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Coastal hazards pose a serious and increasing threat to the wellbeing of coastal communities. Adaptation responses to these hazards ideally need to be embedded in the local adaptation context. However, there is little understanding of factors that shape local adaptation choices, especially in rural and remote island settings. In this paper, we compile data on adaptation responses to coastal hazards and key factors that shape adaptation across 43 towns and villages in four Pacific island nations. Local communities cite erosion as a critical coastal hazard, even more often than coastal flooding and sea level rise. We find that communities prefer protective adaptation responses that use local knowledge and resources eand protect coastal ecosystems. Our findings reveal differences in preferred versus implemented adaptation responses.Ecosystem-based adaptation is the most commonly implemented response to coastal hazards. Seawalls and other hard structures are widely preferred and perceived as effective adaptation responses but are often not implemented due to a lack of social, institutional and technical capacity. Retreat is a highly unpopular adaptation response, and difficult to implement, as coastal communities in this study indicate a strong place attachment and are deeply embedded in their social and natural environment. Our results suggest that the selection of adaptation responses might involve important trade-offs between multiple, potentially conflicting, local priorities, such as the preference for seawalls and the need to protect coastal ecosystems. Findings emphasize the importance of considering the local context when making adaptation choices and show that even when responding to the same hazard, adaptation responses can vary significantly depending on local priorities and capacities.

Pollution from land-based run-off threatens coastal ecosystems and the services they provide, detrimentally affecting the livelihoods of millions people on the world's coasts. Planning for linkages among terrestrial, freshwater and marine ecosystems can help managers mitigate the impacts of land-use change on water quality and coastal ecosystem services. We examine the approaches used for land-sea planning, with particular focus on the models currently used to estimate the impacts of land-use change on water quality and fisheries. Our findings could also be applied to other ecosystem services. This Review encompasses modelling of: large scale drivers of land-use change; local activities that cause such change; run-off, dispersal and transformation of pollutants in the coastal ocean; ecological responses to pollutants; socio-economic responses to ecological change; and finally, the design of a planning response. We find that there is a disconnect between the dynamical models that can be used to link land to sea processes and the simple tools that are typically used to inform planning. This disconnect may weaken the robustness of plans to manage dynamic processes. Land-sea planning is highly interdisciplinary, making the development of effective plans a challenge for small teams of managers and decision makers. Synthesis and applications. We propose some guiding principles for where and how dynamic land-sea connections can most effectively be built into planning tools. Tools that can capture pertinent processes are needed, but they must be simple enough to be implemented in regions with limited resources for collecting data, developing models and developing integrated land-sea plans.

Human disturbance of karst landscapes in tropical volcanic islands present a unique challenge for understanding sediment transport to the coastal zone. Here we present the first evidence of urban drinking water quality impacts from industrial logging in the Solomon Islands. Despite only 6% of the Honiara's drinking water catchment being disturbed by logging, rhodamine dye tracers demonstrated complex karst sinkholes that led to high suspended sediment concentrations being transported from neighbouring Kovi catchment into the Kongulai water supply offtake point for Honiara. This has resulted in the exceedance of practical treatment thresholds of 20 NTU 9.5% of the time, leading to water supply for the majority of Honiara's residents being unavailable for 58 days in 2019. This work highlights the cost-benefit disparity between industrial logging yielding minimal short-term economic yields in comparison to on-going broader impacts of increased coastal sediment transport while restricting water supply to a developing nation's capital.

The COVID-19 pandemic has revealed gaps in our understanding of safe, effective and efficient means of disinfecting high use public spaces. Whilst this creates an opportunity for development and application of innovative approaches such as unmanned aerial vehicle (UAV) based disinfection, unregulated outdoor disinfection using chlorine has led to environmental and public health risks. This study has quantified the efficiency, safety and efficacy of UAV-based spraying of aqueous ozone. Optimised UAV flight characteristics of 4.7 km/h at 1.7 m elevation spraying 2.4 L/min were able to provide >97% and >92% coverage of a 1 m and 2 m wide swath respectively. During spraying operations using 1 mg/L aqueous ozone, atmospheric concentrations of ozone remained within background levels (, Graphical abstract Image 1

Achieving sustainable development globally requires multilevel and interdisciplinary efforts and perspectives. Global goals shape priorities and actions at multiple scales, creating cascading impacts realized at the local level through the direction of financial resources and implementation of programs intended to achieve progress towards these metrics. We explore ways to localize global goals to best support human well-being and environmental health by systematically comparing the UN Sustainable Development Goals (SDGs) with regionally-derived well-being dimensions that encompass components of social–ecological resilience across the Pacific Islands. Our research shows that, in the context of the Pacific, there are overlaps but also significant gaps between regional conceptions of well-being and the globally-derived SDGs. Some dimensions, related to human health and access to infrastructure and finances, are well represented in the SDGs. Other dimensions of high importance when localizing perspectives of well-being, such as those regarding connections between and across people and place and Indigenous and local knowledge, are not. Furthermore, internationally generated indicators may result in trade-offs and measurement challenges in local contexts. Creating space for place-based values in global sustainability planning aligns with international calls for transformational changes needed to achieve global goals. We identify challenges in applying SDG indicators at the local level and provide lessons learned to foster equitable and holistic approaches and outcomes for sustainability.

Gold mining of arsenopyrite ore bodies result in waste tailings that contain elevated levels of arsenic. Disposal of these wastes in a Tailings Storage Facility (TSF) represents a substantial environmental risk if not properly managed. The Gold Ridge mine on Guadalcanal, in the Solomon Islands was abandoned from 2014 to 2018, leaving the TSF with little ongoing environmental management. Surface water quality monitoring observed a threefold increase in surface water arsenic concentrations over a 6-month period when no mining operations were occurring. This study aimed to investigate bottom sediments as the source of elevated concentrations of arsenic in the surface waters of the TSF during mine closure. This was achieved by analysing arsenic concentrations in the surface water, sediment porewaters and by quantifying sediment arsenic flux as dissolved oxygen availability declined. It was evident that bottom sediments of the TSF were the potential source of arsenic, having an average arsenic concentration of 437.9 mg kg−1. In addition, average sediment porewater arsenic concentrations across the TSF were 1.07 mg L−1, with a large central zone of highly elevated concentrations peaking at over 17 mg L−1. Long term sediment core incubations demonstrated arsenic effluxes from all sites monitored under both oxic and hypoxic conditions, ranging from 0.72 mg m−2 day−1 to 7.01 mg m−2 day−1 respectively. These results suggest that arsenic hotspots within the TSF have the capability to contribute to increased arsenic concentrations in surface waters. Management of mine TSF’s should consider these geochemical interactions that can occur in abandoned sites.

This paper summarises the results of an extensive field campaign which demonstrates that high sediment organic matter is the primary driver of methane ebullition in a sub-tropical, freshwater reservoir. Methane emissions from freshwater reservoirs represent an important global methane source. Whilst diffusive methane fluxes are commonly used for predicting total emissions, recent studies show that the under-reported ebullitive fluxes can vary by over three orders of magnitude within an individual system and have a greater relative contribution compared to diffusion. Key to predicting this variability in emission rates is to better understand the primary drivers of different emission pathways, and in particular ebullition. Zones of catchment derived organic material as well as elevated water column chlorophyll a concentration have been associated with increased rates of ebullition. Little Nerang Dam (LND), a subtropical freshwater reservoir in Queensland Australia, consistently experiences high rates of ebullition adjacent to major inflow arms that are both deposition zones of catchment organic material as well as areas with elevated water column chlorophyll a concentration. A year-long study of emission rates was undertaken on LND during which water column chlorophyll a concentration, bottom water temperature and sediment organic matter content were assessed for methane ebullition potential. This included a transect with high-spatial sampling (259 sites) from the dam wall to the ebullition zones to explore the relationship between water column chlorophyll a concentration, sediment organic matter content and methane ebullition. These results showed that ebullition was associated with the large forest litter deposits adjacent to major inflow sites where sediment organic matter content was significantly higher compared with the main body of the reservoir.

The population of Leatherback Sea Turtles (Dermochelys coriacea) in the western Pacific has experienced dramatic declines over the past two decades. The full extent of these declines and the current status of the western Pacific sub-population remains unclear due to the remote nature of these nesting beaches. Zaira, on the southern coast of Vangunu Island in the Western Province of Solomon Islands is a previously undocumented nesting ground for Leatherback Sea Turtles. Whilst leatherbacks in this area have traditionally been harvested by the local communities, the Zaira community independently initiated a full closure over leatherbacks in 1999 as a response to reducing numbers. This study provides an overview of the scientific and traditional knowledge that the Zaira community has used to underpin their community-based management regime of Leatherback Sea Turtles. The community self-initiated the construction of a leatherback hatchery that was able to replicate the ideal nesting temperature for balanced sex ratios. Furthermore, the community developed a nest monitoring and satellite telemetry programme to provide a regional context to their conservation efforts. This community-led approach highlights the important role local communities can play in the conservation of this iconic species.

Whilst future air temperature thresholds have become the centrepiece of international climate negotiations, even the most ambitious target of 1.5 °C will result in significant sea-level rise and associated impacts on human populations globally. Of additional concern in Arctic regions is declining sea ice and warming permafrost which can increasingly expose coastal areas to erosion particularly through exposure to wave action due to storm activity. Regional variability over the past two decades provides insight into the coastal and human responses to anticipated future rates of sea-level rise under 1.5 °C scenarios. Exceeding 1.5 °C will generate sea-level rise scenarios beyond that currently experienced and substantially increase the proportion of the global population impacted. Despite these dire challenges, there has been limited analysis of how, where and why communities will relocate inland in response. Here, we present case studies of local responses to coastal erosion driven by sea-level rise and warming in remote indigenous communities of the Solomon Islands and Alaska, USA, respectively. In both the Solomon Islands and the USA, there is no national government agency that has the organisational and technical capacity and resources to facilitate a community-wide relocation. In the Solomon Islands, communities have been able to draw on flexible land tenure regimes to rapidly adapt to coastal erosion through relocations. These relocations have led to ad hoc fragmentation of communities into smaller hamlets. Government-supported relocation initiatives in both countries have been less successful in the short term due to limitations of land tenure, lacking relocation governance framework, financial support and complex planning processes. These experiences from the Solomon Islands and USA demonstrate the urgent need to create a relocation governance framework that protects people’s human rights.

Coastal fisheries provide staple food and sources of livelihood in Pacific Island countries, and securing a sustainable supply is recognised as a critical priority for nutrition security. This study sought to better understand the role of fish for Pacific Island communities during disasters and in disaster recovery. To evaluate community impacts and responses after natural disasters, focus group discussions were held with men and women groups at ten sites across Shefa, Tafea, Malampa and Sanma provinces in Vanuatu. The combined impacts of category 5 Tropical Cyclone Pam (TC-Pam) in March 2015 and prolonged El-Nino induced drought have had a profound impact across much of Vanuatu. Terrestrial systems had been disproportionately impacted with substantial shortages in drinking water, garden crops, cash crops and damage to infrastructure. Localized impacts were noted on marine environments from TC-Pam and the drought, along with an earthquake that uplifted reef and destroyed fishing grounds in Malampa province. Communities in Malampa and Shefa provinces also noted a crown-of-thorns outbreak that caused coral mortality. The significant reduction in terrestrial-based food and income generation capacity generally led to increased reliance on marine resources to cope and a shift in diets from local garden food to rice. However, limited market access, lack of fishing skills and technology in many sectors of the community reduced the capacity for marine resources to support recovery. A flexible management approach allowed protected areas and species to be utilized as reservoirs of food and income when temporarily opened to assist recovery. These findings illustrate that fish and fisheries management is at the center of disaster preparedness and relief strategies in remote Pacific Island communities. High physical capital (e.g. infrastructure, water tanks and strong dwellings) is key for disaster preparedness, but supporting community social capital for the purpose of natural resource management and human capital for diverse adaptation skills can also improve community resilience. Recognizing the humanitarian value that well managed fisheries resources and skilled fishers can play to disaster relief adds another dimension to the imperative of improving management of coastal fisheries and aligning policies across sectors.

Coastal fish populations are typically threatened by multiple human activities, including fishing pressure and run-off of terrestrial pollution. Linking multiple threats to their impacts on fish populations is challenging because the threats may influence a species directly, or indirectly, via its habitats and its interactions with other species. Here we examine spatial variation in abundance of coral reef fish across gradients of fishing pressure and turbidity in Fiji. We explicitly account for multiple pathways of influence to test the alternative hypotheses that (1) habitat moderates predation by providing shelter, so habitat loss only affects prey fish populations if there are abundant predators, (2) habitat change co-drives biomass of both prey and predator functional groups. We examined responses of 7 fish functional groups and found that habitat change co-drives both predator and prey responses to turbidity. Abundances of all functional groups were associated with changes in habitat cover; however, the responses of their habitats to turbidity were mixed. Planktivore and piscivore abundance were lower in areas of high turbidity, because cover of their preferred habitats was lower. Invertivore, browser and grazer abundance did not change strongly over the turbidity gradient, because different components of their habitats exhibited both increases and decreases with turbidity. The effects of turbidity on fish populations were minor in areas where fish populations were already depleted by fishing. These findings suggest that terrestrial run-off modifies the composition of reef fish communities indirectly by affecting the benthic habitats that reef fish use.

In recent years, Fiji's approach of combining traditional systems of community-based coastal management and modern management systems has become a successful blueprint for marine conservation, particularly the Locally Managed Marine Area (LMMA) network model. As a result of this success, conservation practitioners have imported the Fiji LMMA model to the Solomon Islands and in Vanuatu in hope of replicating the purported success attained in Fiji. This paper argues that because tenure systems and associated political systems in Fiji, the Solomon Islands, and Vanuatu are substantially different, one cannot simply extrapolate the more centralized tenurial and political Fiji model to the decentralized tenurial and politically eclectic Solomons and Vanuatu. This paper provides an analysis of some of the various approaches used in these countries to make a case for why socio-political diversity and historical particulars matter to resource management and conservation-in-practice (and for any development interventions). By examining examples of various nested and polycentric governance approaches—family, community, tribal, confederations, local community-based organizations (CBOs), and Church—it elucidates not only some of the differences between Fiji and Solomon Islands/Vanuatu, but also between Vanuatu and the Solomon Islands. This provides critical insights into some of the myriad of factors impinging on conservation aspirations in these countries and may offer some alternative ways forward not currently considered by conservation practitioners. Finally, the paper provides some guidelines to how to increase the long-term success of marine conservation programs for fisheries management and community-based management initiatives in the region.

SUMMARYDespite a growing body of literature on integrated land–sea management (ILSM), very little critical assessment has been conducted in order to evaluate ILSM in practice on island systems. Here we develop indicators for assessing 10 integrated island management principles and evaluate the performance of planning and implementation in four island ILSM projects from the tropical Pacific across different governance structures. We find that where customary governance is still strongly respected and enabled through national legislation, ILSM in practice can be very effective at restricting access and use according to fluctuations in resource availability. However, decision-making under customary governance systems may be vulnerable to mismanagement. Government-led ILSM processes have the potential to design management actions that address the spatial scale of ecosystem processes and threats within the context of national policy and legislation, but may not fully capture broad stakeholder interests, and implementation may be poorly coordinated across highly dispersed island archipelagos. Private sector partnerships offer unique opportunities for resourcing island ILSM, although these are highly likely to be geared towards private sector interests that may change in the future and no longer align with community and/or national objectives. We identify consistent challenges that arise during island ILSM planning and implementation and offer recommendations for improvement.

Major flood events can dramatically alter the coastal sediment environment. This study established the current sediment distribution in a large sub-tropical embayment, Moreton Bay, Australia, and examined the effect of three recent floods on modifying this distribution. In 2015, surface sediment samples were collected from 223 sites across the study area and analysed for particle size distribution with the resultant sediment distribution mapped. In addition, sampling of flood waters during two major events in 2011 and 2013 was undertaken and particle size distribution of suspended sediment was determined. Data was compared to the result of an earlier large-scale survey completed in 1970, with three large flood events occurring between the two surveys. The sediment environment has undergone a dramatic change with muddy sediments now covering an estimated area of over 860 km 2 , more the double the area found in 1970. Mud is now the dominant sediment type within Moreton Bay.

A developed understanding of site-specific sediment transport processes is key for the assessment of coastal works, such as dredging and environmental management. This study investigates ch...

An expedition to the Kavachi submarine volcano (Solomon Islands) in January 2015 was serendipitously timed with a rare lull in volcanic activity that permitted access to the inside of Kavachi’s active crater and its flanks. The isolated location of Kavachi and its explosive behavior normally restrict scientific access to the volcano’s summit, limiting previous observational efforts to surface imagery and peripheral water-column data. This article presents medium-resolution bathymetry of the main peak along with benthic imagery, biological observations of multiple trophic levels living inside the active crater, petrological and geochemical analysis of samples from the crater rim, measurements of water temperature and gas flux over the summit, and descriptions of the hydrothermal plume structure. A second peak was identified to the southwest of the main summit and displayed evidence of diffuse-flow venting. Microbial samples collected from the summit indicate chemosynthetic populations dominated by sulfur-reducing ε-proteobacteria. Populations of gelatinous animals, small fish, and sharks were observed inside the active crater, raising new questions about the ecology of active submarine volcanoes and the extreme environments in which large marine animals can exist.

Global biophysical data are increasingly accessible due to improvements in remote sensing and open datasets. These datasets can be of particular value in remote and data-poor environments to enable estimates of water quality impacts from catchment land clearing. Given the resources required to collect field observations and calibrate detailed process-based models, global datasets are often the only sources available to parameterise simple models however the comparative use of these data sources in process-based models is relatively unexplored. This study compares the widely applied models of Integrated Valuation of Ecosystem Services and Trade-offs and Soil and Water Assessment Tool (SWAT) to a tropical catchment in the Solomon Islands using globally available data. These uncalibrated models are contrasted with a SWAT model calibrated with measured streamflow and turbidity in the catchment and meteorologically forced by data from a nearby weather station. These catchment models were coupled with models of sedimentation to examine deposition rates in the coastal lagoon adjacent to the catchment. Model validation using measured coastal sedimentation rates demonstrated that simpler modelling approaches (one-dimensional basin sedimentation and two-dimensional sediment extent modelling) were marginally better than more complex approaches (three-dimensional Delft3D) in data-poor conditions. However, investment in local catchment observations significantly improved the accuracy of simulation outputs. This insight can guide decisions about model complexity, data-richness and investment in local environmental monitoring in these challenging environments.

Emissions from flooded land represent a direct source of anthropogenic greenhouse gas (GHG) emissions. Methane emissions from large, artificial water bodies have previously been considered, with numerous studies assessing emission rates and relatively simple procedures available to determine their surface area and generate upscaled emissions estimates. In contrast, the role of small artificial water bodies (ponds) is very poorly quantified, and estimation of emissions is constrained both by a lack of data on their spatial extent and a scarcity of direct flux measurements. In this study, we quantified the total surface area of water bodies 5 m2 across Queensland, Australia, and emission rates from a variety of water body types and size classes. We found that the omission of small ponds from current official land use data has led to an underestimate of total flooded land area by 24 %, of small artificial water body surface area by 57 % and of the total number of artificial water bodies by 1 order of magnitude. All studied ponds were significant hotspots of methane production, dominated by ebullition (bubble) emissions. Two scaling approaches were developed with one based on pond primary use (stock watering, irrigation and urban lakes) and the other using size class. Both approaches indicated that ponds in Queensland alone emit over 1.6 Mt CO2 eq.  yr−1, equivalent to 10 % of the state's entire land use, land use change and forestry sector emissions. With limited data from other regions suggesting similarly large numbers of ponds, high emissions per unit area and under-reporting of spatial extent, we conclude that small artificial water bodies may be a globally important missing source of anthropogenic greenhouse gas emissions.

Benthic cyanobacteria have commonly been a small but integral component of coral reef ecosystems, fulfilling the critical function of introducing bioavailable nitrogen to an inherently oligotrophic environment. Though surveys may have previously neglected benthic cyanobacteria, or grouped them with more conspicuous benthic groups, emerging evidence strongly indicates that they are becoming increasingly prevalent on reefs worldwide. Some species can form mats comprised by a diverse microbial consortium which allows them to exist across a wide range of environmental conditions. This review evaluates the putative driving factors of increasing benthic cyanobacterial mats, including climate change, declining coastal water quality, iron input, and overexploitation of key consumer and ecosystem engineer species. Ongoing global environmental change can increase growth rates and toxin production of physiologically plastic benthic cyanobacterial mats, placing them at a considerable competitive advantage against reef-building corals. Once established, strong ecological feedbacks [e.g., inhibition of coral recruitment, release of dissolved organic carbon (DOC)] reinforce reef degradation. The review also highlights previously overlooked implications of mat proliferation, which can extend beyond reef health and affect human health and welfare. Though identifying (opportunistic) consumers of mats remains a priority, their perceived low palatability implies that herbivore management alone may be insufficient to control their proliferation and must be accompanied by local measures to improve water quality and watershed management.

To meet local and global aspirations toward sustainable resource management, we must first understand what success looks like. At global levels, well-being can be narrowly defined, which may clash with local values and cause adverse impacts. Melanesia is home to a complex mosaic of resource management systems, and finding locally appropriate indicators of success poses particular challenges. We propose that biocultural approaches can assist in developing grounded and appropriate well-being indicators. Biocultural approaches frame issues from the perspectives of place-based communities and work with resource users to develop desired outcomes. In doing so, biocultural approaches recognize links between people and the environment and seek to understand feedbacks between social and ecological components. Biocultural approaches may help to improve the fit between local aspirations and national or international actions and can also cocreate knowledge that draws on local knowledge and practice as well as western science. Here, we report on one such approach in Western Province, Solomon Islands, where rural communities are weighing a variety of trade-offs around the use of natural resources. The work encompasses four locations and seeks to define local needs and priorities, develop appropriate local indicators of success, assess indicator baselines, and catalyze appropriate action. Implementation challenges have included scaffolding between local and national levels and the diversity of the four locations. These have, however, been offset by the engaged nature of indicator creation, which assists communities in planning toward action around local definitions of well-being.

Aim Connectivity structures populations, communities and ecosystems in the sea. The extent of connectivity is, therefore, predicted to also influence the outcomes of conservation initiatives, such as marine reserves. Here we review the published evidence about how important seascape connectivity (i.e. landscape connectivity in the sea) is for marine conservation outcomes. Location Global. Methods We analysed the global literature on the effects of seascape connectivity on reserve performance. Results In the majority of cases, greater seascape connectivity inside reserves translates into better conservation outcomes (i.e. enhanced productivity and diversity). Research on reserve performance is, however, most often conducted separately from research on connectivity, resulting in few studies (

Sea-level rise will change environmental conditions on coral reef flats, which comprise extensive habitats in shallow tropical seas and support a wealth of ecosystem services. Rapid relative sea-level rise of 0.6 m over a relatively pristine coral reef in Solomon Islands, caused by a subduction earthquake in April 2007, generated a unique opportunity to examine in situ coral reef response to relative sea-level rise of the magnitude (but not the rate) anticipated by 2100. Extent of live coral was measured from satellite imagery in 2003, 2006, 2009 and 2012. Ecological data were obtained from microatolls and ecological surveys in May 2013. The reef was sampled at 12 locations where dense live hard coral remained absent, remained present or changed from absent to present following subsidence. Ecological data (substratum depth, live coral canopy depth, coral canopy height, substratum suitability, recruitment, diversity and Acropora presence) were measured at each location to identify factors associated with coral response to relative sea-level rise. Vertical and horizontal proliferation of coral occurred following subsidence. Lateral expansion of live coral, accomplished primarily by branching Acropora spp., resulted in lower diversity in regions which changed composition from pavement to dense live coral following subsidence. Of the ecological factors measured, biotic factors were more influential than abiotic factors; species identity was the most important factor in determining which regions of the reef responded to rapid sea-level rise. On relatively pristine reef flats under present climatic conditions, rapid relative sea-level rise generated an opportunity for hard coral to proliferate. However, the species assemblage of the existing reef was important in determining response to sea-level change, by providing previously bare substrate with a source of new coral colonies. Degraded reefs with altered species composition and slower coral growth rates may be less able to respond to climate change-induced sea-level changes.

Community-based approaches are pursued in recognition of the need for place-based responses to environmental change that integrate local understandings of risk and vulnerability. Yet the potential for fair adaptation is intimately linked to how variations in perceptions of environmental change and risk are treated. There is, however, little empirical evidence of the extent and nature of variations in risk perception in and between multiple community settings. Here, we rely on data from 231 semi-structured interviews conducted in nine communities in Western Province, Solomon Islands, to statistically model differential perceptions of risk and change within and between communities. Overall, people were found to be less likely to perceive environmental changes in the marine environment than they were for terrestrial systems. The distance to the nearest market town (which may be a proxy for exposure to commercial logging and degree of involvement with the market economy) and gender had the greatest overall statistical effects on perceptions of risk. Yet, we also find that significant environmental change is under reported in communities, while variations in perception are not always easily related to commonly assumed fault lines of vulnerability. The findings suggest that there is an urgent need for methods that engage with the drivers of perceptions as part of community-based approaches. In particular, it is important to explicitly account for place, complexity and diversity of environmental risk perceptions, and we reinforce calls to engage seriously with underlying questions of power, culture, identity and practice that influence adaptive capacity and risk perception.

Solomon Islands is rapidly developing its natural resource exploitation sector, but data needed to assess consequent environmental impacts are scarce. We assessed catchments surrounding the Gold Ridge gold mine (Guadalcanal, Solomon Islands) and found that extensive changes in river course, and water and sediment quality have occurred downstream of the gold mine since its development. Sediment run-off from exposed areas associated with the mine pit has increased, elevating turbidity (up to 2450 NTU) and metal and arsenic levels, with levels of the latter being up to 0.141 mg/L in surface waters and 265 mg/kg in sediments. An overfull, inoperative tailings storage facility associated with the currently inactive gold mine with fluctuating arsenic levels (up to 0.087 mg/L in the water; 377 mg/kg in the sediment) presents an ongoing threat to the environment. Arsenic, due to its toxicity, appears to be the greatest threat, with sediment and water guideline levels in rivers exceeded 10-fold and exceeded nearly 20-fold in the tailings dam sediments. Despite elevated metal and arsenic content in the area, no toxic inorganic arsenic was found to have bioaccumulated in locally harvested food. In summary, the natural environment surrounding the Gold Ridge mine has been modified substantially and requires an ongoing monitoring program to ensure the ecosystem services of food and water for the local communities continue to be safe. This study informs not only the local area but also provides a microcosm of the broader global challenges facing the regulation of extractive industries in proximity to subsistence communities.

Coastal ecosystems can be degraded by poor water quality. Tracing the causes of poor water quality back to land-use change is necessary to target catchment management for coastal zone management. However, existing models for tracing the sources of pollution require extensive data-sets which are not available for many of the world’s coral reef regions that may have severe water quality issues. Here we develop a hierarchical Bayesian model that uses freely available satellite data to infer the connection between land-uses in catchments and water clarity in coastal oceans. We apply the model to estimate the influence of land-use change on water clarity in Fiji. We tested the model’s predictions against underwater surveys, finding that predictions of poor water quality are consistent with observations of high siltation and low coverage of sediment-sensitive coral genera. The model thus provides a means to link land-use change to declines in coastal water quality.

Monitoring and evaluation are central to ensuring that innovative, multi-scale, and interdisciplinary approaches to sustainability are effective. The development of relevant indicators for local sustainable management outcomes, and the ability to link these to broader national and international policy targets, are key challenges for resource managers, policymakers, and scientists. Sets of indicators that capture both ecological and social-cultural factors, and the feedbacks between them, can underpin cross-scale linkages that help bridge local and global scale initiatives to increase resilience of both humans and ecosystems. Here we argue that biocultural approaches, in combination with methods for synthesizing across evidence from multiple sources, are critical to developing metrics that facilitate linkages across scales and dimensions. Biocultural approaches explicitly start with and build on local cultural perspectives — encompassing values, knowledges, and needs — and recognize feedbacks between ecosystems and human well-being. Adoption of these approaches can encourage exchange between local and global actors, and facilitate identification of crucial problems and solutions that are missing from many regional and international framings of sustainability. Resource managers, scientists, and policymakers need to be thoughtful about not only what kinds of indicators are measured, but also how indicators are designed, implemented, measured, and ultimately combined to evaluate resource use and well-being. We conclude by providing suggestions for translating between local and global indicator efforts.

Food security is arguably one of the greatest challenges facing humanity. With rapid globalisation, and the global population forecast to reach 9.7 billion by 2050, this problem will only intensify. Fresh fish is the primary source of animal protein for many nations, and this is particularly true for equatorial nations in the Pacific. As fish stocks strain under climate change and increasing fishing pressure, their decline and collapse is becoming a common story. Predicted changes in fish populations indicate that equatorial nations will likely bear the brunt of nutritional insecurity, and this is particularly likely for Pacific nations where agricultural land is limited [1]. Given global threats to fisheries, and their importance to village diets in the Pacific, it is critical that fisheries resources are well managed to ensure food security for future generations. We interviewed 87 women across three villages in Marovo Lagoon, Western Province, Solomon Islands about their role in fisheries and fishery-related activities within their communities. Of the women interviewed, 80.7% indicated that they do fish or harvest invertebrates. 84.5% of fisherwomen were primarily targeting finfish, not invertebrates, and most women (59.4%) indicated that they harvested seafood solely to feed their families. Results from this study contribute to a growing body of literature highlighting the high involvement of women in small-scale fisheries, and their contributions to household food security. This knowledge broadens our understanding of fishery resource utilization in the Solomon Islands, and provides data for strengthening food security through improved fisheries management.

Excess sediment and nutrient runoff from land-based human activities are considered serious threats to coastal and marine ecosystems by most conservation practitioners, resource managers, fishers, and other “downstream” resource users. Deleterious consequences of coastal runoff, including eutrophication and hypoxia, have been observed worldwide. Literature on integrated coastal management offers numerous methods to address land-based activities that generate runoff, but many of these approaches are time- and resource-intensive. Often, high-level conservation managers have few tools to aid in decisions about whether land-based threats that generate runoff are of sufficient concern to warrant further investment in planning and management interventions. To address this decision-making process, we present a decision tree that uses geophysical and ecological characteristics to sort any marine coastal ecosystem into a category of high, moderate, low, or minimal risk from the land-based threats of nutrient and sediment runoff. By identifying situations where runoff could influence biodiversity or ecosystem services, the decision tree assists managers in making informed, and standardized decisions about when and where to invest further efforts in integrated land-sea planning. We ground-truth the decision tree by evaluating it in five very different regions and conclude the tree classifies regions similarly to the existing literature that is available, but based on less information. Recognizing that the decision tree only encompasses environmental variables, we also discuss approaches for interpreting the decision tree's outputs in local social and economic contexts. The tree provides a tool for conservation managers to decide whether the scope of their work should include land-sea planning.

Increasing development in tropical regions provides new economic opportunities that can improve livelihoods, but it threatens the functional integrity and ecosystem services provided by terrestrial and aquatic ecosystems when conducted unsustainably. Given the small size of many islands, communities may have limited opportunities to replace loss and damage to the natural resources upon which they depend for ecosystem service provisioning, thus heightening the need for proactive, integrated management. This study quantifies the effectiveness of management strategies, stipulated in logging codes-of-practice, at minimizing soil erosion and sediment runoff as clearing extent increases, using Kolombangara Island, Solomon Islands as a case study. Further, we examine the ability of erosion reduction strategies to maintain sustainable soil erosion rates and reduce potential downstream impacts to drinking water and environmental water quality. We found that increasing land clearing-even with best management strategies in place-led to unsustainable levels of soil erosion and significant impacts to downstream water quality, compromising the integrity of the land for future agricultural uses, consistent access to clean drinking water, and important downstream ecosystems. Our results demonstrate that in order to facilitate sustainable development, logging codes of practice must explicitly link their soil erosion reduction strategies to soil erosion and downstream water quality thresholds, otherwise they will be ineffective at minimizing the impacts of logging activities. The approach taken here to explicitly examine soil erosion rates and downstream water quality in relation to best management practices and increasing land clearing should be applied more broadly across a range of ecosystems to inform decision-making about the socioeconomic and environmental trade-offs associated with logging, and other types of land use change.

A 2007 earthquake in the western Solomon Islands resulted in a localised subsidence event in which sea level (relative to the previous coastal settings) rose approximately 30–70 cm, providing insight into impacts of future rapid changes to sea level on coastal ecosystems. Here, we show that increasing sea level by 30–70 cm can have contrasting impacts on mangrove, seagrass and coral reef ecosystems. Coral reef habitats were the clear winners with a steady lateral growth from 2006–2014, yielding a 157% increase in areal coverage over seven years. Mangrove ecosystems, on the other hand, suffered the largest impact through a rapid dieback of 35% (130 ha) of mangrove forest in the study area after subsidence. These forests, however, had partially recovered seven years after the earthquake albeit with a different community structure. The shallow seagrass ecosystems demonstrated the most dynamic response to relative shifts in sea level with both losses and gains in areal extent at small scales of 10–100 m. The results of this study emphasize the importance of considering the impacts of sea-level rise within a complex landscape in which winners and losers may vary over time and space.

Low-lying reef islands in the Solomon Islands provide a valuable window into the future impacts of global sea-level rise. Sea-level rise has been predicted to cause widespread erosion and inundation of low-lying atolls in the central Pacific. However, the limited research on reef islands in the western Pacific indicates the majority of shoreline changes and inundation to date result from extreme events, seawalls and inappropriate development rather than sea-level rise alone. Here, we present the first analysis of coastal dynamics from a sea-level rise hotspot in the Solomon Islands. Using time series aerial and satellite imagery from 1947 to 2014 of 33 islands, along with historical insight from local knowledge, we have identified five vegetated reef islands that have vanished over this time period and a further six islands experiencing severe shoreline recession. Shoreline recession at two sites has destroyed villages that have existed since at least 1935, leading to community relocations. Rates of shoreline recession are substantially higher in areas exposed to high wave energy, indicating a synergistic interaction between sea-level rise and waves. Understanding these local factors that increase the susceptibility of islands to coastal erosion is critical to guide adaptation responses for these remote Pacific communities.

There has been a resurgence in community-based management of coral reef resources in the developing world over the last two decades. However, many of the threats to reef ecosystems are increasing at a rate beyond local knowledge acquisition. Consequently, there is a continuing need for management tools and monitoring to support community-based approaches. Using algal, fish and reef indicators we provide a rapid assessment method of herbivorous fishes in Locally Managed Marine Areas in Fiji. The algal indicator technique provided a time-integrated assessment of the process of herbivory within Locally Managed Marine Areas and could be used by untrained community members to quantify management responses. Generally, reefs with higher herbivore biomass had a diverse low biomass of algae typical of healthy reefs. Reefs with fewer herbivores had a higher biomass of turf or leathery algae typical of degraded reefs. These results show that simple ecological indicators can be a useful addition to the existing local knowledge that underpins community-based management.