Temporal variability of macrofauna from a disturbed habitat in Zuari estuary, west coast of India

Natural disturbances along with human interference make the tropical estuaries amongst the most disturbed areas globally. In spite of this, information on the seasonal variability of macrofauna from tropical estuaries is few. Temporal variability of macrofaunal community from Mormugao Bay, Zuari estuary, on the west coast of India was examined from 2003 to 2004 at seven stations. Environmental variability was assessed through physicochemical parameters of water and sediment. The changes in macrobenthic community were assessed using abundance, biomass and species diversity indices. The environmental parameters showed a significant seasonal variation influenced by monsoonal changes. The changes in the environmental conditions brought about variation in the macrobenthic community. Macrofaunal abundance, biomass and species diversity were the highest during post-monsoon influenced by recruitment. In monsoon, the macrobenthic community was dominated by polychaetes (92.17%), whereas bivalves dominated during the post-monsoon (57.7%). The macrofauna showed drastic decline during the stable pre-monsoon season, a period when the highest abundance of fauna is observed in the tropical estuary. Therefore, the macrobenthic community in the area did not follow the seasonal trend generally observed in a tropical estuary. Further, the community during pre-monsoon season was dominated by the opportunistic polychaete species indicating a possible influence of harbour activities in structuring the benthic community of the area.     

Distribution and abundance of macrobenthic polychaetes along the South Indian coast

Macrobenthic polychaetes play a significant role in marine benthic food chain. A study was carried out to observe the abundance and diversity of soft bottom macrobenthic polychaetes along the South Indian coast, along with observations on sediment characteristics. The present study indicated an increase in the polychaete diversity as compared to earlier reports. Sixty-three different forms of polychaetes were identified along the coast, which constitute the bulk of the macrobenthic fauna. Thirty-eight species of polychaetes showed higher abundance along the west coast, whereas 25 species showed higher abundance along the east coast. Seabed composition showed a spatial variation in its composition along the coast. Occurrence of Prionospio pinnata and Capitella capitata the deposit feeders and indicators of organic pollution suggesting the sampled area is organically rich. Polychaete abundance was found to be higher along the west coast and was attributed to loose texture of sediment due to high sand and sandy-silt resulting in higher interstitial space for organisms to harbor. Canonical correspondence analysis indicated that majority of polychaete species preferred low organic carbon, sandy silt, or sandy-clay substratum. The lower polychaete abundance at high organic carbon and high silt and clay areas can be attributed to avoidance of organisms to rich organic matter and suboxic levels, being a possible indication that these characteristics adversely affects the polychaete abundance and distribution.     

Influence of environmental properties on macrobenthos in the northwest Indian shelf

The paper deals with the standing stock of macrobenthic infauna and associated environmental factors influencing the benthic community in the shelf region of the northwest Indian coast. The data were collected onboard FORV Sagar Sampada during the winter monsoon (January–February, 2003) to understand the community structure and the factors influencing the benthic distribution. The environmental parameters, sediment characteristics and macrobenthic infauna were collected at 26 stations distributed in the depths between 30 and 200 m extending from nobreak{Mormugao} to Porbander. Total benthic abundance was high in lower depths (50–75 m), and low values noticed at 30 m depth contour was peculiar. Polychaetes were the dominant group and were more abundant in shallow and middle depths with moderate organic matter, clay and relatively high dissolved oxygen. On the other hand crustaceans and molluscs were more abundant in deeper areas having sandy sediment and low temperature. High richness and diversity of whole benthic groups observed in deeper depths counter balanced the opposite trend shown by polychaete species. Generally benthos preferred medium grain sized texture with low organic matter and high organic matter had an adverse effect especially on filter feeders. Deposit feeding polychaetes dominated in shallow depths while carnivore species in the middle depths. Ecologically, benthos were controlled by a combination of factors such as temperature, salinity, dissolved oxygen, sand and organic matter and no single factor could be considered as an ecological master factor.     

Mumbai harbour, India: gateway for introduction of marine organisms

Ships have been identified as one of the important vectors in the translocation of organisms from one bioregion to another leading to bioinvasion. In this context, harbours serve as a gateway for the introduction of alien species. Surveys were carried out in the vicinity of ports of Mumbai for macrobenthic fauna, zooplankton and hard substratum community on three different occasions during 2001–2002. The study shows that 14 polychaete species are recently introduced to this area. Mytilopsis sallei, a bivalve, which is an invasive species in the Indian context continued to be present but was restricted to enclosed docks, indicating preference for embayed water bodies. The polychaete Protula tubularia was abundant in the hard substratum community and is being reported as a possible ship-mediated introduction.     

Changes in the soft-bottom macrobenthic diversity and community structure from the ports of Mumbai, India

Soft-bottom macrobenthic diversity and community structure were assessed at Mumbai and Jawaharlal Nehru ports during three different periods between 2001 and 2002 (November 2001 post-monsoon 1, April/May 2002 pre-monsoon, and October 2002 post-monsoon 2). A total of 43 macrobenthic invertebrate species belonging to five phyla were recorded. Macrofaunal abundance (PM1 186, PreM 106, and PM2 31 ind m^?2) and species diversity index (PM1 0.87, PreM 0.73, and PM2 0.30) were very low in all the seasons. Polychaetes were the most dominant macrobenthic group (72.09%) followed by decapoda, amphipoda, and bivalves (4.56%). Canonical correspondence analysis showed that sediment texture, temperature, and suspended particulate matter were the most important environmental variables influencing polychaete species composition. Significant seasonal variations were observed, influenced by dissimilar monsoonal patterns. Macrobenthic population density during November 2001 was higher than that of October 2002 post-monsoon season. Pre-monsoon season recorded more carnivorous polychaete species than post-monsoon seasons. The present study showed lower values of polychaete diversity index in all the seasons compared to earlier studies. Out of 31 polychaete species, 19 have been reported for the first time from this area. Polychaete species and Glycera longipinnis, Paraprionospio pinnata, and Cossura coasta recorded from 1985 to 1986 were also observed in the present study. Species like Sigambra constricta, Perinereis cavifrons, Prionospio polybranchiata, and Parheteromastus tenuis were not recorded in the present study, although they were observed during earlier studies in this area.     

Spatial and temporal distribution of macrobenthos in different mangrove ecosystems of Tamil Nadu Coast, India

This paper deals with the spatial distribution and diversity of macrobenthos and their relationships between physico-chemical parameters of the water and sediment in different mangrove habitats of Tamil Nadu, India during different seasons (2008). Among the different ecosystems of mangrove benthic faunal assemblages, macrofauna species number, density, richness, and Shannon-Wiener index were the highest and the Simpson dominance index was medial at riverine mangrove community. However, the Pielou Evenness index of riverine mangrove community was slightly lower than other communities. The similarities among the macrobenthic communities at different sampling sites were determined using Bray-Curtis similarity coefficient and ordinations of non-metric multidimensional scaling (MDS). Thirty-one species were recorded in developing (16 polychaetes, six bivalves, seven gastropods, and two crustaceans), 35 species were recorded in riverine (20 polychaetes, six bivalves, five gastropods, and four crustaceans) and 31 species were recorded in island mangrove ecosystem (19 polychaetes, four bivalves, five gastropods, and three crustaceans). Among the three ecosystems, a total of 46 benthic macrofauna consisting of 27 species of polychaetes, eight species of gastropods, seven species of bivalves, and four species of crustaceans were recorded. However, there were obvious differences among the community structures in the three mangrove habitats. This result implied that the different mangrove ecosystem had different effects on the macrofauna communities and shed light on the macrofauna adaptation capability to specific habitats.     

Organic contaminants and trace metals in flounder liver and sediment from the Amsterdam and Rotterdam harbours and off the Dutch coast

Organic contaminants [polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenylethers (PBDEs), nonylphenols], organotin compounds and trace metals (cadmium, chromium, mercury and zinc) were determined in flounder (Platichthys flesus) liver and sediment from the Amsterdam harbour (North Sea Canal) and Rotterdam harbour (Euromonding) and off the Dutch coast between the Amsterdam and Rotterdam harbour mouths in order to assess the level of contamination in these harbours and to study contamination gradients.     

京杭运河江苏段底栖动物群落结构调查

通过2018年5月在京杭运河江苏段布设23个采样点调查底栖动物群落结构和生境状况,并用Shannon-Wie-ner多样性指数评价底栖动物多样性,用聚类法分析采样点底栖动物群落结构相似性,用ANOSIM分析检验聚类组差异性,用SIMPER对聚类组作主要特征物种分析.结果显示:23个采样点共采集底栖动物42种,其中甲壳纲...     

Recovery assessment of a refined-oil impacted and fire ravaged mangrove ecosystem

An assessment of the diversity and abundance of macrobenthic community in a refined-oil (petrol) impacted and fire-ravaged mangrove ecosystem within the vicinity of a marine receipt terminal facility (Atlas Cove) serving as a distribution and pump station for refined products was carried out. The mangrove ecosystem was subjected to massive petrol spillage from a leaking pipeline and eventual fire outbreak. Following rehabilitation activities, a recovery assessment of the impacted ecosystem was carried out. The field surveys revealed that the petrol leakage and fire outbreak resulted in a near complete destruction of the mangrove ecosystem around the Atlas Cove depot, with macrobenthic species diversity index ranging between 0−0.4, compared to 0.78−0.87 in the control stations. The dominant early arrivals or colonizers of the impacted stations areas were Clibanarius africanus and Callinectes amnicola. Early signs of recovery of the impacted area were observed within about two and a half (2 1/2) to three (3) months, based on diversity and abundance indices respectively. The period of early signs of recovery also coincide with an observed reduction in the total hydrocarbon content (THC) levels in the sediment collected from the impacted stations by about nine folds from 3.67 mg/kg to 0.42 mg/kg within 3 months. Despite the apparent signs of recovery, the need for long-term monitoring of the impacted stations was discussed.     

Comparative study based on sediment characteristics and macrobenthic communities in two Italian lagoons

The aims of this study were to analyse sediment characteristics and macrobenthic assemblages in two very close Italian coastal lagoons (Lesina and Varano) and to assess the different behaviour between the two basins and the relationship between sediment matrix and benthic organisms within and between the two lagoons. The comparative study was performed in July 2007 at 13 sampling sites in Lesina lagoon and 15 sites in Varano basin for sediment grain size, total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP) and macrobenthic structure analyses. Both lagoons were generally dominated by fine-grained sediments (clay and silt components). The average contents of TOC and TN measured in Lesina was higher than in Varano (3.31% vs 2.52% for TOC and 5,200 μg·g^???1 vs 3,713 μg·g^???1 for TN); in contrast, the TP was lower (540 μg·g^???1 vs 620 μg·g^???1). Based on macrobenthic community patterns, the central zone in Varano lagoon and the eastern area in Lesina lagoon were characterised by the lowest abundance (168.7 ind·m^???2 and 503.2 ind·m^???2, respectively) and by the lowest number of species, as highlighted by the diversity indices (Shannon–Wiener, H ^′ range was 0.47–1.45 for Lesina and 0.00–1.68 for Varano; Margalef species richness, d range was 0.00–1.67 for Lesina lagoon and 0.00–2.38 for Varano basin). Ordination diagrams suggested an influence of marine and freshwater inputs on the sediment distribution in Varano lagoon and on macrobenthic assemblages in Lesina lagoon.     

Land use effects on macrobenthic communities in southeastern United States tidal creeks

Runoff from impervious land cover has a major impact on headwater tidal creek ecosystems resulting from ever increasing development along the coastline. Tidal creek habitats can serve as "early warning systems" for anthropogenic stressors due to their proximity to the uplands. In this study, the macrobenthic community was sampled along the longitudinal gradient of tidal creeks (i.e., first order, second order, and third order) in North Carolina, South Carolina, and Georgia which varied in their levels of watershed development (salt marsh, forested, suburban, and urban). This study was designed to assess the condition of macrobenthic communities in tidal creek ecosystems under varying levels of anthropogenic stressors and test whether the conclusions of a previous study in South Carolina (Holland et al., J Exp Mar Biol Ecol 298:151-178, 2004) could be generalized to the southeastern USA. Metrics of community-level and species-specific response within tidal creeks draining watersheds of varying degrees of impervious cover suggest the macrobenthic community may be a useful indicator of development in tidal creeks ecosystems. The differences observed when data from all three states were pooled was consistent with previous findings in South Carolina tidal creeks which illustrates that macrobenthic communities in tidal creeks may react to watershed development in similar patterns along the southeastern coast of the USA.     

Seasonality in the distribution of dinoflagellates with special reference to harmful algal species in tropical coastal environment,Bay of Bengal

A study was carried out in the coastal waters of Kalpakkam, southeast coast of India, to find out the seasonal variation in dinoflagellate community structure. Samples were collected for a period of 4 years during 2006–2010. During the study 69 species of dinoflagellates were encountered among which Ceratium furca and Prorocentrum micans were most common during all the seasons. Genus Ceratium was found to be the most diverse one with 23 species which was followed by genus Protoperidinium with 16 species. Of 69 species, 27 species were considered as dominant based on their abundance during pre-monsoon (PRM), monsoon (MON) and post-monsoon (POM) periods. Relatively high density and diversity of dinoflagellates were encountered during the PRM period as compared to the MON and POM periods. Abundance pattern of dinoflagellates for three seasons showed the following trend: PRM?>?POM?>?MON. Salinity showed a positive correlation with dinoflagellate community showing its importance in dinoflagellate growth and sustenance. Ammonia and phosphate developed negative correlation with dinoflagellate density indicating the utilization of these nutrients by the dinoflagellate community. The presence of three dinoflagellate associations, broadly representing the three seasons experienced at this location, was evident from the cluster analysis. The study revealed presence of 19 relatively abundant toxic/red tide forming dinoflagellate species in the coastal waters of Kalpakkam.     

Microbial contamination of dental unit waterlines in Istanbul, Turkey

The water used in dental unit waterlines (DUWLs) acts as a coolant for the high-speed equipment and as an irrigant during dental treatments. There are kind of water tanks. DUWLs provide a favorable environment for microbial biofilm and multiplation primarily due to the high surface in the tubing and the character of fluid dynamics in narrow, smooth-walled waterlines. Biofilms can harbour opportunist pathogens such as Legionella sp., Pseudomonas sp. Several studies have shown that DUWLs have high levels of microbial contamination. Presence of high level of microbial contamination is an important problem for dentists and dental patients who are immunocompromised. We collected water samples from DUWLs of 20 private dental offices. We have determined that only 2 (3.4%) out of 59 dental unit water samples were found to meet the standard (<200 CFU.ml(-1)) for DUWLs water quality by American Dental Association (ADA). Of the 59 water samples examined, 14 (24%) were positive for Pseudomonas sp. and 18 (30.5%) were positive for fungi. The most common 14 bacterial strains and seven fungi were isolated. Of bacterial strains, 57.1% were identified: Majority of the bacterial species isolated from our samples was identified as Pseudomonas fluorescens, Pasteurella haemolytica, Photobacterium damsela, Ochrobacter anthropi, Moraxella sp., Aspergillus flavus, Penicillium expansum. Legionella sp. were not detected in all water samples.     

Environmental quality assessment combining sediment metal levels, biomarkers and macrobenthic communities: application to the óbidos coastal lagoon (Portugal)

Macroinvertebrate benthic communities are one of the key biological components considered for the assessment of benthic integrity in the context of the Water Framework Directive (WFD). However, under moderate contamination scenarios, the assessment of macrobenthic alterations at community level alone could be insufficient to discriminate the environmental quality of coastal and transitional waters. Keeping this in view, sediment quality of moderately contaminated sites in a coastal lagoon (óbidos lagoon, Portugal) was assessed by the combination of sediment metal levels, Carcinus maenas biomarkers (accumulated metals and oxidative stress responses) and macrobenthic communities. Two sites were selected in confined inner branches (BS and BB) and a third one in the middle lagoon (ML). The site BB presented slightly higher levels of metals in sediment but biological variables calculated for macrobenthic data were not significantly different between sites. The biotic index M-AMBI that is being applied to assess environmental quality of transitional waters in the scope of the WFD pointed either to high (site ML) or good quality status (BS and BB) in the selected sites. However, crabs from BB site presented significantly higher levels of Ni in hepatopancreas than those from ML and macrobenthic community structure was significantly different between BB and ML. Additionally, spatial differences were obtained for oxidative stress parameters suggesting that BB site presented stressors for crabs (higher GST and lower GSH_t at BB site). Factor analysis (PCA) integrating sediment contamination, biomarkers in crabs and macrobenthic data also distinguished BB site as the most environmentally disturbed. On the other hand, at ML site, some macrobenthic variables (equitability and polychaetes’ diversity) were found to be enhanced by current environmental conditions, suggesting the existence of a better sediment quality. Current results pointed to the usefulness of integrating macrobenthic community alterations with responses at organism level (bioaccumulation and biochemical endpoints) in order to increase the accuracy of environmental quality assessment in lagoon systems. Moreover, the application of different statistical methods was also found to be recommendable.     

Incidence of stress in benthic communities along the U.S. Atlantic and Gulf of Mexico coasts within different ranges of sediment contamination from chemical mixtures

Synoptic data on concentrations of sediment-associated chemical contaminants and benthic macroinfaunal community structure were collected from 1,389 stations in estuaries along the U.S. Atlantic and Gulf of Mexico coasts as part of the nationwide Environmental Monitoring and Assessment Program (EMAP). These data were used to develop an empirical framework for evaluating risks of benthic community-level effects within different ranges of sediment contamination from mixtures of multiple chemicals present at varying concentrations. Sediment contamination was expressed as the mean ratio of individual chemical concentrations relative to corresponding sediment quality guidelines (SQGs), including Effects Range-Median (ERM) and Probable Effects Level (PEL) values. Benthic condition was assessed using diagnostic, multi-metric indices developed for each of three EMAP provinces (Virginian, Carolinian, and Louisianian). Cumulative percentages of stations with a degraded benthic community were plotted against ascending values of the mean ERM and PEL quotients. Based on the observed relationships, mean SQG quotients were divided into four ranges corresponding to either a low, moderate, high, or very high incidence of degraded benthic condition. Results showed that condition of the ambient benthic community provides a reliable and sensitive indicator for evaluating the biological significance of sediment-associated stressors. Mean SQG quotients marking the beginning of the contaminant range associated with the highest incidence of benthic impacts (73–100% of samples, depending on the province and type of SQG) were well below those linked to high risks of sediment toxicity as determined by short-term toxicity tests with single species. Measures of the ambient benthic community reflect the sensitivities of multiple species and life stages to persistent exposures under actual field conditions. Similar results were obtained with preliminary data from the west coast (Puget Sound).     

Bacterial communities in urban aerosols collected with wetted-wall cyclonic samplers and seasonal fluctuations of live and culturable airborne bacteria

Airborne transmission of bacterial pathogens from point sources (e.g., ranches, dairy waste treatment facilities) to areas of food production (farms) has been suspected. Determining the incidence, transport and viability of extremely low levels of pathogens require collection of high volumes of air and characterization of live bacteria from aerosols. We monitored the numbers of culturable bacteria in urban aerosols on 21 separate days during a 9 month period using high volume cyclonic samplers at an elevation of 6 m above ground level. Culturable bacteria in aerosols fluctuated from 3 CFU to 6 million CFU/L of air per hour and correlated significantly with changes in seasonal temperatures, but not with humidity or wind speed. Concentrations of viable bacteria determined by fluorescence staining and flow cytometry correlated significantly with culturable bacteria. Members of the phylum Proteobacteria constituted 98% of the bacterial community, which was characterized using 16S rRNA gene sequencing using DNA from aerosols. Aquabacterium sp., previously characterized from aquatic environments, represented 63% of all clones and the second most common were Burkholderia sp; these are ubiquitous in nature and some are potential human pathogens. Whole genome amplification prior to sequencing resulted in a substantial decrease in species diversity compared to characterizing culturable bacteria sorted by flow cytometry based on scatter signals. Although 27 isolated colonies were characterized, we were able to culture 38% of bacteria characterized by sequencing. The whole genome amplification method amplified DNA preferentially from Phyllobacterium myrsinacearum, a minor member of the bacterial communities, whereas Variovorax paradoxus dominated the cultured organisms.     

长江口及其邻近海域春季大型底栖生物群落与环境因子的典范对应分析

2009年4月对长江口及其邻近海域的21个站位进行了大型底栖生物调查,分析了大型底栖动物的环境质量状况,并结合环境因子数据进行了典范对应分析。结果表明,调查共鉴定大型底栖生物56种,多毛类为主要类群。平均生物量为11.26 g/m2,平均丰度为237.4个/m2。生物量、丰度均呈现由近岸向外海递增的趋势。水深、盐度、初级生产力和有机质、重金属是影响调查海域大型底栖生物群落的主要环境因子。大型底栖生物的分布呈现出对有机污染与重金属污染显著的躲避趋势,表明有机污染与重金属污染已显著影响该海域大型底栖生物的生长。而小头虫、寡节甘吻沙蚕、长手沙蚕和丝鳃虫对有机污染和重金属污染展现出较强的的耐受性。     

Cyanobacterial Flora from Polluted Industrial Effluents

Effluents originating from pesticides, agro-chemicals, textile dyes and dyestuffs industries are always associated with high turbidity, colour, nutrient load, and heavy metals, toxic and persistent compounds. But even with such an anthropogenic nature, these effluents contain dynamic cyanobacterial communities. Documentation of cyanobacterial cultures along the water channels of effluents discharged by above mentioned industries along the west coast of India and their relationship with water quality is reported in this study. Intensity of pollution was evaluated by physico-chemical analysis of water. Higher load of solids, carbon and nutrients were found to be persistent throughout the analysis. Sediment and water samples were found to be colored in nature. Cyanobacterial community structure was found to be influenced by the anthropogenic pollution. 40 different cyanobacterial species were recorded from 14 genera of 5 families and an elevated occurrence of Phormidium, Oscillatoria and Chroococcus genera was observed in all the sampling sites.     

Geochemical characterisation of major and trace elements in the coastal sediments of India

Thirty-five surface sediment samples from the Indian continental shelf were recovered offshore from the mouths of the major rivers (Brahmaputra, Ganges, Narmada, Tapti, Godavari, Krishna and Cauvery) discharging into the coastal region of both east and west coasts were analysed using inductively coupled plasma atomic emission spectroscopy for selected major (i.e. Al, Ca, Fe, K, Ti, Mg and Na) and trace elements (e.g. Ba, Co, Cr, Cu, Ga, Ni, P and V), after total dissolution. The main objectives are to understand the processes controlling major and trace elements in the surface sediments and to identify natural and anthropogenic sources in the coastal environment using statistically regressed elemental concentrations to establish regional baseline levels. Metal enrichments observed close to the major urban areas in the east and west coasts are associated with the industrialised activities areas rich in Cu and Co in both the east and west coast sediments. Normalisation of metals to Al indicated that high enrichment factors are in the order of Ca>Ti≥Fe>Na>Mg>Co>Cu>Ga>V>Ba except K and P depletion. This indicated that the characteristic of estuarine sediment showed higher level along the west coast of India, which was reflected in the coastal sediments as similar to the source of its origin from the riverine composition and its abundances.