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The data obtained during the recent decades indicate large-scale climatic changes in the Arctic Ocean, especially in the Siberian shelf seas. The impact of shrinking of the Arctic ice cover on marine net primary production (PP) was mostly studied using satellite-derived estimates of chlorophyll-a (Chl a), sea surface temperature, and sea ice concentrations, as well as various modeling approaches. However, no data are available on the quantitative relations between phytoplankton production and heterotrophic bacterioplankton activity in the broadest and shallowest shelf of the World Ocean - the East Siberian Arctic seas (ESAS). In this paper we present a full set of in situ measurements of main PP and microbial heterotrophy characteristics required for better understanding and further validation of the satellite and modeling approaches. In September–October 2011, during the 57th cruise of RV Akademik M.A. Lavrent'ev , PP, bacterioplankton abundance (BA) and bacterioplankton production (BP), as well the rates of dark CO 2 assimilation (DCA) were determined in the Chukchi, East Siberian, and Laptev seas and in the Gulf of Anadyr of the Bering Sea (a total of 26 stations) by in situ measurements using radiolabeled bicarbonate. All three important production indicators exhibited significant variance within the studied water areas of the Arctic (РР from 0.98 to 54.7 μg C L−1 day−1), (ВР from 1.1 to 17.1 μg C L−1 day−1), and (DCA from 0.23 to 8.7 μg C L−1 day−1). The state of phyto- and bacterioplankton was determined by analysis of the BP/PP and DCA/PP ratios. Active photosynthesis with efficient incorporation of inorganic carbon into the biomass was observed in the Chukchi Sea coastal eastern waters and in the Gulf of Anadyr. On the contrary, the phytoplankton primary production was extremely low in oligotrophic basins of the East Siberian and Laptev seas, while the activity of heterotrophic bacterioplankton consuming organic matter of phytoplankton origin was relatively high. The data of direct measurements can be used for further adjustment of the indirect assessments of production obtained by satellite observations. Glossary East Siberian Arctic seas (ESAS), net primary production (PP), bacterioplankton abundance (BA), bacterial biomass (BB), bacterial production (BP), Arctic Ocean PP (AO-PP), organic matter (OM), dissolved organic matter (DOM), colored dissolved organic matter (CDOM), light CO 2 assimilation (LCA), dark (heterotrophic + chemotrophic) CO 2 assimilation (DCA), production indicators of the surface water layer (PP surf , DCA surf , BP surf), estimated production indicators for the entire depth of the sea (PP int , DCA int , BP int ; mg C m−2 day−1). [Display omitted] • The Arctic seas are characterized by high heterogeneity of phyto- and bacterioplankton activity. • In the Chukchi and Bering seas, autotrophic production is higher than heterotrophic. • In the East Siberian and Laptev Seas, heterotrophic production is similar and higher than autotrophic. • The balance of autotrophic and heterotrophic plankton activity determines the direction of CO 2 flow. [ABSTRACT FROM AUTHOR]

It is largely acknowledged that global mean sea level is rising and accelerating increasing low-lying coastal communities' exposure and vulnerability. The IPCC AR5 identified the Mediterranean Sea as one of the semi-enclosed seas with projected high rate. Impacts of sea level rise (SLR) at local scale affect the number of visitors in highly vulnerable beaches and previous paper have quantified these adverse effects. In this paper we want to say that coastal climate change is not just sea level rise and other climatic factors can affect the optimal beach carrying capacity in complex and uncertain ways. Specifically, the paper shows that the effects of selected climatic factors as wave, rainfall and wind can be opposite to that of SLR and the beach management could even benefit from those trends. • The paper is part of a large research on the management and planning of vulnerable beaches in Sardinia (IT) under climate change. • The main objective of the study was to provide a comprehensive quantification and characterisation of the impacts of climate change on optimal beach carrying capacity. • To the best of our acknowledge, this is the first paper that considers multiple climatic factors. This is in accordance with IPCC advices for more comprehensive studies, wider than sea level rise. • We found that in Southern Sardinia the effects of selected climatic factors as wave, rainfall and wind can be opposite to that of sea level rise and the beach management could even benefit from those trends with more facilities and services. [ABSTRACT FROM AUTHOR]

The River Indus delta is the most prominent feature on the Pakistan coast. Owing to its prominence, mangrove ecosystem, historical, ecological and economic significance it is also a proposed Marine Protected Area (MPA). Currently there are no designated MPAs in Pakistan. This paper presents findings of the Fishery Resource Appraisal Project of Pakistan (FRAPP) a fishery stock assessment carried out for the pelagic and demersal fishery resource of Pakistan from 2009 to 2015 and the Creek Survey Program (CSP) which was part of FRAPP. And discusses how the delta suffers from physical stress. The observations from FRAPP indicates deterioration in the mangrove ecosystem, that are evident in the form of loss of biodiversity and biological productivity. The 600 observations from 10 major creeks showed that trawl catches were a mix of generally small size fish and shrimp. Catches averaged less than 1 kg per tow in all the creeks sampled. Catch weights were somewhat higher in Isaro, WadiKhuddi, Paitiani, Dabbo, Richaal Creeks all of which were near mangrove areas and open sea. The most frequently occurring species of shrimps caught in the trawls belonged to 7 major taxa. The Khobar Creek and Upper Wari Creek are notable for the high rates of occurrence of every group except the Caridea. They are also the only two creeks where the freshwater family Paleomonidae is common. The size composition of the important penaeid family of shrimps in all study areas combined suggests that the smallest shrimps (0.5–1.5 cm carapace length CL) enter the creeks in February/March and adults (5–6 cm CL) move out again 6–12 months later. Four species of Penaeus ( monodon , japonicus , semisulcatus , merguiensis ), two species of Metapenaeus ( monoceros , affinis ), Parapeneoposis stylifera and Solenosera sp. were caught, all in low abundance, less than 0.5 Kg tow −1 . The shrimp catches in the area off the Sindh coast, the catches averaged 4.30 ± 13.40 kg h −1 on the inner shelf (20–50 m) and 1.7 ± 6.6 kg h −1 on the outer shelf (51–200 m). Further east, on the Kori bank, the shrimp catch averaged 4.40 ± 6.6 kg h −1 (inner shelf) and 1.7 ± 6.6 kg h −1 (outer shelf). Penaeus spp. were more abundant in the inshore and Metapenaeus spp. on the outer shelf. The creeks that have a direct connection to the sea and support a natural mangrove stand are significantly more productive than the smaller creeks. Scientific and management questions have arisen that are addressed in order to help revive the delta and hope that this results in a spillover effect that will spread on to the shelf areas. Fisher communities depend heavily on the delta and coastal waters and its natural resources for their livelihood. Their participation and ownership on the resource is over generations, and therefore their involvement is key to proposing any management and conservation initiatives. The study proposes how the delta and its ecosystem in parts should be protected and why and how it is a prime candidate for being declared nationally as protected. This paper proposes a way forward. [ABSTRACT FROM AUTHOR]

Coastal erosion in the changing climate situation is a grievous concern. Global experience varies in this regard due to the variation of the coastal dynamics. Muddy coasts are exceptionally fragile for the welding of the ecological environment, soft sedimentation nature, anthropogenic and natural factors. Therefore, coastal erosion protection is a challenging and daunting task for most of the muddy coasts. Stark pitfalls of the hard structural engineering solution for coastal erosion protection are becoming more prominent. The propensity to adopt nature-based solutions (NbS) for coastal erosion protection, squeeze, and retreat is on the mark, as opposed to grey or engineering solutions. Yet a comprehensive understanding of NbS for coastal protection in the muddy coasts and evidence building from a global perspective is a vacuum. This paper aims to look into the global contexts and experiences of NbSs for coastal protection to provide a cutting-edge analysis of the role of NbS in coastal erosion protection, biodiversity protection, renewing natural habitats, and shielding coastal populations in a changing climate situation. This research uses a systematic review method to explore the global to regional landscape of NbS in coastal erosion, policy framework, and the national experience. The plethora of NbS experience shows the effectiveness in protecting eroding coasts if properly applied in the right conditions under a pragmatic and/or policy-governance approach. Muddy coast in the peri-urban area of littoral countries like Thailand evolves even more critical bio-spheric condition that requires special and urgent attention. The complexity of the muddy coast of the upper Gulf of Thailand has to be critically understood for NbS-driven pivotal pathways to assure sustainable coastal erosion protection and climate-resilient development. • Coastal erosion in the muddy coasts is a grievous concern in the face of climate change. • Protecting coastal erosion is a daunting task as conventional structures are not suitable for fine sediments andexacerbate negative impacts. • Pitfalls of the grey structures necessitate nature-based solutions (NbS) for sediment trap and erosion control. • Global examples of NbS for erosion protection in the muddy coasts are there but not highlighted, overlooked, and less promoted. • The successful implementation of NbS for erosion protection on muddy coasts requires holistic fusion of science, knowledge, skill, and good governance. [ABSTRACT FROM AUTHOR]

Recent observations have heightened concerns that the reduced density of coastal water is leading to a decrease in the frequency of basin water renewal in Norwegian sill fjords. There are indications that coastal water is becoming lighter due to climate change. The renewal of fjord basin water constitutes the primary source of oxygenation in these fjords, and many sill fjords naturally undergo stagnation periods lasting up to several years. In this paper, we have mapped alterations in coastal water using time series data from hydrographic measurements along the coastline, utilizing them as input for a simplified two-layer fjord model. We demonstrate that the temperature has risen, salinity has decreased, and consequently, the density of coastal water has declined since approximately 1990. At a depth of 10 m, the rise in temperature and the reduction in salinity made similar contributions to the decrease in density. However, at depths of 50 and 100 m, the increasing temperature emerged as the primary factor. The density exhibited a more substantial decrease in the upper layers compared to the lower layers. Consequently, not only was the water less dense, but the stability of the water column had also increased. The estimated temperature in the fjord basins increased after 1990 in 98 out of 101 evaluated fjords, with an average increase of 0.6 °C. The altered coastal stratification had an impact on the estimated work against the buoyant forces in the fjord basins. In 78 out of the 101 fjords, the work against buoyant forces by diapycnal mixing increased. In most of the fjord basins where the work against buoyant forces increased, the rise was insufficient to compensate for the decreasing density at the coast. Consequently, basin water renewal occurred less frequently in 65 out of the 101 fjord basins along the Norwegian coast. • Coastal monitoring in Norway show altered coastal climate since 1930. • The Norwegian coastal water has decreased in density. • The stratification along the Norwegian coast is intensified. • Both coastal water and fjord basin got warmer after 1990. • Water exchange in fjord basins occure less frequent than before. [ABSTRACT FROM AUTHOR]

From the 2013 ECSA conference ‘Estuaries and Coastal Areas in Times of Intense Change’ a theme emerged that has ended up being the focus of this Special Issue of Estuarine Coastal and Shelf Science, namely ‘Changes to processes in estuaries and coastal waters due to intense multiple pressures’. Many parts of the world are continuing to experience unprecedented rates of economic growth, and those responsible for managing coastal and estuarine areas must respond accordingly. At the same time, global climate change and sea level rise are also continuing, placing new or more intense pressures on coastal areas that must be dealt with in ways that are as far as possible managed as a result of good scientific understanding. There are other pressures too, which depend on the system concerned. This article provides an overview of the papers contained within the Special Issue and provides a discussion of how these fit within the main theme of intense multiple stressors, considering how a balance can be achieved between the needs of various different stakeholders and interest groups, and the sustainability of the system concerned. We categorise the papers in four main groupings: (1) stressors related to sea level rise; (2) stressors related to changes in fresh water inputs; (3) stressors related to anthropogenic pollution; and (4) the use of indicators as a means of assessing the effects of stressors, and reflect on the fact that despite the diversity of different challenges and geographical regions involved many of the approaches and discussions contained within the Special Issue have strong similarities, leading to a set of overarching principles that should be considered when making recommendations on management strategies. [ABSTRACT FROM AUTHOR]

Abstract: The paper gives an overview of some of the large, shallow, semi-enclosed coastal systems (SECS) in Europe, These SECS are important both from the ecological and the economic perspective (socio-ecological systems) and provide many valuable ecosystem goods and services. Although some of the systems are transitional waters under the Water Framework Directive, this is not the case for all of the systems. The paper adopts a Driver-Pressure-State-Impact-Response approach to analyse the ecological status, vulnerability and future perspectives of these systems in the context of global change. [Copyright &y& Elsevier]

Abstract: Since 2002 there has been an increase in knowledge of many aspects of the biology and ecology of tropical estuarine fishes, as well as significant changes to many estuarine fisheries. Analyses of literature databases (2002–2012) show that: of the c. 600 relevant papers, 52% are primarily related to ecology, 11% to conservation, 11% to anthropogenic and pollution effects on fishes, 9% to fisheries, 7% to aquaculture, 4% to study techniques, and 1% each to fish larvae, effects of fishing, taxonomy, climate change, evolution and genetics. In terms of geographic spread 17% are from North America, 15% from south Asia, 14% from the Caribbean, 13% from Australasia, 12% from Africa and 9% each from South America and SE Asia. Research papers came from 50 countries of which the dominant were USA (15%), India (12%), Australia (11%) and Brazil (7%). Increasing numbers of studies in West Africa, SE and South Asia and South America have increased basic knowledge of the ecology of estuarine fish faunas. Increases in understanding relate to: roles of salinity, turbidity and habitat diversity; connectivity between habitats; water flow; ecological drivers of spatial variability; scale dependent variation; thermal tolerances; movement patterns; food webs; larval adaptations; and the viability of areas heavily impacted by human activities. New reviews both challenge and support different aspects of the estuarine dependence paradigm – still perhaps one of the main research issues – and the protective function of estuaries and mangroves for juvenile fishes has received attention in relation to e.g. predation risks and fisheries. There have also been significant advances in the use of guilds and biodiversity models. Fishing pressures have continued unabated in most tropical estuaries and are summarised and management issues discussed. Understanding of the relationships between fisheries production and mangroves has advanced and significant differences have emerged between Indo-West Pacific and Atlantic systems. The effects of fishing itself have also received attention and research is often related to conservation studies. The effects of anthropogenic activities are reviewed and important advances in mitigation are discussed. Restoration of estuarine habitats, such as mangroves, previously taking place mainly in countries such as Australia and USA, is now occurring in more countries. The design of reserves and the use of protected areas as management tools are gaining credence. Finally, the evidence for actual and potential effects of climate change is discussed. [Copyright &y& Elsevier]

Abstract Sandy beaches comprise 31% of the ice free coasts of the world, providing a variety of ecosystem services essential to support human well-being, particularly protection against erosion and extreme climatic events. These highly dynamic environments are controlled principally by wave energy, tides and grain size, generating complex morphodynamic patterns that translate into strong area variation. Estimates of beach area and its variability are prime inputs for coastal management, a challenge that requires data representing a wide spatiotemporal scale. In this paper, a Landsat-based semi-automated methodology was developed to reconstruct the area of 21 sandy beaches of the Montevideo (Uruguay) coast from 1984 to 2016. This long-term information was also used to discern erosion-accretion cycles by means of wavelet analysis, and to explore the role of climatic forcing on these cycles through linear mixed models. A random forest classification algorithm was applied to Landsat images in order to estimate beach area. Long-term trends described a 27-year cycle with well-delimited quasi-decadal erosion and accretion phases related to climatic configurations. The beach area was negatively affected by an increase in sea level and climatic conditions of the previous year, being positively correlated with sea surface temperature anomalies and offshore winds (which favored accretion) and negatively correlated with onshore winds and intense El Niño Southern Oscillation (ENSO) events (favoring erosion). Our findings, together with the predicted increase in the occurrence and intensity of storms and extreme ENSO events, constitute a worrying scenario, as erosion in this populated coastal zone could have negative social, economic and ecological repercussions. The methodology developed here was useful to detect long-term changes in beach area and is entirely based on open-access information. Therefore, it is potentially applicable at any location on the planet. This approach is also useful to counteract the scarcity of long-term information that has precluded robust assessments of climate change effects on coastal zones. Highlights • Beach area was estimated through random forest classification on Landsat images. • Beach area estimations were based on open data and can be replicated elsewhere. • Sandy beach area showed a 27-year cycle, with defined erosion and accretion phases. • Erosion/accretion patterns in Montevideo beaches responded to climatic conditions. • Beach area model and IPCC predictions suggest an erosive scenario for this coast. [ABSTRACT FROM AUTHOR]

Abstract The Transitional Water Quality Index (TWQI) is a simple tool for assessing the trophic status in shallow transitional water ecosystems, that can be easily implemented from basic monitoring activities. It integrates six metrics: the main causal factors of eutrophication (N and P concentrations), key biological elements (phytoplankton chlorophyll- a , benthic phanerogams and macroalgal cover) and an indicator of the eutrophication effects (dissolved oxygen saturation). This paper investigates the effectiveness of the TWQI to increase the confidence in trophic status assessment and to reduce the uncertainty due to temporal variability. The temporal variability of TWQI and its six single metrics, individually considered, were investigated in Venice Lagoon using data from 29 stations, sampled in July and October 2010, and 8 stations sampled monthly from April 2014 to March 2015. TWQI resulted less affected by seasonal fluctuations than the individual metrics, generally reducing the mean temporal variability by at least 50%. The influence of monitoring frequency on the uncertainty of the trophic status assessment was investigated as percent error of the TWQI annual mean. Means were firstly obtained from 12-monthly samplings. Lower sampling frequencies were also simulated and the deviation from the annual mean derived by monthly sampling was estimated. Overall, the annual mean values of TWQI was much less affected by the sampling frequency than individual indicators (e.g. Dissolved Inorganic Nitrogen). Based on the performance analysis of this study that demonstrates its reliability and efficiency, the TWQI can be recommended as a routine index to be used in large-scale monitoring of the trophic status in shallow transitional water ecosystems. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the combined role of hydrodynamic forcing, sediment transport processes and sea bottom features in determining the location of the meadow upper limit of the endemic Mediterranean seagrass Posidonia oceanica. For this purpose, an approach including extreme wave analysis and numerical modelling is applied to two sandy beach systems located in southern Sardinia (Italy). Information about bathymetry, P. oceanica meadow extension and bottom features has been made available by previous published studies. Based on the 30-year long NOAA hindcast dataset, a wave climate analysis is carried out to identify the incoming storm wave conditions (1 year return period) to be simulated with the Delft3D model package. The simulation results extend the current knowledge highlighting the importance of wave-induced hydrodynamic parameters as limiting factors for the survival of P. oceanica meadows. In particular, the results suggest that on sandy substrata the meadow upper limit lies well offshore of the surf zone, in areas with little morphological activity, where the wave orbital velocities associated to storms are on the order of 0.8 m/s and the mean current magnitude does not exceed 0.5 m/s. On rocky bottoms, the P. oceanica meadow can extend up to the outer surf zone of storms and is thus able to colonize shallow areas subject to stronger hydrodynamic forcings than those observed on sand. This difference in the plant tolerance to wave forcing depending on the substratum type shows how both hydrodynamic and geological factors play a key role in defining the environmental conditions for the development of seagrass meadows. [ABSTRACT FROM AUTHOR]

Abstract: Coastal zones are widely recognised as being particularly vulnerable to future environmental change. Although a significant number of previous papers warn of an increasing tendency in the appearance of eutrophication processes in such systems, very few papers have evaluated the influence of global climate change on eutrophication. In the Mar Menor lagoon (SE Spain), the high biomass of the main primary producer, Caulerpa prolifera Forsskal (Lamououx), covers most of the bottom, and has probably increased the resistance of the lagoon to eutrophication processes through the high uptake of nutrients from the water column and their retention in the sediments, avoiding high phytoplankton densities. Nevertheless, if climate change predictions become true, the current status of the lagoon is likely to collapse, since future environmental conditions could make C. prolifera unable to reach values of net photosynthesis greater than zero, and eutrophication processes are expected to appear. [Copyright &y& Elsevier]

Abstract: The impact of climate change through thermal stress-related coral bleaching on coral reefs of the Western Indian Ocean has been well documented and is caused by rising sea water temperatures associated with background warming trends and extreme climate events. Recent studies have identified a number of factors that may reduce the impact of coral bleaching and mortality at a reef or sub-reef level. However, there is little scientific consensus as yet, and it is unclear how well current science supports the immediate needs of management responses to climate change. This paper provides evidence from the Western Indian Ocean in support of recent hypotheses on coral and reef vulnerability to thermal stress that have been loosely termed ‘resistance and resilience to bleaching’. The paper argues for a more explicit definition of terms, and identifies three concepts affecting coral-zooxanthellae holobiont and reef vulnerability to thermal stress previously termed ‘resistance to bleaching’: ‘thermal protection’, where some reefs are protected from the thermal conditions that induce bleaching and/or where local physical conditions reduce bleaching and mortality levels; ‘thermal resistance’, where individual corals bleach to differing degrees to the same thermal stress; and ‘thermal tolerance’, where individual corals suffer differing levels of mortality when exposed to the same thermal stress. ‘Resilience to bleaching’ is a special case of ecological resilience, where recovery following large-scale bleaching mortality varies according to ecological and other processes. These concepts apply across multiple levels of biological organization and temporal and spatial scales. Thermal resistance and tolerance are genetic properties and may interact with environmental protection properties resulting in phenotypic variation in bleaching and mortality of corals. The presence or absence of human threats and varying levels of reef management may alter the influence of the above factors, particularly through their impacts on resilience, offering the opportunity for management interventions to mitigate the impacts of thermal stress and recovery on coral reefs. These concepts are compiled within an overarching framework of spatial resilience theory. This provides a framework for developing linked scientific and management questions relating to the larger scale impacts of climate change on coral reefs, their management needs and prospects for their future. [Copyright &y& Elsevier]

As international pressure for marine protection has increased, Scotland has increased spatial protection through the development of a Marine Protected Area (MPA) network. Few MPA networks to date have included specific considerations of climate change in the design, monitoring or management of the network. The Scottish MPA network followed a feature-led approach to identify a series of MPAs across the Scottish marine area and incorporated the diverse views of many different stakeholders. This feature led approach has led to wide ranging opinions and understandings regarding the success of the MPA network. Translating ideas of success into a policy approach whilst also considering how climate change may affect these ideas of success is a complex challenge. This paper presents the results of a Delphi process that aimed to facilitate clear communication between academics, policy makers and stakeholders in order to identify specific climate change considerations applicable to the Scottish MPA network. This study engaged a group of academic and non-academic stakeholders to discuss potential options that could be translated into an operational process for management of the MPA network. The results of Delphi process discussion are presented with the output of a management matrix tool, which could aid in future decisions for MPA management under scenarios of climate change. [ABSTRACT FROM AUTHOR]

This paper reports on two three-months field experiments carried out in the Ouano lagoon, New Caledonia. This channel-type lagoon, exposed to meso-tides, south pacific swells and trade winds, has been monitored thanks to a network of currents profilers to understand the dynamics of the lagoon waters. Four typical circulation patterns have been identified, covering all together more than 90% of the survey period. These patterns are mainly driven by the waves and wind features. In particular, obliquely incident waves or strong winds blowing over a sufficient period are able to reverse the typical circulation pattern. The analysis of the vertical structure of the currents through passages shows the regular presence of a nearly linear vertical shear within the water column. [ABSTRACT FROM AUTHOR]

Adaptation in and around estuaries, to ensure the future resilience of both the natural environment and the communities that are located alongside is an increasingly pressing need. As part of an adaptation planning program for the Basque estuaries (northern Spain, south-eastern Bay of Biscay), a modelling system to simulate the morphological response of the Oka estuary to climate change has been developed. Existing knowledge was used as the basis to frame this pilot modelling examining both the short-term change (storm, seasonal, annual) and the longer-term changes (decades to eons). In this paper, we focus on the long-term response and consideration of the output from the process model is limited to the data that was extracted to help parameterize the long-term model. The latter was then used to examine the response of the estuary to the past changes over a historical time scale, where observations from foraminiferal analysis and saltmarsh response were used to establish the predictive validity of the model. Forcing the model with a linear rate of sea level rise representative of the 20th century, the estuary keeps pace with sea level rise in agreement with the observations. An 18.6-year periodic variability was identified over the saltmarshes, by including the effect of the nodal tide, with the last deposition maximum occurring in 2020. The effect of the opening of a saltmarsh that was drained at the beginning of the 18th century was investigated using a simplified schematization and showed sedimentation rates of up to one order of magnitude larger than in natural marsh, in general agreement with the rates obtained in previous studies. To predict the future response of the estuary, simulations with an exponential sea level rise were performed using scenarios obtained from the latest IPCC projections. The estuary fails to keep pace with sea level rise in any of the scenarios considered. The attendant increase in the hydroperiod over the saltmarshes is also likely impact to saltmarsh species productivity and distribution. Despite the simplifications inherent to the model, and the simplifications made in the representation of the estuary and forcing conditions, the methods presented here provide additional insights into long-term behaviour that complement information obtained from more detailed, but short-term, process models. The combined modelling approach allows adaptation measures to climate change to be considered over longer timescales. • Adaptation to climate change is a problem faced by estuaries around the world. • An approach to study adaptation options for the Basque coast (Spain) is proposed. • With a linear rate of sea level rise, the Oka estuary keeps pace with sea level rise. • The Oka estuary fails to keep pace with future projections of sea level rise. • Saltmarsh enclosure and re-opening change the morphological response of the estuary. [ABSTRACT FROM AUTHOR]

Sandy beaches are severely under-represented in the literature on climate-change ecology, yet different lines of evidence suggest that the macrofauna inhabiting these narrow and dynamic environments located at the land-sea interface is being reorganized under the influence of this large scale and long-lasting stressor. This is reflected in macrofaunal sensitivity to increasing sea surface temperature, sea-level rise, extreme events and erosion of the narrow physical habitat. However, evidence of behavioral responses by sandy beach macrofauna that are consistent with expectations under climate change is scarce and fragmentary. In this paper, specific hypotheses are formulated for how behavioral adaptations in sandy beach macrofauna are predicted to respond to climate change impacts. Firstly, a conceptual framework and an overview of macrofauna behavioral adaptation features are provided. Secondly, the effects of main climate change drivers on sandy beaches are summarized. Thirdly, a conceptual framework is developed giving behavioral adaptations of sandy beach macrofauna under climate change pressure. The degree to which observations on behavioral adaptations of beach animals conform to expectations under specific climate change drivers (sea level rise, sea surface temperature, winds and storminess, rainfall, acidification and eutrophication) is explored. Taking into account the empirical evidence and the theoretical framework detailed in the paper, emergent hypotheses/predictions are proposed. Climate change drivers are expected to impact habitat features and consequently the behavioral expression of macrofauna as active responses to habitat changes. Behavioral adaptations are expected to be impaired, more variable or disrupted, thus decreasing fitness, causing local population extirpations and potentially triggering a range of cascading effects of ecological change in the beach ecosystem. Biodiversity loss will be the outcome of the negative pressures driven by climate change. The specificity of sandy beaches as narrow ecotones between sea and land may be lost under climate change pressure, adversely affecting fine-tuned macrofaunal adaptations and therefore ecosystem functioning. Strictly adapted endemic sandy beach fauna will be especially subjected to local extirpations, while species with a large reaction norm (i.e. phenotypic and behavioral plasticity) may face changes by dispersal and exploitation of new niches. Under climate change impacts, biodiversity loss is predicted, which would hamper beach ecosystem resilience. The limits to which sandy beach macrofauna responds and can behaviorally adapt to environmental change are worthy of exploration, in view of the increasing influence of the long-lasting climate driven stressors threatening these ecosystems at risk. Image 1 • An overview of macrofauna behavioral adaptations to sandy beach features is provided. • The effects of main climate change drivers on sandy beaches are summarized. • Specific hypotheses are formulated for how behavioral adaptations are predicted to respond to climate change impacts. • Biodiversity loss will be the outcome of the negative pressures driven by climate change. [ABSTRACT FROM AUTHOR]

The paper discusses various aspects of local and regional storminess, as well as challenges in quantifying its tendencies in the eastern section of the Baltic Sea. The study is based on various long-term data sets, such as wind and sea level observation data from coastal stations and tide gauges of Estonia (1899–2013). It also discusses long-term wave hindcasts (1966–2013), reconstructions of shoreline changes, as well as the limitations and possible shortcomings in each of the data sets. Mostly located on the westerly exposed and windward coast of the semi-enclosed Baltic Sea, the case study area is sensitive to wind and storm climate changes. Different manifestations of storminess delivered somewhat specific results. When analyzed together, the first principal component of storminess was connected to the intensity of regional cyclonic activity along the polar front and had relatively high stages in 1920s–1940s, 1980s–1990s and probably also from 2010. The second component carried a local and more random imprint. Appearing independently of the high NAO or general “storminess” phases, the most notable event-driven extremes in the record were related to this component. Based on our data, we cannot confirm the existence of any general increasing long-term trends for storminess. Wherever the increase exists, it has occurred as a winter-time increase accompanied by the shift of the stormy season from autumn to winter. The spatially contrasting results for westerly and northerly exposed coasts reflect the corresponding variations in local wind, which are connected to the changes in storm track activity above northern Europe and a poleward shift of cyclones' trajectories. [ABSTRACT FROM AUTHOR]

Understanding the response of river flow and estuarine hydrodynamics to climate change, land-use/land-cover change (LULC), and sea-level rise is essential to managing water resources and stress on living organisms under these changing conditions. This paper presents a modeling study using a watershed hydrology model and an estuarine hydrodynamic model, in a one-way coupling, to investigate the estuarine hydrodynamic response to sea-level rise and change in river flow due to the effect of future climate and LULC changes in the Snohomish River estuary, Washington, USA. A set of hydrodynamic variables, including salinity intrusion points, average water depth, and salinity of the inundated area, were used to quantify the estuarine response to river flow and sea-level rise. Model results suggest that salinity intrusion points in the Snohomish River estuary and the average salinity of the inundated areas are a nonlinear function of river flow, although the average water depth in the inundated area is approximately linear with river flow. Future climate changes will shift salinity intrusion points further upstream under low flow conditions and further downstream under high flow conditions. In contrast, under the future LULC change scenario, the salinity intrusion point will shift downstream under both low and high flow conditions, compared to present conditions. The model results also suggest that the average water depth in the inundated areas increases linearly with sea-level rise but at a slower rate, and the average salinity in the inundated areas increases linearly with sea-level rise; however, the response of salinity intrusion points in the river to sea-level rise is strongly nonlinear. [ABSTRACT FROM AUTHOR]

Sandy beach animals show behavioural adaptations that are expressed as contingencies during the life history of individuals to face periodic and episodic environmental changes. Such adaptations include activity rhythms, orientation, zonation, burrowing, escape responses and feeding strategies, the first two being common adaptations to all mobile animals. The complex conditions of a particular beach environment may be integrated in a learning process enhancing the adaptation and survival of individuals and eventually of populations. Evidence exists of genetic determination of some behavioural features that are adaptive in the long term (throughout generations) by increasing individual survival and reproductive potential. The environmental features integrated with the life history of beach animals shape the individual behaviour through ontogenetic processes, as well as population behaviour through evolutionary processes. Thus, behavioural differences among individuals may reflect environmental variation at the local and small/medium temporal scales of beach processes, whereas within-population behavioural coherence and differences among populations may reflect variation at the geographic scale. The different foci stressed by different authors and the variety of evidence dependent upon local geographical and ecological conditions have often resulted in compartmentalised explanations, making generalizations and the repeatability of behavioural studies of beach ecology challenging. There was a need to developing a more synthetic paradigm for beach animal behaviour. This paper gives a brief overview of the theoretical background and keystone studies, which have contributed to our understanding of animal behaviour in sandy beach ecology, and proposes testable hypotheses to be integrated in the beach ecology paradigm. [ABSTRACT FROM AUTHOR]

Abstract: Most attempts to link seabirds and climate/oceanographic effects have concerned the Atlantic and Pacific Oceans with comparatively few studies in the tropical Indian Ocean. This paper examines the reproductive response of the lesser noddy Anous tenuirostris to temporal fluctuations in oceanographic and climatic conditions using 8 years of monitoring data from Aride Island (Seychelles), tropical Western Indian Ocean. We tested the hypothesis that breeding parameters (mean hatching date, mean egg size, hatching and fledging successes) and chick growth are influenced by local, seasonal oceanographic conditions as expressed by ocean primary productivity (surface chlorophyll-a concentrations; CC), sea surface temperature (SST) and wind speed. We also examined the relationship between lesser noddy breeding parameters and climate conditions recorded at the basin-wide scale of the Indian Ocean (Indian Ocean Dipole Mode Index, DMI). Our findings suggest that birds had a tendency to lay slightly larger eggs during breeding seasons (years) with higher CC during April–June (pre-laying, laying and incubation periods). Hatching date was positively related to SST in April–June, with the regression parameters suggesting that each 0.5 °C increase in SST meant a delay of approx.10 days in hatching date. A negative linear relationship was also apparent between hatching success and SST in June–August (hatching and chick-rearing periods), while the quadratic regression models detected a significant effect of wind speed in June–August on fledging success. Body mass increments of growing chicks averaged over 7-day periods were positively related with (2-week) lagged CC values and negatively related with (2-week) lagged SST values. No significant relationship between DMI and lesser noddy breeding parameters was found, but DMI indices were strongly correlated with local SST. Altogether, our results indicate that the reproduction of this top marine predator is dictated by fluctuations in local environmental conditions around the colony, while the effects of large-scale oceanographic processes (DMI) on our study population might be mediated by an effect on local SST. [Copyright &y& Elsevier]

Abstract: Large-scale and local climate patterns are known to influence several aspects of the life cycle of marine fish. In this paper, we used a 9-year database (2003–2011) to analyse the populations of two estuarine resident fishes, Pomatoschistus microps and Pomatoschistus minutus, in order to determine their relationships with varying environmental stressors operating over local and large scales. This study was performed in the Mondego estuary, Portugal. Firstly, the variations in abundance, growth, population structure and secondary production were evaluated. These species appeared in high densities in the beginning of the study period, with subsequent occasional high annual density peaks, while their secondary production was lower in dry years. The relationships between yearly fish abundance and the environmental variables were evaluated separately for both species using Spearman correlation analysis, considering the yearly abundance peaks for the whole population, juveniles and adults. Among the local climate patterns, precipitation, river runoff, salinity and temperature were used in the analyses, and North Atlantic Oscillation (NAO) index and sea surface temperature (SST) were tested as large-scale factors. For P. microps, precipitation and NAO were the significant factors explaining abundance of the whole population, the adults and the juveniles as well. Regarding P. minutus, for the whole population, juveniles and adults river runoff was the significant predictor. The results for both species suggest a differential influence of climate patterns on the various life cycle stages, confirming also the importance of estuarine resident fishes as indicators of changes in local and large-scale climate patterns, related to global climate change. [Copyright &y& Elsevier]

Abstract: Resilience research often includes time series analysis in search of trend shifts. Recently statistical signals including changes in variance and autocorrelation, were proven to be universal indicators of stability. In this paper the suitability of those early warning signals was tested on two case studies: oysters production of France (case study 1) and catch rates of the native oyster in the Solent, UK (case study 2). First, trend analyses were performed and their association to the evolution of the North Atlantic Oscillation (NAO) index was assessed. For the French oyster production, two sinusoidal waves were found in the first and second order residuals with periods of 33 and 8 years. In the Solent, the trend depiction showed after an initial increase, the catch rates of oysters declined over time from West to East. A positive relationship was apparent between NAO and both the production and population data, with a significant correlation in case study 2. Furthermore, a high and significant spectral coherency in the 8 year period of case study 1 revealed a near phase opposition between the influence of NAO and the French oyster production. For the first and second case study, the early warning signals calculated were lag-1 autocorrelation and variance, respectively. In case study 1, the stability of the low frequency wave of the first order residuals could not be assed, the trend of lag 1 autocorrelation was thus not conclusive. However the high but stable lag-1 autocorrelation of the second residuals, revealed a probable underlying stability. In case study 2 significant increase in variance reflected the instability prior to the decline. It is discussed that in periodic signals the number of residual fluctuations needs to be sufficient to allow the generation of an autocorrelation trend within the limits of the sliding window, used for its calculation. The importance of time scale and appropriate de-trending is also questioned when calculating and interpreting early warning signals as indicators of underlying (in)stability. Finally besides their scientific use, also the utility of early warning signals in managerial settings are discussed. [Copyright &y& Elsevier]

Abstract: Several ecosystem components in the North Sea have undergone fundamental changes following climatic change and this paper aims to establish if these changes also have affected macrofauna communities in the southern North Sea. From 1978 to 2005, the macrofauna communities were sampled seasonally in the sublittoral zone off the island of Norderney, one of the East Frisian barrier islands. Abundance, biomass and species numbers of single species or larger taxonomic groups showed differences in long-term variability and eurytherm species dominated in the study area. After the cold winter of 1978/79 until the mid 1980s a higher percentage of arctic-boreal species were found, while after 1988 the percentage of species with a southern distribution in the North Sea increased in connection with a smooth biological regime shift and a positive North Atlantic Oscillation (NAO) index. Interface-feeders dominated the communities, followed by sand lickers and subsurface deposit-feeders. The latter were more abundant after cold winters, probably due to their ability to utilise dead buried faunal organic matter. Multivariate analyses revealed that cold winters affected the community structure more briefly, while a smooth biological regime shift in 1989/1990 and a climate regime shift induced abrupt biological regime shift in 2001/2002 caused longer-term progressive change in the macrofauna community structure. The significant correlation between macrofauna abundance, biomass and species number and the NAO index failed until 2001 due to a change in climate systems over the northern Atlantic hemisphere. [Copyright &y& Elsevier]

Abstract: Coastal wetlands provide important ecosystem services to humanity, but human activity and climate change are rapidly degrading these ecosystems. Thus the conservation and restoration of coastal wetlands becomes an urgent issue. Species facilitation among plants has regained attention of ecologists recently. Many studies in coastal wetlands have revealed direct plant–plant facilitation influencing community structure and ecosystem function, thus improving our understanding of community organization and giving new directions for the restoration of degraded coastal wetlands. Our paper examines studies of direct plant–plant facilitation in coastal wetlands with an emphasis on tests of the stress gradient hypothesis and influences of species facilitation on species zonation, species diversity patterns, phylogenetic diversity and ecosystem function. Investigating how plant–plant facilitation affects ecosystem function is an important future direction, which can provide basic knowledge applicable to the preservation and recovery of coastal wetlands in these times of rapid global change. [Copyright &y& Elsevier]

Abstract: Estuaries are extremely variable and unstable ecosystems subject to a wide range of influences, both natural and anthropogenic. Therefore, assessing the consequences of human impacts is crucial to predict and prevent changes in its communities. The Mondego estuary represents a good example of an impacted coastal system since the beginning of the 1990s until now and hence it has been subject to several physical interventions in an attempt to recover the ecosystem status. The effects of one of the latest intervention that took place in May 2006 were assessed using a monitoring programme carried out subsequently (2006–2009) and compared to a zooplankton database covering the period prior to this intervention (2003–2006). Using five sampling stations, the post-intervention period presented a higher total mesozooplankton density mainly of estuarine species. A station downstream of the intervention zone showed higher abundances of Acartia tonsa when it was previously dominated by the marine congener Acartia clausi. In general, at downstream sampling stations, communities of the two main channels became more homogeneous. However, results should be interpreted with care since during this period, the Mondego estuary experienced climatic variability that could mask or emphasize community responses. This paper contributes to understand the role of zooplankton communities in estuarine systems highlighting the importance of integrating natural, climatic and anthropogenic changes for a better understanding of ecosystems. [Copyright &y& Elsevier]

Abstract: Salt marshes in the St. Lawrence Estuary are subjected to strong seasonal variations with sub-arctic winter conditions. The present paper explores sedimentary processes in the Pointe-aux-Épinettes marsh during the ice-free period. Currents, waves, suspended sediment, and sedimentation rates have been measured in June, August and October 2009. Vegetation growth was monitored during one year on a monthly basis to understand the seasonal impact on the marsh. Vegetation attenuates currents and waves, but this attenuation changes over the year as vegetation disappears along winter. Results show that suspended sediment transport and deposition are controlled by vegetation, wave height, currents, distance from the marsh edge and distance from sediment sources. Suspended sediment concentrations and sedimentation rates were significantly correlated to wave height, highlighting the importance of waves for sediment resuspension transport. Transport was lowest in August when vegetation was high and wave occurrence low. However, vegetation growth didn''t change fundamentally sediments dynamic of the marsh. Within one tide, an important part of sediment transport is only local within the marsh, as shown by the maximum sedimentation rates occurring near unvegetated areas of the marsh. Data provide a spatial understanding of summer sedimentology on cold climate marshes. [Copyright &y& Elsevier]

Abstract: Just as runoff primarily governs the tidally-averaged salinity at a point within a classical estuary, this paper examines the extent to which the salinity of an inverse or negative estuary (one that experiences salinities higher than the adjacent ocean) responds to loss of freshwater. The hypothesis that ’the mean salinity of an inverse estuary varies predictably from the effects of net freshwater loss, and that the mean salinity at any time reflects the integration of these effects during a constant, measurable prior period’ is tested using observations spanning 27 years from Spencer Gulf in South Australia. It is shown that, on any day, the mean salinity of the whole (∼500 km2) of northern Spencer Gulf (NSG), deduced from broad oceanographic surveys on fourteen separate occasions between 1982 and 2009, mirrors the integration of net evaporation for a prior period of approximately six months. Linear regression (with a correlation coefficient of 0.89) indicated that a sustained change of one millimetre per day of net evaporation caused the mean salinity of NSG to change by 0.23. It is also shown that the regression relationship deduced using only 1980s data, remained entirely consistent with new data collected in 2008 and 2009, despite substantial longer-term trends during the intervening decades. Since net evaporation is essentially a continuous variable (measured approximately daily) its use as a proxy measure for mean salinity permits deductions about NSG’s long-term salinity behaviour. For example, the Gulf is inferred to reach its annual maximum salinity three months after the summertime net evaporation maximum, and the annual salinity cycle is almost exactly symmetric between rising and falling phases. This behaviour is surprisingly consistent with a simple one-dimensional model of inverse estuarine salt dynamics. Assuming that desalination, as it affects the mean salinity of the whole of NSG, is equivalent to evaporation in its removal of freshwater, estimates of the changes of NSG mean salinity based on proposed desalination rates, and based on projections of local climate change effects in 2030 and 2070, are provided. Finally, each of the principal oceanographic mechanisms that contributes to the efflux of salt from northern Spencer Gulf is examined to show that anticipated perturbations (both natural and anthropogenic) are not expected to perturb the dynamics beyond the Gulf’s ability to respond in the manner described. [Copyright &y& Elsevier]

Abstract: Coastal zones are particularly vulnerable to climate change effects. Over the last century, sea level rose on average by 10–12 cm per decade and did so at much higher rates in some coastal areas due to land subsidence. The 4th IPCC report highlights the increased vulnerability of the coastal zones around the world due to sea level rises in 21st Century. Key concerns due to sea level rise include flooding and salinisation and its implications for water resources. Rising sea level increases the salinity of both surface water and ground water through salt water intrusion. It is important to determine the impacts of sea level rise on salinity to devise suitable adaptation and mitigation measures and reduce impacts of salinity intrusion in coastal cities. The paper presents the outcomes of a study conducted in the coastal area of Gorai river network in the South West region of Bangladesh for developing a comprehensive understanding of the possible effects of sea level rise with the aid of a hydrodynamic model. A newly developed salinity flux model has been integrated with an existing hydrodynamic model in order to simulate flood and salinity in the complex waterways in the coastal zone of Gorai river basin. The integrated model has been calibrated and validated by numerous comparisons with measurements (tide, salinity). The model has been applied for future scenarios with sea level rise and the results obtained indicate the risk and changes in salinity. Due to sea level rise, the salinity has increased in the river and salinity intrusion length has also increased. Sea level rise of 59 cm produced a change of 0.9 ppt at a distance of 80 km upstream of river mouth, corresponding to a climatic effect of 1.5 ppt per meter sea level rise. [Copyright &y& Elsevier]

Abstract: Cerastoderma edule and Mya arenaria are two common bivalve species in European waters. Longevity and maximum size are much greater in the latter species. Because comparison of species life-history strategies states that a long life span (i.e. high annual survival) generally goes with lower fecundity, we hypothesise that reproductive output would be lower in M. arenaria than in C. edule. In the present paper, we studied the reproductive strategies of these two species in an intertidal and a subtidal area of the western Dutch Wadden Sea, by following seasonal changes in absolute and relative weights of somatic and gonadal tissues in these bivalves. Starting of spawning was similar in the two species, around May, except for intertidal M. arenaria, which initiated spawning in August. Individual energy investment in reproduction was similar for the two species but, unlike M. arenaria, C. edule spawned completely, releasing all energy of gonadal mass in the form of gametes. Mya arenaria used the gonad not only for reproduction but also for storage. In the intertidal area, we found a trade-off between longevity and reproduction, i.e. maximum reproductive output (expressed as a proportion of body mass) was higher in C. edule than in M. arenaria. However, since body size is larger and life span longer in M. arenaria than in C. edule, mean lifetime reproductive output per individual must be higher in the first than in the latter. Based on the differences in reproductive strategies of these two species, we hypothesise that the negative effects of warming climate on bivalve population dynamics in the Wadden Sea will be stronger in C. edule than in M. arenaria. [Copyright &y& Elsevier]

Abstract: Marine and coastal environments are among the most ecologically and socio-economically important habitats on Earth. However, climate change associated with a variety of anthropogenic stressors (e.g. eutrophication) may interact to produce combined impacts on biodiversity and ecosystem functioning, which in turn will have profound implications for marine ecosystems and the economic and social systems that depend upon them. Over period 1980–2000, the environment of the Mondego estuary, Portugal, has deteriorated through eutrophication, manifested in the replacement of seagrasses by opportunistic macroalgae, degradation of water quality and increased turbidity, and the system has also experienced extreme flood events. A restoration plan was implemented in 1998 which aimed to reverse the eutrophication effects, especially to restore the original natural seagrass (Zostera noltii) community. This paper explores the interactions between extreme weather events (e.g. intense floods) and anthropogenic stressors (e.g. eutrophication) on the dynamics of the macrobenthic assemblages and the socio-economic implications that follow. We found that during the previous decade, the intensification of extreme flooding events had significant effects on the structure and functioning of macrobenthic communities, specifically a decline in total biomass, a decline in species richness and a decline in suspension feeders. However, the earlier eutrophication process also strongly modified the macrobenthic community, seen as a decline in species richness, increase in detritivores and a decline in herbivores together with a significant increase in small deposit-feeding polychaetes. After the implementation of the management plan, macrobenthic assemblages seemed to be recovering from eutrophication, but it is argued here that those earlier impacts reduced system stability and the resilience of the macrobenthic assemblages, so that its ability to cope with other stressors was compromised. Thus, heavy flooding in the Mondego region during the recovery process had more severe effects on these assemblages than expected, effectively re-setting the recovery clock, with significant socio-economic impacts (e.g. high mortality of fish in fish farms, and a large decline of economically important species, such as the bivalves Scrobicularia plana and Cerastoderma edule). The frequency and magnitude of these extreme events is predicted to increase in future years [IPCC WGI, 2001. Climate change 2001: the scientific basis, contribution of working group I to the third assessment report of the Intergovernmental Panel on Climate Change (IPCC). In: Houghton, J.T., Ding, Y., Griggs, D.J., Noguer, M., van der Linden, P.J., Xiaosu, D. (Eds.), Cambridge University Press, UK, 944 p.] and there is a risk that impacted ecosystems will never recover fully, with far-reaching consequences for human well being. [Copyright &y& Elsevier]

Small intermittently open lagoons are the most common type of estuary in NSW but the majority of them have no seagrass despite apparently suitable physical and water quality conditions. This paper describes the consequences of a catastrophic drought on trophic structure of primary producers in two intermittently open coastal lagoons that have negligible anthropogenic stress. It examines the roles of various factors influencing primary producers and hence ecosystems in intermittently open lagoons, in both short and long timeframes. Two estuarine lagoons with undisturbed catchments (Durras Lake and Nadgee Lake) experienced decadal scale shift in production dominance from benthic to pelagic and back to benthic following a catastrophic reduction in water levels during drought conditions. Water quality deteriorated significantly (high turbidity, ammonia and chlorophyll) after loss of macrophytes and then re-established to "normal" conditions within 2–3 years. Despite this, macrophytes did not re-appear for 6–7 years. The high proportion of intermittent estuaries with no seagrass was concluded to be a consequence of recruitment limitation, and estuarine morphology shapes the ecology of these lagoons, rather than an inherent inability for seagrass and macrophytes to live in the estuaries. Recruitment of macrophytes required coincident occurrence of multiple rare stochastic events, making chance an important aspect of re-establishment of biological assemblages in disturbance driven ecosystems. Conceptual models derived for northern hemisphere, riverine, surface-water fed estuaries tend to dominate thinking about estuaries in the literature, but are clearly inappropriate for typical southern-hemisphere low-flow and groundwater-dominated intermittent estuaries. Climate change is likely to increase the frequency of occurrence of the conditions that led to the loss of seagrass and macrophytes and therefore potentially reduce the number of intermittent estuaries in NSW with macrophytes. In the systems described, maintenance of regional seagrass populations is reliant on the stochastic survival of some populations to act as source populations. Climate change is predicted to make what are currently "extreme" events more common. This could, in turn, mean that the likelihood of the sort of loss described in our two cases studies could become more common, increasing the proportion of systems with no seagrass and progressively closing the window of opportunity for external recruitment. Potentially, this could lead to localised extinction of seagrass in intermittent estuaries. Image 1 • In NSW 68% of the 184 estuaries have intermittent entrances and little seagrass. • Drought and low lake levels caused seagrass mortality in two pristine estuaries. • This was followed by eutrophic and then oligotrophic water conditions. • Macrophytes only recruited 6–8 years later due to entrance closure. • Extreme events will increase with Climate Change and threaten macrophyte populations. [ABSTRACT FROM AUTHOR]

This paper identifies the low-elevation coastal zone (LECZ) populations and developing regions most vulnerable to sea-level rise and other coastal hazards, such as storm surges, coastal erosion and salt-water intrusion. The focus is on the rural poor in the LECZ, as their economic livelihoods are especially endangered both directly by coastal hazards and indirectly through the impacts of climate change on key coastal and near-shore ecosystems. Using geo-spatially referenced malnutrition and infant mortality data for 2000 as a proxy for poverty, this study finds that just 15 developing countries contain over 90% of the world's LECZ rural poor. Low-income countries as a group have the highest incidence of poverty, which declines somewhat for lower middle-income countries, and then is much lower for upper middle-income economies. South Asia, East Asia and the Pacific and Sub-Saharan Africa account for most of the world's LECZ rural poor, and have a high incidence of poverty among their rural LECZ populations. Although fostering growth, especially in coastal areas, may reduce rural poverty in the LECZ, additional policy actions will be required to protect vulnerable communities from disasters, to conserve and restore key coastal and near-shore ecosystems, and to promote key infrastructure investments and coastal community response capability. [ABSTRACT FROM AUTHOR]