Marine Mangroves Research Articles

A global assessment of mangrove soil organic carbon sources and implications for blue carbon credit.

Mangroves can retain both autochthonous and allochthonous marine and/or terrestrial organic carbon (OC) in sediments. Accurate quantification of these OC sources is essential for the proper allocation of blue C credits. Here, we conduct a global-scale analysis of sediments autochthonous and allochthonous OC contributions in estuarine and marine mangroves using stable isotopes. Globally, mangrove-derived autochthonous OC was the main contributor to estuarine and marine mangrove top-meter soil organic carbon (SOC) (49% and 62%, respectively). Less marine allochthonous OC (21%) was deposited than terrestrial allochthonous OC (30%) in estuarine mangrove sediments. Estuarine mangroves accumulated more SOC in sediments than marine mangroves (282 ± 8.1 Mg C ha-1 and 250 ± 5.0 Mg C ha-1, respectively), primarily due to the additional terrestrial OC inputs. Globally, marine mangroves held 67% of the total mangrove SOC, reaching 3025 ± 345 Tg C, while 1502 ± 154 Tg C was stored in estuarine mangrove sediments. The findings emphasize the substantial influence of coastal environmental settings on OC contributions, underlining the necessity of accurate OC source quantification for the effective allocation of blue carbon credits.

Bacterial Communities across Multiple Ecological Niches (Water, Sediment, Plastic, and Snail Gut) in Mangrove Habitats.

Microbial composition across substrates in mangroves, particularly in the Middle East, remains unclear. This study characterized bacterial communities in sediment, water, Terebralia palustris snail guts, and plastic associated with Avicennia marina mangrove forests in two coastal lagoons in the Sea of Oman using 16S rDNA gene MiSeq sequencing. The genus Vibrio dominated all substrates except water. In the gut of snails, Vibrio is composed of 80-99% of all bacterial genera. The water samples showed a different pattern, with the genus Sunxiuqinia being dominant in both Sawadi (50.80%) and Qurum (49.29%) lagoons. There were significant differences in bacterial communities on different substrata, in particular plastic. Snail guts harbored the highest number of unique Operational Taxonomic Units (OTUs) in both lagoons, accounting for 30.97% OTUs in Sawadi and 28.91% OTUs in Qurum, compared to other substrates. Plastic in the polluted Sawadi lagoon with low salinity harbored distinct genera such as Vibrio, Aestuariibacter, Zunongwangia, and Jeotgalibacillus, which were absent in the Qurum lagoon with higher salinity and lower pollution. Sawadi lagoon exhibited higher species diversity in sediment and plastic substrates, while Qurum lagoon demonstrated lower species diversity. The principal component analysis (PCA) indicates that environmental factors such as salinity, pH, and nutrient levels significantly influence bacterial community composition across substrates. Variations in organic matter and potential anthropogenic influences, particularly from plastics, further shape bacterial communities. This study highlights the complex microbial communities in mangrove ecosystems, emphasizing the importance of considering multiple substrates in mangrove microbial ecology studies. The understanding of microbial dynamics and anthropogenic impacts is crucial for shaping effective conservation and management strategies in mangrove ecosystems, particularly in the face of environmental changes.

USG matrix analysis and power interest to improve community environmental awareness: A case study of mangrove land cover to support community and environmental education

This study employed a mixed-method approach to analyze the composition of mangrove forests. The transect method and remote sensing through supervised classification using Google Earth Engine (GEE) were utilized to assess changes in mangrove areas in 2017, 2019, and 2021. The findings suggest that this study should be included in population and environmental education courses. The results revealed that Avicennia marina mangroves had the highest importance index (INP) values at three different locations. Between 2017 and 2019, mangrove areas decreased from 30.62 hectares to 27.98 hectares. However, from 2019 to 2021, the mangrove area increased from 27.98 hectares to 29.18 hectares, largely due to reforestation efforts in the Pulau Dua Nature Reserve. The NDVI (Normalized Difference Vegetation Index) values indicated "bushy" criteria, ranging from 0.43 to 1.00. The Normalized Difference Mangrove Index (NDMI) values fell into the "Rare" (-1.00 to 0.32) and "Medium" (0.33 to 0.43) categories. The Urgency, Seriousness, and Growth (USG) matrix analysis and Power Interest assessment identified illegal logging, erosion, and waste as significant causes of mangrove decline. Stakeholders, including village chiefs, religious leaders, traditional leaders, and youth leaders, must focus on preserving the mangrove ecosystem in the CAPD. The study's results are vital for educational purposes, particularly in population and environmental education courses. These courses should address environmental issues, prevention strategies, and conservation activities, which can be integrated into the curriculum. This will enable youth to contribute effectively to environmental awareness programs.

Effect of Giving Api-Api (Avicennia marina ) Mangrove Leaf Solution In Artificial Feed On The Immunity Response and Growth of Vannamei Shrimp (Litopenaeus vannamei)

The purpose of this study was .to determine the effect of giving Avicennia marina mangrove leaf solution on artificial feed to increase the immune response and growth of vannamei shrimp. The parameters observed in this study were the enhancement of PA value (Phagocytosis Activity), ADG (Average Daily Growth), FCR (Feed Conversion Ratio), and EPP (Efficiency of Feed Utilization). The vannamei shrimp used was PL-20 fry with the weight of 1,09 – 1,13 gâ‹…head-1 and density 1 shrimp L-1. The method used in this study was an experimental method in the laboratory, with a completely randomized design (CRD) with 4 treatments and 3 replications. This research was conducted by adding Avicennia marina mangrove leaf solution to the feed, with treatments of A (control), B (125 "°), C (175 "°), and D (225 "°). The addition of Avicennia marina leaf solution to the feed had a significant effect on the increase of phagocytosis activity and growth of the shrimp with F count of 30,773 which was higher than the F table of 4,06. Moreover, the best dose obtained in treatment D which resulted in an increase in PA was 61,9%, ADG was 0,22 gâ‹…day-1, FCR was 1,29, and EPP was 79,04%.

Metagenomic 16S rRNA analysis and predictive functional profiling revealed intrinsic organohalides respiration and bioremediation potential in mangrove sediment

BackgroundMangrove sediment microbes are increasingly attracting scientific attention due to their demonstrated capacity for diverse bioremediation activities, encompassing a wide range of environmental contaminants.Materials and methodsThe microbial communities of five Avicennia marina mangrove sediment samples collected from Al Rayyis White Head, Red Sea (KSA), were characterized using Illumina amplicon sequencing of the 16S rRNA genes.ResultsOur study investigated the microbial composition and potential for organohalide bioremediation in five mangrove sediments from the Red Sea. While Proteobacteria dominated four microbiomes, Bacteroidetes dominated the fifth. Given the environmental concerns surrounding organohalides, their bioremediation is crucial. Encouragingly, we identified phylogenetically diverse organohalide-respiring bacteria (OHRB) across all samples, including Dehalogenimonas, Dehalococcoides, Anaeromyxobacter, Desulfuromonas, Geobacter, Desulfomonile, Desulfovibrio, Shewanella and Desulfitobacterium. These bacteria are known for their ability to dechlorinate organohalides through reductive dehalogenation. PICRUSt analysis further supported this potential, predicting the presence of functional biomarkers for organohalide respiration (OHR), including reductive dehalogenases targeting tetrachloroethene (PCE) and 3-chloro-4-hydroxyphenylacetate in most sediments. Enrichment cultures studies confirmed this prediction, demonstrating PCE dechlorination by the resident microbial community. PICRUSt also revealed a dominance of anaerobic metabolic processes, suggesting the microbiome’s adaptation to the oxygen-limited environment of the sediments.ConclusionThis study provided insights into the bacterial community composition of five mangrove sediments from the Red Sea. Notably, diverse OHRB were detected across all samples, which possess the metabolic potential for organohalide bioremediation through reductive dehalogenation pathways. Furthermore, PICRUSt analysis predicted the presence of functional biomarkers for OHR in most sediments, suggesting potential intrinsic OHR activity by the enclosed microbial community.

Analysis of Mangrove Leaf Litter Decomposition Rate in Mangrove Ecosystem of Muara Pagatan, South Kalimantan

Mangroves are the dominant ecosystem in coastal areas and estuaries and one of the most productive ecosystems in the world. Mangroves are an essential component in a complex food chain and have the potential for the life of various marine and terrestrial biotas, microorganisms, and macroorganisms. The decomposition of mangrove leaf litter by fungal bacteria produces nutrient source that is beneficial for fish, shrimps, and crabs. This study discusses the production and decomposition rate of mangrove leaf litter in the mangrove ecosystem of Muara Pagatan, South Kalimantan. With transect and litter trap methods, litter production during the observation ranged from 218.51 - 858.28 g/m2/45day. Of the four types of mangroves found, the highest litter production was found in Rhizophora mucronata mangrove species at 858.28 g/m2/45day, followed by Bruguiera gymnorrhiza species at 268.52 g/m2/45day, and the lowest litter production was Avicennia marina mangrove species at 222.9 g/m2/45day and Sonneratia alba at 218.51 g/m2/45day. The remaining dry weight during observation ranged from 1.06 g - 2.46 g. In sum, the highest litter productivition and decomposition rate was found in Rhizophora species and litter was not completely decomposed after 45 days.

Overview of Environmental Conditions from Land Use Changes in Pesisir Selatan

Land use planning is the use of land for certain purposes. One issue that may arise during land planning is whether the land is appropriate or suitable for a particular purpose. For local governments, it is very important to know the income potential that exists through land use planning. One of the benefits of writing this article is to get an overview of environmental conditions and the efforts of the Pesisir Selatan Regency government in environmental management. With the increase in population, quality of life, and community welfare, land is needed to meet various needs and facilities. However, the amount of land is relatively fixed, which causes problems in land use in rural and urban areas. This study investigates the conditions of Land Use, Land Conversion, and Potential in Pesisir Selatan Regency. This research produces several conclusions, namely 1) Land in Pesisir Selatan Regency is very suitable for plantation cultivation because of its condition; and 2) Pesisir Selatan Regency has a lot of potential for mining, coastal and marine cultivation, mangroves, and coral reefs.

Synthesis of Zinc Oxide Nanoparticles From Aqueous Extract of Avicennia marina Mangrove Leaves and Their Antibacterial Activities Against Oral Pathogens.

Introduction The field of nanotechnology is currently being extensively researched. Nanoparticles (NPs) are used in many fields, such as engineering and medicine, owing to their nanoscale dimensions. Zinc (Zn) appears to be the most desirable metal NP, as it is being applied in various drug delivery systems and other fields. The green synthesis of the NPs used in this study makes it affordable and nonpolluting. Avicennia marina leaves possess antimicrobial properties and a high secondary metabolite content. This study aimed to synthesize ZnO NPs from the aqueous extracts of A. marina mangrove leaves and assess their antibacterial activities against oral pathogens. Methodology The leaves of A. marina were dried to obtain a preprocessed powder, and from that, an aqueous extract was prepared. ZnO NPs were then synthesized by adding the aqueous extract to 100 mL of ZnS solution and mixing it in an orbital shaker. They were observed both visually and by ultraviolet (UV) spectrophotometry to confirm their synthesis. The antibacterial properties of these ZnO NPs were assayed using the disc diffusion method on three different oral bacterial strains (Streptococcus mutans, Staphylococcus aureus,and Klebsiella sp.). Results For the synthesis process, it was seen that zinc oxide (ZnO) NPs exhibited a deepening in coloration. Additionally, the UV spectrum analysis revealed a notable absorbance value of 1.2 at a wavelength of 320 nm. The antibacterial efficacy against S. mutans, S. aureus, and Klebsiella sp. was assessed by measuring the zone of inhibition in diameter. At a dosage of 100 µg/mL of ZnO NPs, the inhibition zones were found to be 7.5 ± 0.2, 9.5 ± 0.5, and 9.5 ± 1.2 mm for S. mutans, S. aureus, and Klebsiella sp., respectively. Similarly, at a concentration of 75 µg/mL, the inhibition zones were measured to be 7 ± 0.25, 9 ± 1, and 7.5 ± 0.5 mm for the respective bacterial strains. Conclusions This study synthesizes ZnO NPs using A. marina leaf aqueous extract in a sustainable and eco-friendly manner. The ZnO NPs' antibacterial activities against oral infections indicate their use in dental products. These NPs have promising potential for nanomedicine and oral health studies due to their antibacterial properties and ecologically sustainable manufacturing.

Deciphering the probiotic properties and safety assessment of a novel multi-stress-tolerant aromatic yeast Pichia kudriavzevii HJ2 from marine mangroves

With the increasing demand for diversified health, the characteristic probiotics species resources need to be expanded. Here, a novel marine multi-stress-tolerant aromatic yeast Pichia kudriavzevii HJ2 was identified from marine mangrove. Based on the characterization of probiotic properties in vivo and in vitro, the yeast could assimilate multiple carbon sources, and generate volatile flavor metabolites, achieved a 79.98% cholesterol removal rate with efficient in vivo survival and adhesion capabilities, and showed a strong antioxidant capacity. HJ2 also released hydrolase and fermented dietary fiber to yield SCFAs, contributing to disease prevention and treatment. Then, the safety was assessed according to phenotype and whole genome-sequencing analysis. No virulence genes or ARGs were annotated in the HJ2 genome. A few biogenic amines (BA)-related genes were observed, but the production of various BA and total BA were far below the food-defined thresholds. HJ2 did not produce virulence enzymes such as DNase, phospholipase, gelatinase, or coagulase, and exhibited sensitivity to amphotericin B and anidulafungin without β-hemolysis. An in vivo acute toxicity test conducted on mice demonstrated that HJ2 is safe. In conclusion, HJ2 could be considered safe and be further used as a potential probiotic candidate for further clinical trials.

Aboveground carbon stock of marine mangroves in Kepulauan Seribu Islands

Mangroves, as one of the important blue carbon ecosystems, store large amounts of organic carbon. In the last decades, carbon stock assessment in mangrove ecosystems has been increased intensely following international agreements targeted at reducing global carbon emission. Many studies have investigated carbon stock potential in mangrove ecosystems, however, little is known about carbon stocks of mangroves growing in carbonate setting in small islands. These marine mangroves usually receive little or no terrestrial input, thus may have limited nutrient availability to support their growth. Meanwhile, their contribution to a global carbon inventory cannot be neglected. Here, we assessed biomass carbon stock of marine mangroves in Kepulauan Seribu, Jakarta, by using published allometric equations. Data collection was conducted in seven small islands; Burung Island, Kongsi Island, Pari Island, Lancang Besar Island, Lancang Kecil Island, Pramuka Island, and Rambut Island. The total average aboveground carbon stock was 46.68 Mg C ha−1, with Rhizopora sp. as the dominant species. The highest carbon stock was measured in Pari Island (72.1 ± 30.4 C ha−1), followed by Lancang Kecil Island (62.4 ± 38.6 Mg C ha−1), Kongsi Island (54.1 ± 27.0 Mg C ha−1), Rambut Island (52.1 ± 21.6 Mg C ha-1), Burung Island (47.9 ± 21.0 Mg C ha−1), Lancang Besar Island (31.3 ± 13.8 Mg C ha−1), and the lowest was in Pramuka Island (6.8 ± 4.8 Mg C ha-1). Mangrove aboveground carbon in these islands were comparable to those in other areas. Having thousands of small islands, Indonesia thus has a significant contribution to global climate change mitigation.

Analysis of The Heavy Metal Content of Copper (Cu) in The Sediments and Leaves of The Avicennia marina Mangrove in The Wonorejo Mangrove Ecotourism Area, Surabaya

Mangrove plants have the ability to accumulate heavy metals and help reduce the concentration level of pollutants in water. Sediment and leaves of Avicennia marina have the potential to be indicators of the heavy metal copper content in an area. The aim of this research is to determine the content of the heavy metal copper in soil sediments and leaves of the Avicennia marina mangrove in the Jagir River and Avur River in the Wonorejo Mangrove Ecotourism Area. The research method used is a descriptive method with a field survey. Sampling was calculated starting from the Jagir River flow in the Wonorejo Mangrove Ecotourism area (points A1, A2, A3) and the Avur River flow in the Wonorejo Mangrove Ecotourism area (points B1, B2, B3). Analysis of heavy metals in samples using Atomic Absorption Spectrophotometry (AAS). The test results showed that the highest content of the heavy metal copper (Cu) in the sediment and leaves of Avicennia marina Jagir River were 21.05 ppm and 16.10 ppm respectively. The highest content of the heavy metal copper (Cu) in the sediment and leaves of Avicennia marina in the Avur River in the Wonorejo Mangrove Ecotourism Area, Surabaya is 20.50 ppm and 17.10 ppm. The correlation coefficient for sediment and leaves of Avicennia marina in the Jagir River is 0.822 and in the Avur River is 0.829. The correlation between sediment and Avicennia marina leaves is positive with a very strong correlation.

Mangrove carbon budgets suggest the estimation of net production and carbon burial by quantifying litterfall

Soil carbon burial is the major process enabling mangroves to function as carbon sinks. However, the amount of deposited materials derived from allochthonous or autochthonous inputs in the soil carbon pool of mangroves remains uncertain. Mangrove-derived carbon burial is often laboriously estimated by monitoring the production and decomposition. In this study, ten carbon budgets covering different habitat features were constructed in situ for two mangrove species (Kandelia obovata and Avicennia marina) with distinct root structures. The mangrove-derived carbon burial rate was 0.25–1.55 Mg C ha−1 yr−1 for K. obovata and 0.36–1.00 Mg C ha−1 yr−1 for A. marina. Combined with other studies, there were positive and linear correlations between the carbon burial rate and litterfall production for the two mangroves, which suggests that the carbon burial rate for K. obovata and A. marina can be estimated using 14.8 % and 10.9 % of the litterfall production rate, respectively. The results of dbRDA with DistLM models further showed that wind speed and precipitation were the main factors affecting carbon burial in K. obovata and A. marina mangroves.

THE CONCEPT OF SUSTAINABLE DEVELOPMENT WITH THE MANGROVE AVICENNIA MARINA AS A REDUCTOR OF WAVE ENERGY

Coastal building construction is considered risky of abrasion by sea waves. One alternative that can be used as an effort to prevent abrasion is to take advantage of pneumatophore and litter of the Avicennia marina mangrove. The purpose of this study was to determine the effectiveness of Avicennia marina pneumatophore and litter for attenuating sea waves. The applied research methods were Transect-squared, Spot-check, and Sondani methods. The measurement of wave data employed SBE 26Plus and RBRDuo T.D. They were carried out at 5 stations with thicknesses of 3 m, 5 m, 10 m, 20 m, and 50 m respectively. The obtained raw data was then processed and the largest value of pneumatophore was produced at STA 1. The mangrove was able to attenuate the energy as much as 50% with the ratio of pneumatophore + litter + other factors = 14,93% + 16,44% + 18,63%. At STA 2, the attenuated energy was 54% with a ratio of 10,36% + 7,08% + 36,55%. At STA 3, the attenuated energy was 83% with a ratio of 5,43% + 2,29% + 75,28%. At STA 4, 91% of the energy was attenuated with a ratio of 4,22% + 1,05% + 85,73%. The farthest mangrove, at STA 5, attenuated the energy as much as 92%, with a ratio of 3,90% + 0,48% + 87,62%. It is safe to infer that the suppression of wave energy by pneumatophore and litter on the coast has the greatest effectiveness as the pneumatophore releases optimal bending power and the litter bears the smallest porosity value, while such other factors as large trees, core trees, seedlings, piles, sedimentation, and twigs dominate are more dominant as the mangrove thickness increases.

Sulfur metabolism in subtropical marine mangrove sediments fundamentally differs from other habitats as revealed by SMDB

Shotgun metagenome sequencing provides the opportunity to recover underexplored rare populations and identify difficult-to-elucidate biochemical pathways. However, information on sulfur genes, including their sequences, is scattered in public databases. Here, we introduce SMDB (https://smdb.gxu.edu.cn/)—a manually curated database of sulfur genes based on an in-depth review of the scientific literature and orthology database. The SMDB contained a total of 175 genes and covered 11 sulfur metabolism processes with 395,737 representative sequences affiliated with 110 phyla and 2340 genera of bacteria/archaea. The SMDB was applied to characterize the sulfur cycle from five habitats and compared the microbial diversity of mangrove sediments with that of other habitats. The structure and composition of microorganism communities and sulfur genes were significantly different among the five habitats. Our results show that microorganism alpha diversity in mangrove sediments was significantly higher than in other habitats. Genes involved in dissimilatory sulfate reduction were abundant in subtropical marine mangroves and deep-sea sediments. The neutral community model results showed that microbial dispersal was higher in the marine mangrove ecosystem than in others habitats. The Flavilitoribacter of sulfur-metabolizing microorganism becomes a reliable biomarker in the five habitats. SMDB will assist researchers to analyze genes of sulfur cycle from the metagenomic efficiently.

Benthic nitrate removal capacity in marine mangroves of Guadeloupe, Lesser Antilles.

Mangrove sediments are known to be potentially active reducing zones for nitrogen removal. The goal of this work was to investigate the potential for nitrate reduction in marine mangrove sediments along a canal impacted by anthropogenic activity (Guadeloupe, Lesser Antilles). To this end, the effect of nitrate concentration, organic carbon load, and hydraulic retention time was assessed as factors affecting these nitrate reduction rates. Nitrate reduction potential was determined using flow-through reactors in marine mangrove sediments collected along "The Canal des Rotours" in Guadeloupe. Potential nitrate reduction rates, in the presence of indigenous organic carbon, generally increased upon increasing nitrate supply from around 120nmol cm-3 h-1 (low nitrate) up to 378nmol cm-3 h-1 (high nitrate). The potential for nitrate reduction increased significantly with the addition of mangrove leaves, whereas the addition of simple, easily degradable carbon (acetate) resulted in an almost fivefold increase in nitrate reduction rates (up to 748nmol cm-3 h-1 ). The hydraulic retention time also had an impact on the nitrate reducing capacity due to an increased contact time between nitrate and the benthic microbial community. Marine mangrove sediments have a high potential to mitigate nitrogen pollution, mainly governed by the presence of large amounts of degradable carbon in the form of litter. The mangrove sediments from this Caribbean island, currently exposed to a small tidal effect, could increase their nitrate elimination capacities due to prolonged water retention via engineering.

Bioconcentration of Lead at Avicennia Marina in Mangunharjo, Semarang Coastal Area

This study aims to determine the bioconcentration of heavy metal Lead Pb in seawater, sediment, and mangrove plants of Avicennia marina and to determine the bioconcentration factor of heavy metal Lead Pb in mangrove which was conducted in January 2022 in Mangunharjo coastal area. The method used in this research was a survey method with quantitative analysis. The samples of A. marina mangroves were divided into three categories of stem diameter, namely small (3 – 8 cm), medium (6 – 15 cm), and large (11 – 23 cm). Measurement of heavy metal concentrations using AAS (Atomic Absroption Spectrophotometry). Heavy metal bioconsentration in Mangunharjo is classified as high exceeding quality standards. The study revealed that the concentration of heavy metal Lead Pb in the seawater ranged from 0.672 - 0.867 mg/L, in sediments it ranged from 56.50 – 65.96 mg/kg, and in the roots and leaves of mangroves A. marina ranged from 6.209 – 24,883 mg/kg. The bioconcentration factor of heavy metal Lead Pb ranges from 0.185 to 0.227, so that the mangrove A. marina in Mangunharjo Water Area can be classified as an excluder species.

Phytochemical profile and toxicity of extracts from the leaf of Avicennia marina (Forssk.) Vierh. collected in mangrove areas affected by port activities

• The toxicity of A. marina leaves was evaluated in ethyl acetate extract and methanol extract. • Ethyl acetate extract of A. marina which had potential toxicity, was analyzed for the phytochemical profile and total phenol. • Phytochemical profile were analyzed using preliminary phytochemical and GC–MS analysis which revealed presence major compounds, including fatty acids, phenols, terpenes, alkaloids, alcohols, hydrocarbons. • The first record of phytochemical and toxicity profiles of A. marina leaves collected from mangrove areas affected by port activity waste. Mangrove leaves are natural materials with various sources of toxic bioactive compounds that can be developed for the pharmaceutical field. Avicennia marina mangrove vegetation on the coast of South Sumatra is dense, and its location is unique because it is close to port activity waste. Environmental influences at the site are thought to have an impact on the diversity of bioactive compounds. The study was conducted to analyze the phytochemical profile of A. marina leaf extract using GC–MS analysis and its potential toxicity through Brine Shrimp Lethality Assay. Samples were taken from mangrove vegetation near Tanjung Api-Api Port, South Sumatra. Furthermore, the sample was conducted toxicity test on brine shrimp, total phenol analysis, preliminary phytochemical test, and GC–MS analysis. Based on the results of toxicity tests, the value of LC 50 ethyl acetate extract amounted to 454 μg/mL, and methanol extract amounted to 740 μg/mL. Furthermore, ethyl acetate extract contained 1.3205 mg GAE/g total phenol, and phytochemical test results contained saponins, flavonoids and steroids. GC–MS analysis detected major compounds, including groups of fatty acids, phenols, terpenes, alkaloids, alcohols, hydrocarbons and minor compounds of cannabinoids and amines. Ethyl acetate extract of A. marina leaves produced a structure of bioactive compounds that had been reported to have potential as anticancer, antimicrobial, anti-inflammatory, anti-insecticide and antioxidant. The results of this study were expected to provide important information in finding sources of bioactive compounds, taking into account the more real influence of extrinsic environments.

Bioaccumulation of Heavy Metals Pollutants in Pichavaram Mangrove Ecosystem, Southeast Coast of India

Studies on contaminant bioaccumulation in tropical mangrove ecosystems are very limited. An attempt has been made to assess sources of primary productivity and chemical bioaccumulation behavior in true and associated mangrove plants, water, and sediments from the Pichavaram Mangrove Ecosystem. The water, sediment, and plant materials were collected at 7 different locations and the samples were analyzed to determine the concentration of heavy metals using a flame atomic absorption spectrophotometer. The result reviles that the maximum lead concentrations of 5.48 ppm/g were accumulated in sediment samples collected from shrimp pond effluent and 4.26 ppm/l from water during post-monsoon. The maximum Zinc concentration of 12.34 ppm/g was observed in sediment samples collected from degraded mangrove forests during post-monsoon and 10.99 ppm/g was observed in sediment samples during the summer season. Higher heavy metals concentration was observed during spring and summer this may be due to increased biological activities, land runoff and rainfall during these seasons. The maximum Copper concentration 9.07 ppm/g was observed in sediment at degraded mangrove forest during post-monsoon and 8.16 ppm/g was observed in sediment during the summer season. Heavy metals concentrations in different parts of A. marina mangrove plants were analyzed. In leaf sample, Pb 5.44 ppm/g in shrimp pond effluent site, Cd 4.97 ppm/g in degraded site, Zn 4.43 ppm/g in degrading site, Cr 2.17 ppm/g in Freshwater zone at Vellar, Hg 1.68 ppm/g in shrimp pond effluent site, Cu 0.86 ppm/g in Freshwater zone at Upannar was recorded. In stem sample Pb 6.89 ppm/g and Zn 5.67 ppm/g in the degraded site, Cd 5.27 ppm/g in the natural site, Hg 4.91 ppm/g in degrading, Cr 2.49 ppm/g and Cu 0.87 ppm/g in Freshwater zone at Upannar was recorded. In Avicennia roots, Cr 10.89 ppm/g in shrimp pond effluent, Pb 10.17 ppm/g in natural site, Cd 6.89 ppm/g in freshwater zone at Vellar, Zn 6.86 ppm/g in degrading mangrove site, Hg 5.48 ppm/g in degraded site, Cu 0.92 ppm/g in backwater mouth was recorded. Heavy metals contamination was observed in almost all the samples in higher concentrations. The results indicate that Avicennia marina have a greater potential to observe and accumulate higher concentration than associated mangroves. A. marina plant can be used for phytoremediation to remove the heavy metals from the mangrove ecosystem and will help for ecological studies, conservation and sustainable management of the mangrove habitats.

Effects of polysaccharide-based silver and selenium nanoparticles on growth performance, biochemical parameters, and immune response of Cyprinus carpio

Avicennia marina mangrove leaves polysaccharide (AMLP) was used for the synthesis of polysaccharide-based selenium (AMLP-SeNPs) and silver nanoparticles (AMLP-AgNPs). The synthesized nanoparticles were further characterized by UV-Vis, DLS, FT-IR, X-ray diffraction, and HR-TEM analysis. A 60-day (8 weeks) feeding trial experiment was conducted to investigate the effects of AMLP, AMLP-SeNPs, and AMLP-AgNPs dietary supplementation on growth performance parameters, blood parameters, immunological and enzymatic profiles in Cyprinus carpio. The characterization results of AMLP-SeNPs and AMLP-AgNPs confirmed the formation of well-stabilized spherical nanoparticles with a mean particle size of 37.25 and 72.40 nm, respectively having a crystalline structure. The feeding experiment results demonstrated that 2 mg/kg of AMLP-SeNPs followed by 0.2 mg/kg of AMLP-AgNPs showed significantly (p ˂ 0.05) higher final weight, weight gain (WG), specific growth rate (SGR%), protein and lipid efficiency, and lower food conversion ratio as compared to other groups. The catalase, superoxidase dismutase, and glutathione peroxidase activity were significantly (p ˂ 0.05) higher in the group fed 2 mg/kg supplemented AMLP-SeNPs. Total protein and globulin contents were significantly (p ˂ 0.05) higher and albumin concentration was significantly lower in fish that received 2 mg/kg of AMLP- SeNPs as compared to control. A significant increase in serum HDL and decrease in LDL and MDA concentrations were observed in the group supplemented with 2 mg/kg of nano selenium. The body's crude lipid, protein, moisture, and ash were not significantly different from the control. The AMLP-SeNPs showed significantly (p ˂ 0.05) lower aspartate aminotransferase (AST), alanine aminotransferase (ALT), and higher alkaline phosphatase (ALP) activities compared to other test groups. The relative percentage survivability (RPS%) was higher in AMLP-SeNPs (84.6%) followed by AMLP-AgNPs (76.7%) after 8th weeks of supplementary diets as compared to control groups. Overall, the finding of these studies revealed that the inclusion of AMLP-SeNPs improved the growth performance and antioxidant defense system, enhance immune response, and provide resistance against Aeromonas hydrophila in Common carp.

Community structure of benthic macroinvertebrates in native and introduced mangroves of northern Beibu Gulf, China: Implication for restoring mangrove ecosystems

Introduced mangroves are widely used to restore mangrove ecosystems in South China. Results of potential impacts on indicative benthic macroinvertebrates are divergent. We explored the community structure of benthic macroinvertebrates in the mangrove ecosystem of northern Beibu Gulf, China across four habitats: native Avicennia marina mangrove, introduced Laguncularia racemosa mangrove, native-introduced mixed mangrove, and unvegetated intertidal flat. Based on the Hill number, community structure was estimated from the dimensions of estimated species richness, diversity, evenness, and species composition similarity. Benthic macroinvertebrates in the unvegetated flat significantly differed from the other three assemblages in mangroves; introduced L. racemosa mangrove had relatively distinct benthic macroinvertebrate assemblage from the native A. marina and the mixed mangroves, with lower species richness and similarity but higher diversity and evenness. Considering the lack of unanimous conclusion of potential impact on benthic macroinvertebrates under complex species interactions, native mangroves should be of top priority in ecosystem restoration.