Salt marshes are globally widespread, found on low-lying coastal shores, and are highly effective at long-term carbon storage; thus, they are vital for climate change impact mitigation. Accurate carbon stock estimation requires an understanding of local-scale spatial variability of carbon storage and the facilitating processes. Few studies investigate the cumulative impact of controlling factors on within-site carbon distribution. This study utilises 60 cores from a salt marsh in Turvey Nature Reserve (Rogerstown Estuary), on the Irish east coast, to investigate spatial variability in soil organic carbon (SOC) content, alongside bio-sedimentary, and environmental factors. Mean carbon density (CD) was 11.1 ± 4.2 kg m−3 at 10-cm depth, ranging from 5.2 to 22 kg m−3 (423

Saltmarshes provide many vital benefits (ecosystem services), including carbon sequestration, flood protection and nutrient exchange. As “carbon sinks”, these ecosystems sequester carbon up to twice the rate of terrestrial forests. Recent national and international carbon emissions targets highlight the importance to both protect and increase the area of coastal saltmarshes. In addition, these intertidal wetlands are influenced by complex interacting bio-sedimentary and hydrological processes, thus restoration projects need to consider the various processes impacting such ecosystems. To address carbon emissions targets, upscaled estimates of carbon accumulation are required, for which modelling and time-consuming field surveys are employed. An understanding of within-marsh controls on soil organic carbon content (SOC) and the resulting feedbacks (sedimentary, hydrological, geomorphological, ecological) can improve field survey efficiency and provide training data for models. Such data aids in constraining uncertainties around scaled-up carbon accumulation estimates per unit area saltmarsh for regional, national and international inventories. Quantitative data on the variation in SOC and the facilitating processes remains relatively scarce.This research investigates SOC distribution, alongside potential explanatory factors within unmanaged and managed saltmarshes. Through the collection of sediment samples (near-surface, core), alongside location-specific data on elevation, inundation, biomass and accretion rates in Turvey Nature Reserve (Co. Dublin), this project aims to quantify the impact of several key factors (e.g. drainage, topography, biomass and accretion) on carbon accumulation. SOC will be determined through Loss-on-Ignition laboratory analysis. An existing carbon accumulation model will then be improved upon, and the updated model will be utilised to inform an investigation of future carbon storage potential under various climate scenarios.Initial results from an on-going project are presented to provide quantitative field- and laboratory-derived data, enhancing knowledge of within- and between-marsh variation of SOC in saltmarshes.

Effective beach management depends on a fundamental understanding of how beach morphology evolves over seasonal to decadal timescales. Understanding coastal morphological evolution typically relies on extensive spatiotemporal datasets and complex numerical models, requiring significant resources and specialised expertise. On many coasts, data and resources are limited and alternative approaches to gaining coastal management insights are required. Centred on the practical application of beach state theory we design a methodological framework, based on the two-step model developed by McLachlan et al. (2018), aimed at supporting coastal management on Dollymount Strand, Dublin, Ireland, an area lacking systematic geomorphological assessment and monitoring. The framework is comprised of two key components: (1) the prediction of morphodynamic beach state (via the twostep model), and (2) the validation of this predicted beach state with cross-shore profile surveys. Results from the two-year pilot application of this framework on Dollymount Strand, Dublin, Ireland, reveal significant insights into seasonal and storm-driven beach state transitions occurring on the upper beach. While sandy beach dynamics are inherently site-specific, the development of a scalable and adaptable framework, rooted in established beach state theory, has the potential to further develop the work of McLachlan et al. (2018) to enhance the usability of beach state theory and the two-step model for coastal management purposes for other sites globally.

Coastal environments are highly dynamic, making monitoring of suspended sediment concentration (SSC) both challenging and essential. SSC serves as an indicator of coastal processes, storm impact, water quality and ecosystem service delivery. However, direct measurement of SSC is costly, logistically difficult and spatially limited. Although remote sensing offers a promising alternative by estimating SSC from surface reflectance, it requires calibration and is often constrained by site-specific applicability. This study presents a machine learning framework for national-scale SSC estimation using Landsat-8 and Sentinel-2 imagery, calibrated with 147 in situ SSC samples. Several models were evaluated, with XGBoost yielding the best performance (R2 = 0.72, RMSE = 17 mg/L). SHapley Additive exPlanations values were used for model interpretability. Visible and infrared bands, along with geographic features, were identified as key predictors, reflecting the importance of coastal typology in shaping the SSC-reflectance relationship. The model's value was demonstrated through a 10-year spatio-temporal analysis of SSC in Wexford Harbour. Seasonal patterns showed higher estuarine mixing in winter, while high SSC events coincided with rainfall and strong winds, indicating responsiveness to meteorological drivers. These findings highlight the potential of integrating remote sensing and machine learning for scalable, interpretable and cost-effective SSC monitoring.

Sand dunes on barrier islands, such as North Bull Island in Dublin Bay, often provide natural defences against coastal erosion and storm surge impact on landward habitats, communities, and infrastructure. The ability of dunes to withstand erosion during a storm depends primarily on the height and extent of the foredune relative to the elevation of the storm surge, parameters that are highly variable alongshore. This study investigates the alongshore variations in the coastal protection provided by foredunes on North Bull Island during a 1-in-16-year storm, using a modified version of the FEMA-540 Rule. Results indicate clear alongshore variability in foredune morphology and vulnerability to extreme event-induced dune failure, with seven out of ten analysed foredune sections vulnerable during a 1-in-16-year storm. Alongshore variations in aeolian sand transport patterns observed on three on-/alongshore wind days hint at the cause for this alongshore variation in foredune morphology and vulnerability. Observed aeolian sand transport occurred primarily as streamers, varied significantly between days and alongshore, and was not explained by beach sediment moisture content or grain size, mean wind speeds, or wind direction. It was, however, significantly influenced by mean gust speeds. Overall, our study underscores the need for continuous measurement of aeolian sand transport and environmental variables at multiple alongshore locations and points in time to fully assess the coastal protection provided by foredunes. It also highlights the importance of adaptive management strategies to enhance sediment supply and retention, encourage foredune development, and bolster the ability of barrier islands to act as an effective natural barrier for low-lying landward coastal regions in the face of climate change and sea-level rise.

Storm events are major drivers of morphological evolution on sandy beaches. Due to challenges around data acquisition and availability, however, our ability to quantify and predict storm impacts remains limited for many sites globally. For sandy beaches that are not systematically monitored, non-representative topographic data often has to be used as model input without understanding or quantifying the potential inaccuracies it can introduce into storm impact predictions. Dollymount Strand, Dublin, Ireland, is part of a barrier island that provides critical flood and erosion protection to the capital city. Despite this important function, the sandy beach is not currently subject to any systematic coastal monitoring, raising the question as to what frequency of monitoring would allow sufficiently accurate predictions of storm impacts to the upper beach. In this study, we investigate the influence of 'outdated' topographic input data on storm-impact predictions. In doing so, we present the first storm impact assessment for Dollymount Strand, analysing the beach's response to Storm Betty and Storm Agnes in 2023. We calibrated a 1D XBeach model at three distinct beach transect locations, overall achieving good Brier Skill Scores (>0.60) for 4/6 storm profiles, a mean absolute volumetric error (MAE) of 2.67 m(3)/m, and a mean relative percentage error of 38.34 %. Our analysis of model performance based on 'outdated' topographic information incorporated 4 historical surveys taken over a two-year period between 2021 and 2023. Despite observed variability in upper beach slope and volume, the MAE for predicted subaerial volume change showed minimal difference overall, ranging from 2.33 m(3)/m (a decrease in MAE compared to when immediate pre-storm input data was used) to 3.0 m(3)/m (using data collected approximately 2 years prior). Our results underscore the importance of locally specific geomorphological context. Where dune vulnerability was already elevated, for example, at Transect 3, we find that even relatively small discrepancies in modelled subaerial volume change can lead to an under- or over-estimation of beach lowering that can have a relatively large impact on dune exposure. This initial assessment of subaerial volume change for Dollymount Strand beach provides an important baseline for future studies on the resilience and evolution of this critical urban barrier system.

IntroductionTidal marsh wetlands provide essential and valuable services to the wider interconnected marine and coastal environment, although the complex intertwined processes in morphological evolution remain insufficiently understood owing to synchronized data scarcity, limiting the development of numerical models and management strategies.MethodsThis study investigated the hydrodynamic, biological, sediment and morphological processes on the Doulong tidal wetlands, Jiangsu, China, using a one-year field dataset that captured spatial and seasonal variations.Results and discussionOur results indicate that biophysical interactions among multiple processes could result in some overlooked sedimentary behaviours and bio-morphological patterns in tidal marsh wetlands. Firstly, the dominance of alongshore currents caused a rapid alongshore expansion of saltmarsh patches, by which the marsh edge achieved seaward advancing, markedly different from the widely reported cross-shore expansion. Secondly, results showed that the particle size of sediment near the marsh edge coarsened when plants withered and then fined when plants grew, indicating that the seasonal variation trend of sediment grain size in saltmarshes was opposite to the trend of vegetation biomass. Thirdly, the interaction between vegetation and stranded marine debris formed banded debris zones within the saltmarsh, where debris bands could cause a biomass reduction of up to 58%, disrupting the commonly-observed parabolic biomass-elevation relationship. Meanwhile, the seasonal variation of vegetation and hydrodynamics could alter the debris positions and hence result in the formation of multiple parallel debris bands. Overall, this study provides a synchronized dataset and elucidates specific bio-morphological relationships and processes that have thus far not been systematically documented, enhancing the comprehensive understanding of tidal marsh wetland evolution.

There is an urgent need to address coastal dynamics as a fundamental interaction between physical and biological processes, particularly when trying to predict future biological-physical linkages under anticipated changes in environmental forcing. More integrated modelling, support for observational networks and the use of management interventions as controlled experimental exercises should now be vigorously pursued.

Coastal saltmarshes provide globally important ecosystem services including 'blue carbon' sequestration, flood protection, pollutant remediation, habitat provision and cultural value. Large portions of marshes have been lost or fragmented as a result of land reclamation, embankment construction, and pollution. Sea level rise threatens marsh survival by blocking landward migration where coastlines have been developed. Research-informed saltmarsh conservation and restoration efforts are helping to prevent further loss, yet significant knowledge gaps remain. Using a mixed methods approach, this paper identifies ten research priorities through an online questionnaire and a residential workshop attended by an international, multi-disciplinary network of 35 saltmarsh experts spanning natural, physical and social sciences across research, policy, and practitioner sectors. Priorities have been grouped under four thematic areas of research: Saltmarsh Area Extent, Change and Restoration Potential (including past, present, global variation), Spatio-social contexts of Ecosystem Service delivery (e.g. influences of environmental context, climate change, and stakeholder groups on service provisioning), Patterns and Processes in saltmarsh functioning (global drivers of saltmarsh ecosystem structure/function) and Management and Policy Needs (how management varies contextually; challenges/opportunities for management). Although not intended to be exhaustive, the challenges, opportunities, and strategies for addressing each research priority examined here, providing a blueprint of the work that needs to be done to protect saltmarshes for future generations.

Salt marshes play an important role in coastal protection by reducing the impact of waves and shoreline erosion risks. While mature vegetation is responsible for the persistence and stability of marsh ecosystems, seedling survival of pioneer species is especially crucial for marsh propagation. Marsh seedlings, however, may be threatened by climate change induced increased coastal storm surge intensity and accompanying (extreme) wave conditions, imposing stronger drag forces on marsh seedlings. We test the hypothesis that drag forces experienced by seedlings increase with horizontal orbital velocity ( U w ) in a species-specific manner, and that the drag forces experienced are individual-plant trait-mediated. To test our hypotheses, seedlings of four contrasting pioneer marsh species ( Bolboschoenus maritimus , Schoenoplectus tabernaemontani , Spartina anglica , and Puccinellia maritima ) were exposed to storm wave conditions in a flume, where U w and experienced drag forces were measured. Linear mixed effect models demonstrated that seedling’s susceptibility to storm wave conditions is at least partly mediated by individual plant traits. Drag forces experienced by seedlings tended to increase with U w , and with stem length and diameter. The interplay of both traits was complex, with increasing stem length being the most important trait accounting for increases in drag forces experienced at low to moderate U w , while the stem diameter became more important with increasing U w . Furthermore, experienced drag forces appeared to be affected by species-specific traits such as rigidity and leaf growth, being highest for Bolboschoenus maritimus and lowest for Puccinellia maritima . Our results provide important mechanistic insights into the drivers of tidal marsh seedling vulnerability to storm wave conditions due to experienced drag, both based on the traits of individual plants and species-specific ones. This type of knowledge is of key importance when modelling saltmarsh establishment and resilience under climate change.

Although women are as well educated as men, they do not reach a proportion in management that reflects their workforce share. Obviously, different actors' policies are required to help promote women to leading positions. This paper addresses the question of whether the introduction and existence of special promotion programs for women impact the probability of reaching a management position. Social role and expectation state theory argue why it is difficult for women to rise to leadership positions. On the organisational level, the "homophily principle" leads to state dependence which is one explanation for the persistence of male leadership. Hence, it is argued that women need special opportunities to demonstrate their skills. Mentoring programs could be one way to support women in their careers. In multivariate analyses, probit models are estimated to model the influence of promotion programs on the probability of reaching a leading position. The estimations are based on a German linked employer-employee dataset of almost 142,000 women employed in 3,240 establishments. The dataset covers the time from 2008 to 2014 and allows to control for individual and firm-specific variables. The results show that the introduction of women-friendly policies increases the probability of reaching a managerial position, whereas the existence of such programs does not have an impact.

Salt marshes provide a variety of ecosystem services, including habitat provision, pollutant storage and attenuation of waves and currents. However, marsh edge, surface and interior erosion is common on many shores due to shear and impact forces applied by waves or currents, as well as gravitational failure. To forecast the future provision of these ecosystem services, the resistance of marsh substrates to hydrodynamic forcing must be determined. At present, a variety of methods exist to measure resistance to failure (e.g. shear vane, torvane and Cohesive Strength Meter; CSM), but what these different methods are measuring, and therefore the differences that result from using different methods, are often poorly specified - or even ignored. While shear vane and torvane devices have, until recently, been used interchangeably in salt marsh studies, the data collected is highly variable within individual datasets, between sites using the same technique, and between techniques at an individual site. In UK marshes, we find that the shear vane apparatus records a higher undrained shear strength than the torvane on the same substrate, possibly due to greater interaction between roots and the larger blades of the shear vane instrument (compared to the torvane). Our results also show that the vane-based and CSM devices measure two different processes, with vanes quantifying the bulk resistance of the substrate to shear and mass movement, while the CSM records the process of grain-by-grain erosion from the substrate surface. These two distinct measurements were not related, so our research challenges the common assumption that substrates with a higher resistance to bulk failure processes also have a high erosion threshold.

The Coastal Atlas of Ireland edited by Robert Devoy, Val Cummins, Barry Brunt, Darius Bartlett, and Sarah Kandrot, Cork University Press, 2021, 912 pp., £59.00 (hbk), ISBN 978-1-7820-5451-1.

Salt marshes provide diverse ecosystem services including coastal protection, habitat provision and carbon sequestration. The loss of salt marshes is a global scale phenomenon, of great socio-economic concern due to the substantial benefits that they provide. However, the causes of spatial variability in marsh loss rates are inadequately understood for the purposes of predicting future ecosystem distributions and functions under global environmental change. This study investigated the relationship between the presence of different saltmarsh plants and the mechanical properties of the underlying substrate that relate to its vulnerability to erosion. Relationships between three halophytes (Puccinellia spp., Spartina spp. and Salicornia spp.) and sediment stability were assessed and compared to unvegetated substrates using in-situ and laboratory tests of substrate geotechnical properties and sediment characteristics. Sampling was conducted at two UK sites with contrasting sedimentology, one sand-dominated and one clay-rich. Sediment samples, collected simultaneously with measurements of shear strength, were analysed for moisture content, particle size and organic, carbonate and mineral compositions. These data were then used to explore the contribution of plant type, alongside the sedimentological parameters, to measured shear strength.Shear strength of the sediment varied between and, to a lesser extent, within sites, with the four cover types having a similar effect on shear strength within sites relative to each other. Sediments covered by Puccinellia spp exhibit the highest shear strength, while bare sediments exhibit the lowest. The effect of vegetation type on shear strength was greater in the coarser sediments of Warton Sands. Surface cover type made a significant contribution to exploratory statistical models developed for the prediction of sediment shear strength. The findings support existing recognition that vegetation can enhance sediment shear strengths but extend the insight reveal differences in this effect that show generality between sedimentological settings. Further, the combination of methods provides insight into the fundamental mechanics by which various measures of sediment stability may be affected by different surface cover types. Cohesion appears to be a more appropriate descriptor sediment erodibility than shear strength or friction angle and is most greatly enhanced by the presence of a fine, fibrous root system such as that of Puccinellia. A more detailed understanding of the multi-scale mechanisms which plants confer strength to substrates is needed to better anticipate their impact on sediment erodibility, and therefore salt marsh vulnerability.

Coastal wetlands are dynamic bio-physical systems in which vegetation affects the movement of water and sediment, which in turn build and maintain the landform and ecosystem. Wetlands are an effective buffer against coastal erosion and flooding, enhance water quality and human health and wellbeing. Numerous field and laboratory experiments have quantified the reduction of waves by coastal ecosystems. Numerical models, however, are only able to capture observed reduction in wave energy when calibration coefficients are obtained by comparison with measured dissipation rates. A deeper understanding of how wave attenuation varies over time, with local flow conditions and ecosystem properties, is still lacking and should be acquired from a greater range of ecosystem types and geographical settings. Few studies have observed the detailed seasonal variations in how coastal wetlands function as wave buffers and how such seasonal variations might be explained. Equally, few studies have focused on the effect of coastal reed beds on wave dynamics. This study addresses both: i) seasonal variability in wave dissipation through reed vegetation and ii) intricate connections between reed vegetation and the physical context (meteorological and topographical) that might explain such variability. We present observations of wind generated wave transformation through two Phragmites australis reed beds in the Razelm-Sinoe Lagoon System, Danube Delta, Romania. We find that seasonal changes in vegetation density and biomass, as well as meteorological conditions, affect observed wave conditions within the first few meters of the reed beds. Our results also show a preferential reduction of higher frequency waves, irrespective of reed stem diameter or density and suggest the potential importance of seasonal vegetation debris to observed wave dissipation. Such complex and non-linear biogeomorphic effects on wave dissipation are not currently well understood or captured in the parameterisation of vegetation-induced wave dissipation. Our study highlights the importance of an accurate and temporally granular quantification of nearshore bathymetry, wetland topography, and vegetation to fully understand, model, and manage bio-physical interactions in coastal wetlands. More specifically, our results point towards the need for spatially and temporally explicit wave decay functions in emergent reed vegetation. This is particularly critical where the accurate evaluation of the flood and erosion risk contribution of any wetland is required as part of nature-based coastal protection solutions.

This study reports on a mode design experiment in which a Web starting mode was introduced for the first time in the Institute for Employment Research Establishment Panel. A cross-sectional sample of establishments was randomized to be interviewed via the traditional face-to-face procedure or aWeb-first sequential mixed-mode design with face-to-face follow-ups. Extensive administrative data were used to estimate and compare nonresponse bias at multiple phases of the sequential mixed-mode design, and assess the relationship between mode design and establishment characteristics on the likelihood of response. We show that the final response rates and nonresponse bias were similar between both mode designs, but these results contrasted with the results at each phase of the sequential mode design. Larger establishments were significantly more likely to respond in the Web mode compared to the face-to-face mode. A moderate cost savings (of about 14% per respondent) was estimated for the Web-first sequential mode design.

EDITORIAL article Front. Mar. Sci., 02 August 2022Sec. Coastal Ocean Processes https://doi.org/10.3389/fmars.2022.988804

Salt marshes are globally distributed, vegetated intertidal wetlands and marsh edge erosion is common on many shores. To understand how and why marsh edge erosion occurs, the response of salt marsh substrates to applied shear and vertical stress must first be quantified. This response is likely influenced by marsh substrate biological, geochemical and sedimentological composition. However, currently there is little systematic research into the between-marsh variability in these properties and how they affect both marsh edge erosion processes and the ability of a marsh to maintain its position vertically within the tidal frame. This paper compares two marshes of contrasting sedimentology at Tillingham marsh, East England and Warton marsh, Northwest England. Soil shear strength and compressibility are determined by applying geotechnical methods to determine marsh resistance to shear and vertical effective stresses. This research was able to isolate the influence of roots on substrate shear strength in a three-dimensional sample. In response to vertical effective stress, both the expected displacement magnitude and the vertical recovery potential of a marsh substrate are affected by past stress conditions on the marsh, particularly those resulting from desiccation. The substrate response to vertical effective stress also influences substrate shear strength through the effect of consolidation on the void ratio (or bulk density). We present evidence for the connection between marsh composition and substrate behaviour under applied stress. The results shed light on potential determinants of marsh resistance to edge erosion, which is ultimately essential for the informed implementation of both nature-based coastal flood defences and coastal restoration schemes.

The coastal protection function provided by the vegetation of tidal wetlands (e.g. salt marshes) will play an important role in defending coastlines against storm surges in the future and depend on how these systems respond to such forcing. Extreme wave events may induce vegetation failure and thereby risking loss of functionality in coastal protection. However, crucial knowledge on how hydrodynamic forces affect salt-marsh vegetation and whether plant properties might influence plant resistance is missing. In a true-to-scale flume experiment, we exposed two salt-marsh species to extreme hydrodynamic conditions and quantified wave-induced changes in plant frontal area, which was used to estimate plant damage. Moreover, half of the plants were artificially weakened to induce senescence, thus allowing us to examine potential seasonal effects on plant resistance. Morphological, biomechanical as well as biochemical plant properties were assessed to better explain potential differences in wave-induced plant damage. Our results indicate that the plants were more robust than expected, with pioneer species Spartina anglica showing a higher resistance than the high-marsh species Elymus athericus . Furthermore, wave-induced plant damage mostly occurred in the upper part of the vegetation canopy and thus higher canopies (i.e. Elymus athericus ) were more vulnerable to damage. Besides a taller canopy, Elymus athericus had weaker stems than Spartina anglica , suggesting that biomechanical properties (flexural stiffness) also played a role in defining plant resistance. Under the highest wave conditions, we also found seasonal differences in the vulnerability to plant damage but only for Elymus athericus . Although we found higher concentrations of a strengthening compound (biogenic silica) in the plant material of the weakened plants, the flexibility of the plant material was not affected indicating that the treatment might not has been applied long enough. Nevertheless, this study yields important implications since we demonstrate a high robustness of the salt-marsh vegetation as well as species-specific and seasonal differences in the vulnerability to plant damage.

Salt marshes deliver vital ecosystem services by providing habitats, storing pollutants and atmospheric carbon, and reducing flood and erosion risk in the coastal hinterland. Net losses in salt marsh areas, both modelled globally and measured regionally, are therefore of concern. Amongst other controls, the persistence of salt marshes in any one location depends on the ability of their substrates to resist hydrodynamic forcing at the marsh front, along creek margins and on the vegetated surface. Where relative sea level is rising, marsh elevation must keep pace with sea-level rise and landward expansion may be required to compensate for areal loss at exposed margins. This paper reviews current understanding of marsh substrate resistance to the near-instantaneous (seconds to hours) forcing induced by hydrodynamic processes. It outlines how variability in substrate properties may affect marsh substrate stability, explores current understanding of the interactions between substrate properties and erosion processes, and how the cumulative impact of these interactions may affect marsh stability over annual to decadal timescales. Whilst important advances have been made in understanding how specific soil properties affect near-instantaneous marsh substrate stability, less is known about how these properties interact and alter bulk substrate resistance to hydrodynamic forcing. Future research requires a more systematic approach to quantifying biological and sedimentological marsh substrate properties. These properties must then be linked to specific observable erosion processes, particularly at the marsh front and along creek banks. A better understanding of the intrinsic dynamics and processes acting on, and within, salt marsh substrates will facilitate improved prediction of marsh evolution under future hydrodynamic forcing scenarios. Notwithstanding the additional complications that arise from morphodynamic feedbacks, this would allow us to more accurately model the future potential protection from flooding and erosion afforded by marshes, while also increasing the effectiveness of salt marsh restoration and recreation schemes. (c) 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd