This land is your land, this could be marsh land: Property parcel characteristics of marsh migration corridors in Rhode Island, USA.

Salt marshes, critical habitats offering many ecosystem services, are threatened by development, accelerated sea level rise (SLR) and other anthropogenic stressors that are projected to worsen. As seas rise, some salt marshes can migrate inland if there is adjacent, permeable, undeveloped land available. Facilitating marsh migration is necessary for coastal resilience efforts, but extensive coastal development can make finding suitable migration corridors challenging. This work seeks to characterize changes in land use, ownership, and economic value at the property parcel level within current versus future marsh areas for the state of Rhode Island, USA. We find that most parcels currently containing salt marsh are publicly owned, whereas most adjacent parcels projected to contain new salt marsh in 2050 are privately owned. Additionally, parcels containing new marsh in 2050 have 47% higher per-hectare assessed values than parcels containing current marsh. We describe the locations and characteristics of parcels within migration corridors with the lowest per-hectare values that may be the most cost-effective for marsh conservation practitioners to protect. This study highlights the expanding land use types and landowner sets that will be involved in marsh conservation decisions, and the economic value of potential migration corridors where costly tradeoffs may be necessary to promote coastal resilience.

Framework for multirisk climate scenarios across system receptors with application to the Metropolitan City of Venice.

Climate change influences the frequency of extreme events that affect both human and natural systems. It requires systemic climate change adaptation to address the complexity of risks across multiple domains and tackle the uncertainties of future scenarios. This paper introduces a multirisk analysis of climate hazard, exposure, vulnerability, and risk severity, specifically designed to hotspot geographic locations and prioritize system receptors that are affected by climate-related extremes. The analysis is demonstrated for the Metropolitan City of Venice. Representative scenarios (RCP4.5 and RCP8.5) of climate threats (i.e., storm surges, pluvial flood, heat waves, and drought) are selected and represented by projections of Regional Climate Models for a 30-year period (2021-2050). A sample of results is as follows. First, an increase in the risk is largely due to drought, pluvial flood, and storm surge, depending on the areas of interest, with the overall situation worsening under the RCP8.5 scenario. Second, particular locations have colocated vulnerable receptors at higher risk, concentrated in the urban centers (e.g., housing, railways, roads) and along the coast (e.g., beaches, wetlands, primary sector). Third, risk communication of potential environmental and socio-economic losses via the multirisk maps is useful to stakeholders and public administration. Fourth, the multirisk maps recommend priorities for future investigation and risk management, such as collection of sensor data, elaboration of mitigations, and adaptation plans at hotspot locations.

Toward improved sediment management and coastal resilience through efficient permitting in California.

The value of sediment for helping coastal habitats and infrastructure respond to sea level rise is widely recognized. Across the country, coastal managers are seeking ways to beneficially use sediment sourced from dredging and other projects to counter coastal erosion and protect coastal resources. However, these projects are difficult to permit and have been slow to actualize. This paper draws on interviews with sediment managers and regulators in California to explore the challenges and opportunities for habitat restoration and beach nourishment within the current permitting regime. We find that permits are costly, difficult to obtain, and sometimes stand as a barrier to more sustainable and adaptive sediment management. We next characterize streamlining approaches and describe entities and ongoing efforts within California that apply them. Finally, we conclude that to keep pace with coastal losses due to climate change impacts, efforts toward efficient permitting must be accelerated and approaches diversified to support coastal resilience practices state-wide, in a timeframe that will allow coastal managers to innovate and adapt.

Effects of dredging activities and seasonal variation on coastal plankton assemblages: results from 10 years of environmental monitoring.

Coastal zones support the most productive marine ecosystems, yet they are increasingly threatened by anthropogenic stressors such as dredging. In this study, we investigated how seasonal variation and dredging activities conducted during the construction of a harbor and submarine base (Sepetiba Bay, RJ, Brazil) affected the phytoplankton and zooplankton assemblages. The observed temporal variability at five different sites over 10 years revealed that dredging exceeds the expected influence of dry and rainy seasons on plankton abundance and diversity. In general, the abundance of both groups increased during dredging due to the resuspension of nutrients and benthic organisms. This increase was particularly evident in the dinoflagellate Scrippsiellaa cuminata, the diatoms Thalassiosira rotula and Nitzschia longissima, and the herbivorous zooplankton Acartia clausii and Pseudevadne tergestina. Moreover, season and dredging activities synergistically influenced plankton assemblages, resulting in larger seasonal variations during dredging activities. After the end of the harbor construction, plankton abundance decreased and remained low until the end of the monitoring, which may indicate persistent changes in the biodiversity and ecosystem functioning of impacted areas.

Landowner behavior can determine the success of conservation strategies for ecosystem migration under sea-level rise.

The human aspects of conservation are often overlooked but will be critical for identifying strategies for biological conservation in the face of climate change. We surveyed the behavioral intentions of coastal landowners with respect to various conservation strategies aimed at facilitating ecosystem migration for tidal marshes. We found that several popular strategies, including conservation easements and increasing awareness of ecosystem services, may not interest enough landowners to allow marsh migration at the spatial scales needed to mitigate losses from sea-level rise. We identified less common conservation strategies that have more support but that are unproven in practice and may be more expensive. Our results show that failure to incorporate human dimensions into ecosystem modeling and conservation planning could lead to the use of ineffective strategies and an overly optimistic view of the potential for ecosystem migration into human dominated areas.

Coastal Stakeholders' Perceptions of Sea Level Rise Adaptation Planning in the Northern Gulf of Mexico.

Planning for sea level rise (SLR) is a complex process that involves scientific uncertainty and local and regional political tradeoffs. As part of a 6-year transdisciplinary research project in the northern Gulf of Mexico, we conducted focus groups with coastal stakeholders (natural resource managers, community planners, and environmental communicators) to gain a better understanding of their planning and adaptation activities for SLR. This paper reports on participants' perceptions about adaptation and their current adaptation activities and strategies. While stakeholders were concerned about SLR and thought adaptation had challenges, they still shared optimism and a commitment to planning. The findings identify different types of SLR adaptation initiatives in which participants were involved as well as types of perceived barriers to adaptation planning, and major recommended strategies to address them. The paper concludes with a discussion of findings, connections to related SLR adaptation literature, practical implications for coastal resiliency, and directions for future research.

Living shorelines enhanced the resilience of saltmarshes to Hurricane Matthew (2016).

Nature-based solutions, such as living shorelines, have the potential to restore critical ecosystems, enhance coastal sustainability, and increase resilience to natural disasters; however, their efficacy during storm events compared to traditional hardened shorelines is largely untested. This is a major impediment to their implementation and promotion to policy-makers and homeowners. To address this knowledge gap, we evaluated rock sill living shorelines as compared to natural marshes and hardened shorelines (i.e., bulkheads) in North Carolina, USA for changes in surface elevation, Spartina alterniflora stem density, and structural damage from 2015 to 2017, including before and after Hurricane Matthew (2016). Our results show that living shorelines exhibited better resistance to landward erosion during Hurricane Matthew than bulkheads and natural marshes. Additionally, living shorelines were more resilient than hardened shorelines, as they maintained landward elevation over the two-year study period without requiring any repair. Finally, rock sill living shorelines were able to enhance S. alterniflora stem densities over time when compared to natural marshes. Our results suggest that living shorelines have the potential to improve coastal resilience while supporting important coastal ecosystems.

The role of nature-based infrastructure (NBI) in coastal resiliency planning: A literature review.

The use of nature-based infrastructure (NBI) has attracted increasing attention in the context of protection against coastal flooding. This review is focused on NBI approaches to improve coastal resilience in the face of extreme storm events, including hurricanes. We not only consider the role of NBI as a measure to protect people and property but also in the context of other ecological goods and services provided by tidal wetlands including production of fish and shellfish. Although the results of many studies suggest that populated areas protected by coastal marshes were less likely to experience damage when exposed to the full force of storm surge, it was absolutely critical to place the role of coastal wetlands into perspective by noting that while tidal marshes can reduce wave energy from low-to-moderate-energy storms, their capacity to substantially reduce storm surge remains poorly quantified. Moreover, although tidal marshes can reduce storm surge from fast moving storms, very large expanses of habitat are needed to be most effective, and for most urban settings, there is insufficient space to rely on nature-based risk reduction strategies alone. The success of a given NBI method is also context dependent on local conditions, with potentially confounding influences from substrate characteristics, topography, near shore bathymetry, distance from the shore and other physical factors and human drivers such as development patterns. Furthermore, it is important to better understand the strengths and weaknesses of newly developed NBI projects through rigorous evaluations and characterize the local specificities of the particular built and natural environments surrounding these coastal areas. In order for the relevant science to better inform policy, and assist in land-use challenges, scientists must clearly state the likelihood of success in a particular circumstance and set of conditions. We conclude that "caution is advised" before selecting a particular NBI method as there is no "one size fits all" solution to address site-specific conditions.

The effectiveness of beach mega-nourishment, assessed over three management epochs.

Resilient coastal protection requires adaptive management strategies that build with nature to maintain long-term sustainability. With increasing pressures on shorelines from urbanisation, industrial growth, sea-level rise and changing storm climates soft approaches to coastal management are implemented to support natural habitats and maintain healthy coastal ecosystems. The impact of a beach mega-nourishment along a frontage of interactive natural and engineered systems that incorporate soft and hard defences is explored. A coastal evolution model is applied to simulate the impact of different hypothetical mega-nourishment interventions to assess their impacts' over 3 shoreline management planning epochs: present-day (0-20 years), medium-term (20-50 years) and long-term (50-100 years). The impacts of the smaller interventions when appropriately positioned are found to be as effective as larger schemes, thus making them more cost-effective for present-day management. Over time the benefit from larger interventions becomes more noticeable, with multi-location schemes requiring a smaller initial nourishment to achieve at least the same benefit as that of a single-location scheme. While the longer-term impact of larger schemes reduces erosion across a frontage the short-term impact down drift of the scheme can lead to an increase in erosion as the natural sediment drift becomes interrupted. This research presents a transferable modelling tool to assess the impact of nourishment schemes for a variety of sedimentary shorelines and highlights both the positive and negative impact of beach mega-nourishment.

Host-associated microbes mitigate the negative impacts of aquatic pollution.

Pollution can negatively impact aquatic ecosystems, aquaculture operations, and recreational water quality. Many aquatic microbes can sequester or degrade pollutants and have been utilized for bioremediation. While planktonic and benthic microbes are well-studied, host-associated microbes likely play an important role in mitigating the negative impacts of aquatic pollution and represent an unrealized source of microbial potential. For example, aquatic organisms that thrive in highly polluted environments or concentrate pollutants may have microbiomes adapted to these selective pressures. Understanding microbe-pollutant interactions in sensitive and valuable species could help protect human well-being and improve ecosystem resilience. Investigating these interactions using appropriate experimental systems and overcoming methodological challenges will present novel opportunities to protect and improve aquatic systems. In this perspective, we review examples of how microbes could mitigate negative impacts of aquatic pollution, outline target study systems, discuss challenges of advancing this field, and outline implications in the face of global changes.

Contradictions in human-nature relationships threaten coastal resilience and sustainability in the Bohai Rim Region, China.

Under the challenge of global environmental change and rapid development, tremendous risks brought about by natural disasters and human activities have increased environmental pressures for sustainable development. How to improve coastal resilience in the process of urban development has become an important topic in academia. In this study, a variable fuzzy recognition model was used to measure the level of coastal resilience in 17 cities in the Bohai Rim region, and then the kernel density, thiel index, and random forest model were used to explore the spatiotemporal characteristics and influencing factors of coastal resilience. The results show that (1) The overall resilience level of the Bohai Rim region is increasing over time, but at a relatively slow rate. (2) Coastal resilience has significant spatial unevenness, with high-level cities dominated by Tianjin, Qingdao, Yantai, etc. and low-level cities dominated by Cangzhou, Panjin, Yingkou, Binzhou, etc. (3) The influence of economic development, infrastructure, innovation ability, technology investment, and government regulation on coastal resilience decreases in order. Based on the research findings, the study can not only make suggestions for the actual regulation strategy but also provide empirical and theoretical experience for other coastal countries.

Monitoring Arctic permafrost coastal erosion dynamics using a multidecadal cross-mission SAR dataset along an Alaskan Beaufort Sea coastline.

Arctic coasts are transition zones influenced by terrestrial, marine, and cryospheric factors. Due to the degradation of the cryosphere exacerbated by climate change, many segments of Arctic coasts are characterized by severe erosions and thus resulting in many social-economic consequences. To assess the imminent coastal risks and increasing organic carbon fluxes released from Arctic erosional coasts, continuous monitoring of shoreline movement is necessary. Conventional studies employ spaceborne multi-spectral optical images to detect ample Arctic coasts' dynamics; nonetheless, the frequent cloud cover and Arctic haze limit the number of usable images. Thence, most studies merely utilize a few image pairs to estimate long-term rate changes, which deter statistically meaningful trend analysis and are likely biased by intra-annual variations. This study employs cross-mission synthetic aperture radar (SAR) images that are cloud-penetrating and weather-independent to depict 32-year spatiotemporal changes of Drew Point Coast along the Alaskan Beaufort Sea. To efficiently and robustly extract shorelines, a non-manual intervention-required and cross-SAR sensor applicable approach is proposed. Based on the automatically delineated time series shoreline positions, each coastal segment's position-time records are modeled with a statistic-based coastal dynamics classification scheme that enables constructing non-linear trends of inter-decadal recession rates. Results reveal that 83.7 % of the coast exhibits continuous erosion during 1992-2023. Dynamically, 48.6 % of coast demonstrates polynomial change patterns with an erosive rate higher than -6 m/yr. Remarkably, 22.5 % of the coast has been statistically significantly accelerating. For instance, the erosional rate nearly double (93.8 %) between Drew Point and McLeod Point, while between Lonely and Pitt Point, the most erosive segment in the study coast, the retreating rate increases 285.57 % from -5.92 to -22.81 m/yr. These findings exemplify the high heterogeneity of Arctic coastal changes and highlight the opportunities of using spaceborne SAR data to empower the management and conservation of Arctic coasts.

Evolution and influencing factors of coastal resilience in the East China Sea.

The coastal zone serves as a crucial hub for economic and population concentration. Amid the context of high-intensity development and global climate change, uncertain risks from diverse sources-including extreme weather events (i.e., high temperatures, typhoons, and excessive precipitation), natural disasters (i.e., floods, tsunamis, landslides, and mudslides), and societal disruptions (i.e., economic crises and viral diseases)-are escalating rapidly. Enhancing coastal resilience to minimize these risk impacts is progressively becoming a mandatory requirement for the sustainable development of coastal zones. However, existing research primarily focuses on distinct disasters, the ecological environment, or specific socio-economic aspects, thereby lacking a comprehensive theoretical framework and thorough analysis of the factors influencing coastal resilience. Here, we construct a theoretical framework centered on the unique traits and processes of coastal resilience, analyze the spatiotemporal evolution characteristics of coastal resilience from a grid and administrative division standpoint, and utilize geographic detectors to determine the factors influencing coastal resilience while considering the modifiable areal unit problem (MAUP). Our findings indicate that: (1) Coastal resilience in the East China Sea (ECS) initially declined but then increased, transitioning from a lower to a medium level. Barring the pressure index, other dimensional indices had an upward trend; (2) Continuous improvements were observed in coastal resilience across different land uses. Forests, waters, and oceans demonstrated higher resilience levels than other lands, with construction land resilience developing swiftly. The effect of changes in land use types on coastal resilience showed a rapid initial increase and subsequent decrease; (3) The change pattern of coastal resilience in the ECS is mainly unchanged and slightly increased. Areas with the most drastic changes were concentrated in Shanghai, northern Zhejiang, and central Fujian, with the main change patterns continuously rising; (4) The primary factors influencing coastal resilience in the ECS included gross domestic product and infrastructure construction level. Advanced industrial structure, technological and educational prowess, and effective government management are important determinants of coastal resilience development. The significance of human factors continues to grow. Our findings offer valuable insights for optimizing national spatial planning of coastal zones, responding to internal and external impacts, achieving resilient coastal zones, and implementing a comprehensive sustainable management approach.

Microplastic pollution threats coastal resilience and sustainability in Xiamen City, China.

Microplastics have raised growing awareness due to their ubiquity and menaces to coastal resilience and sustainability. The abundance, distribution, and characteristics of microplastics in water and organisms in Xiamen were evaluated. Results showed that the average abundance of microplastics in the surface water of Xiamen Bay was 1.55 ± 1.94 items/m3. The dominant color, size, shape, and polymer type were white, 1.0-2.5 mm, and fragments and lines, and polyethylene and polypropylene, respectively. The average abundance of microplastics in the fish in Xiamen was 2.44 ± 1.56 items/g wet weight. They were dominated by fibers of blue polyethersulfone and polyethylene terephthalate, and sizes <2.5 mm. There was a negative correlation between the polymer type in fish and that in water, while a positive correlation between shapes of microplastics of both fish species. Results will aid in formulating management measures for preventing microplastic pollution in Xiamen, ultimately promoting coastal resilience and sustainability of coastal communities.

Nature-Based Restoration Simulation for Disaster-Prone Coastal Area Using Green Infrastructure Effect.

Floods in coastal areas are caused by a range of complex factors such as typhoons and heavy rainfall, and this issue has become increasingly serious as interference has occurred in the social-ecological system in recent years. Given the structural limitations and high maintenance costs of the existing gray infrastructure, the need for a nature-based restoration plan utilizing green infrastructure has been raised. The purpose of this study is to simulate the restoration process through the quantification of green infrastructure effects along with resilience in disaster-prone coastal areas, and to present it as nature-based restoration planning. For this purpose, first, a disaster-prone area was derived from Haeundae-gu, Busan, Republic of Korea, which was affected by typhoons. In order to simulate the runoff from typhoon "Chaba" in the target area and the effects of reducing the runoff of green infrastructure, relevant data was collected and a model constructed. Finally, the effects of the green infrastructure as applied to the disaster-prone area were quantified by means of resilience and a nature-based restoration plan was presented. As a result of this study, first, the runoff reduction effect was greatest when the maximum biotope area ratio of 30% was applied to the artificial ground. In the case of the green roof, the effect was the greatest 6 h following the typhoon passing through, and the effects of the infiltration storage facility was greater 9 h following the same. Porous pavement exhibited the lowest runoff reduction effect. In terms of resilience, it was found that the system was restored to its original state after the biotope area ratio of 20% was applied. This study is significant in that it analyzes the effects of green infrastructure based upon the concept of resilience and connects them to nature-based restoration planning. Based on this, it will be provided as an important tool for planning policy management to effectively respond to future coastal disasters.

Climate change and coastal morphodynamics: Interactions on regional scales.

Climate change and its impacts, combined with unchecked human activities, intensify pressures on coastal environments, resulting in modification of the coastal morphodynamics. Coastal zones are intricate and constantly changing areas, making the monitoring and interpretation of data a challenging task, especially in remote beaches and regions with limited historical data. Traditionally, remote sensing and numerical methods have played a vital role in analysing earth observation data and supporting the monitoring and modelling of complex coastal ecosystems. However, the emergence of artificial intelligence-based techniques has shown promising results, offering the additional advantage of filling data gaps, predicting data in data-scarce regions, and analysing multidimensional datasets collected over extended periods of time and larger spatial scales. The main objective of this study is to provide a comprehensive review of the existing literature, discussing both traditional methods and various emerging artificial intelligence-based approaches used in studying the coastal dynamics, shoreline change analysis, and coastal monitoring. Ultimately, the study proposes a climate resilience framework to enhance coastal zone management practices and policies, fostering resilience among coastal communities. The outcome of this study aligns with and supports particularly SDG 13 of the UN (Climate Action) and advances it by identifying relevant methods in coastal erosion studies and proposing integrated management plans informed by real-time data collection and analysis/modelling using physics-based models.

What evidence exists on the performance of nature-based solutions interventions for coastal protection in biogenic, shallow ecosystems? A systematic map protocol.

BACKGROUND: Anthropogenic pressures and climate change threaten the capacity of ecosystems to deliver a variety of services, including protecting coastal communities from hazards like flooding and erosion. Human interventions aim to buffer against or overcome these threats by providing physical protection for existing coastal infrastructure and communities, along with added ecological, social, or economic co-benefits. These interventions are a type of nature-based solution (NBS), broadly defined as actions working with nature to address societal challenges while also providing benefits for human well-being, biodiversity, and resilience. Despite the increasing popularity of NBS for coastal protection, sometimes in lieu of traditional hardened shorelines (e.g., oyster reefs instead of bulkheads), gaps remain in our understanding of whether common NBS interventions for coastal protection perform as intended. To help fill these knowledge gaps, we aim to identify, collate, and map the evidence base surrounding the performance of active NBS interventions related to coastal protection across a suite of ecological, physical, social, and economic outcomes in salt marsh, seagrass, kelp, mangrove, shellfish reef, and coral reef systems. The resulting evidence base will highlight the current knowledge on NBS performance and inform future uses of NBS meant for coastal protection. METHODS: Searches for primary literature on performance of NBS for coastal protection in shallow, biogenic ecosystems will be conducted using a predefined list of indexing platforms, bibliographic databases, open discovery citation indexes, and organizational databases and websites, as well as an online search engine and novel literature discovery tool. All searches will be conducted in English and will be restricted to literature published from 1980 to present. Resulting literature will be screened against set inclusion criteria (i.e., population, intervention, outcome, study type) at the level of title and abstract followed by full text. Screening will be facilitated by a web-based active learning tool that incorporates user feedback via machine learning to prioritize articles for review. Metadata will be extracted from articles that meet inclusion criteria and summarized in a narrative report detailing the distribution and abundance of evidence surrounding NBS performance, including evidence clusters, evidence gaps, and the precision and sensitivity of the search strategy.

Erratum: Environment predicts seagrass genotype, phenotype, and associated biodiversity in a temperate ecosystem.

[This corrects the article DOI: 10.3389/fpls.2022.887474.].

Environment predicts seagrass genotype, phenotype, and associated biodiversity in a temperate ecosystem.

Coastal vegetative ecosystems are among the most threatened in the world, facing multiple anthropogenic stressors. A good example of this is seagrass, which supports carbon capture, coastal stabilization, and biodiversity, but is declining globally at an alarming rate. To understand the causes and consequences of changes to these ecosystems, we need to determine the linkages between different biotic and abiotic components. We used data on the seagrass, Zostera marina, collected by citizen scientists across 300 km of the south coast of the United Kingdom as a case study. We assembled data on seagrass genotype, phenotype, infauna, and associated bathymetry, light, sea surface temperature, and wave and current energy to test hypotheses on the distribution and diversity of this temperate sub-tidal ecosystem. We found spatial structure in population genetics, evident through local assortment of genotypes and isolation by distance across a broader geographic scale. By integrating our molecular data with information on seagrass phenotype and infauna, we demonstrate that these ecosystem components are primarily linked indirectly through the effects of shared environmental factors. It is unusual to examine genotypic, phenotypic, and environmental data in a single study, but this approach can inform both conservation and restoration of seagrass, as well as giving new insights into a widespread and important ecosystem.

Using marsh organs to test seed recruitment in tidal freshwater marshes.

Premise: Seed recruitment niches along estuarine elevation gradients are seldom experimentally field-tested under tidal regimes of the Pacific Northwest of North America. Addressing this knowledge gap is important to better understand estuary restoration and plant community response to sea level rise. Methods: Germination was tested in marsh organ mesocosms across an elevation gradient (0.5-1.7 m above mean sea level). Seeds were sown on sterile peat moss, and the tops of pipes were secured with horticultural "frost cloth" to ensure no experimental seeds were washed out and no new seeds were introduced. The trials tested artificial and overwinter chilling regimes, as well as the presence and/or absence of a near-neighbor transplant. Results: Carex lyngbyei had significant elevation-driven germination after overwinter and artificial chilling. Schoenoplectus tabernaemontani had near-significant germination across elevation after overwinter chilling, and germination in the absence of competition was significantly greater than with a near-neighbor transplant. Discussion: Carex lyngbyei had the highest germination rate at higher elevations, which suggests restricted seed recruitment potential and required clonal expansion to extend into lower marsh elevations. Identifying species-specific recruitment niches provides insight for restoration opportunities or invasive species monitoring, as well as for estuary migration under sea level rise.