Pichavaram Mangrove Research Articles

Total Heterotrophic Bacterial Load in the Gut of Detritus Fishes: A Case Study of Pichavaram Mangrove Environment, Southeast Coast, India

Total heterotrophic bacterial (THB) load of detritus fin and shell fishes collected from mangrove environment were investigated. The collected fish and prawn samples were subjected to the microbiological study. The THB load was higher in milk fish (Chanos chanos) (2.24 x 105 CFU/g) followed by Indian white prawn (Fenneropenaeus indicus) (3.16 x 105 CFU/g) than the Liza parsia (1.90 x 105 CFU/g) and Penaeus monodon (1.88 x 105 CFU/g). A total of 355 bacterial strains were isolated and identified, in which 64, 57, 51, 47, 44, 42, 21, 29, 355 strains were belongs to Pseudomonas spp., Aeromonas spp., Bacillus spp., Enterobacter spp., Vibrio spp., Flavobacterium spp., Alcaligenes spp. and Acinetobacter spp., Pseudomonas spp. and Aeromonas spp., respectively. The present work showed that the Bacillus spp., were higher in the gut of fish and prawn samples studied. This work suggests that these bacteria can be effectively used as supplement in fish/prawn feed for commercial aquaculture or as probiotic to enhance the colonization in fish/prawn gut.

Growth performance of Ceriops decandra (Griff.) Ding Hou propagules as influenced by PGR – a conservation effort

Vegetative propagation could be an important advantage and also envisioned to be the best alternative for planting stock production in the absence or lack of seeds. In the Pichavaram mangrove forest Ceriops decandra (Rhizophoraceae) is one of the most endangered species and IUCN also declared this species as near threatened. Propagation of Ceriops decandra, by propagule cuttings, treated with Plant growth regulators is feasible and it was possible to produce three saplings from one propagule. The effect of plant growth regulators like IBA, NAA, GA3 on optimum growth medium and period of nursery care for mangrove saplings of Ceriops decandra were studied and the results revealed that best growth performance was recorded when the cuttings were treated with GA3 alone up to 2000 ppm. Combination of NAA and IBA increased the rooting and leaf formation. Among the treatments GA3 enhanced the number of leaves and roots, Shoot and root length, fresh and dry weight of roots increased to larger extent. All the plants are transferred to field in the mangrove forest of Pichavaram, Tamilnadu, India.ECOPRINT 22: 21-28, 2015

Spatial variability of heavy metals in estuarine, mangrove and coastal ecosystems along Parangipettai, Southeast coast of India

An elaborate survey on the contamination of heavy metals was carried out in surface sediments of different ecosystems such as Vellar-Coleroon estuarine, Pichavaram mangrove and coastal region of Parangipettai, Southeast coast of India. The study was intended since, the coal based thermal power plant and oil refinery plant are proposed to set up along this coast and aquaculture industries and dredging activities are developing. The parameters such as soil texture, pH, total organic carbon (TOC) and heavy metal (Fe, Mn, Cu, Cd, Zn and Ni) concentrations were analyzed for the surface sediments during pre and postmonsoon seasons. Among the metals analyzed, Fe and Mn were found to have dominant as the levels were recorded as 11,804 μg g−1 and 845.2 μg g−1 respectively. A significant correlation was observed between total organic carbon (TOC) and heavy metals. In the mangrove ecosystem, the levels of heavy metals found to be maximum indicating that the rich organic matter acts as an efficient binding agent for metals. The overall finding of the present study indicated that the sediments from the entire Vellar-Coleroon estuarine and Pichavaram mangrove ecosystems were found moderately polluted with cadmium metal. The result of cluster analysis indicated disparity in accumulation of heavy metals in sediments of different ecosystems due to the variations in organic matter. The heavy metals were transported from land to coastal through flood during monsoon season reflecting the variations in their levels in different ecosystems at postmonsoon season.

Geochemical variations of core sediments of Pichavaram Lagoon, southeast coast of Tamil Nadu, India: a provenance and paleoenvironmental study

The present study aims to identify the natural and anthropogenic imprints left by the accumulation of elements and to determine/identify the current level of enrichment of major oxides in the Pichavaram mangrove sediments. Pichavaram mangrove is a dynamic intertidal environment lying in between the Vellar and Coleroon estuaries in the Cauvery delta along the east coast of India. In the present study, results of texture studies reveal highly variable depositional environment in upper and lower portion of Core 1 and middle portion of Core 2. In both the cores, decrease in grain size is observed in the upper portion which may suggest that the sediments in the upper portion were deposited at low energy condition. Mn/Al, Mg/Al, Ca/Al, Ti/Al, P/Al and K/Al ratios are found to be low in the both the core samples. Ti elemental ratio is lower in both core samples indicating that Ti concentrations in marine sediments are the best indicators of lithogenous material flux to the marine environment. The concentration of various elements in the core can be summarized as Si > Al > Fe > Mn > Mg > Ca > Ti > P > K. The PIA values of Core 1 indicate that the sediments were derived from predominant weathering up to 40 cm and the remaining sediments derived from unweathered matrices. Plagioclase Index of Alteration (PIA) values of most of the downcore samples of Core 2 are found to be more than 40 suggesting the predominance of weathering activity. Low PIA values are observed at the depth of 54–70 cm indicating the moderately weathered nature of the sediments in the study area. Positive correlation between Fe and Mg and their negative relationship with silica indicates the presence of ferromagnesian debris in top of the sediments. Major oxide geochemistry indicates a heterogeneous and moderately weathered to unweathered source for the sediments of the present study area.

Phytochemical and Traditional uses on Acanthus ilicifolius (L)

Acanthus ilicifolius is a spiny herb found in mangrove of southern Thailand. It is also widely distributed in India and other tropical regions of Asia. The plant is reported to contain phytochemicals including alkaloid and wide range of glucosides (lignan and phenylethanoid). In traditional medicine, the plant is used in the treatment of diseases ranging from snake bite to skin diseases. A. ilicifolius (sea holly) occurs in tropical Asia and Africa, through Malaya to Polynesia. It is a vine shrub or tall herb, up to 1.5 m high, scarcely woody, bushy, with very dense growth. Common names of which are holy leaved acanthus, sea holly and holy mangrove. A. ilicifoliusis abundantly available in freshwater ecosystem of Pichavaram mangroves located in southeast coast of India. The review analyses traditional medicinal usage, and phytochemical investigations done on the A. ilicifoliusis medicinal plant.

Isolation, Screening and Evaluation of Antifouling Activity of Mangrove Associated Bacterium, Bacillus subtilis subsp. subtilis RG

In the present study, an attempt has been made to explore the antifouling activity of bacterial strains isolated from the root and rhizosphere soil of Pichavaram mangroves, India. Altogether, 14 different mangrove associated bacterial strains (MAB1–14) were isolated and screened for antagonistic activity against fouling bacterial strains. Screening results inferred that, five (35.71 %) out of 14 MAB isolates exhibited antagonistic activity. Among them, MAB6 showed notable growth inhibitory activity and it was identified as Bacillus subtilis subsp. subtilis through 16S rRNA gene sequencing. The crude ethyl acetate extract of B. subtilis subsp. subtilis RG strongly inhibited (8–13 mm) the growth of fouling bacterial strains. Minimum inhibitory concentration (MIC) of extract against fouling bacterial strains was ranged between 25 and 50 µg/ml; whilst minimum bactericidal concentration was ranged from 50 to 100 µg/ml, respectively. This extract has also effectively inhibited the growth of fouling microalgal strains with the MIC range of 50–100 µg/ml, respectively. Anticrustacean assay using Artemia franciscana larvae showed the LC50 value of 264.89 µg/ml. Further, the lower EC50 value (63.46 µg/ml) than the LC50 value (156.32 µg/ml) and 100 % recovery of mussel Perna indica in toxicity assay inferred the non-toxic nature of the extract.

Effect of ingestion and waterborne routes under different shrimp densities on white spot syndrome virus susceptibility in three commercially important penaeid shrimps

A study was undertaken to evaluate some factors that are important for better management of the white spot syndrome virus (WSSV). We examined the likelihood of that the mud crab (Scylla serrata) is a potential carrier of WSSV in shrimp farms and then compared susceptibility of three shrimp species to WSSV, and finally tested the effects of shrimp stocking density and transmission routes on the intensity of WSSV infection under experimental conditions. Mud crabs were collected from the crab fattening unit of Pichavaram mangroves area, southeast coast of India. The infectivity test was conducted on Penaeus monodon, P. indicus, Litopenaeus vannamei under three different shrimp densities and two different routes of infection. Each treatment was executed in triplicate of 100L tanks. The results showed that S. serrata is a carrier of WSSV. Among three species of shrimps, P. indicus was most susceptible and L. vannamei was most resistant in term of cumulative mortality. Ingestion route was more effective than waterborne route on WSSV outbreaks. Cumulative mortality of shrimps due to WSSV infection increased with increasing shrimp density. The result of this study is important to improve management especially to minimize the WSSV infection in the shrimp farms.

The natural diet of the mud crab Scylla olivacea (Herbst, 1896) in Pichavaram mangroves, India

Food and feeding habits of mud crab Scylla olivacea (Herbst, 1896) in Pichavaram mangroves was investigated quantitatively and qualitatively for a period of two years from June 2010 to May 2012. Gut contents from 1737 specimens comprising 843 males and 894 females in the size range between 45mm and 148mm were examined. Crustaceans form the predominant food item in a majority of size groups in terms of percentage wet weight and frequency of occurrence, while molluscs showed a preference in few size groups. The other dietary items includes fishes, detritus, mud and sand and miscellaneous. Gut content analysis revealed no significant variation between the quantities of food consumed by both sexes. Feeding intensity was higher in juveniles and subadults of both sexes than that of adults, revealing a greater preference to feed on fast moving prey such as crustaceans and fishes. The results of the present study indicate that S. olivacea in Pichavaram mangroves exhibited a clear preference for crustaceans.

Carapace width-weight relationship, age, growth and longevity of the mud crabScylla olivacea(Herbst, 1796) in the Pichavaram mangroves, south-east India

The present study provides novel information on carapace width-weight (CWR) relationship and growth parameters of the mud crabScylla olivacea(Herbst, 1796) inhabiting the Pichavaram mangroves, east coast of India based on length frequency data sets during June 2010 to May 2012. CWR revealed linear regression between carapace width and weight in both sexes, and overall CWR exponent (b) values acquired for males and females are 3.035 (r2= 0.962) and 2.925 (r2= 0.933) respectively. The growth parameters, CW∞,Kandtoderived for males and females were 148.05, 0.762 year−1and −0.637 and 138.80 mm, 0.856 year−1and −0.681 respectively. The growth ofS. olivaceawas assessed through various methods in such a way that the outcome of one method functions as a rider, check and control over the other.

Density of waterbirds in relation to habitats of Pichavaram mangroves, Southern India

Tropical mangroves are one of vital coastal systems which support migratory and resident waterbird species round the year. Globally the potential of mangrove habitats in relation to support waterbirds is poorly understood. We examined density of waterbirds in five different habitats: mudflats, open water, emerging mangroves, well-grown mangroves and adjacent agriculture lands of Pichavaram mangroves of southeast coast of India between the years 2004 and 2007. Among the habitats, the density of waterbirds was high in the mudflats followed by agriculture land, emerging mangroves, open water and well-grown mangroves. The work suggested on improvement of the habitats for supporting considerable density of the waterbirds.

Sediment biomarker profiles trace organic matter input in the Pichavaram mangrove complex, southeastern India

The nature and distribution of lipid biomarkers (n-alkanes, n-alkanols, sterols and triterpenols) were investigated in five dated sediment cores from the Pichavaram mangrove–estuarine complex in order to: 1) identify the organic matter (OM) sources and its preservation and 2) trace recent changes associated with coastal processes and anthropogenic activities. The mangrove sediment extracts have higher biomarker concentration (22.6±13.3μg/g dry weight) than the estuarine extracts (6.42±4.92μg/g dry weight). Triterpenols are dominant biomarkers in both estuarine and mangrove sediments, and constitute >50% of the total lipid extracts. The presence of n-alkanols (n-C26,28,30) and abundance of phytosterols (stigmasterol and β-sitosterol) and triterpenols (taraxerol, β-amyrin, germanicol, and lupeol) indicate that mangrove vegetation is the primary source of sedimentary OM. The high abundance and unimodal distribution of the long-chain n-alkanes (mainly n-C25,27,29), and high values of Terrestrial Aquatic Ratio (TAR 2.4 to 41) and Carbon Preference Index (CPI>8) indicate dominance (and better preservation) of higher plant derived immature OM in mangrove sediments. In contrast, the weak dominance of high molecular weight n-alkanes, low CPI (0.75 to 0.90) and TAR (1.9 to 5.7) values, and the presence of high C27 and C28 sterols indicate that phytoplankton/algal derived OM is more pronounced in estuarine sediments. Diagenetic changes in sedimentary OM indicate that some of the lipid fractions are reactive, and as a result, they degrade more rapidly than bulk OM. These compounds follow first order decay kinetics, and concur with the downcore diagenetic changes in coastal areas. Resistance to degradation among the different lipid classes show the trend: n-alkane>sterol>triterpenol>n-alkanol. Finally, the study indicates that less freshwater discharge from the Coleroon River is causing a gradual change in mangrove vegetation. There is less input of OM derived from mangrove vegetation into recent sediments. Biomarker trends also indicate that less salt tolerant Rhizophora spp. are gradually replaced by more salt tolerant vegetation consisting of Sueda spp. and Aviccenia spp.

Jeffries Matusita-Spectral Angle Mapper (JM-SAM) spectral matching for species level mapping at Bhitarkanika, Muthupet and Pichavaram mangroves

Abstract. This paper proposes a novel hyperspectral matching algorithm by integrating the stochastic Jeffries-Matusita measure (JM) and the deterministic Spectral Angle Mapper (SAM), to accurately map the species and the associated landcover types of the mangroves of east coast of India using hyperspectral satellite images. The JM-SAM algorithm signifies the combination of a qualitative distance measure (JM) and a quantitative angle measure (SAM). The spectral capabilities of both the measures are orthogonally projected using the tangent and sine functions to result in the combined algorithm. The developed JM-SAM algorithm is implemented to discriminate the mangrove species and the landcover classes of Pichavaram (Tamil Nadu), Muthupet (Tamil Nadu) and Bhitarkanika (Odisha) mangrove forests along the Eastern Indian coast using the Hyperion image dat asets that contain 242 bands. The developed algorithm is extended in a supervised framework for accurate classification of the Hyperion image. The pixel-level matching performance of the developed algorithm is assessed by the Relative Spectral Discriminatory Probability (RSDPB) and Relative Spectral Discriminatory Entropy (RSDE) measures. From the values of RSDPB and RSDE, it is inferred that hybrid JM-SAM matching measure results in improved discriminability of the mangrove species and the associated landcover types than the individual SAM and JM algorithms. This performance is reflected in the classification accuracies of species and landcover map of Pichavaram mangrove ecosystem. Thus, the JM-SAM (TAN) matching algorithm yielded an accuracy better than SAM and JM measures at an average difference of 13.49 %, 7.21 % respectively, followed by JM-SAM (SIN) at 12.06%, 5.78% respectively. Similarly, in the case of Muthupet, JM-SAM (TAN) yielded an increased accuracy than SAM and JM measures at an average difference of 12.5 %, 9.72 % respectively, followed by JM-SAM (SIN) at 8.34 %, 5.55% respectively. For Bhitarkanika, the combined JM-SAM (TAN) and (SIN) measures improved the performance of individual SAM by (16.1 %, 15%) and of JM by (10.3%, 9.2%) respectively.

‘Climate portfolio’ of Pichavaram mangrove region of Tamil Nadu coast, India: an add-on information for adaptation policy planning

The lack of comprehensive information on the climate of the coastal region results in insufficient understanding of the impact of changing climate on the coastal ecosystems and also impedes in framing suitable climate-based adaptation strategies and policies at the regional and local level. Monitoring current climate change demands a historical perspective, as much as possible, and framing a baseline climate data is important for establishing a reference point to assess climate change. Thus, the study of past climate change relies critically on the availability of datasets that characterize the climate of the region. In this context, the objective of this article is to provide climate portfolio (collection of climate information) of Pichavaram mangrove region of Tamil Nadu coast, India, and to give an outline of its predicted impacts. Climate data of the past 60 years have been collected, and the trend analysis of major climatic variables such as temperature, rainfall, relative humidity and wind speed has been studied statistically. This research article critically appraises the available climate data, identifies general patterns of climate change in the coastal region and highlights the gaps in existing knowledge on the impact of climate change at the local level. It gives a holistic approach on understanding climate at local level and provides baseline climate information. This, in turn, is expected to shore up in framing suitable adaptation strategies and policies for the coastal region with the most valuable ecosystem such as mangroves.

Rare Earth Elements As Biogeochemical Indicators In Mangrove Ecosystems (Pichavaram, Tamilnadu, India)

Abstract Mangrove forests are coastal wetland that can be sinks for material derived from terrestrial and marine settings. This study aims to establish the abundance, distribution, and enrichment of rare earth elements (REE) to track the sediment sources and infer biogeochemical processes occurring in the mangrove wetlands. Five sediment cores were collected throughout the Pichavaram mangroves in November 2010. The sampling sites were chosen based on vegetation cover, land-use pattern, and human interference. The vertical profile of the retrieved sediment cores were sub-sectioned, air dried, and homogenized into a powder before analysis. Higher REE concentration in Pichavaram sediments indicates dominance of input from the natural sources like weathering. Preferential REE enrichment was attributed to the alkaline pH (7–8.5) and reducing conditions prevailing in the mangrove environment allowing removal of MREE and LREE by adsorption and precipitation as Fe-Mn oxyhydroxides in sediments. Post Archean Australian Shale (PAAS)-normalized plots depicted convex subparallel shale-like patterns with similar enrichment. Pichavaram sediments showed strongly positive Eu anomalies, similar to that observed in Kaveri River sediments, validating the origin of REE in Pichavaram sediments as an outcome of natural weathering of post-Archean charnockitic and gneissic terrane. Also positive Eu anomalies indicated the prevalence of reducing conditions in Pichavaram. Cores near the estuarine mouth showed highly mixed vertical profile as compared to the undisturbed mangrove sites. Principal-component analysis delineated three main processes controlling REE distribution in Pichavaram, namely natural weathering, inherent physicochemical processes, and in situ biogeochemical processes occurring in this mangrove environment.

The Coleroon river flow and its effect on the Pichavaram mangrove ecosystem

The fresh water reaching an estuary fluctuates on many scales and the fluctuation in the flow over a time period is also due to the anthropogenic activities like construction of dams, diversions and upstream withdrawals. These fluctuations may have profound effects on the estuarine ecosystem, which usually has remarkable biological productivity and diversity. A desktop analysis is carried out by compiling historical records of discharge and other hydrological information to study the dynamics of the river Coleroon, a distributary of the Cauvery River, Tamil Nadu, India. Remote sensing analysis was carried out on images ranging from the years 1977 to 2008 and the changes in the Pichavaram mangrove areas adjoining the Coleroon were studied by comparing the results with the freshwater flow into the ecosystem. Environmental flow analysis indicates that the minimum flow needed for a healthy mangrove system in Pichavaram is 750.75 cumecs; however, this is currently achieved only 12 % of the time. The reduction in freshwater flow over the years has resulted in loss of species diversity and degradation of the mangroves; this needs to be corrected immediately to conserve the Pichavaram mangrove ecosystem.

Antimycobacterial activity of certain mangrove plants against multi-drug resistant Mycobacterium tuberculosis

Objectives: The present study was conducted aiming to identify a potent mangrove plant against Mycobacterium tuberculosis using rapid method, luciferase reporter phage (LRP) assay. Methods: Seven mangrove plants viz., Ceriops decandra, Aegiceras corniculatum, Excoecaria agollacha,Avicennia officinalis, Rhizophora mucronata, Suaeda monoica and Sesuvium portulacastrum were collected from Pichavaram mangrove forest in the east coast of, Tamil Nadu. Hexane and methanol extracts were obtained and antimycobacterial activity was done by LRP assay at the concentration of 500 μg/ml. Mycobacterial strains viz. reference strain M. tuberculosis H37Rv and two clinical isolates of M. tuberculosis, one sensitive and the other resistant to Streptomycin, Isoniazid, Rifampicin and Ethambutol used for this study. Results: Methanol extract of E. agollacha showed maximum antimycobacterial activity followed by A. corniculatum and A. officinalis at 500 μg/ml concentration. The remaining four plants (Suaeda monoica, Sesuvium portulacastrum, R. mucronata and C. decandra) showed less or no activity. However, hexane extracts of all the tested plants failed to inhibit the mycobacterial strains. Conclusions: Among the seven plants tested, E. agollacha was found to have better anti-TB activity. Further studies based on bioassay guided fractionation and phytochemical analysis may useful to identify the potent antimycobacterial molecule(s) from this mangrove plant. Asian Journal of Medical Science, Volume-5(3) 2014: 54-57 http://dx.doi.org/10.3126/ajms.v5i3.9171

Climate‐induced Late‐Holocene ecological changes in Pichavaram estuary, India

AbstractVariation in sedimentology as well as freshwater and marine palynomorphs has been studied in ecological perspective in two 2.5‐ and 5‐m deep sediment cores deposited since 3440 and 3630 cal BP, respectively in the central part of Pichavaram mangrove wetland, Cauvery River delta. The palynological and sedimentological results of the sediments reveal a monsoonal circulation and a climatic shift from warm and humid with strengthened monsoon (3630–3190 cal BP) to dry and arid (~2750–760 cal BP). Since the last millennium (~760 cal BP), Pichavaram estuary has been influenced by a similar cyclicity but with a less wet and humid climate due to weakened monsoon conditions. These ecological changes in turn affect the relative sea level rise and fall which is reflected by the variability/extinction of freshwater and marine palynomorphs. The estuary remained an active water channel between ~3630 and 2750 cal BP, responding to the strengthened monsoon, during which the freshwater algal remains with thecamoebians and marine dinoflagellate cysts and foraminiferal linings both dominated with a ratio of 1.5 for marine/freshwater forms. After this period, since ~2750 cal BP there has been a dominance of marine forms with a ratio of 4.5 for marine/freshwater forms, indicating fluvio‐marine sediment deposition and suggesting the recent landward intrusion of seawater during weakened monsoon conditions. Freshwater thecamoebians are vulnerable to the salinity >3 in the aqueous soil solution of estuarine sediment, and therefore serve as an excellent proxy for monitoring salinity gradient along with short‐term high resolution palaeoecological fluctuations induced by climate and relative sea‐level changes in an estuarine ecosystem.

NUMERICAL SIMULATION OF TIDAL CIRCULATION IN THE PICHAVARAM MANGROVE ESTUARY

A vertically averaged numerical model is developed using the Surface water Modeling System (SMS) for t he Pichavaram Mangrove Estuary to study the tidal characteristics which en ables the simulation of the whole water circulation within the water body. The Pichavaram mangrove ecosystem is a complex network of creeks, mangroves and mud flats housed between t he Vellar and Coleroon rivers, 15 km north of Chidambaram, Tamil Nadu, Ind ia. A portion of the Coleroon river drains into the mangroves, and tidal flow is through the Coleroon mouth and a small inflow from an inlet in the north. The reduction of freshwater flow over the years has led to a degradation of the mangroves and changes in sedimen tation patterns. The results are calibrated against data collected previously. From the simulated results it is noticed that the tflow from the Coleroon mouth dominates the ent ire system. The maximum flood and ebb tide speed reached 0.777 ms -1 and 0.468 ms -1 during monsoon and post monsoon periods, respectiv ely. The tide showed a pronounced asymmetry in mangroves and a 12% increas e in total depth of water with a maximum increase i n water level of about 5 cm is noticed between monsoon and post monsoon cond itions. The dominance of ebb tide is noticed due to friction in the mangrove forest, which has resulted in slower flood current and greater tidal asymmetry in the waterway.

Evaluation of secondary metabolites from mangrove associated fungi Meyerozyma guilliermondii

BackgroundMangrove associated fungi are the second most diverse organisms that remain less explored. Cytotoxic and antibacterial activities of foliar fungus Meyerozyma guilliermondii were investigated. MethodsFoliar fungus was isolated from the leaves of Rhizophora mucronata collected from Pichavaram mangrove forest, Tamilnadu. Extracts from liquid state culture were tested for cytotoxicity against two cancer cell lines using the MTT assay. Antibacterial activity was determined using the well diffusion method. The DNA was isolated from the fungi, and the ITS region of 5.8s RNA was sequenced. The spectral properties (GC/MS) of the purified compounds were determined. ResultsThe ethyl acetate extracts showed potent cytotoxicity against Hep2 and human breast adenocarcinoma (MCF-7) cell lines with IC50 values of 1.25 and 0.625 μg/ml, respectively. Antibacterial activity of the fungal extract was demonstrated against five test organisms. The fungus was found to be a new strain based on ITS sequence and database in NCBI Blast tool. ConclusionResults indicate the potential for production of bioactive agents from mangrove foliar fungi.

Trace metal fractionation in the Pichavaram mangrove–estuarine sediments in southeast India after the tsunami of 2004

The geochemistry of coastal sediments of southern India was altered after the tsunami in 2004. A five-step sequential extraction procedure was applied to assess the effects of tsunami on mobility and redistribution of selected elements (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn). Ten surface sediments and three cores were analyzed for different metal fractions (exchangeable, carbonate, reduced, oxidized, and residual). Total metal concentrations increased in mangrove sediments after the tsunami, but their spatial distribution did not show significant variation (except Mn). The sediments were mixed by the tsunami, and there was lack of variation in metal concentrations in different fractions with depth (except Pb and Mn). High concentrations of Pb and Zn occurred in the oxide fractions, whereas Cu, Cr, Cd, and Ni were high in the organic and sulfide-rich fractions. Metals in the residual fraction (lattice bound) had the highest concentration suggesting their non-availability and limited biological uptake in the system. Most of the metals (except Mn) do not constitute a risk based on the different geochemical indices.