Anthropocene Coasts最新文献

Recreational beaches are widely distributed in coastal cities. Investigating the coupling mechanisms between anthropogenic interventions and natural coastal processes on sediment grain-size distribution is critical for maintaining and enhancing recreational beach functionality and value. This study examines three major recreational beaches within Zhanjiang Bay, conducting comparative analyses of surface sediment characteristics including representative grain-size metrics, granulometric composition, and statistical parameters. Key findings include: (a) significant variations in mode size (0.87–1.89 φ) and D₁₀ values (-0.80 to -0.09 φ) among the three beaches, contrasted with limited differences in D₅₀ and D₉₀ metrics; (2) dominance of medium sand (26.16–39.14%) and coarse sand (26.75–31.43%) fractions, supplemented by fine and very coarse sand components, with central transects exhibiting higher medium-coarse sand concentrations than southern/northern sections; (3) sorting coefficient gradients (0.90–1.21) ranking central > northern > southern beaches, while mean grain size (0.83–1.21 φ), skewness (-0.12 to -0.02), and kurtosis (0.87–1.18) show no distinct spatial patterns. Sediment grain-size distribution patterns are governed by four primary mechanisms: artificial nourishment inputs, anthropogenic sediment modification (harvesting/excavation), natural sediment supply processes, and hydrodynamic forcing. This research establishes a typical framework for characterizing recreational beach sediments, advancing understanding of multi-factor controlled grain-size distribution patterns and sediment transport dynamics.

Dark carbon fixation (DCF) is an integral component of the global carbon sink. However, quantitative data on its contribution to total carbon fixation in estuaries are scarce, and factors driving DCF remain under exploration. In this study, radio-¹⁴C labeling and molecular techniques were employed to investigate the temporal-spatial distribution of DCF and photosynthesis rates in the Yangtze Estuary and its adjacent coastal areas (YEA), along with the potential microorganisms involved. DCF rates ranged from 0.17 to 3.79 μmol C L⁻¹ h⁻¹ in the YEA, accounting for 15.4–97.7% of integrated total daily carbon fixation, suggesting the large variability in both DCF rates and their contributions to the carbon sink. An estimate based on ¹⁵NH₄Cl labeling experiments revealed that the contribution of DCF by ammonia-oxidizing microorganisms was low (< 3.97%) in surface waters of the YEA. Bacteria bearing the cbbL-IA&IC gene were the potential essential contributors to DCF, while eukaryotic phytoplankton harboring the cbbL-ID gene may also contribute to DCF through light-independent β-carboxylation. DCF rates were mainly influenced by nutrients, particulate organic carbon, and salinity, which affect microbial abundance. Our findings underscore the importance and variability of the DCF process in human-impacted estuarine and coastal waters, contributing to a better understanding of microbial carbon fixation processes and their potential mechanisms.

Wildlife in coastal zones is often affected by anthropogenic and environmental factors that intensify at the interface of land and water. Seabirds are particularly susceptible to disturbances when they breed in large, dense colonies, such as direct harm from extreme weather and interference, or exposure of eggs and chicks to predators due to indirect human activities. All these factors potentially impact the Black Skimmer (Rynchops niger), a seabird that is considered vulnerable in much of its range across the Americas. This study quantified disturbances affecting two skimmer colonies within a Critical Wildlife Area in southwest Florida, a coastal area of rapidly growing human population. Skimmers experienced a wide array of disturbances that caused a total of 195 flushing events, at a rate of almost 2 per hour throughout the 3-month study period. Natural and anthropogenic disturbances were occurring simultaneously and at roughly similar frequencies at the two colonies. Weather and unexplained disturbances caused a higher portion of skimmers to flush at one colony, and weather led to longer flushing events at the other colony. Flushing responses were stronger on weekends at the second colony. Notably, breeding skimmers faced considerable disturbance despite existing within a monitored protected area. Given the overlap of disturbance types across the breeding season, this study demonstrates the need for measures to protect skimmers from anthropogenic and environmental stressors, including further study of how these factors impact reproductive success of colonies. It illustrates the challenges faced by waterbirds around the globe, amid growth in coastal human communities during this era of rapid environmental change.

Coastal wetlands face dual threats from climate change and human disturbances, while they provide important ecosystem functions and deliver essential ecosystem services. Exploring the drivers behind coastal wetland changes will benefit sustainable coastal ecosystem management. Based on GlobaLand30 data, this study systematically assessed the spatiotemporal changes and drivers of China’s coastal marsh changes during 2000–2020 by incorporating land-use transformation process and various anthropogenic and environmental factors from public datasets. Our findings revealed a net increase of 865.8 km² in coastal marsh area during 2000–2020, with distinct regional variations. Coastal marsh changes were more evident north of 30°N, particularly in the Bohai Rim region (37–41°N) and the Yangtze River Delta (30–33°N). Over 75% of major coastal marsh gains (> 1,250 ha) and losses (> 1,000 ha) based on 25 km² hexagonal grids occurred in these two regions during 2000–2020. The increase in the proportion of major coastal marsh loss grids (> 1,000 km²) from 80.0% to 89.8% in these two regions during 2010–2020 suggests that some areas continued to deteriorate, highlighting that total area changes may mask important local dynamics. While driving factors varied across latitudes, land reclamation remained the dominant reason for coastal wetland loss. Reclamation induced coastal marsh loss accounting for over 60% of the total losses across all sea regions during different periods. In the Bohai Rim, the latitudinal distribution of marsh losses aligned with aquaculture changes patterns, while marsh gains primarily resulted from ecological recovery. In the East China Sea region where the Yangtze Delta is located, accretion contributed over 65% of total gains during both 2000–2010 and 2010–2020 periods. The areas of significant coastal marsh changes in the East China Sea region spatially overlapped with the distribution range of Spartina alterniflora. Based on the analysis of driving forces and ecological issues, this study proposed region-specific adaptive management strategies. Future research should strengthen the quantitative analysis of multiple driving forces’ interactions to provide a scientific basis for developing more targeted land-sea management strategies.

Cephalopods contribute to the food security of coastal communities in the Philippines. Despite their importance, the role of cephalopods in local food security remains relatively underexplored, posing challenges for effective coastal resource management. This study applies a modified food security framework (FAO 2006) to analyze the four dimensions of food security—availability, access, utilization, and stability—in the cephalopod fishery of Malalison Island, Philippines. The island's local management system includes a Territorial Use Rights for Fisheries scheme integrated with a Marine Protected Area, operating under a community-based management. Data was collected in 36 semi-structured interviews and during a focus group discussion with ten fishers featuring a participatory mapping activity. Findings reveal that while cephalopods remain a stable food source, cephalopods are perceived by fishers to be threatened by climate change, unsustainable fishing practices, illegal activities, as well as resource and physical constraints among fishers. To ensure cephalopods as a source of food security, future research and coastal management efforts should prioritize biological surveys and catch landing data collection, together with enhanced enforcement and community engagement.

Mangrove ecosystems play a vital role in climate change mitigation by capturing and storing carbon, particularly in their soils. As essential coastal wetlands, they contribute significantly to blue carbon sequestration, helping to offset greenhouse gas emissions and mitigate global change. This study evaluates vegetation and soil carbon stocks, along with their economic valuation, across three distinct geomorphological settings: bordering mangroves in Nusa Lembongan, estuarine mangroves in Benoa Bay, and riverine mangroves in Estuary Perancak. Soil samples were analyzed for organic carbon, bulk density, and various physical and chemical properties, and carbon economic value was estimated using the World Bank’s proposed carbon tax rates. The results revealed significant differences (ρ < 0.05) in soil carbon stocks across the sites, with Estuary Perancak showing the highest values due to its riverine characteristics, while Nusa Lembongan had the lowest values, attributed to sandy soils and limited organic input. Vegetation carbon stocks did not differ significantly among the locations. The economic assessment highlighted a range of values, from 27,622 to 87,925 USD tonCO₂⁻¹ ha⁻¹, demonstrating the financial benefits of mangrove conservation and restoration. Strong positive correlations were observed between soil carbon storage and parameters such as canopy coverage, water content, and clay content, whereas bulk density and salinity were negatively correlated. These findings underscore the critical influence of geomorphology on carbon sequestration in both vegetation and soil, while highlighting the ecological and economic value of mangroves. The study provides valuable insights to support sustainable management and conservation strategies, contributing to global climate mitigation efforts and advancing Sustainable Development Goals (SDGs) 13, 14, and 15.

Estuaries are low- elevation morphological areas that are highly susceptible to submersion and flooding, and particularly so in view of the rising sea level. As with coastlines, where many adaptation strategies are under consideration (relocation, adaptation of buildings, nature-based solutions, etc.), future adaptation strategies for estuaries involve a number of different ways of converting the area, all of which must be developed on the appropriate spatial and temporal scales and in agreement with the local people. In this regard it is appropriate to examine the views of local residents in an estuarine context. Do they feel vulnerable? What are their perceptions of how planning has evolved in relation to climate change, and what are their preferences in respect of risk management? This article presents the results of an enquiry carried out downstream of the Loire estuary in an area characterized by industry, urban development and natural spaces. The survey involved 633 individuals whose views on the relationships between the local residents and their territory, in terms of fluviomarine risks and adaptation procedures, were collected by completing a questionnaire. The results reveal that few of the people surveyed are worried about fluviomarine risks, although they are aware of the ongoing climate change and that areas close to where they live are under threat. On the other hand, they feel much more threatened by the industrial risk which is characteristic of the Loire estuary. In terms of adaptation strategies the results are highly consensual, although sometimes confused, and could reveal a lack of ‘concern’ about these topics. The results of this research highlight determining factors such as time spent in the community and at home, the elements inherent to estuarine environments, and the memory of local risks. These elements could be useful for stakeholders in large industrialized estuaries wishing to embark on an adaptation strategy or submersion risk management.

The Baros coastal area in Yogyakarta, a mangrove conservation and ecotourism site, experiences high accumulation of anthropogenic marine debris (AMD) due to its location at the Opak River estuary. In addition, the presence of mangroves can trap debris carried by river flow, causing structural changes and a decrease in the function of the mangrove ecosystem. Therefore, it is necessary to analyze anthropogenic marine debris in mangrove areas as an integrated handling effort, both in terms of policy, control, and implementation. This study assesses mangrove habitat characteristics, AMD distribution, and environmental quality using the Clean Coast Index (CCI) and Hazardous Items Index (HII). The results showed that the characteristics of mangrove habitat, consisting of landward and middle zones, are freshwater/tasteless since they are only submerged during high tide conditions. Meanwhile, the seaward zone is brackish water since it is submerged all the time. The substrate of the landward zone consists of sand and clay, whilst the middle and seaward zones are predominantly composed of sand. Furthermore, our results indicate that macro debris (96%) and plastic waste (76%) dominate the area, with 83% of the study area classified as ‘very dirty’ and 50% under Class IV for hazardous debris, the mangrove ecosystem is at significant risk. The presence of sharp debris poses significant risks to ecosystem health. Given the critical AMD levels, urgent intervention is necessary to prevent further degradation of the mangrove ecosystem.

Coastal areas are one of the most vulnerable regions being subjected to multiple hazards while sheltering people, diverse ecosystems, key infrastructure and other assets. Climate change will produce expected changes to the drivers affecting these hazardous events which when coupled with the uncertainty of the degree of the adverse impacts, place vulnerable coastal communities in intractable circumstances. In regions with limited access to human and financial resources, like in Caribbean Small Island Developing States (SIDS), there must be a focus on practical solutions and tools that can support optimal decision-making in coastal areas. The adoption of nature-based approaches is but one solution to mitigating these potentially deleterious effects, reducing vulnerability and enhancing coastal resilience. Through physical modelling, this study explores how the changes to selected characteristics of synthesized offshore coral reefs affect the hydrodynamics in the nearshore zone and seeks to formulate quantitative relationships for practical applications. These quantitative relationships can serve to support the assessment of present-day levels of protection offered by coral reefs and provide an insight into how future changes of these coastal ecosystems and offshore conditions, whether caused by man or natural influences, can affect the nearshore hydrodynamics. Assessment of the potential future levels of protection under different scenarios allow for a holistic optimization of proposed coastal solutions. The outputs of this study demonstrated a good correlation between the wave height after the reef and the above reef velocities with the incident wave conditions, the reef width and the water depths on the reef. The experimental results also support the trends observed from other studies in terms of wave attenuation, albeit to a smaller extent. The relationships between assessed experimental parameters generally corroborated with anticipated patterns although the wave reflection in the flume appeared to skew some output. The expressions produced from this study, though limited given the experimental scope, demonstrate a methodology which can be readily augmented to improve the assessment of existing and future levels of protection offered by coral reefs in order to implement hazard mitigation strategies that not only reduce the risk to assets in coastal areas, but incorporate natural systems in a meaningful way to support valuable co-benefits to these coastal communities.

Surface ocean plastic and microplastic concentration have intensified in the past decade, bringing multiple potential adverse effects to ecosystems. This increased presence and related persistence of plastics in the marine environment pose questions about their interaction with sea-surface organisms, which are usually impacted by hazardous chemical leachates. Coastal regions, as entry pathways of most plastic litter through mismanaged plastic waste on land and river runoff, are zones of high plastic accumulation. The interactions of free-floating marine organisms and buoyant plastic debris (BPD) are identified as one of the issues of concern that would potentially harm future global biodiversity, needing immediate public attention and action. This article addresses emerging and underexplored ecological impacts of the plastic problem by focusing on the interaction of the sea surface layer pelagic community with BPD. The plastic litter and their macro and micro variants harbor organisms of diverse lineage, and this nursing stimulates direct behavioral and physiological changes that are able to alter the structure and the composition of a community. Such BPD-induced alteration impairs elementary traits of the most diverse group of bio-indicator and keystone organisms, such as buoyancy mechanisms and bio-physical coupling behaviors. Subsequently, such crucial impacts on remarkable eco-indicator organisms can potentially generate novel marine environmental challenges. Policy interventions on such ubiquitous nexus of BPD and sea-surface dwelling organisms that potentially disrupt crucial ecological indicators are necessary to tackle the associated social, environmental, and economic impacts.