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.
The Canterbury earthquakes resulted in numerous changes to the waterways of Ōtautahi Christchurch. These included bank destabilisation, liquefaction effects, changes in bed levels, and associated effects on flow regimes and inundation levels. This study set out to determine if these effects had altered the location and pattern of sites utilised by inanga (Galaxias maculatus) for spawning, which are typically restricted to very specific locations in upper estuarine areas.
Extensive surveys were carried out in the Heathcote/Ōpāwaho and Avon/Ōtākaro catchments over the four peak months of the 2015 spawning season. New spawning sites were found in both rivers and analysis against pre-earthquake records identified that other significant changes have occurred.
Major changes include the finding of many new spawning sites in the Heathcote/Ōpāwaho catchment. Sites now occur up to 1.5km further downstream than the previously reported limit and include the first records of spawning below the Woolston Cut. Spawning sites in the Avon/Ōtākaro catchment also occur in new locations. In the mainstem, sites now occur both upstream and downstream of all previously reported locations. A concentrated area of spawning was identified in Lake Kate Sheppard at a distinctly different location versus pre-quake records, and no spawning was found on the western shores. Spawning was also recorded for the first time in Anzac Creek, a nearby waterway connected to Lake Kate Sheppard via a series of culverts. Overall the results indicate that spawning is taking place in different locations from the pre-quake pattern. Although egg survival was not measured in this study, sites in new locations may be vulnerable to current or future land-use activities that are incompatible with spawning success. Consequently, there are considerable management implications associated with this spatial shift, primarily relating to riparian management. In particular, there is a need to control threats to spawning sites and achieve protection for the areas involved. This is required under the New Zealand Coastal Policy Statement 2010 and is a prominent objective in a range of other policies and plans.mainstem, sites now occur both upstream and downstream of all previously reported locations. A concentrated area of spawning was identified in Lake Kate Sheppard at a distinctly different location versus pre-quake records, and no spawning was found on the western shores. Spawning was also recorded for the first time in Anzac Creek, a nearby waterway connected to Lake Kate Sheppard via a series of culverts.
Overall the results indicate that spawning is taking place in different locations from the pre-quake pattern. Although egg survival was not measured in this study, sites in new locations may be vulnerable to current or future land-use activities that are incompatible with spawning success. Consequently, there are considerable management implications associated with this spatial shift, primarily relating to riparian management. In particular, there is a need to control threats to spawning sites and achieve protection for the areas involved. This is required under the New Zealand Coastal Policy Statement 2010 and is a prominent objective in a range of other policies and plans.
The Papua New Guinea (PNG) marine aquarium fishery was partly managed by total allowable catch (TAC) limits, implemented since the fishery's inception in 2008. Species-specific TACs, based on stock assessments conducted prior to the commencement of fishing, were established for all fish and invertebrate species presumed to be fished by the fishery. By analysing the selectivity of the PNG fishery in 2012, a large portion (74.9%) of the managed fish diversity (n = 267 species) was found to be “weakly” to “strongly” avoided relative to their availability. More than half (53.2%; n = 142) of the fish species with TACs were never fished in 2012. Of those species with TACs that were actually fished, 76.8% (n = 96) of fish and all invertebrate catches never exceeded 1% of their TACs. Catches of only seven fish species exceeded 10% of their TACs. Catch records also identified 124 fish species that were fished in the absence of species-specific TACs. Unbiased recursive partitioning was used to examine ecological attributes of these species to help identify flaws in the methods used for initial TAC assignment. Refining the role species-specific TACs play in the management of this fishery is necessary to optimise managerial resources. The lessons learned from this approach to marine aquarium fishery management are likely to be of interest and value to PNG, other developing island nations, and marine aquarium fisheries globally.
Size generally dictates metabolic requirements, trophic level, and consequently, ecosystem structure, where inefficient energy transfer leads to bottom-heavy ecosystem structure and biomass decreases as individual size (or trophic level) increases. However, many animals deviate from simple size-based predictions by either adopting generalist predatory behavior, or feeding lower in the trophic web than predicted from their size. Here we show that generalist predatory behavior and lower trophic feeding at large body size increase overall biomass and shift ecosystems from a bottom-heavy pyramid to a top-heavy hourglass shape, with the most biomass accounted for by the largest animals. These effects could be especially dramatic in the ocean, where primary producers are the smallest components of the ecosystem. This approach makes it possible to explore and predict, in the past and in the future, the structure of ocean ecosystems without biomass extraction and other impacts.
Rising seas will impact millions of coastal residents in coming decades. The vulnerability of coastal populations exposed to inundation will be greater for some sub-populations due to differences in their socio-demographic characteristics. Many climate risk and vulnerability assessments, however, model current populations against future environments. We advance sea-level rise risk assessments by dynamically modeling environmental change and socio-demographic change. We project three scenarios of inundation exposure due to future sea-level rise in coastal Georgia from 2010 to 2050. We align the sea-level rise projections with five population projection scenarios of socially vulnerable sub-populations via the Hamilton-Perry method and the theory of demographic metabolism. Our combined fast sea-level rise and middle population scenarios project a near doubling of the population exposed, and a more than five-fold increase for those at risk (i.e., residing in a census tract with high social vulnerability) and most at risk (i.e., high social vulnerability and high exposure) compared to the same estimate based on 2010 population data. Of vulnerable sub-populations, women had the largest absolute increase in exposure for all scenario combinations. The Hispanic/Latinx population's exposure increased the largest proportionally under the fast and medium sea-level rise projections and elderly people's (65+) under the slow sea-level rise scenario. Our findings suggest that for coastal areas experiencing rapid growth (or declines) in more socially vulnerable sub-populations, estimates based on current population data are likely to underestimate (or overestimate) the proportion of such groups' risk to inundation from future sea-level rise.
Understanding global patterns of biodiversity change is crucial for conservation research, policies and practices. However, for most ecosystems, the lack of systematically collected data at a global level limits our understanding of biodiversity changes and their local-scale drivers. Here we address this challenge by focusing on wetlands, which are among the most biodiverse and productive of any environments1,2 and which provide essential ecosystem services3,4, but are also amongst the most seriously threatened ecosystems3,5. Using birds as an indicator taxon of wetland biodiversity, we model time-series abundance data for 461 waterbird species at 25,769 survey sites across the globe. We show that the strongest predictor of changes in waterbird abundance, and of conservation efforts having beneficial effects, is the effective governance of a country. In areas in which governance is on average less effective, such as western and central Asia, sub-Saharan Africa and South America, waterbird declines are particularly pronounced; a higher protected area coverage of wetland environments facilitates waterbird increases, but only in countries with more effective governance. Our findings highlight that sociopolitical instability can lead to biodiversity loss and undermine the benefit of existing conservation efforts, such as the expansion of protected area coverage. Furthermore, data deficiencies in areas with less effective governance could lead to underestimations of the extent of the current biodiversity crisis.
A crucial goal of ecosystem-based management is to maintain the delivery of ecosystem services (ESS) over time. This requires ESS to be assessed repeatedly over time, a task that becomes extremely challenging in data-poor coastal areas, where the lack of data and resources sums up with the intrinsic difficulties of assessing marine and coastal ESS. This implies the need to develop simple ESS assessment methods and to optimize the monitoring effort required to implement them. The aim of this work is to identify which are the key monitoring priorities for ESS mapping in data-poor coastal areas, in the perspective of ecosystem-based management implementation. In order to do so, the ESS provided by Posidonia oceanica meadows in the northern African Mediterranean coastal area have been chosen as a case study, and assessed by mapping the service providing, benefiting and connecting areas. Different input data and methods have been tested to explore how the mapping approach can be kept as simple as possible to ensure a broad applicability, and which are the crucial data required, in order to optimize the monitoring effort. The spatial distribution of the habitat providing the ESS resulted to be the data to which the mapping outcomes are more sensitive, and should be thus considered a key monitoring priority. The other input data can be kept as simple as (1) an expert-driven estimate of the service connecting area, to be understood as an ecologically meaningful range of influence of the focal habitat, and (2) globally available datasets for mapping the service benefiting areas. Overall, this results in an aggregated mapping of the multiple ESS provided by a marine habitat, which, according to our results, seems to be an advisable strategy for a first ESS assessment suitable for application in a data-poor context.
The coastal zone in the Arctic is being extensively used for recreational activities. Simultaneously, there is an increasing pressure from commercial activities. We present results from a discrete choice experiment implemented in Arctic Norway, revealing how households in this region make trade-offs between recreational activities and commercial developments in the coastal zone. Our results show that, although people prefer stricter regulation of commercial activities, they welcome expansion in marine industries like aquaculture and marine fishing tourism. We also find evidence of high willingness-to-pay for new jobs; and this may partly explain the preferences for the commercial facilities in spite of the visual intrusion they create. On the other hand people expressed a clear dislike for littering of the beaches. Hence, the message to policy makers is to allow for commercial development in the coastal zone, but only under strict regulations, especially related to measures reducing the amount of marine debris.
Molecular mechanisms underlying coral larval competence, the ability of larvae to respond to settlement cues, determine their dispersal potential and are potential targets of natural selection. Here, we profiled competence, fluorescence and genome-wide gene expression in embryos and larvae of the reef-building coral Acropora millepora daily throughout 12 days post-fertilization.
Gene expression associated with competence was positively correlated with transcriptomic response to the natural settlement cue, confirming that mature coral larvae are “primed” for settlement. Rise of competence through development was accompanied by up-regulation of sensory and signal transduction genes such as ion channels, genes involved in neuropeptide signaling, and G-protein coupled receptor (GPCRs). A drug screen targeting components of GPCR signaling pathways confirmed a role in larval settlement behavior and metamorphosis.
These results gives insight into the molecular complexity underlying these transitions and reveals receptors and pathways that, if altered by changing environments, could affect dispersal capabilities of reef-building corals. In addition, this dataset provides a toolkit for asking broad questions about sensory capacity in multicellular animals and the evolution of development.
Advocates of marine biodiversity conservation have intensified their calls for the rapid expansion of marine protected areas (MPAs) across the globe, while researchers continue to examine why some people in affected communities support MPAs and others oppose them. Drawing on an ethnographic study of dispossession and the micropolitics of marine conservation in southeastern Tanzania, this paper examines the local dynamics pertaining to the Mnazi Bay-Ruvuma Estuary Marine Park (MBREMP) in rural Mtwara on Tanzania's border with Mozambique. In-depth interviews with 160 individuals and eight focus group discussions with 48 participants were conducted in four sea-bordering villages. By analyzing the narratives of people living in the MBREMP's catchment area regarding their lived experiences with the MBREMP, the paper highlights inter-village and intra-village similarities and differences in the perceived significance and social impact of the MBREMP. Through narratives, people revealed their feelings of angst, disempowerment and vulnerability, emanating from their awareness of the state-directed dispossession they had experienced. The MBREMP's gendered impact was evident as women frequently blamed the park rangers for making their lives difficult through unreasonable and coercive restrictive practices. The paper argues that to achieve the laudable global goals of marine biodiversity conservation, it is imperative that the social complexities of the local context, livelihood concerns, gender relations, social hierarchies and the diverse perspectives of residents are ethnographically documented and integrated into policies leading to the practice of good governance of MPAs.