Journal of Coastal Conservation最新文献

Overfishing remains a global concern, however effective management from well valuation of fisheries may efficiently reduce the impact of fishing. Therefore, it is important to evaluate the biomass of Indian Mackerel fishery in order to maintain the stock. Catch-based Monte Carlo maximum sustainable yield (CMSY) method and Length-based Bayesian Biomass (LBB) methods are frequently used to evaluate fish stock. Eighteen years effort-catch and length frequency data from commercial fishing were utilize to estimate the current biomass. The calculated biological reference points from Bayesian state-space Schaefer production model (BSM) at r = 0.618, k = 68,700, maximum sustainable yield (MSY) = 10,600. However, CMSY at r = 0.662, k = 6800, MSY = 11,200. Biomass in 2021 at maximum sustainable yield 2021 (B₂₀₂₁/B_MSY) = 0.436 (< 1) and fishing rate F₂₀₂₁/F_MSY = 1.94 (> 1) values explain the Indian Mackerel fishery is at exploited state. However, results using LBB model defines as B/B_MSY = 0.65 (< 1.0) and fishing rate F/F_MSY = 3.33 (> 1.0) and mean length/optimum length (L_mean/ L_opt) obtained at 1.3 and L_95th/ L_inf at 0.95. Based on suggested prior biomass range (B/B_MSY =0.5–0.8) for stock assessment also indicates that the Indian Mackerel fishery is in unsustainable state from the study area. Monitoring of illicit fishing practices in the area is recommended. Measures need to be implemented for the protection of these valuable resources.

The habitat heterogeneity hypothesis predicts that increasing habitat structural complexity will result in greater species richness and diversity. We employed ants as a model organism to investigate the significance of coastal vegetation in sandy soils (“restinga”) in northern Brazil for the conservation of biodiversity. This investigation involved assessing the distribution patterns of ants in restingas in different areas along the coast and different vegetation types. Ants were systematically sampled across six sites in the state of Bahia (Busca Vida, Praia do Forte, Imbassaí, Baixio, Barra do Itariri and Costa Azul) and four distinct restinga habitat types (Forest, Shrub, Beach vegetation habitat, and Humid zone) using pitfall trap, Winkler sampling and entomological umbrella techniques. We assessed whether there are differences in diversity, beta diversity, and ant composition according to the different Restinga vegetation types and sites. A total of 152 ant species were collected, distributed across 43 genera and eight subfamilies. Ant richness per sample and site did not differ according to the type of vegetation. However, we observed a variation in the composition of ants according to the different types of vegetation and sites studied. We observed that regardless of the type of vegetation, the main component responsible for the variation in the composition of ant species is the turnover, that is, the substitution of species between sites. Our study points out the importance of restinga for conservation, with a habitat complexity gradient that increases from beach to inland proportional to the ant diversity, especially in forest habitats.

This study focuses on detecting and mitigating soil salinization in four coastal areas of the Mekong Delta (Vietnam). Salinity patterns in the soils of the Mekong River Delta are not random but linked to land use practices and distance to the sea. We examine two quick yet reliable remote sensing-based techniques to detect the coastal aquaculture area and separate it from the inland freshwater farmland. These techniques can eventually be used to identify locations with an elevated risk of salinization in other coastal regions. Finally, we investigate a salinization mitigation solution based on creating a managed aquifer recharge system along the buffer zone that separates the coastal aquaculture area from the inland freshwater agriculture area. The implementation of an infiltration pond system is technically feasible in the Mekong Delta provided that hydrogeological characteristics, the fresh-saline interface position, and freshwater demands are considered. The transitional zone between freshwater agriculture and brackish water aquaculture in Bac Lieu, Soc Trang, Tra Vinh and Ben Tre provinces is optimal for implementing an aquifer recharge/freshwater barrier scheme.

Historically, maritime trade has been a major driver of economic growth and cross-cultural interchange, especially in antiquity. Because of its advantageous position and extensive maritime history, the Persian Gulf has been essential in bridging cultures and promoting the exchange of ideas and products. This article explores the historical evidence of maritime trade in the Persian Gulf, emphasising its revolutionary influence on the region’s history, especially during the pivotal Bronze Age. The article also emphasises how important it is to acknowledge the Persian Gulf’s historical significance as a crucial commerce route connecting Europe, Africa, and East and West Asia. The paper uses these realisations to support the growth of Chabahar Port as a pillar of economic independence and regional collaboration. Through the application of historical lessons and the embracement of sustainable maritime trade, the Persian Gulf and the Makoran Sea have the potential to resurface as centres of cultural and economic interaction, thereby promoting global wealth and connectedness.

This paper presents the development of a Hybrid Model (HM) integrated with a Bayesian Network (BN) for comprehensive coastal vulnerability and risk assessment, with a focus on Konyaaltı Beach, Antalya, Turkey. The HM incorporates critical environmental parameters such as wind, waves, currents, and sediment transport to simulate conditions at vulnerable coastal areas and perform risk assessments for storm effects, flooding, and erosion. The model includes submodules for predicting coastal storms, quantifying sediment transport rates, assessing tsunami inundation severity, and categorizing storms based on beach typologies. The Adaptive Neuro-Fuzzy Inference System (ANFIS) is utilized for significant wave height predictions, enhancing the model's accuracy. The integration of hydrodynamic modeling, Bayesian networks, and ANFIS offers a robust framework for assessing coastal vulnerability and informing sustainable management practices. The study's results highlight the necessity for integrated risk management strategies, including adaptive infrastructure design, zoning and land use regulations, ecosystem-based management, and continuous monitoring and model refinement to enhance coastal resilience against dynamic environmental forces. This research provides valuable insights for mitigating the impacts of hazards on urban developments, contributing to the advancement of sustainable coastal management.

Mangroves are an important coastal ecosystem in the global cycle of carbon and climate change mitigation. Unfortunately, a significant loss of mangrove forests has significantly increased carbon emissions over recent years. This research aims to measure the carbon stocks and potential carbon storage of the Tuntang Estuary mangrove forest. Sixteen quadrant plots at six sites were used to collect data on above- and below-ground carbon (roots and sediment). Several published allometric formulas were used for estimating the above and below-ground (root) carbon, while the Walkley and Black method was used to analyze sediment organic carbon. This study showed that the potential of total carbon stocks in this mangrove forest was approximately 0.08 × 10⁶ (± 0.02) Mg C or equivalent to 0.29 × 10⁶ (± 0.05) Mg CO₂e. The largest average percentage of carbon stocks (62%) was stored in sediment, 24.57% in mangrove tree biomass, and 13.43% in root biomass. This study discovered that coastal abrasion has a natural effect on mangrove forests and that human activities, particularly aquacultures, also contribute to the low total stock of carbon. The ecotourism site had the highest overall stock of carbon due to the extensive conservation efforts of all stakeholders, including visitors. This study highlights the crucial role of conserving mangroves as a strategy for achieving sustainable development goals, particularly in the context of climate change mitigation.

Soil salinity influences soil quality and other essential plant nutrients, reducing productivity and soil fertility in the Hatiya Upazila (Upazila is the second lowest tier of regional administration in Bangladesh), a coastal district of Noakhali, which is the soil saline vulnerable region of Bangladesh. This study determined the area’s soil salinity level, current crop production condition, and related soil salinity level of Hatiya Upazila. This research aimed to evaluate the effect of soil salinity on soil nutrients and other soil characteristics. To conduct this study, we randomly collected 78 soil samples from the 26 villages with three replicable samples from each sampling location and nine chemical characteristics of the soil samples evaluated. We mapped the soil salinity and other soil properties using the inverse distance weighting (IDW) interpolation techniques in ArcGIS software (version 10.8) environment. Also, we used Pearson’s correlation coefficient and linear regression models to evaluate the impact of soil salinity on the chemical properties of the soil. Results show that 38% of the study area has mild salinity, while 8% of the study area is affected by moderate salinity. In addition, around 4% of the study area is affected by high salinity. The reverse relation occurs when soil salinity is high and phosphorus, total nitrogen, organic matter, and carbon levels are low. According to statistical analysis, soil salinity (EC) is closely related to Na and K (r = 0.422). Soil salinity (EC) negatively affects OM, TN, P, and OC. The pH or sulphur content (EC) had no effect on the salinity of the soil. Among OCs, OM and TN have a favourable and strong relationship among themselves. These findings will benefit many stakeholders from the public and private sectors and local leaders in taking appropriate action to decrease the impact of soil salinity on agricultural production.

Shrub encroachment in coastal wetlands leads to heterogeneous distribution of soil resources, which may affect soil particle size distribution (PSD). Fractal theory was widely used to quantify the characteristics of soil PSD. However, exploration on the spatial changes in PSD of deep soil layers due to shrub-encroached vegetation succession is limited. Multifractal theory and GIS spatial analysis tools were used to spatially quantify the changes in soil PSD at different soil layers (0–80 cm) in a coastal wetland landscape (100 × 120 m) encroached by a native shrub Tamarix chinensis in the Yellow River Delta (YRD), China. We also discussed the potential mechanisms of soil PSD changes contributed by shrub encroachment. The results showed that higher content of fine sand, medium sand and coarse sand, while lower content of silt and very fine sand in 0–10 cm were observed in T.chinensis patches than in single T. chinensis and bare land (p < 0.05). In 30–40 cm, however, T.chinensis patches have higher soil clay content (p < 0.05). The generalized dimensional spectrum and multifractal parameters indicated that soil PSD in shrub patch area exhibited greater width and higher heterogeneity. Multifractal method could explain the changes of soil PSD better than single fractal dimension (D), and the Capacity Dimension (D₀) was the most effective one to quantify the soil PSD characteristics. The values of D₀ showed a clear order of shrub patch > single shrub > bare land in each layer. In addition, the D₀ suggested that influences of T.chinensis on soil PSD can remain 70 cm below the surface in our case. Considering the complex sedimentary process in the YRD, the processes of water and wind erosion mediated by shrub encroachment, the positive feedback based on plant preferences and the mixed effects of shrub and grass species might promote the redistribution of soil particle size. Encroachment in coastal wetland of the YRD caused changes in soil PSD, especially at the surface soil layer. Multifractal parameters could quantify subtle characteristics of soil PSD in shrub-encroached area. Our work indicates that shrub encroachment in coastal wetland plays a significant role in altering regional and even global soil environments.

Defining the most suitable intervention to mitigate coastal hazards in a specific area, under an integrated coastal management strategy, is complex for several reasons including the lack of stakeholders’ consensus. In this respect, Cost-Benefit Analyses (CBAs) can help decision-makers to better understand the environmental, social and economic implications of a planned intervention. Nevertheless, CBAs are not yet largely applied in coastal management studies, as could be expected. Hence, this work aims to consolidate the use of a CBA to support coastal management decisions, considering its application to a real case study. The case study consists in evaluating the long-term impacts, benefits and costs of a detached breakwater for the protection of a coastal village located on the Portuguese northwest coast against flooding and erosion. This assessment was made based on the estimation of the costs of the structure and the benefits associated with the protection of the coastal community and natural areas, considering morphodynamics’ forecasts determined through numerical modelling. Out of several configurations defined based on length (L; in meters) and distance to the shoreline (D; in meters), four detached breakwater scenarios were selected. Results demonstrate that scenario L200D200 can be a feasible solution with overall low costs and low benefits; L300D400 can be an alternative solution with higher costs but higher benefits too. The consolidation of the CBA described is a step forward to improving the expedition of future analysis and proof of its potential in what concerns analysis at the local scale.

The encroachment of woody shrubs in grass-dominated coastal salt marsh ecosystems has potentially influenced soil physical and chemical processes at various scales. Understanding the effects of shrub encroachment on those ecosystems requires assessments of the spatial heterogeneity in soil variables across multiple scales. Combined with GIS spatial tools and sampling data, we evaluated the vertical (0–80 cm) and spatial characteristics of soil pH and soil salinity (or electrical conductivity, EC) in a coastal wetland that experienced 40 years of shrub (specifically, the Tamarix chinensis species) encroachment. In order to obtain the information of the spatial patterns and scale domains of soil pH and EC, we employed the lacunarity analysis method. Furthermore, we utilized both Mantel test and Pearson correlation to identify their relationship. The results revealed that shrub encroachment had notable impacts on the magnitude and spatial patterns of soil pH and EC. These effects were driven by specific encroaching processes. Specifically, large shrub patches (SP) resulted in a significant rise in soil pH and a noteworthy reduction in soil EC. In addition, small shrub clusters (SC) caused a notable reduction in soil EC, but did not have significant impacts on soil pH. The impacts of shrubs on soil pH were primarily observed in 0–20 cm, whereas their effects on soil EC extended to deeper soil layers (e.g., up to 60 cm). Shrub encroachment also increased the landscape heterogeneity of both soil pH and EC, with the effects being more pronounced on soil EC. The lacunarity analysis revealed that the spatial heterogeneity of soil EC differed significantly among four depths, 0–20, 20–30, 30–60, and 60–80 cm, while the heterogeneity of soil pH varied significantly between two depths of 0–60 and 60–80 cm. Furthermore, soil pH and soil EC showed a strong spatial association, with a negative relationship observed between the two variables within each soil layer. Our study at the landscape scale highlights the opposite responses of soil pH and EC in saline-alkali wetlands to shrub encroachment. By understanding the impacts of shrubs on soil properties, we can enhance our ability to effectively restore and manage these degraded ecosystems.