapt that we tie to the components of the chain of impact they affect: ecological vulnerability or social vulnerability. A systematic literature review is used to investigate quantitatively how scientific effort over the past 25 years is responding to the challenge posed by GEC on coral reefs and to identify gaps in research. A growing literature has focused on these impacts and on management strategies to sustain coral reef social-ecological systems. We identify 767 peer reviewed articles published between 1990 and 2016 that address coral reef management in the context of GEC. The rate of publication of such studies has increased over the years, following the general trend in climate research. The literature focuses on protect strategies the most, followed by mitigate and adapt strategies, and finally repair strategies. Developed countries, particularly Australia and the United States, are over-represented as authors and locations of case studies across all types of management strategies. Authors affiliated in developed countries play a major role in investigating case studies across the globe. The majority of articles focus on only one of the four categories of actions. A gap analysis reveals three directions for future research: (1) more research is needed in South-East Asia and other developing countries where the impacts of GEC on coral reefs will be the greatest, (2) more scholarly effort should be devoted to understanding how adapt and repair strategies can deal with the impacts of GEC, and (3) the simultaneous assessment of multiple strategies is needed to understand trade-offs and synergies between actions.

Biogeographic constraints to marine conservation in a changing climate

The siting of protected areas to achieve management and conservation objectives draws heavily on biogeographic concepts of the spatial distribution and connectivity of species. However, the marine protected area (MPA) literature rarely acknowledges how biogeographic theories underpin MPA and MPA network design. We review which theories from biogeography have been incorporated into marine spatial planning and which relevant concepts have yet to be translated to inform the next generation of design principles. This biogeographic perspective will only become more relevant as climate change amplifies these spatial and temporal dynamics, and as species begin to shift in and out of existing MPAs. The scale of climate velocities predicted for the 21st century dwarfs all but the largest MPAs currently in place, raising the possibility that in coming decades many MPAs will no longer contain the species or assemblages they were established to protect. We present a number of design elements that could improve the success of MPAs and MPA networks in light of biogeographic processes and climate change. Biogeographically informed MPA networks of the future may resemble the habitat corridors currently being considered for many terrestrial regions.

Quality assessment of pollution indicators in marine water at critical locations of the Gulf of Mannar Biosphere Reserve, Tuticorin

The present study focused on the shoreline environment of urban and industrial areas, and the aim of this study was to assess the coastal water quality in the Gulf of Mannar Biosphere Reserve. Water samples were collected from five different coastal sites during the premonsoon and monsoon seasons. The samples were analyzed following the standard methods. The results showed that the levels of microbiological indicators in the samples highly exceeded the regional and national standard seawater permissible limits, and environmental parameters such as the total suspended solid and dissolved oxygen were affected significantly (p<0.05). To identify frequent pollution indicators, their levels should be estimated to determine possible pollution in coastal ecosystems due to human interventions.

Drivers of coral reef marine protected area performance

Coral reefs are severely threatened and a principal strategy for their conservation is marine protected areas (MPAs). However the drivers of MPA performance are complex and there are likely to be trade-offs between different types of performance (e.g. conservation or welfare related outcomes). We compiled a global dataset from expert knowledge for 76 coral reef MPAs in 33 countries and identified a set of performance measures reflecting ecological and socio-economic outcomes, achievement of aims and reduction of threats, using spatial or temporal comparisons wherever possible. We wanted to test the extent to which distinct types of performance occurred simultaneously, understood as win-win outcomes. Although certain performance measures were correlated, most were not, suggesting trade-offs that limit the usefulness of composite performance scores. Hypotheses were generated as to the impact of MPA features, aims, location, management and contextual variables on MPA performance from the literature. A multivariate analysis was used to test hypotheses as to the relative importance of these "drivers" on eight uncorrelated performance measures. The analysis supported some hypotheses (e.g. benefit provision for the local community improved performance), but not others (e.g. higher overall budget and more research activity did not). Factors endogenous to the MPA (such as size of the no-take area) were generally more significant drivers of performance than exogenous ones (such as national GDP). Different types of performance were associated with different drivers, exposing the trade-offs inherent in management decisions. The study suggests that managers are able to influence MPA performance in spite of external threats and could inform adaptive management by providing an approach to test for the effects of MPA features and management actions in different contexts and so to inform decisions for allocation of effort or funds to achieve specific goals.

Climate-Smart Design for Ecosystem Management: A Test Application for Coral Reefs

The interactive and cumulative impacts of climate change on natural resources such as coral reefs present numerous challenges for conservation planning and management. Climate change adaptation is complex due to climate-stressor interactions across multiple spatial and temporal scales. This leaves decision makers worldwide faced with local, regional, and global-scale threats to ecosystem processes and services, occurring over time frames that require both near-term and long-term planning. Thus there is a need for structured approaches to adaptation planning that integrate existing methods for vulnerability assessment with design and evaluation of effective adaptation responses. The Corals and Climate Adaptation Planning project of the U.S. Coral Reef Task Force seeks to develop guidance for improving coral reef management through tailored application of a climate-smart approach. This approach is based on principles from a recently-published guide which provides a framework for adopting forward-looking goals, based on assessing vulnerabilities to climate change and applying a structured process to design effective adaptation strategies. Work presented in this paper includes: (1) examination of the climate-smart management cycle as it relates to coral reefs; (2) a compilation of adaptation strategies for coral reefs drawn from a comprehensive review of the literature; (3) in-depth demonstration of climate-smart design for place-based crafting of robust adaptation actions; and (4) feedback from stakeholders on the perceived usefulness of the approach. We conclude with a discussion of lessons-learned on integrating climate-smart design into real-world management planning processes and a call from stakeholders for an "adaptation design tool" that is now under development.

Integrating Climate Change Resilience Features into the Incremental Refinement of an Existing Marine Park

Marine protected area (MPA) designs are likely to require iterative refinement as new knowledge is gained. In particular, there is an increasing need to consider the effects of climate change, especially the ability of ecosystems to resist and/or recover from climate-related disturbances, within the MPA planning process. However, there has been limited research addressing the incorporation of climate change resilience into MPA design. This study used Marxan conservation planning software with fine-scale shallow water (<20 m) bathymetry and habitat maps, models of major benthic communities for deeper water, and comprehensive human use information from Ningaloo Marine Park in Western Australia to identify climate change resilience features to integrate into the incremental refinement of the marine park. The study assessed the representation of benthic habitats within the current marine park zones, identified priority areas of high resilience for inclusion within no-take zones and examined if any iterative refinements to the current no-take zones are necessary. Of the 65 habitat classes, 16 did not meet representation targets within the current no-take zones, most of which were in deeper offshore waters. These deeper areas also demonstrated the highest resilience values and, as such, Marxan outputs suggested minor increases to the current no-take zones in the deeper offshore areas. This work demonstrates that inclusion of fine-scale climate change resilience features within the design process for MPAs is feasible, and can be applied to future marine spatial planning practices globally.

Conservation Planning for Coral Reefs Accounting for Climate Warming Disturbances

Incorporating warming disturbances into the design of marine protected areas (MPAs) is fundamental to developing appropriate conservation actions that confer coral reef resilience. We propose an MPA design approach that includes spatially- and temporally-varying sea-surface temperature (SST) data, integrating both observed (1985-2009) and projected (2010-2099) time-series. We derived indices of acute (time under reduced ecosystem function following short-term events) and chronic thermal stress (rate of warming) and combined them to delineate thermal-stress regimes. Coral reefs located on the Brazilian coast were used as a case study because they are considered a conservation priority in the southwestern Atlantic Ocean. We show that all coral reef areas in Brazil have experienced and are projected to continue to experience chronic warming, while acute events are expected to increase in frequency and intensity. We formulated quantitative conservation objectives for regimes of thermal stress. Based on these objectives, we then evaluated if/how they are achieved in existing Brazilian MPAs and identified priority areas where additional protection would reinforce resilience. Our results show that, although the current system of MPAs incorporates locations within some of our thermal-stress regimes, historical and future thermal refugia along the central coast are completely unprotected. Our approach is applicable to other marine ecosystems and adds to previous marine planning for climate change in two ways: (i) by demonstrating how to spatially configure MPAs that meet conservation objectives for warming disturbance using spatially- and temporally-explicit data; and (ii) by strategically allocating different forms of spatial management (MPA types) intended to mitigate warming impacts and also enhance future resistance to climate warming.

Assessing pollution in marine protected areas: the role of a multi-biomarker and multi-organ approach

Marine protected areas (MPAs) are vulnerable to many pressures, including pollution. However, environmental quality monitoring in these areas traditionally relies on only water chemistry and microbiological parameters. The goal of the current study was to investigate the role of a set of biomarkers in different target organs (liver, kidney, and gills) of fish in order to assess the environmental quality of an MPA (MTs, GPx, GST, GSH, DNA damage, LPO, AChE, and condition index). Chemical analyses were also performed on liver and muscle tissues to evaluate metal body burdens, and PAHs were identified in bile. A demersal fish (Cathorops spixii) that is widely consumed by the local population was used as bioindicator species, and the results were integrated using multivariate analysis. The use of the biomarker approach allowed for the identification of both seasonal and spatial variations in pollution sources around the Environmental Protected Area of Cananéia-Iguape-Peruíbe (APA-CIP). Higher metal body burdens associated with biological responses were found in the sites under the influence of urban areas during the dry season, and they were found in the sites under the influence of the Ribeira de Iguape River (RIR) during the rainy season. The liver was found to be more responsive in terms of its antioxidant responses, whereas gills were found to be more responsive to biomarkers of effect. These results show that this set of biomarker analyses in different organs of fish is a useful tool for assessing chemical pollution in an MPA.

Evidence for multiple stressor interactions and effects on coral reefs

Concern is growing about the potential effects of interacting multiple stressors, especially as the global climate changes. We provide a comprehensive review of multiple stressor interactions in coral reef ecosystems, which are widely considered to be one of the most sensitive ecosystems to global change. First, we synthesized coral reef studies that examined interactions of two or more stressors, highlighting stressor interactions (where one stressor directly influences another) and potentially synergistic effects on response variables (where two stressors interact to produce an effect that is greater than purely additive). For stressor-stressor interactions, we found 176 studies that examined at least 2 of the 13 stressors of interest. Applying network analysis to analyze relationships between stressors, we found that pathogens were exacerbated by more costressors than any other stressor, with ca. 78% of studies reporting an enhancing effect by another stressor. Sedimentation, storms, and water temperature directly affected the largest number of other stressors. Pathogens, nutrients, and crown-of-thorns starfish were the most-influenced stressors. We found 187 studies that examined the effects of two or more stressors on a third dependent variable. The interaction of irradiance and temperature on corals has been the subject of more research (62 studies, 33% of the total) than any other combination of stressors, with many studies reporting a synergistic effect on coral symbiont photosynthetic performance (n = 19). Second, we performed a quantitative meta-analysis of existing literature on this most-studied interaction (irradiance and temperature). We found that the mean effect size of combined treatments was statistically indistinguishable from a purely additive interaction, although it should be noted that the sample size was relatively small (n = 26). Overall, although in aggregate a large body of literature examines stressor effects on coral reefs and coral organisms, considerable gaps remain for numerous stressor interactions and effects, and insufficient quantitative evidence exists to suggest that the prevailing type of stressor interaction is synergistic.

Understanding the scale of Marine protection in Hawai'i: from community-based management to the remote Northwestern Hawaiian Islands

Ancient Hawaiians developed a sophisticated natural resource management system that included various forms of spatial management. Today there exists in Hawai'i a variety of spatial marine management strategies along a range of scales, with varying degrees of effectiveness. State-managed no-take areas make up less than 0.4% of nearshore waters, resulting in limited ecological and social benefits. There is increasing interest among communities and coastal stakeholders in integrating aspects of customary Hawaiian knowledge into contemporary co-management. A network of no-take reserves for aquarium fish on Hawai'i Island is a stakeholder-driven, adaptive management strategy that has been successful in achieving ecological objectives and economic benefits. A network of large-scale no-take areas for deepwater (100-400m) bottomfishes suffered from a lack of adequate data during their initiation; however, better technology, more ecological data, and stakeholder input have resulted in improvements and the ecological benefits are becoming clear. Finally, the Papahānaumokuākea Marine National Monument (PMNM) is currently the single largest conservation area in the United States, and one of the largest in the world. It is considered an unqualified success and is managed under a new model of collaborative governance. These case studies allow an examination of the effects of scale on spatial marine management in Hawai'i and beyond that illustrate the advantages and shortcomings of different management strategies. Ultimately a marine spatial planning framework should be applied that incorporates existing marine managed areas to create a holistic, regional, multi-use zoning plan engaging stakeholders at all levels in order to maximize resilience of ecosystems and communities.

Climate change influences on marine infectious diseases: implications for management and society

Infectious diseases are common in marine environments, but the effects of a changing climate on marine pathogens are not well understood. Here we review current knowledge about how the climate drives host-pathogen interactions and infectious disease outbreaks. Climate-related impacts on marine diseases are being documented in corals, shellfish, finfish, and humans; these impacts are less clearly linked for other organisms. Oceans and people are inextricably linked, and marine diseases can both directly and indirectly affect human health, livelihoods, and well-being. We recommend an adaptive management approach to better increase the resilience of ocean systems vulnerable to marine diseases in a changing climate. Land-based management methods of quarantining, culling, and vaccinating are not successful in the ocean; therefore, forecasting conditions that lead to outbreaks and designing tools/approaches to influence these conditions may be the best way to manage marine disease.

One size does not fit all: the emerging frontier in large-scale marine conservation

On the 20th anniversary of the Convention on Biological Diversity, a network of very large marine protected areas (the Big Ocean network) has emerged as a key strategy in the move to arrest marine decline and conserve some of the last remaining relatively undisturbed marine areas on the globe. Here we outline the ecological, economic and policy benefits of very large-scale MPAs and show their disproportionate value to global marine conservation targets. In particular we point out that very large-scale MPAs are a critical component of reaching the Aichi targets of protecting 10% of global marine habitats by 2020, because in addition to encompassing entire ecosystems, they will bring forward the expected date of achievement by nearly three decades (2025 as opposed to 2054). While the need for small MPAs remains critical, large MPAs will complement and enhance these conservation efforts. Big Ocean sites currently contain more than 80% of managed area in the sea, and provide our best hope for arresting the global decline in marine biodiversity.

Modelling coral reef futures to inform management: can reducing local-scale stressors conserve reefs under climate change?

Climate change has emerged as a principal threat to coral reefs, and is expected to exacerbate coral reef degradation caused by more localised stressors. Management of local stressors is widely advocated to bolster coral reef resilience, but the extent to which management of local stressors might affect future trajectories of reef state remains unclear. This is in part because of limited understanding of the cumulative impact of multiple stressors. Models are ideal tools to aid understanding of future reef state under alternative management and climatic scenarios, but to date few have been sufficiently developed to be useful as decision support tools for local management of coral reefs subject to multiple stressors. We used a simulation model of coral reefs to investigate the extent to which the management of local stressors (namely poor water quality and fishing) might influence future reef state under varying climatic scenarios relating to coral bleaching. We parameterised the model for Bolinao, the Philippines, and explored how simulation modelling can be used to provide decision support for local management. We found that management of water quality, and to a lesser extent fishing, can have a significant impact on future reef state, including coral recovery following bleaching-induced mortality. The stressors we examined interacted antagonistically to affect reef state, highlighting the importance of considering the combined impact of multiple stressors rather than considering them individually. Further, by providing explicit guidance for management of Bolinao's reef system, such as which course of management action will most likely to be effective over what time scales and at which sites, we demonstrated the utility of simulation models for supporting management. Aside from providing explicit guidance for management of Bolinao's reef system, our study offers insights which could inform reef management more broadly, as well as general understanding of reef systems.

Does herbivorous fish protection really improve coral reef resilience? A case study from new caledonia (South Pacific)

Parts of coral reefs from New Caledonia (South Pacific) were registered at the UNESCO World Heritage list in 2008. Management strategies aiming at preserving the exceptional ecological value of these reefs in the context of climate change are currently being considered. This study evaluates the appropriateness of an exclusive fishing ban of herbivorous fish as a strategy to enhance coral reef resilience to hurricanes and bleaching in the UNESCO-registered areas of New Caledonia. A two-phase approach was developed: 1) coral, macroalgal, and herbivorous fish communities were examined in four biotopes from 14 reefs submitted to different fishing pressures in New Caledonia, and 2) results from these analyses were challenged in the context of a global synthesis of the relationship between herbivorous fish protection, coral recovery and relative macroalgal development after hurricanes and bleaching. Analyses of New Caledonia data indicated that 1) current fishing pressure only slightly affected herbivorous fish communities in the country, and 2) coral and macroalgal covers remained unrelated, and macroalgal cover was not related to the biomass, density or diversity of macroalgae feeders, whatever the biotope or level of fishing pressure considered. At a global scale, we found no relationship between reef protection status, coral recovery and relative macroalgal development after major climatic events. These results suggest that an exclusive protection of herbivorous fish in New Caledonia is unlikely to improve coral reef resilience to large-scale climatic disturbances, especially in the lightly fished UNESCO-registered areas. More efforts towards the survey and regulation of major chronic stress factors such as mining are rather recommended. In the most heavily fished areas of the country, carnivorous fish and large targeted herbivores may however be monitored as part of a precautionary approach.

Modelling coral reef futures to inform management: can reducing local-scale stressors conserve reefs under climate change?

Climate change has emerged as a principal threat to coral reefs, and is expected to exacerbate coral reef degradation caused by more localised stressors. Management of local stressors is widely advocated to bolster coral reef resilience, but the extent to which management of local stressors might affect future trajectories of reef state remains unclear. This is in part because of limited understanding of the cumulative impact of multiple stressors. Models are ideal tools to aid understanding of future reef state under alternative management and climatic scenarios, but to date few have been sufficiently developed to be useful as decision support tools for local management of coral reefs subject to multiple stressors. We used a simulation model of coral reefs to investigate the extent to which the management of local stressors (namely poor water quality and fishing) might influence future reef state under varying climatic scenarios relating to coral bleaching. We parameterised the model for Bolinao, the Philippines, and explored how simulation modelling can be used to provide decision support for local management. We found that management of water quality, and to a lesser extent fishing, can have a significant impact on future reef state, including coral recovery following bleaching-induced mortality. The stressors we examined interacted antagonistically to affect reef state, highlighting the importance of considering the combined impact of multiple stressors rather than considering them individually. Further, by providing explicit guidance for management of Bolinao's reef system, such as which course of management action will most likely to be effective over what time scales and at which sites, we demonstrated the utility of simulation models for supporting management. Aside from providing explicit guidance for management of Bolinao's reef system, our study offers insights which could inform reef management more broadly, as well as general understanding of reef systems.

A decision support framework for science-based, multi-stakeholder deliberation: a coral reef example

We present a decision support framework for science-based assessment and multi-stakeholder deliberation. The framework consists of two parts: a DPSIR (Drivers-Pressures-States-Impacts-Responses) analysis to identify the important causal relationships among anthropogenic environmental stressors, processes, and outcomes; and a Decision Landscape analysis to depict the legal, social, and institutional dimensions of environmental decisions. The Decision Landscape incorporates interactions among government agencies, regulated businesses, non-government organizations, and other stakeholders. It also identifies where scientific information regarding environmental processes is collected and transmitted to improve knowledge about elements of the DPSIR and to improve the scientific basis for decisions. Our application of the decision support framework to coral reef protection and restoration in the Florida Keys focusing on anthropogenic stressors, such as wastewater, proved to be successful and offered several insights. Using information from a management plan, it was possible to capture the current state of the science with a DPSIR analysis as well as important decision options, decision makers and applicable laws with a the Decision Landscape analysis. A structured elicitation of values and beliefs conducted at a coral reef management workshop held in Key West, Florida provided a diversity of opinion and also indicated a prioritization of several environmental stressors affecting coral reef health. The integrated DPSIR/Decision landscape framework for the Florida Keys developed based on the elicited opinion and the DPSIR analysis can be used to inform management decisions, to reveal the role that further scientific information and research might play to populate the framework, and to facilitate better-informed agreement among participants.