Management Of Coastal Ecosystems Research Articles

Distribution patterns, risk assessment and potential sources of heavy metals in sediment in the Qiongzhou Strait, China

Risk assessment and pollutant source analysis are crucial tools for the management and protection of coastal ecosystems. The distribution patterns, risk assessment, and potential sources of heavy metals (Cd, Cr, Fe, Ni, Cu, Zn, As, Hg, and Pb) in surface sediment were analyzed in the Qiongzhou Strait, China, in summer and autumn of 2022. Heavy metals in autumn showed higher ecological risk than that in summer. Seasonal shifts in ocean currents may result in variations in heavy metal accumulation and dispersion. Cd and Hg were the priority heavy metals found, and according to the Positive Matrix Factorization results, the study area contains five sources of pollution, with natural sources, shipping-related activities, and industrial activities being the primary contributors. This study indicated that pollutants from adjacent areas should be considered for managing the environmental quality of Qiongzhou Strait.

Does spending time with nature affect people’s desire to protect it? A case study of Nigerian beachgoers

ABSTRACT This study explores the intricate relationship between beach conservation and human behaviour, focusing on beachgoers in Lagos State, Nigeria. It underlines the importance of nature connection in determining people’s willingness to pay (WTP) for the management and preservation of coastal ecosystems. As well as providing spaces for recreation, beaches provide vital ecosystem services such as flood protection and contributions to biodiversity, but they are often threatened by human-induced actions such as pollution. The research investigates pathways through which individuals connect with nature, highlighting beauty, compassion, emotion, contact and meaning. It reveals that participants primarily establish their connection through the aesthetic appeal of beaches. Additionally, the study uncovers a positive WTP for beach management, with most participants willing to contribute modest amounts. The study’s implications point to the need for holistic beach management strategies in Nigeria that balance economic development and environmental conservation. Ultimately, this research underscores the importance of strengthening connections between individuals and the natural world to foster pro-environmental behaviour and financial contributions to conservation efforts.

Tracking annual changes of coastal aquaculture ponds in China during 1986–2021

The rapid expansion of coastal aquaculture ponds has made outstanding contributions to global food security and economic development in coastal areas, but this expansion inevitably has a significant impact on coastal ecosystems. Strengthening the spatiotemporal monitoring of aquaculture ponds is crucial for optimizing coastal land use and efficiently managing aquaculture ponds. However, aquaculture pond data on national scale and interannual variability are lacking. Here, we utilized Landsat times series images from 1986 to 2021 to generate annual maps of aquaculture ponds in China's coastal areas and investigated its spatiotemporal characteristics. We find that the overall accuracy of our aquaculture ponds classification was over 90% each year. Aquaculture ponds were concentrated in Bohai Bay, the Jiangsu Coastal Plain, and the Pearl River Delta in China's coastal areas. The time series of aquaculture ponds change could be divided into three stages: rapid growth (1986–2000), stable growth (2001–2016), and a slow decline (2017–2021). The spatial evolution of aquaculture ponds was characterized by (1) continuous seaward expansion, (2) continuous inland and seaward expansion, (3) continuous inland expansion, (4) continuous expansion and then shrinkage, and (5) rapid shrinkage. Moreover, the main aquaculture ponds classification errors were salt pans, reservoirs, abandoned ponds, port facilities, lakes, and pit ponds. Our study demonstrated a new method for applying satellite remote sensing for coastal ecosystem management, and our maps and findings can be used to optimize the development and sustainability of coastal aquaculture ponds.

Trade‐Off Between Light Deprivation and Desiccation in Intertidal Seagrasses Due To Periodic Tidal Inundation and Exposure: Insights From a Data‐Calibrated Model

AbstractSome seagrass species thrive in shallow intertidal zones globally, adapting to periodic tidal inundation and exposure with distinctive physiological traits and offering crucial ecosystem services. However, predicting the responses of intertidal seagrasses to external stressors is hampered by the complexity of the dynamic and harsh environments they occupy. Intertidal seagrass growth models, especially those incorporating dynamic physiological responses, are scarce in the literature. Our study comprehensively collated relevant data from the literature to parameterize the relationship between air exposure, seagrass leaf water content and photosynthetic efficiency to inform new growth rate functions for generalizable intertidal seagrass growth models. We tested the applicability of these model formulations for scenarios with varying physiological process assumptions, seagrass species, tidal conditions, meadow elevations and water turbidity. We found that neglecting air‐exposed physiological responses (i.e., leaf water content loss and reduced photosynthetic efficiency) can substantially overestimate seagrass growth rates. We also observed a trade‐off between light deprivation and desiccation on intertidal seagrass growth under specific tidal ranges and turbidity conditions. This can yield an “optimal” elevation where overall stress of desiccation (increasing with meadow elevation) and light deprivation (decreasing with meadow elevation) are minimized. The predicted optimal elevation, that is, the most suitable habitat for intertidal seagrass, moves upward as water turbidity increases. Our study provides conceptual and quantitative guidance for ecological modelers to include air exposure responses of intertidal seagrasses in coastal ecosystem models. The model also helps to evaluate the viability of intertidal seagrass habitats and inform decisions on coastal ecosystem management under changing environmental conditions.

Potential Carbon Stock of Seagrass Biomass in Malang Regency

Research on blue carbon content in seagrass beds also has important implications for coastal ecosystem management. The goals of this research are: (1) To determine the composition of seagrass species; (2) to analyze the health of the seagrass ecosystem; and (3) and to analyze the carbon content stored in seagrass biomass on the coast of Malang Regency. This research was conducted in 2018 at five stations, namely: Kondang Merak Beach (St 1), Balekambang Beach (St 2), Gatra Beach (St 3), Sendangbiru Beach (St 4), and Waru-Waru Beach (St 5) of Malang Regency. The method used to collect data refers to Seagrass Watch. The biomass value of seagrass species can be estimated by measuring the wet weight and dry weight of seagrass. Analysis of carbon content in seagrass biomass can be calculated using a method that refers to The First Nation-Wide Assessment Identifies Valuable Blue-carbon. There are five types of seagrasses found on five beaches in Malang Regency, namely: Halodule pinifolia, Halodule uninervis, Halophila ovalis, Syringodium isotifolium, and Thalassia hemprichii. This seagrass meadow ecosystem is in an unhealthy condition, with a small biomass value. Seagrass beds that are formed only in the form of small spots (1.19 Ha) are known to be able to store carbon of 0.0544 Mg C.

Seasonal variations of a coastal fish community in relation to environmental parameters - A case study of the Sylt-Rømø Bight, southeastern North Sea

The Wadden Sea is a transition area between land, rivers, and the North Sea. It is of great ecological importance for a wide range of fish species that use it in the course of their life cycle for various purposes. It is a highly dynamic environment and is subject to strong seasonal patterns and annual variations in abiotic conditions. The Sylt-Rømø Bight (SRB) is a semi-enclosed tidal basin in the northern Wadden Sea between the islands of Sylt (Germany) and Rømø (Denmark). Monthly monitoring data of juvenile fish taken in the SRB from 2007 to 2019 were analyzed to determine the changes in species composition in comparison to previous monitoring programs (1989–1995). The long-term trends, common patterns, and potential effects of environmental parameters (sea surface temperature (SST), salinity, chlorophyll a, and the North Atlantic Oscillation (NAO) winter indices) were determined. In total, 55 species were recorded and only 22 of these together accounted for more than 95% of the total abundance for the entire monitoring. Results showed a changed species composition as we did not find two boreal, one Lusitanian, and one circum-temperate species recorded in the previous programs. Instead, one boreal, six Lusitanian, and one Atlantic species were observed for the first time. The fish community was dominated by high seasonal fluctuations of abundance with either dome-shaped, increasing, or decreasing trends. Dynamic Factor Analysis (DFA) partitioned the fish community into three seasonal assemblages based on SST preferences. Redundancy Analysis (RDA) revealed that environmental parameters explained 29 % of the variations in the fish community. These variances were partly a result of the spring immigration of Lusitanian species and the emigration of boreal species and vice versa in autumn. The absence of four previously reported species and the addition of eight new species support the hypothesis that warm-adapted species are increasing in the Wadden Sea. The inclusion of these seasonal variations into conservation and management practices is critical to the sustainable management of marine and coastal ecosystems covering spawning, nursery, and feeding grounds.

Analysis of Integrated Coastal Management in Cuba

Integrated coastal zone management (iczm) arises as a response to the challenges and problems faced by coastal zones around the world due to population growth, urbanization, industrialization and the exploitation of natural resources. This approach has been developed in response to the need to more effectively address coastal ecosystem management and development planning in these critical areas. However, integrated coastal zone management is a strategy that seeks to balance the protection and conservation of coastal ecosystems with the sustainable development of human activities that depend on these resources. Below is the diagnostic proposal for Cuba on its currently existing administrative-legal subsystem and related to the iczm, a useful analysis in the design of the policy for better governance of its coastal spaces. The methodology followed is the Decalogue, a tool used by the 13 member countries of the Ibero-American Network of Integrated Coastal Management (red ibermar), the key topics analyzed were: public policies, regulations, institutions, competencies, instruments, public information, resources, training. and training, education for sustainability and public participation. Keywords: Cuba, comprehensive diagnosis, coastal management, Management Decalogue.

Assessment of species diversity, biomass and carbon stock of mangrove forests on Belitung Island, Indonesia

Abstract. Henri, Farhaby AM, Supratman O, Adi W, Febrianto S. 2023. Assessment of species diversity, biomass and carbon stock of mangrove forests on Belitung Island, Indonesia. Biodiversitas 24: 6761-6769. Mangroves are highly productive ecosystems that provide important ecosystem services for people and nature, including climate change mitigation. This study analyzed species diversity, biomass value, and estimated carbon stocks in mangrove forest ecosystems on Belitung Island, Indonesia. The data collection method is carried out by creating a linear plot consisting of several circular subplots. Data analysis was carried out to determine the frequency, density, important value index, biomass (above-ground and below-ground biomass), and carbon content. The results of research on mangrove ecosystems on Belitung Island obtained ten species of mangroves dominated by Rhizophora apiculata Blume found in all research sites. The density of mangroves in the four locations (>1,500 trees/ha) is very dense. In contrast, the location in Juru Seberang (1,349 trees/ha) is categorized as moderate because it is the location of previous reforestation. Rhizophora apiculata has an important value index at the tree (161.24%) and sapling (149.24%) levels. Mangroves on Belitung Island have a total biomass value (225.08 t ha-1), estimated carbon content (112.54 t C ha-1), and carbon dioxide (CO2) absorption of 413.02 t CO2 ha-1. Sustainable coastal ecosystem management can significantly reduce carbon emissions from the land use sector and maintain ecosystem services in these coastal habitats, considering Belitung Island as one of the archipelago areas.

Compound extreme inundation risk of coastal wetlands caused by climate change and anthropogenic activities in the Yellow River Delta, China

The coastal wetlands of the Yellow River Delta (YRD) in China are crucial for their valuable resources, environmental significance, and economic contributions. However, these wetlands are also vulnerable to the dual threats of climate change and human disturbances. Despite substantial attention to the historical shifts in YRD's coastal wetlands, uncertainties remain regarding their future trajectory in the face of compound risks from climate change and anthropogenic activities. Based on a range of remote sensing data sources, this study undertakes a comprehensive investigation into the evolution of YRD's coastal wetlands between 2000 and 2020. Subsequently, the potential fate of coastal wetlands is thoroughly analyzed through the Land Use/Cover Change (LUCC) simulation using System Dynamic-Future Land Use Simulation (SD-FLUS) model and the extreme water levels projection integrated future sea-level rise, storm surge, and astronomical high tide in 2030, 2050, and 2100 under scenarios of SSP1-2.6, SSP2-4.5, and SSP5-8.5. Results revealed that YRD's coastal wetlands underwent a marked reduction, shrinking by 1688.72 km2 from 2000 to 2020. This decline was mostly attributed to the substantial expansion in the areas of artificial wetlands (increasing by 823.78 km2), construction land (increasing by 767.71 km2), and shallow water (increasing by 274.58 km2). Looking ahead to 2030–2100, the fate of coastal wetlands appears to diverge based on different scenarios. Under the SSP1-2.6 scenario, the area of coastal wetland is projected to experience considerable growth. In contrast, the SSP5-8.5 scenario anticipates a notable decrease in coastal wetlands. Relative to the inundated area suffered from the current extreme water levels, the study projects a decrease of 6.8%–10.6% in submerged coastal wetlands by 2030 and 9.4%–18.2% by 2050 across all scenarios. In 2100, these percentages are projected to decrease by 0.4 % (SSP2-4.5) and 27.1% (SSP5-8.5), but increase by 35.7% (SSP1-2.6). Results suggest that coastal wetlands in the YRD will face a serious compound risk from climate change and intensified human activities in the future, with climate change being the dominant factor. More efficient and forward-looking measures must be implemented to prioritize the conservation and management of coastal wetland ecosystems to address the challenges, especially those posed by climate change.

Sea otter recovery buffers century-scale declines in California kelp forests

The status of kelp forests and their vulnerability to climate change are of global significance. As the foundation for productive and extensive ecosystems, understanding long-term kelp forest trends is critical to coastal ecosystem management, climate resiliency, and restoration programs. In this study, we curate historical US government kelp canopy inventories, develop methods to compare them with contemporary surveys, and use a machine learning framework to evaluate and rank the drivers of change for California kelp forests over the last century. Historical surveys documented Macrocystis and Nereocystis kelp forests covered approximately 120.4 km2 in 1910–1912, which is only slightly above surveys in 2014–2016 (112.0 km2). These statewide comparisons, however, mask dramatic regional changes with increases in Central California (+57.6%, +19.7 km2) and losses along the Northern (-63.0%, -8.1 km2), and Southern (-52.1%, -18.3 km2) mainland coastlines. Random Forest models rank sea otter (Enhydra lutris nereis) population density as the primary driver of kelp changes, with benthic substrate, extreme heat, and high annual variation in primary productivity also significant. This century-scale perspective identifies dramatically different outcomes for California’s kelp forests, providing a blueprint for nature-based solutions that enhance coastal resilience to climate change.

“Green Finance towards Achieving SDG14 – An Overview of the Challenges & Opportunities in the Context of Bangladesh”

Green Finance, alternatively Sustainable Finance, is one of the fastest growing economic sectors in the world now a day. This paper provides an outline of green financing status of Bangladesh, endows with a portrayal on the different sources of green finance available in Bangladesh, provides an insight into the green finance landscape in the country in general and represents the challenges and prospective for greening growth of Bangladesh towards achieving SDG14. Greening the economy involves improving environmental quality and combating climate change which poses political, economic and financial challenges. Major challenges are about financing climate protection and climate change adaptation and how we can fill the funding gap. The goal of SDG 14 is to prevent and reduce ocean pollution, promote sustainable management and protection of marine and coastal ecosystems. Green finance faces many challenges as such in achieving SDGs created a huge financial gap in Bangladesh. This requires the mobilization and use of a variety of financial sources, including domestic revenue, development assistance, private sector investment, and public-private partnerships. The global economic downturn, violent conflict in some countries, biodiversity loss, water, dry land, forest degradation, and climate change pose challenges to peace and prosperity. Due to lack of capacities of banks and financial institutions, the lack of a proper understanding of the risks and returns of green projects, and the underdeveloped equity and bond markets decelerating the expected growth of green projects in Bangladesh. Lack of coordination among the respective agencies, poor financial governance, and the absence of a national policy oversight body and mainstreaming green finance toward SDG14 are some of the key policy issues that Bangladesh needs to address and to promote green financing to achieve sustainable development goals (i.e. SDG14) for reinstallation of coastal and marine ecosystem.

Impact of wildfire ash on bacterioplankton abundance and community composition in a coastal embayment (Ría de Vigo, NW Spain)

Wildfire ash can have an impact on coastal prokaryotic plankton. To understand the extent to which community composition and abundance of coastal prokaryotes are affected by ash, two ash addition experiments were performed. Ash from a massive wildfire that took place in the Ría de Vigo watershed in October 2017 was added to natural surface water samples collected in the middle sector of the ría during the summer of 2019 and winter of 2020, and incubated for 72 h, under natural water temperature and irradiance conditions. Plankton responses were assessed through chlorophyll a and bacterial abundance measurements. Prokaryotic DNA was analyzed using 16S rRNA gene partial sequencing. In summer, when nutrient concentrations were low in the ría, the addition of ash led to an increase in phytoplankton and bacterial abundance, increasing the proportions of Alteromonadales, Flavobacteriales, and the potentially pathogenic Vibrio, among other taxa. After the winter runoff events, nutrient concentrations in the Ría de Vigo were high, and only minor changes in bacterial abundance were detected. Our findings suggest that the compounds associated with wildfire ash can alter the composition of bacterioplanktonic communities, which is relevant information for the management of coastal ecosystems in fire-prone areas.

Geophysical Assessment of Coastal Erosion in Nigeria's Coastal Regions: Strategies for Protection and Management

The main purpose of this geophysical assessment was to learn as much as possible about how coastal erosion happens in Nigeria's coastal areas. The end goal was to come up with effective and efficient ways to manage and protect these areas. The research employed a variety of geophysical methodologies, such as GPR, electrical resistivity tomography (ERT), and bathymetric surveys, to collect essential data. GPR was utilized to examine the properties of soil and sediment beneath the surface. This investigation unveiled regions where soil cohesion was diminished, rendering them vulnerable to erosion. The organization ERT conducted a comprehensive analysis to determine the scope of saltwater intrusion and the dynamics of groundwater, with a specific focus on identifying areas susceptible to erosion. Bathymetric surveys were conducted to evaluate alterations in submerged topography and shoreline morphology over time, thereby elucidating patterns of shoreline regression. The assessments yielded significant insights into the vulnerabilities of coastal erosion, revealing distinct correlations among soil characteristics, saltwater intrusion, and shoreline alterations. The findings above provide a basis for the formulation of specific strategies to preserve and oversee Nigeria's susceptible coastal areas, thereby fostering the sustainable management of coastal ecosystems and ensuring the protection of coastal communities.

Delineating expert mangrove stakeholder perceptions and attitudes towards mangrove management in Sri Lanka using Q methodology

Effective decision-making is key to the successful conservation and management of natural resources. Mangrove ecosystems all over the world provide an array of ecosystem goods and services and are managed by a wide range of stakeholders representing various sectors. The position of mangroves in the land-sea interface and the rapid development of coastal areas in the Global South make mangrove conservation and management more challenging than the management of other coastal ecosystems. Sri Lankan mangroves are degrading due to numerous natural and anthropogenic causes in recent years. Mangrove degradation in Sri Lanka is further exacerbated by the economic crisis following the COVID-19 pandemic. The coastal communities near mangroves in Sri Lanka heavily depend on mangrove goods and services (more than before, due to a lack of livelihood alternatives), despite formal “no entry” rules by the government. This study’s objectives are to delineate the viewpoints of mangrove management experts to understand current mangrove management in Sri Lanka and to provide baseline data for effective decision-making. We used Q methodology, during which 71 mangrove experts representing 21 stakeholder groups were asked to individually rank statements regarding mangrove management. These rankings were subsequently clustered using Principal Component Analysis, allowing the identification of clusters of opinions regarding mangrove management. Stakeholder’s perceptions were clustered into three discourses: community-oriented management, government-oriented management, and management in synergy between government and communities for effective mangrove conservation. Our findings emphasize the multifaceted nature of mangrove management in Sri Lanka, revealing diverse perspectives among stakeholders. Our results further highlight the need for a collaborative approach to the co-management of mangroves in Sri Lanka. We recommend that mangroves be co-managed by the government and local communities ensuring environmental sustainability in Sri Lanka and beyond.

The spatial and seasonal variability of nutrient status in the seaward rivers of China shaped by the human activities

Understanding the riverine nutrient status is of paramount importance to the management of coastal ecosystems. This study investigated the spatial and seasonal variability of nutrient status in the seaward rivers of China at a national scale, using the latest observational data (2020–2023). A total of 126 rivers were considered, covering nearly all rivers in China that enter adjacent seas. The average flux of total nitrogen (TN) to the sea amounts to about 8968 tons d-1, while the total phosphorus (TP) and ammonium (AN) flux are about 329 tons d-1 and 276 tons d-1, respectively. In general, the river nutrient fluxes are higher in summer, with the Southern China (SC) showing higher levels than the Northern China (NC). This pattern is largely regulated by the spatio-temporal characteristics of runoff. By contrast, the spatio-temporal pattern of riverine nutrient concentration differs from it slightly. Riverine TN/TP concentration typically shows higher levels in NC, peaking in winter/summer, while the spatio-temporal variations of AN are minimal. The coal-fired heating prevalent in NC during winter causes severe atmospheric nitrogen pollutions, contributing to the heightened TN concentration in local rivers. At the meantime, the vast cropland in NC creates a substantial demand for the phosphorus fertilizer, responsible for the elevated TP concentration in northern rivers. The seasonal variation of TP concentration is mainly driven by rainfall, which exacerbates the loss of phosphorus from croplands into nearby rivers, leading to a simultaneous increase in riverine TP and turbidity levels during summer. This process is particularly pronounced in NC, due to elevated phosphorus levels in croplands and more concentrated summer rainfall. The present study suggests the crucial role of human activities in shaping the riverine nutrient status in China, which will be of practical significance for the future environmental management.

Bacterial community driven nitrogen cycling in coastal sediments of intertidal transition zone

Microorganisms inhabiting in coastal sediments significantly affect the nitrogen cycling in coastal waters and ecosystems. However, the bacterial community that related to the key active nitrogen transformation processes in intertidal transition zone are still not understood. Across a long flat intertidal zone at depths from 0 to 3 m in Daya Bay, China, the bacterial communities in sediments and their driven nitrogen cycling potential were evaluated with environmental factors and 16S rRNA sequencing. The results showed that the intertidal zone is a divide for environmental factors as pH, salinity and C/N ratio, instead of an average shift from freshwater to salt water. At the same time, the environmental factors influenced the abundance of bacterial community related to nitrogen cycling. Across the intertidal zone, the dominant nitrogen transformation processes were different. At the high tide and middle tide sites, the primary nitrogen cycling process was nitrification that worked with Nitrosomonadaceae, Nitrospiraceae, 0319-6A21, and wb1-A12. At the low tide sites, nitrogen fixation was the dominant function conducted by Bradyrhizobiaceae. The reduction of nitrate was carried out with the help of Xanthomonadales but relatively weak in all sampling sites especially for low tide sites. This was mostly because the richness and evenness of bacterial community were the lowest at the low tide sites. Meanwhile, the pH, Cl−, salinity, NH4+, NO3− and C/N ratio were the important factors that shaped the composition of local bacterial community. Further, the nonmetric multidimensional scaling results indicated that there were significant statistical differences in the composition of bacterial community among samples at different layers. The dominant nitrogen cycling processes in coastal sediments at different tide levels were revealed in this study, which offered an extended concept of nitrogen transformation along the groundwater discharge path in the intertidal transition zone. The distributions and compositions of bacterial communities and predicted functions provided a new insight for coastal environment and ecosystem management.

Intercomparison of marine tracer and catchment-based submarine groundwater discharge estimates for a karst aquifer

Submarine groundwater discharge (SGD) is a major source of solutes to the ocean. Consequently, the accuracy of estimates of the magnitude and seasonal variability of SGD is critical for the management of coastal marine ecosystems. However, very few intercomparison studies between different conceptual approaches have been made to assess the reliability and consistency of SGD flow estimates while simultaneously gauging the applicability of underlying models and budget assumptions in real-world scenarios. To date, intercomparison efforts have focused on homogeneous aquifers, and less so on highly heterogeneous aquifers such as karst systems. Here we compare the results of tracer-based (salt mass balance, tidal prism and radon mass balances) and catchment-based methods (water balance, semi-distributed karst network model) to assess SGD at a data-rich coastal location. All approaches tested here reveal a positive relationship between SGD fluxes and groundwater level measured close to the preferential groundwater flow pathways in the phreatic karst aquifer (e.g. water-saturated conduits or fracture network). We use this finding to derive site-specific relationships between groundwater level and SGD flow rates. We derive these relationships from least square fitting of Darcian and Non-Darcian models and regression analysis. The relationships validate the findings derived independently from hydraulic/hydrogeological modelling of the complex karst networks. By combining various estimates made with distinct assumptions, this method produces robust estimates of the SGD seasonal variability, essential to develop optimal management strategies of SGD resources in coastal karstic regions. Where direct measurements of SGD are not possible, monitoring of coastal groundwater level close to preferential phreatic groundwater pathways can be thus used as a useful indicator to compare past groundwater flow measurements and derive site-specific relationships, particularly in settings where large flow rate changes are present such as karst aquifers.

Assessing coastal bathymetry and climate change impacts on coastal ecosystems using Landsat 8 and Sentinel-2 satellite imagery

Coastal ecosystems are facing heightened risks due to human-induced climate change, including rising water levels and intensified storm events. Accurate bathymetry data is crucial for assessing the impacts of these threats. Traditional data collection methods can be cost-prohibitive. This study investigates the feasibility of using freely accessible Landsat and Sentinel satellite imagery to estimate bathymetry and its correlation with hydrographic chart soundings in Port Klang, Malaysia. Through analysis of the blue and green spectral bands from the Landsat 8 and Sentinel 2 datasets, a bathymetry map of Port Klang's seabed is generated. The precision of this derived bathymetry is evaluated using statistical metrics like Root Mean Square Error (RMSE) and the coefficient of determination. The results reveal a strong statistical connection (R2 = 0.9411) and correlation (R2 = 0.7958) between bathymetry data derived from hydrographic chart soundings and satellite imagery. This research not only advances our understanding of employing Landsat imagery for bathymetry assessment but also underscores the significance of such assessments in the context of climate change's impact on coastal ecosystems. The primary goal of this research is to contribute to the comprehension of Landsat imagery's utility in bathymetry evaluation, with the potential to enhance safety protocols in seaport terminals and provide valuable insights for decision-making concerning the management of coastal ecosystems amidst climate-related challenges. The findings of this research have practical implications for a wide range of stakeholders involved in coastal management, environmental protection, climate adaptation and disaster preparedness.

Identification of seagrass beds using high-resolution satellite imagery to basic inventory data supporting coastal ecosystem management (Case study: Lancang Island)

Seagrass habitat is an important element of the coastal marine ecosystem, as it influences all major fields in the coastal environments. Due to anthropogenic and natural pressure, such identification of habitat distribution becomes crucial. Remote sensing can provide the best solution regarding time and cost to extract seagrass beds’ spatial and temporal information. When the low spatial resolution satellite image provides low accuracy and high uncertainty of seagrass distribution, we assess the high spatial resolution image product, the WorldView-2 image, to identify the seagrass bed distribution in Lancang Island. We confidently found that higher resolution images could leverage the mapping quality, especially on the seagrass beds, which could be highly sensitive to miss-detection. We can produce 83,75% overall accuracy using pixel-based classification; this is better among other low-resolution images for Instants, Landsat, and Sentinel. Our results suggest that the WorldView-2 image could perform better on seagrass beds identification, yet further improvement on more robust classification methods and algorithms could amplify the mapping and monitoring strategy. Based on this, it can be used as basic data to support future coastal ecosystem management on Lancang Island.

Evaluation and analysis of coastal complex ecological resilience based on multidimensional data: A case study of East China Sea

Coastal areas are characterized by frequent interactions among natural, social, and economic factors. However, intensive development has degraded coastal ecosystems. To effectively implement environmental protection measures, it is crucial to have a comprehensive understanding of the current state of these systems. Resilience, which represents the capacity of an ecosystem for sustainable development, plays a significant role in this regard. Here, we focus on the East China Sea coastal zone and establish an evaluation system to quantitatively assess the resilience of the coastal complex ecosystem using multi-source data. We analyze the spatiotemporal evolution and characteristics of coastal resilience from 2005 to 2020 and investigate the factors that influenced the spatial differentiation of resilience along the coast. We found that over the 16-year period, the resilience of the coastal complex ecosystem in the East China Sea fluctuated with a downward trend, and had notable spatial heterogeneity and a substantial sea-land gradient. Factors related to human activities have increasingly contributed to the spatial differentiation of resilience in the complex ecosystem. Our findings provide valuable support and guidance for the protection, restoration, sustainable utilization, and management of coastal complex ecosystems.