Beach Nourishment Research Articles

Beach nourishment response and recent morphological evolution of Minnesota Point, Lake Superior

Beach nourishments are a popular nature-based alternative to armoring for shoreline erosion mitigation, but nourishments have been criticized due to their environmental impacts and uncertain sustainability. Monitoring is often nonexistent or insufficient to constrain nourishment longevity and inform the renourishment interval required to maintain shoreline protection. This study uses a combination of topobathymetric surveys, high-resolution satellite-derived shorelines, and coastal engineering analyses to investigate the recent evolution of Minnesota Point and the fate of three beach nourishments constructed adjacent to littoral barriers. We use semi-empirical formulations for sediment compatibility, wave runup, and longshore sediment transport to inform the observed nourishment behavior. Minnesota Point experienced widespread foredune retreat averaging 7±2.8 m from 2009–2019 and 130,000(70,000–140,000) m3 of sediment was eroded during this interval. The 2019 nourishment at the Superior Entry was rapidly eroded by strong storms, losing >80% of the added beach width by the following spring. The 2020 and 2021 nourishments at the Duluth Entry retained >80% of the nourishment material at the time of the last topobathymetric survey in the fall of 2022, and satellite-derived shorelines indicate that the beach remained 10 m wider than pre-nourishment conditions at the end of 2023. Modeled longshore transport rates over the period 2009–2022 averaged 11,400 m3 yr−1 northwestward at the Superior Entry, nearly 3x greater than the 4000 m3 yr−1 southeastward transport modeled at the Duluth Entry. These observations show that differences in shoreline orientation, littoral sediment supply, and grain size compatibility can lead to contrasting beach nourishment longevities, and this study provides additional measurements of Minnesota Point’s long-term morphological change which can help inform coastal resiliency efforts.

Mechanical properties and restoring force model of Squeezing Rub-type Particle Damper

The sliding effect of isolation bearings has been proven to effectively mitigate the seismic effects on large-span bridges. However, it also results in excessive relative displacement between the main girder and piers during earthquakes. In this study, a pioneering Squeezing Rub-type Particle Damper (SRPD) is developed to address this issue. In order to verify the damping characteristics of SRPDs and investigate the working principle of squeezing friction energy dissipation, five quasi-static tests were conducted on SRPDs using two particle damping materials with different compactness levels. In order to compare the energy dissipation performance, comparative tests were conducted on Non-Squeezing-type Particle Dampers (NSPDs) and SRPDs. Utilizing regression analysis, two skeletal curve models for SRPDs were proposed, alongside a detailed restoring force model that incorporates considerations for both the pinching effect and stiffness degradation phenomena observed during the loading and unloading phases. The experimental results demonstrate that the maximum damping force of SRPDs can reach 16 times that of NSPDs, and the energy dissipation of each loading cycle can reach 21.06 times that of NSPDs. SRPDs exhibits improved energy dissipation performance when using high-density blended quartz sand. After sand replenishment repairs,damping force and energy dissipation per cycle of SRPDs were significantly enhanced. The proposed restoring force models of SRPDs aligns well with the experimental curves, underscoring its efficacy in accurately characterizing the hysteresis performance of SRPDs.

Effects of nourished beach morphology on storm response

AbstractField observations on storm induced beach changes are important to improve our effort on beach management. This study compared storm induced beach changes caused by hurricane Hermine in 2016 (4 years after a beach nourishment) and Tropical Storm Eta in 2020 (2 years after a beach renourishment) along the barrier-island coast of west-central Florida. Pre-Eta beach were 1 to 2 times wider than that of pre-Hermine. Since Hurricane Hermine and TS Eta generated a similar hydrodynamic condition for the study site, comparing beach changes induced by these two storms provides a unique opportunity to investigate the response of different antecedent beach conditions to energetic events. The shore protection effect of beach nourishment is apparently evidenced by the fact that post-Eta shoreline was located seaward of those post-Hermine at half of the beach-profile locations in the study area. The shore protection effect in the subaerial portion of the beach, however, is not obvious for the other half of beach profiles where shoreline positions were retreated to similar locations after these two storms. Instead, their shore protection effect occurred in the sub-aqueous portion of the beach and was indicated by higher sandbar crests located closer to the shoreline, which can dissipate and reduce incoming wave energy. The shoreline elevation needs to be properly defined (Mean High Water vs Mean Low Water line) as it is used as a proxy to represent beach volume loss. For Hermine induced beach change, no significant correlation exists between MHW line change and beach volume loss. While a significant correlation exists between MHW line change and beach volume loss induced by TS Eta. This correlation pattern switched if the shoreline here is defined as mean low water line. For efficient beach/shoreline management, multiple proxies (e.g., sandbar height and location of its crest and trough) in addition to shoreline change should be used to assess the performance of beach nourishment project.

Beach nourishment for coastal aquifersimpacted by climate change and population growth using machine learning approaches

Groundwater in coastal regions is threatened by saltwater intrusion (SWI). Beach nourishment is used in this study to manage SWI in the Biscayne aquifer, Florida, USA, using a 3D SEAWAT model nourishment considering the future sea level rise and freshwater over-pumping. The present study focused on the development and comparative evaluation of seven machine learning (ML) models, i.e., additive regression (AR), support vector machine (SVM), reduced error pruning tree (REPTree), Bagging, random subspace (RSS), random forest (RF), artificial neural network (ANN) to predict the SWI using beach nourishment. The performance of ML models was assessed using statistical indicators such as coefficient of determination (R2), Nash–Sutcliffe efficiency (NSE), means absolute error (MAE), root mean square error (RMSE), and root relative squared error (RRSE) along with the graphical inspection (i.e., Radar and Taylor diagram). The findings indicate that applying SVM, Bagging, RSS, and RF models has great potential in predicting the SWI values with limited data in the study area. The RF model emerged as the best fit and closely matched observed values; it obtained R2 (0.999), NSE (0.999), MAE (0.324), RRSE (0.209), and RMSE (0.416) during the testing process. The present study concludes that the RF model could be a valuable tool for accurate predictions of SWI and effective water management in coastal areas.

Addressing the climate adaptation tracking gap: an assessment method and its application to the Caribbean region

This article addresses the climate adaptation tracking gap. Indeed, we still ignore the intensity, nature, spatial distribution, effectiveness, and recent evolution of adaptation efforts at the national, regional, and global scales. We propose a web-based replicable assessment method using key variables to document adaptation efforts: country/territory, location, goal, implementation date, type of action, holder, funding source. Applying it to the Caribbean region, we analyzed 100 coastal adaptation actions. This studies the method while also highlighting the difficulties faced to track adaptation. We found that coastal adaptation efforts are substantial and increasing in the Caribbean, revealing the use of diversified adaptation actions; prevalence of hard protection (51%); increase use of Nature-based Solutions (22%); limited use of retreat (6%); and accommodation (2%). Combined actions (17%) increased over time, due to the failure of single actions and need to find tradeoffs between human asset protection encouraging hard protection and the maintenance of attractive tourist beaches encouraging beach nourishment. Puerto Rico and Trinidad and Tobago fall under the engineering-based “one-size-fits-all” adaptation model, whereas Jamaica and Barbados experiment diversified options and combinations of options. Jamaica, Puerto Rico, Trinidad and Tobago, and Barbados are particularly active in taking adaptation action, while most dependent islands and sub-national island jurisdictions have no adaptation action reported. Considering the advantages and limitations of a web-based method compared to a field-based approach, we recommend the combined use of these two complementary approaches to support adaptation tracking and help structuring communities of practice to the benefits of decision-makers and practitioners and scholars.

Surf zone hazards before and after a beach nourishment in Virginia, USA

Beach nourishment is the leading coastal protection technique in the United States to combat erosion, enhance resilience to storm surge, and maintain recreational value. Despite these benefits, anecdotal reports suggest that beach nourishments elevate the surf zone hazard to beach patrons by steepening the beach face and altering the shoreface morphology such that conditions are more favorable for rip current formation. This study analyzes lifeguard rescue reports collected on the United States Atlantic Coast before and after a 2019 beach nourishment in Virginia Beach, Virginia, to assess whether the nourishment was correlated with an increased hazard to beach patrons. The data indicate that regardless of nourishment status, rescues were most probable during periods of high rip current probability (moderate to large wave heights and low-obliquity wave angles), along with low water level. To formally quantify pre-versus post-nourishment hazards, the proportion of rescues observed in nourished versus unnourished beach zones was compared with bootstrapped distributions of the pre-nourishment rescue proportions. Although the proportion of rescues in the nourished section of the beach exceeds the pre-nourishment average, it is not outside the overall range of pre-nourishment values obtained by random resampling. Consequently, there is insufficient evidence to conclude that the existing coastal management beach nourishment strategy increased the hazard to beach patrons at Virginia Beach.

Beach Nourishment Protection against Storms for Contrasting Backshore Typologies

Beach Nourishment Protection against Storms for Contrasting Backshore Typologies

The recreational and economic value of Florida beaches

Florida is the world’s top travel destination and. if it were its own country, it would have more tourist visits than any other country. Its sandy beaches extend a shoreline length almost as great as the combined lengths of sandy beaches in California, Texas, and North Carolina. Florida’s beaches are easily America’s recreational playground. Every year, Florida beaches attract approximately 70% more day visits than combined attendance at national parks, college and professional sports, amusement parks, cruises, and NASCAR events. Beach tourism plays a huge role in Florida’s economy. Manufacturing and residential construction are major industries in Florida, but their revenues are each a fraction of beach-oriented tourist spending. Florida’s farmland, ranches, and forests cover 75% of its land area, but beach-oriented tourist spending is more than 10 times the total receipts of all Florida agriculture and forestry. Beach-oriented tourists generate $23.3 billion in tax revenues annually. These tax revenues are more than double the combined salaries of Florida K-12 public school teachers, law enforcement officers, and instructors at colleges and universities. Some Florida beaches have sand deficits because dams on rivers have blocked sand that normally would flow to the coast, and navigation projects have diverted sand out of the littoral system to ebb and flood shoals. Beach nourishment has then been needed to restore and maintain the beaches. Beaches widened by nourishment have not only been a magnet for tourists, but have also protected bil- lions of dollars of shore infrastructure from hurricanes. Beach nourishment has been a bargain, with beach-oriented tourists in Florida generating six times more tax revenues each year than have been spent on Florida beach nourishment during the 80 years from 1944-2023 (in 2022 dollars to account for inflation). Most Florida beach nourishment has been placed in the past 50 years, and beach-oriented tourists have generated $310 dollars in tax revenues and $1070 in Gross Domestic Product (GDP) annually for every $1 spent on beach nourishment. Miami Beach is a good example of the economic benefits of beach nourishment. It had almost no beach in the mid-1970s because of erosion, causing tourism to drop rapidly and itself to become a “seedy backwater of debt-ridden hotels.” Beach nourishment starting in 1978 caused a boom in tourism, and today Miami Beach has the most valuable property in Florida — worth more than the value of all Florida cropland. Miami Beach has had a return of $550 in tourist-generated taxes and $3900 in GDP for every $1 spent on beach nourishment.

Influence of structure characteristics on wave transmission and shoreline response at a low-crested segmented breakwater in Little Egg Harbor Township, NJ

Graveling Point Beach, a public beach within Little Egg Harbor Township, New Jer- sey, has been experiencing long-term erosion. To address the issue, a living shoreline project consisting of four low-crested rubble-mound breakwaters and a beach nour- ishment was constructed beginning in fall 2022 (structures) and finishing in spring 2023 (beach nourishment). A variety of field methods were used to investigate the influence of the breakwater system on wave transmission and beach fill evolution. The observations are then compared to common empirical estimations. A median wave transmission coefficient of 0.4 was measured for incident waves with a median height and peak period of 9 cm and 2 sec, respectively. The observed transmission coefficient was higher than that predicted by models such as Briganti et al. (2003) and Van der Meer and Daemen (1994) suggesting other processes such as diffraction may be influencing the results. Structure from Motion (SfM) was used to generate a series of Digital Elevation Models (DEMs) which show salients forming behind the structures. The resulting salient growth was compared to the model of Suh and Dalrymple (1987), which was shown to overpredict the amplitude of the salient at Graveling Point. However, the expected relationship of breakwaters with increased offshore distance having shorter salient lengths was generally observed. The equation was refit using the field data at Graveling Point and laboratory data with similar wave heights and periods from Suh and Dalrymple to derive a modified model that may be more appropriate in low-energy environments

Evaluation of beach nourishment in Mar del plata, Argentina: An application of the CoastSat toolkit

Sandy coasts play a crucial role in various human activities and support the economies of many coastal states. Due to their importance, coastal erosion mitigation techniques are often implemented. Among these techniques, beach nourishment is considered an environmentally acceptable method for coastal protection and restoration. In this work, a methodology for the evaluation of such projects is proposed and applied to the biggest beach nourishment project in the city of Mar del Plata, Argentina. The nourishment was carried out between 1998 and 1999 in Playa Grande (PG), Varese (V) and Bristol (B) bays. The CoastSat toolkit was implemented to obtain shoreline positions from satellite imagery and to derive a 36-year monthly time series of beach width in the region. For the analysis, three distinctives time lapses are identified: pre-intervention, response, and new equilibrium. An exponential decay function was fitted to determine the response lapse and its characteristics. Metrics such as mean beach width and trends were computed and used to compare the condition of beaches before and after the project. Results show that the region experienced a net growth after nourishment, with beach width doubling in Bristol and Playa Grande, and increasing tenfold in Varase. Nourishment did not alter the erosive trends of Playa Grande and Bristol, nor the growth trend of Varese. Regarding renourishment planning, according to our findings, for Playa Grande and Bristol beaches to achieve a net growth of 1 m, it would require the deposition of 17 m³ of sediment per meter of coastline. This study highlights the suitability of the CoastSat toolkit for assessing the effectiveness of beach regeneration.

Ad Hoc Adaptations to Climate Change in Coastal Communities

Climate change disproportionately impacts coastal residents in the United States. Existing studies document institutional efforts to adapt to sea level rise through projects like seawalls, beach nourishment, and property acquisitions to protect communities from rising seas. Such studies capture institutional adaptations, but do not include ad hoc adaptations by homeowners impacted by climate change. How are homeowners adapting to climate hazards? This paper analyzes ethnographic and interview data from 100 households in two coastal counties in North Carolina, a state with one of the most climate vulnerable shorelines in the country. This analysis of homeowner response considers ad hoc adaptations along the North Carolina coast. Results show that homeowners recognize climate hazards and regularly adapt on their own within the context of institutionally maintained flood protection infrastructure and transportation access to the places where they live. Residents are aware of and attempt to access support for home adaptations when programs or funds are available to them after disasters and do so with varying levels of success, though the more pervasive adaptations to chronic stress are not supported by government programs or insurance mechanisms. Ad hoc adaptations may provide short-term protection from climate hazards but have questionable long-term efficacy as sea levels rise and storm strength and frequency increases. Leaving communities and households to adapt on their own as chronic climate hazards outpace institutional response exacerbates existing inequalities by relying on residents with different levels of resources and agency to adapt.

Innovation in coastal governance: management and expectations of the UK’s first sandscaping scheme

Many coastal places around the UK face change, with impacts on communities, livelihoods, and landscapes. A tidal surge in 2013 caused significant erosion and flooding on the east coast of England (UK). This was the catalyst for the innovative Bacton to Walcott Coastal Management Scheme, also known as the Sandscaping Scheme, implemented in summer 2019. It is a one-off, large-scale beach nourishment scheme with a design prediction of 15–20 years functional life, the first of its kind in the UK and worldwide outside of the Netherlands. Through stakeholder interviews and a household questionnaire survey, this paper examines the institutional and political challenges, expectations, and hopes associated with this Scheme just before its implementation. The findings indicate that a combination of factors enabled technical and institutional experimentation and innovation at this location: critical erosion risk at a site of strategic infrastructure adjacent to two highly vulnerable villages, extensive stakeholder collaboration across scales, resolute leadership, and recognition of co-benefits. Although most interviewees and local residents foresaw significant benefit from the Scheme—not least respite from the deep anxiety caused by the threat of flooding and erosion risk—tensions were expressed around uncertainty beyond the Scheme’s lifetime and the need to start effective conversations about future adaptation options for the area. This study provides reflections for similar nature-based coastal management schemes elsewhere. It highlights the fundamental challenges facing the governance of natural and social coastal systems for adapting to current and future coastal change and the importance of articulating local and sometimes intangible understandings and expectations of adaptive coastal management interventions.

Citizen perceptions of Great Lakes coastline change and management efforts

Fluctuating water levels, nearshore flooding and associated coastal erosion present management challenges for coastal communities around the world. Along the Great Lakes, integrated coastal zone management efforts involve a complex array of people and institutions, which include citizens of coastal communities. At this point in time, there are few studies focused on community members' perceptions of and views on current management efforts on the Great Lakes. To address this need, the present study analyzes survey data from the public and six Great Lake communities with three objectives in mind. One, to understand perceptions of the causes of coastline change and the hazards associated with these changes. Two, to understand the consequences of coastline change for people and the greater community. Three, to understand citizens’ viewpoints about different strategies for managing coastline changes and the parties responsible for managing the coastline. Study results indicate conflicting perceptions between community members about common coastline management efforts (e.g. armoring, beach nourishment, and setbacks). They also indicate a general lack of knowledge about the complexities and responsible parties for coastline management, which in some cases, may be individual property owners themselves. The results of this study suggest efforts to educate citizens may be critical for future stewardship of the Great Lakes, which requires community partnerships and buy in to be successful.

Observed beach nourishment development in a semi-enclosed coastal embayment

Beaches are important coastal features that provide vital ecosystem services; however, these systems are threatened by coastal erosion, sea-level rise, and coastal squeeze. Beach nourishments are a commonly applied coastal protection measure to mitigate erosion and flood risks while maintaining or enhancing recreational values. Nourishments vary in scale from mega-nourishments to small-scale nourishments, where the latter has typically been less studied due to the limited resources for monitoring. Meanwhile, with rising sea levels, the implementation of small-scale nourishments is expected to increase, and there is a need for more knowledge about the morphological evolution and technical lifetime of these interventions. In this study, the morphological responses of small-scale beach nourishment (total volume 20,000 m3 which amounts to 30 m3 added per m alongshore) are observed and quantified over various timescales, considering the initial adjustment, long-term development, and event-driven response. The investigated nourishment is implemented in a partly sheltered coastal embayment in the semi-enclosed Baltic Sea, which has a complex interaction between waves and water levels. Furthermore, the beach is surrounded by hard structures, a rock revetment at the back, and a harbor mole and a groin, influencing the longshore and cross-shore sediment transport. The results show that substantial reduction in subaerial volume can be attributed to specific events. In addition, we observed considerable spatial variation in the sediment re-distribution induced by hard structures and variability in the nearshore bathymetry. The lifetime of the beach nourishment is just over two years. The nourished material remains in the system at the end of the lifetime but is not available for beach recovery. Still, the added subaerial volume has eroded at the midsection, and the protective beach width has been reduced, leaving the rock revetment exposed with reduced protection for the hinterland. The energy conditions at the site are highly episodic, which impacts morphological evolution, and observations indicate that the development is event-driven.

Sediment source and dose influence the larval performance of the threatened coral Orbicella faveolata.

The effects of turbidity and sedimentation stress on early life stages of corals are poorly understood, particularly in Atlantic species. Dredging operations, beach nourishment, and other coastal construction activities can increase sedimentation and turbidity in nearby coral reef habitats and have the potential to negatively affect coral larval development and metamorphosis, reducing sexual reproduction success. In this study, we investigated the performance of larvae of the threatened Caribbean coral species Orbicella faveolata exposed to suspended sediments collected from a reef site in southeast Florida recently impacted by dredging (Port of Miami), and compared it to the performance of larvae exposed to sediments collected from the offshore, natal reef of the parent colonies. In a laboratory experiment, we tested whether low and high doses of each of these sediment types affected the survival, settlement, and respiration of coral larvae compared to a no-sediment control treatment. In addition, we analyzed the sediments used in the experiments with 16S rRNA gene amplicon sequencing to assess differences in the microbial communities present in the Port versus Reef sediments, and their potential impact on coral performance. Overall, only O. faveolata larvae exposed to the high-dose Port sediment treatment had significantly lower survival rates compared to the control treatment, suggesting an initial tolerance to elevated suspended sediments. However, significantly lower settlement rates were observed in both Port treatments (low- and high-dose) compared to the control treatment one week after exposure, suggesting strong latent effects. Sediments collected near the Port also contained different microbial communities than Reef sediments, and higher relative abundances of the bacteria Desulfobacterales, which has been associated with coral disease. We hypothesize that differences in microbial communities between the two sediments may be a contributing factor in explaining the observed differences in larval performance. Together, these results suggest that the settlement success and survival of O. faveolata larvae are more readily compromised by encountering port inlet sediments compared to reef sediments, with potentially important consequences for the recruitment success of this species in affected areas.

Coastal resilience and shoreline dynamics: assessing the impact of a hybrid beach restoration strategy in Puducherry, India

Puducherry, a Union Territory of India, has been strongly affected by severe erosion after the construction of the Puducherry port in 1989. To mitigate this cause, the National Institute of Ocean Technology, Chennai, and the Puducherry government implemented a beach restoration strategy involving a hybrid solution in 2017 for coastal protection/stabilization and the restoration of the lost beach. The strategy involved deploying a steel reef into the nearshore sea and implementing beach nourishment processes. To monitor the coastal morphological changes after implementing the coastal protection strategy, the Digital Shoreline Analysis System, was adopted to calculate the rate of shoreline change statistics for the years 2016 to 2022. It uses spatio-temporal shoreline positions from multi-temporal satellite imagery. The shorelines are extracted from the Sentinel-2A satellite images by a Normalized Differential Water Index based semi-automated model. Statistical parameters in DSAS analyze the shorelines to determine the shoreline changes in this area. The results reveal the remarkable resilience of a newly restored beach, where the linear regression rate statistics in Zone A show an average accretional rate of 2.92m/yr. Alternatively, Zone B exhibits an average erosion rate of -0.23m/yr, with intermittent sandy beaches experiencing maximum erosion rates of -1.63m/yr. The influence of longshore current direction and sediment transport on shoreline movement is evident in seasonal analysis, with shoreline development and recession primarily observed near shore protection structures. The study’s outcome provides valuable insights for coastal management, offering a reliable approach for shoreline monitoring post-implementation of mitigation projects.

Environmental risk assessment of coastal dredging based on clustering of meteocean forcing

Dredging and dumping in-situ sediments is a fundamental operation for most coastal engineering projects and coastal defense projects, such as the construction of breakwaters, beach nourishment and land reclamation. Future projections in terms of coastal hazard suggest that coastal protection and land reclamation project will be more and more frequent. In this context, the assessment of the environmental and socio-economic impact of the risk induced by dredging is a fundamental step during both the design stage and the operational management. Most of the standard practices and available risk assessment frameworks rely on the numerical prediction of the sediment plume in the large field driven by coastal circulations forced by tides, winds and waves. In this study, we formulated a new risk assessment framework based on an unsupervised machine learning clustering algorithm, K-means clustering, for generating representative meteocean scenarios subsequently used to force a regional circulation model. Moreover, we introduced three criteria of hazard/risk based on the spatial and temporal evolution of the suspended sediment concentration that explained different environmental impacts and two new methods to synthetically present the risk values. The major improvement of the present framework is that the final probability of risk fully describes the statistics in terms of hydrodynamic and dredging conditions.This framework presents the probability analysis of risk spatial distribution based on representative hydrodynamic conditions and dredging scenarios, which is a major improvement of this study compared with previous risk assessment strategies that were unable to predict quantified dredging risk before field construction. Finally, to demonstrate the potentiality of the risk assessment framework, we applied this methodology to the Hong Kong Water and Pearl River Estuary (China) as a pilot case.

SandSnap: Measuring and mapping beach grain size using crowd-sourced smartphone images

Sediment grain size is a critical parameter for sediment mobilization and transport, but often has the highest uncertainty of any coastal sediment transport model input parameter. SandSnap is an initiative to engage the public to amass a beach grain size database by taking photos of the beach sand with a coin in the image for scale and uploading the image to a web application. Images are analyzed with two deep learning convolutional neural networks one to detect the coin and the second to measure the grain size, which is trained on sediment samples within the sand regime. The results for nine gradation metrics are returned to the user within 2 min of image upload. Results from 263 test images have a mean percent error of −6.5% and median absolute error of 22.4% for the median grain size (d50) with a small fine bias of −0.042 mm. The use of the database is highlighted by applying SandSnap output as an input to the AeoLiS aeolian sediment transport model to predict coastal dune growth at a nearly national scale using the full eight grain size classes (d10 – d90) from the SandSnap database. These outputs are used to inform the potential value of having spatially comprehensive grain size distribution information as part of coastal engineering design and planning. Education and outreach techniques for the SandSnap initiative are described in the manuscript. Though some challenges remain, the spatially and temporally robust beach grain size database being developed by SandSnap will help to improve numerous coastal engineering analyses including coastal resilience and vulnerability quantification, beach nourishment life cycle and uncertainty analysis, beach compatibility for the beneficial use of dredged sediment, and large-scale coastal morphology modeling.

Examining the potential impacts of a coastal renourishment project on the presence and abundance of Escherichia coli.

Erosion poses a significant threat to oceanic beaches worldwide. To combat this threat, management agencies often utilize renourishment, which supplements eroded beaches with offsite sand. This process can alter the physical characteristics of the beach and can influence the presence and abundance of microbial communities. In this study, we examined how an oceanic beach renourishment project may have impacted the presence and abundance of Escherichia coli (E. coli), a common bacteria species, and sand grain size, a sediment characteristic that can influence bacterial persistence. Using an observational field approach, we quantified the presence and abundance of E. coli in sand (from sub-tidal, intertidal, and dune zones on the beach) and water samples at study sites in both renourished and non-renourished sections of Folly Beach, South Carolina, USA in 2014 and 2015. In addition, we also measured how renourishment may have impacted sand grain size by quantifying the relative frequency of grain sizes (from sub-tidal, intertidal, and dune zones on the beach) at both renourished and non-renourished sites. Using this approach, we found that E. coli was present in sand samples in all zones of the beach and at each of our study sites in both years of sampling but never in water samples. Additionally, we found that in comparison to non-renourished sections, renourished sites had significantly higher abundances of E. coli and coarser sand grains in the intertidal zone, which is where renourished sand is typically placed. However, these differences were only present in 2014 and were not detected when we resampled the study sites in 2015. Collectively, our findings show that E. coli can be commonly found in this sandy beach microbial community. In addition, our results suggest that renourishment has the potential to alter both the physical structure of the beach and the microbial community but that these impacts may be short-lived.

Spatial Cumulative Assessment of Impact Risk-Implementing Ecosystem-Based Management for Enhanced Sustainability and Biodiversity in the Black Sea

Marine ecosystems are becoming increasingly vulnerable to cumulative anthropogenic effects and pressures. Therefore, various methodological approaches and tools have been designed to apply cumulative impact appraisal schemes and better assess the dynamics and interactions among pressures affecting marine ecosystems. This study aims to apply the Spatial Cumulative Assessment of Impact Risk for Management (SCAIRM) tool for the Black Sea coastal waters considering human activities, pressures, and effects on different ecosystem components coupled with one management scenario development for actual and new emerging sectors. According to the SCAIRM, the primary pressure on the marine ecosystem was identified as introducing or spreading non-indigenous species from shipping. Additionally, when considering cumulative impact, activities related to coastal defense and flood protection, particularly beach nourishment works, were found to have the highest impact. This is due to the cumulative scores associated with the physical loss from permanent alteration or removal of seabed substrates, and temporary or reversible physical disturbances to the seabed. The scenario development indicated that after shipping, oil and gas exploitation is anticipated to become the second-highest risk sector for additional impact in the Romanian Black Sea. Additionally, the increased military activities related to the war in Ukraine present escalating risks that must be considered in EBM strategies. The results assess the possible effects of human activities and the associated pressures to direct management toward achieving sustainability, biodiversity protection, and the marine ecosystem’s integrity.