Journal of Coastal Conservation最新文献

In this piece of work, we provide comments on the paper: “Solar system planetary alignment triggers tides and earthquakes” by Awadh (2021). The paper claimed to undertake quantitative statistical analysis of earthquakes and planetary alignment across the world and, particularly, in the Zagros Region. As a result of his statistical analysis, he claimed that the alignment of the Earth with two planets in a straight line would generate earthquakes. However, after a careful review of the paper, we found that the analysis was qualitative in its major part. It is suffering from a lack of clarity for planetary alignment data and methods, in addition to a deficiency in earthquake data. We found that the major two tables (i.e., Tables 2 and 5) used by Awadh (2021) to demonstrate the relationship and the planetary alignment were not accurate. Our work demonstrates the problems of relying on inadequate and inappropriate datasets of Awadh’s (2021) paper.

The Sagar is the largest inhabited island in the Ganges delta in India. In the recent decades the island experiences severe stress and coastal instability due to multiple setbacks such as high erosion, degradation of coastal vegetation, frequent cyclones, dynamic changes in land features and rapid population growth. This study aims in assessing the spatial dynamics of the land features of the island during the past 45 years from 1972 to 2017 as two scenarios i) Short-term and ii) Long-term to evaluate the impacts on its coastline. The extended aim of the study was to predict the status of the land features in the island for the next two decades, ie 2027 and 2037 using CA–MARKOV model. The study indicated continuous loss of land to sea and depletion of coastal features such as mangroves, mudflats and sand dunes in both the scenarios. In view of the continuous erosion of the island’s coast, protective embankments have been constructed to protect life and property. The study indicated damage of embankments due to erosion over time. Analysis of recent changes indicated that strengthening the existing embankments together with restoration of natural systems such as mangroves would minimize erosion though it may not serve as an ultimate solution to combat erosion. Based on the population density living in close proximity to such eroding coasts along with its prevailing protection measures, the study classified such stretches as hotspots of category I, II and III.

Abstract

Globally, mangroves have been promoted to protect the coastal ecosystems and human settlements against weather vagaries including climate change impacts. However, climate change can also affect the mangrove ecosystems, affecting their ability to mitigate losses and damages caused by climate change. Recognizing the need to understand the impact of climate change on the ability of mangroves to mitigate loss and damage, this paper presents the impact of climate change on mangrove ecosystems in Dat Mui commune, Ngoc Hien district, Ca Mau province, Vietnam by using community-based methods. Results showed that the most noticeable impact of climate change is the loss in mangrove area, aquatic resources, and coastal erosion prevention. In addition, there is a decline in timber, firewood supply, and habitat of mangrove species. Despite adaptation actions taken by the local authorities and households, mangrove ecosystems are is still facing loss and damage. Solutions have been proposed to help the local and national authorities and communities to address losses and damages caused by the climate change.

Abstract

This study presents a bioeconomic model of prey-predator interactions incorporating the presence of refuges for prey species to mitigate predation. The main objective is to assess the impact of prey refuges on prey biomass, predator biomass, catches, fishing effort, and profits for fishermen exploiting these marine species. The model analyzes system positivity and boundedness, examines equilibrium points and their stability, and conducts numerical simulations by varying the refuge availability parameter (m) to interpret the effects on fishing effort, catches, and profits across different scenarios. The findings shed light on the dynamics of the ecosystem and highlight the importance of refuge availability in sustainable fisheries management, supporting the conservation of marine resources and the well-being of fishermen.

This study delves into the nutraceutical potential of microalgae in brackishwater aquaculture, with a focus on a case study conducted in the Muttukadu estuary, Tamil Nadu, India. The research involved the collection, identification, culture standardization, nutrient profiling, antioxidant and antibacterial properties of seven microalgal species in the brackishwater ecosystem, including Thalassiosira weissflogii, Chaetoceros gracilis, Nannochloropsis oculata, Chlorella marina, Tetraselmis sp, Isochrysis galbana and Arthrospira maxima. The growth kinetics analysis highlighted N. oculata and C. marina with an extended log phase and significantly higher growth rates. Proximate analysis revealed the highest protein content (62.46 ± 3.45%) in A. maxima. I. galbana showed significantly higher lipid content (33.08 ± 2.18%), while T. weissflogii had 20.11 ± 1.02%. Fatty acid profiling identified the highest percentage of polyunsaturated fatty acids (69.51%) in A. maxima, followed by Tetraselmis sp (56.32%). Methanolic extracts from C. marina and T. weissflogii displayed notably higher total phenolic content. A. maxima exhibited the highest total antioxidant activity, and C-Phycocyanin (CPC) extracts showed the highest inhibition zones against pathogenic bacteria. This study underscored the diversity of commercially important microalgal species in the tropical estuarine brackishwater ecosystem. The nutrient composition analysis emphasized the abundance of essential macronutrients, micronutrients, vitamins, and bioactive compounds. These findings contribute to understanding microalgae's nutraceutical potential in brackishwater aquaculture, suggesting their suitability for large-scale cultivation and utilization in aquaculture and other food-producing industries. Moreover, the bioactive compounds present in these microalgae offer opportunities for developing novel nutraceutical formulations with potential health benefits.

The objective of this study is to develop a global terrain and altitude map by combining a digital twin model and deep learning technique on Florida's coastal area. Utilizing USGS data, we are able to represent diverse landforms while ensuring the accuracy of elevation changes. In order to mitigate projection distortions, we rescaled 5000 map segments worldwide, ensuring that key geographical features are included. We segment the terrain into seven distinct classes: Water, Grassland, Forest, Hills, Desert, Mountain, and Tundra. The map features are enhanced by median filtering and each class is color-coded. Random parameters were introduced in overlapping image sets in order to ensure variety and prevent redundancy. On these seven terrain classes, the U-Net network is used to perform segmentation tasks. In order to monitor the performance of the model, we implemented cross-validation. The model's effectiveness is demonstrated by robust ROC curve analysis and high AUC values, which indicate accurate terrain categorization. Using deep learning methods and satellite imagery from Google Earth, the primary objective is to develop a digital twin of Florida's coastline. The digital twin serves as both a physical and simulation model, accurately resembling real-world locations. In addition to the achievement of detailed terrain mapping, this approach is likely to have significant applications in environmental monitoring and urban planning as well. In terms of reliability and performance, the digital twin model is expected to be a significant advancement in the field of geographical information systems.

Abstract

Muaragembong is a Citarum River estuarine ecosystem that has a lowland coast, a delta environment, tidal mudflats, and mangroves along the coast. Muaragembong has recently experienced severe coastal erosion in the last decade due to mainly rapid land cover changes in coastal areas, generating sediment imbalances and diminishing coastal resistance to wave action. In this study, the combination of multispectral bands from Landsat images and GIS approaches supported by ground observation was used to determine satellite-based coastline and land cover changes from 1990 to 2020. With a maximum rate of 132.55 m/year, Desa Pantai Bahagia is the most vulnerable area to coastal erosion. Meanwhile, coastal accretion has occurred at Desa Harapanjaya on a constant basis, with a peak accretion rate of 52.13 m/year. The combined extents of eroded and accreted shorelines along the coast of Muaragembong are approximately − 1,707.09 and + 512.14 hectares, respectively. Since the 1980s, the extensive clearance of mangroves for shrimp and fish ponds, along with the decreased sediment input into the estuary due to dam construction, are likely to have had a significant impact on coastal erosion in Muaragembong. Since current measures are insufficient to deal with ongoing coastal erosion, a comprehensive approach and long-term solutions are required for sustainable coastal zone management. This study provides a detailed analysis of shoreline changes over the last three decades and their impact on land cover change, enabling conservation practitioners to allocate their resources more wisely and efficiently to the most critical and prioritized coastal conservation regions.

This work presents an engaging hands-on activity designed to teach school students about nature based solutions (NBS) and their role in achieving high-quality water systems within a sustainable circular economy. Through this activity, students actively participate in building a small constructed wetland (CW) and test its effectiveness under various contamination scenarios. The activity was tested with school teachers, undergoing refinements based on their feedback. This iterative development process has ensured the activity’s effectiveness in engaging both school students and the public. Further, the CW model can be scaled-up for specific school projects focused on improving water quality. This activity offers valuable opportunities to enhance ocean literacy, promote understanding on NBS and raise awareness about aquatic ecosystems contamination and the importance of environmental sustainability.

Deltas are areas where the land and ocean interact in a variety of ways and are an element of the coastal environment. These ecosystems possess unique biological diversity and has been attracting human settlements for centuries. However, deltaic regions are prone to recurring hazards. Soil and water in these regions are always under threat due to cyclonic storms and backwater flow in rivers and creeks. The quality of the soil and water in these regions has a major impact on agricultural output. Kultali block of South 24 parganas district in the state of West Bengal is the part of Sundarbans delta and agricultural activities in the area was difficult due to non-availability of the freshwater and salinity of soil and groundwater during non-monsoon season. Different farm structures were introduced for better management of water for agriculture in this region. A study was undertaken in Kultali block to assess the spatial variations in soil and groundwater salinity after introduction of those farm structures and suggesting the land and water utilization plan for better agricultural production. Observation wells at different locations and depths were installed for monitoring the groundwater in the area. The salinity of the soil and groundwater was monitored for evaluating seasonal change in soil and groundwater quality. The result of the study indicated that pre-monsoon soil and groundwater salinity was more than the post monsoon period. Groundwater salinity was increasing with the depth. Also, the areas near to the river and the creek showed higher salinity level than the rest of the plots in the study area. Soil and groundwater salinity and its spatial and temporal variation maps will be useful for planning agricultural activities in the area.

Abstract

Political attention for and research on nature-based solutions in coastal flood an erosion risk management has increased significantly in recent years. Literature suggests that there remains a historical inertia towards nature-based solutions due to the continued predominance of classical grey infrastructures like dikes and stone revetments. In this regard, Schleswig–Holstein can act as a living laboratory as it has a long tradition of applying grey and green infrastructures as well as nature-based measures like salt marsh enhancement techniques to protect against coastal flooding and erosion. Based on an assessment of structural and non-structural coastal flood and erosion risk management measures in Schleswig–Holstein, this paper elaborates on the prospects of grey and green infrastructures in the context of stronger sea level rise.

This article concludes that nature-bases solutions for coastal flood and erosion risk management are not a recent development. Nature-based management of green infrastructures can significantly improve their functionality, also with regard to the expected stronger SLR, and includes non-structural measures like codes and prohibitions. Green infrastructures and their nature-based management successfully complement and support grey infrastructures i.e., as green as possible, as grey as necessary. However, with the exception of dunes as natural flood defenses, green infrastructures cannot render grey infrastructures superfluous.