This study investigates the impact of Hurricane Fiona on sandy beaches and foredunes within Prince Edward Island National Park (PEINP). Fiona was the strongest storm to strike the island in nearly a century, with significant wave heights reaching 8 metres. Its impact on sandy beach-dune systems provides an opportunity to gauge the effectiveness of current PEINP's management policies and practices, and to consider potential changes that enhance the role of foredunes and beaches as natural defences against future storms and rise in relative sea level. Survey data and ground/UAV photography were used to compare various locations before (October 2021 to July 2022) and after (October 2022 and May 2023) the storm. High dunes experienced stoss slope erosion without significant changes in the height or position of the foredune crest, offering protection to landward areas. Low dunes were substantially eroded, leading to overwash in certain areas, and dunes located on bedrock and till were completely eroded, exposing the underlying surface. Hurricane Fiona's impact highlights the need of reinforcing current management strategies in PEINP that aim at safeguarding the natural biotic and abiotic components of beach-dune systems, and securing the accommodation space needed for their natural inland migration with rising sea level.

Estimates of total sand volume in foredunes are commonly made for purposes of predicting coastal erosion and inundation potential during major storms, which is of critical importance for resource management and engineering purposes. However, changes in dune volume through time are potentially of greater relevance to process geomorphologists because volume changes are diagnostic of the long-term evolution of beach-dune systems and can be related to drivers of change (e.g., storm climatology, sediment supply, human action). The methods by which dune volume change estimates are made vary widely in the literature because there are no established protocols that provide guidance on the horizontal distances over which volume integration should be performed. In addition, identifying a diagnostic geomorphic feature such as the dune toe as a limit on integration is fraught with subjective uncertainties. In this paper, an objective methodology for quantifying dune volume change directly (rather than absolute volume) is proposed that is simple, intuitive, and robust. The horizontal limits of integration are identified by zero-crossings in the topographic change profiles between two transect surveys taken at different times, and this avoids challenges associated with identification of the dune toe as a fixed profile feature. Instead, the proposed method focuses on locations of morphodynamic significance where there has been a transition from erosion to accretion in the time interval between surveys.

The impact of waves, storm surge, and aeolian transport associated with Post-tropical Storm Fiona (offshore significant wave height ∽ 8 m, storm surge up to 2 m) on the sandy beaches and foredunes of the north shore of Prince Edward Island National Park (PEINP), Canada, are assessed. Management policies and practices, as they apply to sandy beach systems within PEINP, are reviewed in the context of the shoreline changes attributed to Fiona. The effectiveness of these policies and practices are evaluated to inform the potential performance of beach-foredune systems as natural protection measures that mitigate the impacts of large-magnitude storms and relative sea-level rise (RSLR) on shoreline change. The analyses utilise survey data, ground photography, and unoccupied aerial vehicle (UAV) imagery collected before (October 2021 to July 2022) and after (October 2022 and May 2023) Fiona. In general, the largest dunes were characterised by erosion of the stoss slope, with landward retreat of the dune toe by < 6 m and minimal impact on crest height and position. Small foredunes (< 5 m in height) generally showed significantly greater erosion in terms of dune profiles, with dune breaching occurring at some locations. Foredunes perched on bedrock and till, which were typically smallest in size, were subject to complete erosion, thereby exposing the hard underlying surface. Overall, the impact of Fiona on sandy beach systems in PEINP was relatively modest in many locations, reflecting the success of existing management policies and practices that protect and maintain the integrity of foredunes by minimizing human impacts and avoiding ‘coastal squeeze’.

Dune systems in Atlantic Canada are relatively small given a relatively low sediment supply. The dunes are built primarily of reworked sediments as relative sea level (RSL) has risen. The foredune (at least) is reworked several times a decade by extreme weather events and many are transgressing on a decadal scale as a result of normal geomorphic processes. The key drivers shaping the dunes are, however, changing over time with climate change.The rate of RSL rise is accelerating, which will almost certainly mean an acceleration of dune transgression rates. As well, there is some evidence that storms are becoming more frequent and sea ice is diminishing, meaning more frequent reactivation.Predicting how dunes will respond to changes in the key controlling variables on an annual or decadal scale is challenging. Examination of how the dunes evolve on a decadal to century scale, however, suggests that the dunes in Atlantic Canada should continue to exist. Thus, we advocate using a dune management approach that focuses on minimizing human impacts and allowing natural processes to continue unimpeded. The highest priority for managing our coastal dunes should be to provide them with sufficient accommodation space into which they can transgress naturally.

Tidal marshes (including saltmarshes) provide remarkable value for many social (cultural, recreational) and environmental (fish production, water quality, shoreline protection, carbon sequestration) services. However, their extent, condition, and capacity to support these services are threatened by human development expansion, invasive species, erosion, altered hydrology and connectivity, and climate change. The past two decades have seen a shift toward working with managers to restore tidal marshes to conserve existing patches or create new marshes. The present perspective examines key features of recent tidal marsh restoration projects. Although optimism about restoration is building, not all marshes are the same; site-specific nuances require careful consideration, and thus, standard restoration designs are not possible. Restoration projects are effectively experiments, requiring clear goals, monitoring and evaluation, and adaptive management practices. Restoration is expensive; however, payment schemes for ecosystem services derived from restoration offer new ways to fund projects and appropriate monitoring and evaluation programs. All information generated by restoration needs to be published and easily accessible, especially failed attempts, to equip practitioners and scientists with actionable knowledge for future efforts. We advocate the need for a network of tidal marsh scientists, managers, and practitioners to share and disseminate new observations and knowledge. Such a network will help augment our capacity to restore tidal marsh, but also valuable coastal ecosystems more broadly.

Over the last 20 years, innovations have led to the development of exciting new technologies and novel applications of established technologies, collectively increasing the scale, scope, and quality of research possible in tidal marsh systems. Thus, ecological research on marshes is being revolutionized, in the same way as ecological research more generally, by the availability of new tools and analytical techniques. This perspective highlights current and potential applications of novel research technologies for marsh ecology. These are summarized under several themes: (1.) imagery - sophisticated imaging sensors mounted on satellites, drones, and underwater vehicles; (2.) animal tracking - acoustic telemetry, passive integrated transponder (PIT) tags, and satellite tracking, and (3.) biotracers - investigation of energy pathways and food web structure using chemical tracers such as compound-specific stable isotopes, isotope addition experiments, contaminant analysis, and eDNA. While the adoption of these technological advances has greatly enhanced our ability to examine contemporary questions in tidal marsh ecology, these applications also create significant challenges with the accessibility, processing, and synthesis of the large amounts of data generated. Implementation of open science practices has allowed for greater access to data. Newly available machine learning algorithms have been widely applied to resolve the challenge of detecting patterns in massive environmental datasets. The potential integration on digital platforms of multiple, large data streams measuring physical and biological components of tidal marsh ecosystems is an opportunity to advance science support for management responses needed in a rapidly changing coastal landscape.

Salt marsh ecosystems and the seascapes in which they are embedded serve as critical habitats for species harvested by fisheries (1), which provide food and economic security for hundreds of millions of people (2). Historical marsh losses coupled with increasing pressures from coastal development and climate change place these intertidal ecosystems and surrounding uplands under growing threat (3). Preventing further losses of salt marshes and associated fisheries production will require greater public awareness and difficult choices in coastal policy and management, underpinned by greater understanding of marsh function.

Salt marshes are ecologically and globally vital ecosystems. Unfortunately, world-wide salt marsh loss has been extensive, and until recently there has been little effort to undo the loss of similar to 30,500 ha of salt marshes in Bay of Fundy, Canada, since European colonization. To better understand salt marsh restoration in the upper Bay of Fundy, we monitored sediment deposition and community dynamics in 2 managed realignment salt marsh restoration sites and 2 reference sites from 1 y pre-breach to 8 y post-breach in Aulac, New Brunswick. Because of the initial elevational disparity (similar to 2 m) between site types, substantial amounts of sediment were deposited immediately after breaching the old dike (>50 cm in some locations). After 7-8 y, mean sediment deposition was 34-67 cm in the restoration sites, and 6 cm in a reference site. To date, we identified three stages of vegetative community succession: (i) rapid deposition of unconsolidated sediment and loss of terrestrial vegetation, but Spartina pectinata remained (1 y post-breach), (ii) colonization and spread of S. alterniflora and loss of S. pectinata (2-5 y post), and (iii) high percent cover and decreased spatial variability of S. alterniflora (mean stem density: 345 stems m(-2), 6-8+ y post). We expect the fourth stage of vegetative community succession will be defined by spread of S. patens throughout restoration sites. Invertebrate community on emergent marsh and water column community in salt pools were variable and lagged behind vegetative community. Our study reported the first managed realignment in Maritime Canada, and the first such realignment in an ice-influenced and megatidal (similar to 14 m tidal amplitude) region.

Salt marshes are highly effective carbon (C) sinks and have higher rates of soil C burial (per square meter) than terrestrial ecosystems. Marsh reclamation and anthropogenic impacts, however, have resulted in extensive losses of salt marshes. Restoration of marshes drained and "reclaimed" for agriculture (referred to in Canada as dykelands) and degraded marshes can generate C credits, but only if C burial is reliably quantified. To date, studies reporting on C burial rates have been limited primarily to restored marshes which are more than 10 years old. Here we report on a study which assessed C burial six years after the return of tidal flooding to a section of dykeland in Aulac, New Brunswick on Canada's Bay of Fundy. The C burial rate in the restored marsh averaged 1 329 g C m-2 yr-1, more than five times the rate reported for a nearby mature marsh. Carbon density in the recovering marsh was relatively consistent with depth and although salt marsh cordgrass (Spartina alterniflora) became established in 2012, the bulk of the C in the new marsh deposit is assumed to be allochthonous. Financial constraints are a barrier to marsh restoration projects and C markets could provide a considerable source of funding for restoration work in the future. For marsh restoration projects to be recognized in C crediting systems, however, it must also be demonstrated that the allochthonous C would not otherwise have been sequestered; the potential for this is discussed.

The form, height and volume of coastal foredunes reflects the long‐term interaction of a suite of nearshore and aeolian processes that control the amount of sand delivered to the foredune from the beach versus the amount removed or carried inland. In this paper, the morphological evolution of more than six decades is used to inform the development of a simple computer model that simulates foredune growth. The suggestion by others that increased steepness of the seaward slope will retard sediment supply from the beach to the foredune due to development of a flow stagnation zone in front of the foredune, hence limiting foredune growth, was examined. Our long‐term data demonstrate that sediment can be transferred from the beach to the foredune, even with a steep foredune stoss slope, primarily because much of the sediment transfer takes place under oblique rather than onshore winds. During such conditions, the apparent aspect ratio of the dune to the oncoming flow is less steep and conditions are not as favourable for the formation of a stagnation zone. The model shows that the rate of growth in foredune height varies as a function of sediment input from the beach and erosion due to storm events, as expected, but it also demonstrates that the rate of growth in foredune height per unit volume increase will decrease over time, which gives the perception of an equilibrium height having been reached asymptotically. As the foredune grows in size, an increasing volume of sediment is needed to yield a unit increase in height, therefore the apparent growth rate appears to slow. Copyright © 2018 John Wiley & Sons, Ltd.

The objectives of this chapter are to (1) document lessons learned from the design, implementation and monitoring of a salt marsh restoration in the upper Bay of Fundy, Canada, and (2) consider how the lessons can be applied to future restoration projects. The Fort Beausejour salt marsh restoration sites are exposed to very large tides (up to 14 m), waves, and snow and ice in winter. This project involved a managed re-alignment, with two restoration cells and two reference sites. Before breaching, design criteria were established (e.g., the restoration cells must fully flood at high tide and drain slowly) and a hydrodynamic model was used to test breaching options. Pre-restoration monitoring was completed in 2009-2010, the old dike was breached in October 2010, and post-breach monitoring commenced thereafter. Measurements of water level, velocities, and discharge at one breach, compared very well to model predictions. Likewise, patterns of sediment deposition were as predicted, and sedimentation rates were as expected based on empirical studies done in the area. The bioengineering species saltwater cordgrass (Spartina alterniflora) took 2 years to colonize the cells; it initially spread vegetatively and then by seeds. Plant cover became extensive in year 5 post-breach. Invertebrate and salt pool biological communities are lagging behind. Lessons learned include: (1) plan for future conditions and provide adequate accommodation space for development of a new marsh; (2) multi-level partnerships are critical to the success of such projects; (3) monitoring with a research focus ensures observation and quantification of unexpected phenomena; and (4) the design process used, including the hydrodynamic model, was successful and can be used again for similar situations.

Despite widespread recognition that landforms are complex Earth systems with process-response linkages that span temporal scales from seconds to millennia and spatial scales from sand grains to landscapes, research that integrates knowledge across these scales is fairly uncommon. As a result, understanding of geomorphic systems is often scale-constrained due to a host of methodological, logistical, and theoretical factors that limit the scope of how Earth scientists study landfonns and broader landscapes.This paper reviews recent advances in understanding of the geomorphology of beach-dune systems derived from over a decade of collaborative research from Prince Edward Island (PEI), Canada. A comprehensive summary of key findings is provided from short-term experiments embedded within a decade-long monitoring program and a multi-decadal reconstruction of coastal landscape change. Specific attention is paid to the challenges of scale integration and the contextual limitations research at specific spatial and/or temporal scales imposes.A conceptual framework is presented that integrates across key scales of investigation in geomorphology and is grounded in classic ideas in Earth surface sciences on the effectiveness of formative events at different scales. The paper uses this framework to organize the review of this body of research in a 'scale aware' way and, thereby, identifies many new advances in knowledge on the form and function of subaerial beach-dune systems.Finally, the paper offers a synopsis of how greater understanding of the complexities at different scales can be used to inform the development of predictive models, especially those at a temporal scale of decades to centuries, which are most relevant to coastal management issues. Models at this (landform) scale require an understanding of controls that exist at both 'landscape' and 'plot' scales. Landscape scale controls such as sea level change, regional climate, and the underlying geologic framework essentially provide bounding conditions for independent variables such as winds, waves, water levels, and littoral sediment supply. Similarly, a holistic understanding of the range of processes, feedbacks, and linkages at the finer plot scale is required to inform and verify the assumptions that underly the physical modelling of beach-dune interaction at the landform scale.

A seminal paper by Schumm and Lichty (1965, Am. J. Sci. 263; 110-119) was instrumental in demonstrating how a comprehensive and complete understanding of geomorphic systems necessitated deep knowledge about process-response dynamics across a range of temporal and spatial scales. Nevertheless, contemporary research that integrates knowledge across scalar domains remains surprisingly uncommon, perhaps because of methodological, theoretical, logistical, and pragmatic factors that inadvertently favor myopic perspectives on landform studies. A decade-long research agenda conducted on the north shore of PEI provides insights into major uncertainties associated with deploying process-based knowledge derived from plot (micro) scale experimentation on aeolian sediment transport across the beach-dune profile for the purpose of extrapolating to landform (meso) scale outcomes that are relevant to coastal resource managers. Results from short-term, instrumented experiments can only be understood within the broader context of the landform (meso) and landscape (macro) drivers and controls that mediate the potential range of short-term processes. For example, predicting the volume of sediment delivered to the foredune system annually is, to first order, dependent largely on the wind climatology and character of the beach sediments. However, long-term monitoring demonstrates that sediment delivery is also dependent on a much wider range of variables at the micro (e.g., moisture content, wind steering, turbulence production), meso (e.g., vegetation phenology, snow cover, fetch effects, nearshore sediment supply), and macro (e.g., sea-level rise, geological framework) scales. A proposed classification of system state variables is proposed for sandy beach-dune systems, predicated on the ideas of Schumm and Lichty (1965), that makes apparent some of these contextual inter-dependencies.

Assessing aeolian beach-surface dynamics using a remote sensing 1 approach 2 3 Irene Delgado-Fernandez, Robin Davidson-Arnott, Bernard O.Bauer, Ian J. 4 Walker, Jeff Ollerhead, Hosahng Rhew 5 6 7 1Centre for Coastal & Marine Research, School of Environmental Sciences, University of Ulster, 8 Coleraine, UK, BT52 1SA 9 2Department of Geography, University of Guelph, Guelph, ON, Canada, N1G 2W1, 10 rdarnott@uoguelph.ca 11 3Earth & Environmental Sciences and Geography, University of British Columbia, Kelowna, BC, 12 Canada, V1V 1V7, bernard.bauer@ubc.ca 13 4Department of Geography, University of Victoria, Victoria, BC, Canada, V8W 3R4, 14 ijwalker@uvic.ca 15 5Department of Geography & Environment, Mount Allison University, Sackville, NB, Canada, 16 jollerhead@mta.ca 17 6Coastal and Estuarine Morphodynamics Laboratory, Department of Oceanography, INHA 18 University, 253 YongHyun-Dong, Nam-gu, Incheon, 402-751, Korea, 19 rhew0503@hanmail.net 20 21 22

Prediction of sand transport from the beach to the dune has generally been modelled using wind data from a nearby weather station assuming transport-limited conditions. On mid-latitude coasts sand transport often occurs under supply-limited conditions and measured deposition in the foredune is generally much smaller than predicted. Delgado-Fernandez (2011) developed a modelling approach that incorporated reductions in transport due to factors limiting supply, including the fetch effect, surface moisture and the presence of snow. Application of the model is restricted because of the rich data set on supply-limiting variables from which it was developed – hourly values based on a camera monitoring system. Here we test whether the modelling approach can be simplified to provide robust estimation of annual sand supply to the foredune using only meteorological data from a weather station, tide tables and simple representations of the beach morphology. Testing of the model is being carried out in two stages. In the first stage we use data from a nearby weather station to predict sand transport and the effects of supply-limiting variables at the same location and for the same period used to develop the Delgado-Fernandez model. This permits calibration of the weather station model against the original model output. In the second stage the weather station model is applied to data for the same period for another site about 2 km away with differing beach width and orientation. It is then run for three previous years for the two sites. In this stage the success of the model is evaluated by comparing the total predicted transport to the magnitude of annual sand deposition at each of the two sites.

Sea ice is widely held to be decreasing in coastal waters where it is known to be effective in attenuating wave energy. This process is critical for understanding nearshore sediment transport and coastal change in ice-infested waters. We explore the attenuation of waves shoaling in nearshore ice using a simple attenuation model, hydrodynamic modelling, field studies, and daily charts of sea ice. The attenuation model is drawn from studies in deep water and modified for shallow water using field measurements. In a simple but common configuration where ice lies in a band onshore and waves enter from open water, the theory that wave energy decays exponentially as waves enter ice appears to hold true in shallow and deep water. The wave energy density in ice relates to the incoming wave energy density, attenuation distance, and an attenuation coefficient related to ice concentration and floe diameter. Much of the variability in measurements is explained by the theory, but substantial uncertainty remains. Prediction potential might be improved with higher resolution wave measurements and modelling, consideration of the rebuilding of attenuated waves in partial ice cover, and separate treatment of new ice. The adapted semiempirical theory is likely generally applicable to ice-infested coastal waters, but field studies in particular environments will be required to calibrate attenuation.

ABSTRACTThe purpose of this study was to quantify relationships between season, sediment availability, sediment transport pathways, and beach/foredune morphology at Greenwich Dunes, PEI. This was done for periods ranging from a few days to multiple decades using erosion pins, bedframe measurements, annual surveys, and digital photogrammetry using historical aerial photographs. The relative significance of seasonal/annual processes versus response of the foredune system to broader geomorphic controls (e.g. relative sea level rise, storms, etc.) was also assessed.The data show that there are clear seasonal differences in the patterns of sand supply from the beach to the foredune at Greenwich and that there are differences in sediment supply to the foredune between the east and west reaches of the study area, resulting in ongoing differences in foredune morphology. They also demonstrate that models that incorporate wind climate alone, or even models that include other factors like beach moisture, would not be able to predict the amount of sediment movement from the beach to the foredune in this environment unless there were some way to parameterize system morphology, especially the presence or absence of a dune ramp.Finally, the data suggest that the foredune can migrate landward while maintaining its form via transfers of sediment from the stoss slope, over the crest, and onto the lee slope. Although the rate of foredune development or recovery after disturbance changes over time due to morphological feedback, the overall decadal evolution of the foredune system at Greenwich is consistent with, and supports, the Davidson‐Arnott (2005) conceptual model of dune transgression under rising sea level. Copyright © 2012 John Wiley & Sons, Ltd.