Mangrove Structure Research Articles

Assessment of mangrove structures and biomass on islands along the Java Sea: a case study on Bawean Islands and Karimunjawa Islands

Mangroves on the islands along the Java Sea play a crucial role in supporting biodiversity, protecting coastlines, and sequestering carbon. However, there is a lack of information on mangrove structure and biomass in the area. This study aimed to assess the mangrove structures and biomass on Desa Daun, located on the Bawean Islands, and Kemujan Island, located on the Karimunjawa Islands, respectively. The study utilized a combination of line transect and quadrant plot methods with a size plot of 10x10 m. We established 7 line transects and 28 quadrant plots in the mangrove forest of Desa Daun and similarly set up 7 line transects and 21 quadrant plots on Kemujan Island. Within each quadrant, the mangrove species were identified, and their diameters at breast height (DBH) were recorded. To assess the relative significance of each species, the importance value index (IVI) was calculated, and allometric equations were applied to estimate biomass and carbon storage in the trees. PlanetScope imagery was also used to quantify the carbon stock of mangroves on those islands. In Desa Daun, 13 mangrove species were identified, while 12 species were recorded on Kemujan Island. The species Nypa fruticans and Excoecaria agallocha exhibited the highest IVI in Desa Daun and Kemujan Island, respectively. Notably, Rhizophora apiculata demonstrated the greatest biomass in both locations, with measurements of 43.08 Mg B/ha in Desa Daun and 102.22 Mg B/ha in Kemujan Island. Overall, mangrove stands on Desa Daun stored biomass of 113.60 Mg B/ha and carbon of 50.98 Mg C/ha, whereas mangrove stands on Kemujan Island stored biomass of 295.04 Mg B/ha and carbon of 131.95 Mg C/ha. Mangrove stands of the whole Bawean Islands sequestered 22,941 Mg C, while Karimunjawa Islands hold much higher C stocks, 79,451 Mg C. Despite being smaller in size, the Karimunjawa Islands have more extensive mangrove coverage compared to the Bawean Islands due to their geomorphological characteristics, which in turn influence their mangrove structures and carbon stocks. However, the loss of mangroves in the Karimunjawa Islands due to aquaculture expansions could increase carbon loss in the islands.

Dendrometrical Structure and Physicochemical Analysis of Mangrove Sediments from the Nyong River Estuary (Cameroon, Atlantic Coast)

Mangrove estuaries are not immune to the threats posed by climate and anthropogenic constraints on aquatic environments. In the Nyong River estuary, mangrove ecotone has capital importance for biodiversity conservation due to its localization in the Douala-Edéa protected area. For this study, seven quadrats were delimited in aim to evaluate mangrove structure and assessed his interplay with sediment and water physicochemical characteristics. The study revealed a total of 120 individuals of 4 regularly encountered species over a distance of 14 km: <i>Rhizophora racemosa, Avicennia germinans, Rhizophora harrisonii </i>and <i>Phoenix reclinata</i> palms. The marshy soils under the mangrove have Total Nitrogen percentages varying between 0.04 and 0.68%. Total Organic Carbon (from 2.20 to 8.61%) and Total Organic Matter (from 3.66 to 14.64%) contents have a similar pattern. The ratios of Carbon and Nitrogen (C/N) reflect the presence of organic matter and plant debris over a large proportion of the estuary. The ratio of Nitrogen and Phosphate (N/P) reflects the low availability of nitrogen in relation to phosphorus. The cation elements evolve on average in the order Ca<sup>2+</sup> ˃Mg<sup>2+</sup> ˃Na<sup>+</sup> ˃K<sup>+</sup>. This study provides information that would help explore linkages for future research on biogeochemical balance in mangrove sediment and their implementation.

Mangroves as Coastal Protection for Restoring Low-Energy Waterfront Property

Mangroves offer vital ecological advantages including air and water filtration, coastal and estuarine habitat provision, sediment stabilization, and wave energy dissipation. Their intricate root systems play a key role in safeguarding shorelines from tsunamis and erosive storms by dissipating wave energy. Moreover, mangroves shield against boat wakes and wind-waves, thus naturally bolstering shoreline defense. Wave dissipation is a function of forest width, tree diameter, and forest density. Restoration efforts of juvenile mangroves in Florida’s Indian River Lagoon (IRL) aim to reduce wave energy in areas vulnerable to erosion. Physical model testing of wave dissipation through mangroves is limited due to the complexity in representing the mangrove structure, where prop roots are non-uniform in both diameter and location. Previous studies have quantified wave-dissipating effects through the use of scaled and parameterized mangrove structures. This study measures the dissipation effects of live mangroves in a wave flume, forced by conditions representative of the IRL. These measurements are used to validate a parameterized dowel model. Error between wave attenuation factors for the live mangrove and dowel system was on average 2.5%. Validation of the modularized dowel system allowed for further parameterized testing to understand forest structure effects, such as sediment stabilization and wave attenuation. Maximum wave attenuation achieved in this study was 27–35% corresponding to a 40–60% reduction in wave energy depending on the configuration of the system. The wave reduction resulted in a 50–70% decrease in sediment erosion from the berm. The dowel tests indicate a target minimum thickness for mangrove root systems of 0.6 m for shoreline stabilization and restoration in the IRL.

Analysis Of The Mangrove Structure In The Dong Rui Commune Based On Multispectral Unmanned Aerial Vehicle Image Data

Mangroves are one of the most important types of wetlands in coastal areas and perform many different functions. Assessing the structure and function of mangroves is a premise for the management, monitoring and development of this most diverse and vulnerable ecosystem. In this study, the unmanned aerial vehicle (UAV) Phantom 4 Multispectral was used to analyse the structure of a mangrove forest area of approximately 50 hectares in Dong Rui commune, Tien Yen district, Quang Ninh Province – one of the most diverse wetland ecosystems in northern Vietnam. Based on the visual classification method combined with the results of field taxonomic sampling, a mangrove tree classification map was established for UAV with three species, Bruguiera gymnorrhiza, Rhizophora stylosa, and Kandelia obovata, achieving an overall accuracy = 86.28%, corresponding to a Kappa coefficient =0.84. From the images obtained from the UAV, we estimated and developed maps and assessed the difference in tree height and four vegetation indices, including the normalized difference vegetation index (NDVI), green normalized difference vegetation index (GNDVI), enhanced vegetation index (EVI), and green chlorophyll index (GCI), for three mangrove plant species in the flying area. Bruguiera gymnorrhiza and Rhizophora stylosa reach an average height of 4 to 5 m and are distributed mainly in high tide areas. Meanwhile, Kandelia obovata has a lower height (ranging from 2 to 4 m), distributed in low-tide areas, near frequent flows. This study confirms the superiority of UAV with red edge and near-infrared wave bands in classifying and studying mangrove structures in small-scale areas.

Identification of mangrove damage and mangrove ecosystem management efforts in Ekasoghi Tourism, Saronggi District, Sumenep Regency

The Saronggi District area, Tanjung Village has experienced changes in the structure of mangroves which resulted in a decrease in the number of mangroves due to mangrove tourism, lack of awareness of the importance of mangroves, and damage due to human activities. The purpose of this study is to find the causes of mangrove damage and formulate policies in the management of mangrove ecosystems in the Ekagoghi tourist area. This research was conducted with visual observation (descriptive narrative) and SWOT analysis to consider management policy strategies. The types of mangroves found on the coast of Ekasoghi in Sumenep Regency consist of species Osbornia octodonta, Sonneratia alba, Avicennia marina, Rhizophora mucronata, Lumnitzera racemosa, and Rhizopora apiculata which have been damaged by natural factors and human actions. The causes of mangrove damage include high beach abrasion so that beach erosion occurs and causes a reduction in nutrients and seaweed cultivation which causes damage to mangrove trees due to the charts used. Policies that need to be carried out for the management of mangrove ecosystems on Ekasoghi Beach, namely by holding wanamina cultivation (silvofishery) and the implementation of an ecopreneurship system, can be considered to develop policies directed to explore profit potential and maintain the sustainability of the existence of preserving mangrove ecosystems. This policy certainly needs to be supported by strengthening community institutions and cooperation between government institutions.

Mangrove Tree Community Structure And Community Participation Of Mangroves In Ciletuh-Palabuhan Ratu Geopark, Sukabumi

The Cikadal mangrove forest area is part of the Ciletuh-Palabuhanratu Geopark in Mandrajaya Village. The area of ​​this mangrove forest is 5 ha and has been reforested. The purpose of this research is to describe the community structure of mangrove plants after reforestation and the participation of the community in the Ciletuh-Palabuhanratu Geopark. Mangrove structure data collected using PCQ (Point Centered Quarter Method) as well as a questionnaire for community knowledge and participation in managing mangroves. The results showed that there were two types of mangroves in this area, namely Avicinnea officinalis and Rhizophora apiculata. The results of the Important Value Index with the highest score being 182.7, Rhizophora apiculata while for Avicinnea officinalis was 117.3. Knowledge of local communities about mangroves and their conservation and local community participation is in the medium-high category.

Blue Carbon in Mangroves of the Arid Zones of San Ignacio and El Dátil Lagoons, El Vizcaino Biosphere Reserve, Baja California, Mexico

Estimation of carbon (C) stocks revealed a very high carbon sequestration potential of mangroves, which play a major role in the global C cycle. The C stored in the biomass of live trees can be estimated from above- and below-ground measurements, i.e., tree diameter and height, leaf litter, root biomass, necromass, and soil. The allocation of biomass and C in the scrub mangrove forest is influenced by various factors, including low structural development. The objective of this study was to estimate the carbon stock (in relation to biomass) and storage in the soil of the San Ignacio and El Dátil lagoons in an arid region of the north Pacific. Above-ground biomass (AGB) was estimated based on mangrove structure and leaf litter; below-ground biomass (BGB) was measured by extracting root cores (45 cm depth) and soil (1.2 m depth). Biomass values were converted to carbon with allometric equations. We found an inverse relationship between BGB content (roots) and above-ground structural development, with a mean total biomass (AGB + BGB) of 101.7 MgC ha−1. Below-ground carbon content (roots, necromass, and soil) was 2.8 times higher than above-ground carbon content (trees and litter). Control sites (devoid of vegetation) adjacent to the mangrove have recorded low carbon stocks of 7.3 MgC ha−1, which supports the recommendations for conserving and restoring degraded areas. The present study contributes valuable information on carbon related to mangrove biomass and stored in the soil of arid mangrove areas of northwestern Mexico.

Combining otolith chemistry and genetics to infer the population structure of yellow snapperLutjanus argentiventris

AbstractDeveloping a metapopulation framework contributes to the understanding of spatial processes and structures in populations, providing basic information for conservation biology. However, the extent to which the metapopulation structure differs geographically and across life history stages is unexplored for most fishes. Here, we compared the population structure and connectivity patterns of juvenile yellow snapperLutjanus argentiventrisin mangroves of the Eastern Tropical Pacific Ocean. In both the Gulf of California and Galápagos, these fish experience an array of environmental and oceanographic conditions that produce unique otolith microchemistry signatures and genetic population structures. In the Galápagos Archipelago, we used otolith microchemistry and microsatellite DNA, while for the Gulf of California, we only used otolith microchemistry. We observed relatively small differences in the otolith microchemistry at the ecoregion spatial scale (10–100 km2) for the Galápagos and the Gulf of California (classification accuracy of 57% and 64%, respectively). At the finer mangrove spatial scale (~1 km2), we found larger differences in the otolith microchemistry among the Gulf of California mangroves (classification accuracy ~90%) than in Galápagos (classification accuracy ~24%), potentially related to a stronger environmental gradient in the former. Based on otoliths, 75% of juveniles were migrants among mangroves in the Galápagos, in contrast to only around 10% of juveniles being migrants among the Gulf of California mangroves, suggesting a metapopulation structure characterized by high rates of self‐recruitment for snappers in the Gulf of California. For Galápagos, both otolith microchemistry and genetics supported the presence of a source–sink metapopulation structure for the yellow snapper, with high levels of connectivity in mangroves within the Eastern and Western ecoregions (FST = 0.003,p < 0.05). By combining tools that assess connectivity at multiple timescales (microchemistry and genetics) at different life stages and ecosystems, we provide a more complete elucidation of metapopulation structure forL. argentiventris. The approach employed here can be applied to other tropical fishes with broad distribution ranges and ontogenetic changes across complex habitats such as mangroves, seagrasses, and coral reefs.

Assessment of the changes in the structure of mangroves based on stand age in Bang La, Hai Phong, Vietnam

The mangrove forest area in Bang La (Hai Phong) is 370 ha, and tree density is 5,885 individuals/ha, distributed along the upper bank of the Van Uc River with high tidal flats. Detected 20 species of mangrove plants belonging to 19 genera, 16 families, and two divisions. The survey results show that the Bang La mangrove forest ecosystem has three forest types, the forest community is older than 15 years old, the forest community is from 10 to 15 years old, and the forest community is less than 10 years old. Kandelia obovata, Sonneratia caseolaris, and Rhizophora stylosa, is the dominant plant species. In each forest biome of different ages, there are different dominant species. The general composition formula for the study area is 47.2 Ko + 46.9 Sc + 1.8 Ks + 2.1 Ai + 2.0 Ac. The paper results showed that the more than ten years mangrove community is a stable forest biome. Mangroves from 10 years old should be planned with different species to increase the diversity in species structure and enhance the ability to stabilize the community and withstand changes in coastal habitats.

Mapping seahorses in a Brazilian estuary: mangrove structures as key predictors for distribution and habitat preference.

Planning for effective conservation demands an accurate understanding of the ecological aspects of species, particularly their distribution and habitat preferences. This is even more critical in the case of data-poor, rare, and threatened species, such as seahorses, mainly when they inhabit vulnerable ecosystems like estuaries. Given the importance of better understanding these parameters to design seahorse conservation strategies, we mapped the distribution and assessed habitat preferences of longsnout seahorses (Hippocampus reidi) in a mangrove estuary in a Brazilian protected area. Using generalised linear mixed-effects models we found that dense mangrove cover macro-habitats and shallow depths predicted seahorse sightings and higher densities. Furthermore, the selective index of micro-habitats used by seahorses showed that seahorses exhibited a preference for mangrove structures as holdfasts (i.e., fallen branches). Due to the significant importance of mangroves in providing suitable habitats for H. reidi in estuaries, it is crucial to enforce the protection of these ecosystems in conservation and management strategies for the species.

The mangrove ecosystem in a harbor-impacted city in Dumai, Indonesia: A conservation status

The city of Dumai has mangrove resources in various conditions due to the presence of industry in the area. This study aims to analyze the conservation status of the vegetation structure and to study the spatial variability and the interaction of mangrove vegetation environmental parameters on the coast of the city of Dumai. The study was conducted at ten observation stations, with the study area divided into three parts. Data were obtained by measuring line transects and establishing 10 m × 10 m sample plots, while environmental parameters were measured in situ and ex situ. The mangrove vegetation and structure were examined based on their ecological indices. The comparison between diversity indices was analyzed by analysis of variance (ANOVA). Mangrove species that were differentiated between sections were analyzed using similarity of percentage (SIMPER), and environmental factors affecting vegetation and mangrove structure were analyzed based on principal component analysis (PCA). The species identification results revealed 13 species, including Avicennia lanata, that are classified as vulnerable globally. Based on the importance value index (IVI), Rhizophora apiculata, Xylocarpus granatum, Sonneratia alba and Avicennia alba were identified as the most important species. The ecological index showed that the mangrove diversity is low (01.06–01.90) with an even distribution (00.41–01.00). The mangrove density varied from 00.79 to 570.87 individuals/ha, and the basal area ranged from 00.00–08.99 m2/ha. The maturity index showed that station VIII had a high maturity level (80.56), followed by Stations X, IX and IV (77.08, 72.22 and 53.70, respectively). Between the north and south and between the south and center, S. alba was the distinguishing species (25.19% and 15.45% dissimilarity), while in the north and central areas, R. apiculata was found to be a differentiating species (22.70% dissimilarity). The environmental condition parameters showed a strong relationship to the density and basal level of the mangrove areas.

Exploring sustainable mangrove management policy, challenges and structure: a case study of Nadi and Momi districts, Fiji Island

ABSTRACT Besides being socially and ecologically beneficial for Fiji’s human needs, mangrove management often clashes with development interests, such as tourism threatening their sustainability. To address these issues, the study analyzes mangrove management in practice, especially governance and institutional arrangements at the local level, to better understand how these arrangements function and influence mangrove resources. The study highlights the experiences of four villages within the Momi and Nadi districts, which gives us rich insight into the local-level dynamics of mangrove management within different types of arrangements over mangrove forests. A total of four types of surveys and analysis were conducted in this study including content analysis, talanoa sessions,, questionnaire surveys and an ecological survey. The study found that the existing legallframework indicated several challenges that have contributed to the poor management of mangroves over the years. This includes fragmented policy, lack of clarity on jurisdiction over mangrove resources among multiple ministries and these aspects are challenges highlighted in the study. The mangrove structure in the Nadi mangrove area changed drastically over the years, whilst in Momi, the changes are not visible, both indicated by the respondent .(Ecological survey shows that the Momi district`s mangorve forest has the highest tree densities when compared to Nadi district. The findings of this study are expected to substantially impact sustainable management strategies in addressing the environmental, social and economic impact of development on mangrove loss. The study recommends a mechanism such as PES to sustainably manage mangrove ecosystems and support policy implementation.

Community Structure and Carbon Content of Mangroves in the Tanjung Batu Sekotong Area in the Middle of West Lombok

The purpose of this research was to determine the community structure and the amount of carbon content and mangrove uptake in the Tanjung Batu Sekotong area, Central Lombok, West Lombok. This type of research is descriptive research. This research was conducted in the Tanjung Batu Sekotong area, Central Lombok, West Lombok. The variables observed were individual mangrove species, mangrove height and trunk diameter at breast height. Then the data obtained were analyzed for density, frequency, cover area, important value index, diversity index, biomass and carbon content. Collecting data on mangrove plant communities used a combined method, namely line and square transects. The research results obtained found 6 species, namely Avicennia alba, Avicennia marina, Rhizophora Apiculata, Rhizophora mucronata, Rhizophora stylosa, and Sonneratia alba. Carbon content and carbon absorption of mangroves in the Tanjung Batu Sekotong Tengah Region, West Lombok. The total carbon content of the tree category is 34.4246 tons C/ha, an average of 5.7374 tons C/ha and the sapling category with a total of 14.4312 tons C/ha, an average of 4.1232 tons C/ha. Mangrove carbon uptake in the tree category with a total of 126.3381 tons C/ha, an average of 21.0564 tons C/ha and mangrove absorption in the sapling category with a total of 52.9625 tons C/ha, an average of 8.8271 tons C/ha.

Biodiversity and Ecological Structure of Mangrove in Coastal Waters of Dafi Village, Biak Numfor Regency

Biodiversity and Ecological Structure of Mangrove in Coastal Waters of Dafi Village, Biak Numfor Regency

Carbon store dynamics in the structure of mangrove in the southern Pacific of Mexico

Mangroves are recognized as the wetlands with the most significant capacity to store carbon, this ability to store carbon is due to their high productivity and the low rates of organic matter decomposition. The study area is one of the Intensive Carbon Monitoring Sites (SMIC, initials in Spanish) in Mexico. In the southern coast of the Mexican Pacific, in the La Encrucijada Biosphere Reserve (REBIEN). The SMIC has an extension of 1x1 km. In this area there are eight conglomerates. Each conglomerate contains four circular-shaped secondary units of 400 m2. The inventory includes trees ≥ 2.5 cm of DBH (Diameter at breast height). Tree species, DBH, height, canopy diameter, the basal area and tree density. Tree biomass was quantified, and the carbon store was determined using the biomass-to-carbon conversion factor of 0.48. The carbon in standing dead trees was estimated using the methodology of Kauffman et al. (2012). The environmental parameters quantified: interstitial salinity, pH, temperature and flood level. Results R. mangle is the dominant species, conglomerate 2 presented the highest tree density and conglomerate 4 the lowest. Conglomerates 8 and 4 had the highest averages for DBH, basal area, height, and crown area, in contrast, the conglomerates 1, 5, and 2, had the lowest averages. In the study area, the fall of trees was the factor that most affected the aboveground (aerial) carbon content, which increased 6.91 and 3% respectively during the second and third year of monitoring. Natural mortality increased and affected mostly young trees 2.5 to 10 cm tall. Wood extraction remained constant during the three years of study. During the three years of study, conglomerate 6 presented the highest biomass averages with 210.4 Mgha-1 and carbon stores of 101.0 MgCha-1; in contrast, conglomerate 5 registered the lowest average with 124.9 Mgha-1 and 60.0 MgCha-1 . R. mangle presents the biggest store of carbon with 60.4 MgCha-1. This mangrove system registered an increase in natural mortality during the study period, which could be the result of the massive amounts of sediment the river has been carrying after the passage of Hurricane “Stan” in 2005.

Community Structure and Health Conditions of Mangrove in Sabu Raijua

Mangrove ecosystem has an important role for the coastal ecosystem in Sabu Raijua which is included in the TNP Laut Sawu conservation area. Its designation as a water conservation area indicates that the area is an important for the protection of fishery diversity and other marine resources. Mangroves play an important role for the diversity of marine biota because of their role as a breeding ground, foraging, and nursery ground for various types of marine biota. For this reason, the role of mangrove ecosystems as supporting conservation areas is very important. The functioning of the mangrove ecosystem can be seen based on the community structure and ecosystem quality conditions. This study aims to determine the condition of the community structure and health conditions of mangroves on Sabu Raijua Island. The survey location was obtained at 5 observation stations spread across Sabu Island. The results showed that 8 species of mangrove were identified with the dominance of Mangrove Lumnitzera racemosa with an IVI value of 191%. The percentage of canopy cover found ranged from 33 – 58% with an average value of 46%. Density ranges from 23 – 45 ind/plot, with an average of 31 ind/plot. The Mangrove Health Index (MHI) value in was 36.51 ± 14.05% which is included in the Moderate category. The high value of the standard deviation (14.05) indicates that there are still mangrove locations in Sabu Raijua that have poor conditions (Poor).

Performance Evaluation of Mangrove Species Classification Based on Multi-Source Remote Sensing Data Using Extremely Randomized Trees in Fucheng Town, Leizhou City, Guangdong Province

Mangroves are an important source of blue carbon that grow in coastal areas. The study of mangrove species distribution is the basis of carbon storage research. In this study, we explored the potential of combining optical (Gaofen-1, Sentinel-2, and Landsat-9) and fully polarized synthetic aperture radar data from different periods (Gaofen-3) to distinguish mangrove species in the Fucheng town of Leizhou, Guangdong Province. The Gaofen-1 data were fused with Sentinel-2 and Landsat-9 satellite data, respectively. The new data after fusion had both high spatial and spectral resolution. The backscattering coefficient and polarization decomposition parameters of the fully polarized SAR data which could characterize the canopy structure of mangroves were extracted. Ten different feature combinations were designed by combining the two types of data. The extremely randomized trees algorithm (ERT) was used to classify the species, and the optimal feature subset was selected by the feature selection algorithm on the basis of the ERT, and the importance of the features was sorted. Studies show the following: (1) When controlling a single variable, the higher the spatial resolution of the multi-spectral data, the higher the interspecific classification accuracy. (2) The coupled Sentinel-2 and Landsat-9 data with a 2 m resolution will have higher classification accuracy than a single data source. (3) The selected feature subset contains all types of features in the optical data and the polarization decomposition features of the SAR data from different periods: multi-spectral band > texture feature > polarization decomposition parameter > vegetation index. Among the optimized feature combinations, the classification accuracy of mangrove species was the highest, the overall classification accuracy was 90.13%, and Kappa was 0.84, indicating that multi-source and SAR data from different periods coupling could improve the discrimination of mangrove species. (4) The ERT classification algorithm is suitable for the study of mangrove species classification, and the classification accuracy of extremely random trees in this paper is higher than that of random forest (RF), K-nearest neighbor (KNN), and Bayesian (Bayes). The results can provide technical guidance and data support for mangrove species monitoring based on multi-source satellite data.

The coastal protection and blue carbon benefits of hybrid mangrove living shorelines

Hybrid living shorelines use a combination of engineered structures with natural ecosystems to achieve coastal protection and habitat restoration outcomes, with added co-benefits such as carbon sequestration. Rock fillets constructed along eroding estuarine banks are designed to accumulate sediment, establish mangroves, and stabilise the shoreline. There is, however, a lack of data to support whether rock fillets are achieving these goals. We used a chronosequence of rock fillets to determine their effect on mangrove development, bank stabilisation and carbon sequestration in four estuaries in New South Wales, Australia. Aboveground biomass and adult density increased with age of rock fillets, and mangrove structure was similar to a natural fringing mangrove after 15 years. The rock fillets accumulated sediment, which reduced the eroded estuary bank height, however, little effect of the fillets on bank slope was observed. Sediment carbon stocks were not different between rock fillets, eroding estuary banks and natural fringing mangroves. Rock fillet design had a significant effect on mangrove structure and coastal protection function, with greater wave transmission through lower rock fillets, suggesting design optimisation is needed. As the construction cost of the rock fillets was equal or less than traditional rock revetments, where suitable they present a more economic and environmentally sustainable solution to estuarine erosion management.

4D Printed Shape Memory Polyurethane-Based Composite for Bionic Cartilage Scaffolds

Repair of articular cartilage defects is a major challenge in orthopedic surgery due to the deficient self-regeneration capability. Cartilage tissue engineering scaffolds provide a promising approach to cartilage defect repair. Proper mechanical properties, interconnected internal structure, customized shape, and minimally invasive treatment are urgent requirements for a qualified cartilage scaffold. Here, a shape memory composite used for cartilage defects is prepared by adding nanohydroxyapatite into a shape memory polyurethane matrix, exhibiting good mechanical properties and biocompatibility. Based on its rheological properties, the composite melt can be printed into 4D printed structures with high precision and quality in a simple and clean way. Inspired by the structure of mangroves, a bionic 4D printed cartilage scaffold is designed and manufactured, presenting a good shape memory performance at a temperature close to body temperature. The 4D printed cartilage scaffold can expand from a conveniently insertional shape to a deployed shape to match defect, providing a novel idea for the personalized and minimally invasive treatment of cartilage defects.

Stand structure and environmental factors of mangroves of Abdasa, Gujarat, India

Marine biology,marine ecology,Phytoplankton, marine algae, zooplankton, nekton, benthos, corals and coral reefs, ecology, zoogeography and systematics, primary production and experimental work on ecosystem including energy flow at different trophic levels, population dynamics and theoretical models, recycling of matter, influence of environmental factors on metabolic activity, marine microbiology, mariculture and experimental work on propagation of cultivable species, biology of fishes, marine reptiles, sea birds and mammals, physical, chemical, geological and meteorological features of the environments related to marine biology, marine environmental damage caused by pollution and engineering works, underwater observations, conservation of living resources, modifications in methodology and techniques and development of new apparatus related to marine sciences