The effect of ship scrapping industry and its associated wastes on the biomass production and biodiversity of biota in in situ condition at Alang

Effect of microfibers induced toxicity in marine sedentary polychaete Hydroides elegans: Insight from embryogenesis axis

Presence of surgical face masks in the environment are more than ever before after the COVID-19 pandemic, and it poses a newer threat to aquatic habitats around the world due to microfibers (MFs) and other contaminants that get discharged when these masks deteriorate. The mechanism behind the developmental toxicity of MFs, especially released from surgical masks, on the early life stages of aquatic organisms are not well understood. Toxicity test were developed to examine the effects of MFs released from surgical facemask upon deterioration using the early gametes and early life stages of marine sedentary polychaete Hydroides elegans. For MFs release, cut pieces of face masks were allowed to degrade in seawater for different time points (1 day, 30 days and 120 days) after which the fibers were obtained for further toxicity studies. The gametes of H. elegans were exposed to the MFs (length < 20 μm) separately for 20 min at a concentration of 50 MFs/ml before fertilization. In addition, we also analyzed the experimental samples for heavy metals and organic substances released from face masks. Our findings demonstrated that gametes exposed to MFs affected the percentage of successful development, considerably slowed down the mitotic cell division and significantly postponed the time of larval hatching and also produced an adverse effect during embryogenesis. When the sperm were exposed fertilization rate was decreased drastically, whereas when the eggs were exposed to MFs fertilization was not inhibited but a delay in early embryonic development observed. In addition the release of heavy metals and other volatile organics from the degrading face masks could also contribute to overall toxicity of these materials in environment. Our study thus shows that inappropriately discarded face masks and MFs and other pollutants released from such face masks could pose long-term hazard to coastal ecosystems.

A Rapid Bioassay Test for Assessing Environmental Contamination Using the Marine Sedentary Polychaete Hydroides elegans

To investigate the impact of environmental contaminants on the early life stages of the marine polychaetae Hydroides elegans, a toxicity test was designed. In our previous study, we reported gametes and embryos of H. elegans were sensitive to heavy metal pollution and effluents. In continuation of this, we used H. elegans gametes to assess the water quality of samples taken along the southeast coast of India. The samples were collected from five different locations of the Chennai coast (Muttu Kadu, Neelangarai, Marina, Royapuram, and Ennore), and two different bioassay toxicity tests were performed. Sperm and eggs were pre-exposed to water samples taken from different locations to assess the water quality. Water samples collected from Ennore station and the Royapuram fish landing center were found to be more polluted than those collected from other locations. Sperm were shown to be more sensitive than eggs. The different morphological effects produced by water samples reflected the defects in the early differentiation of embryonic cells. Since fertilization can be inhibited in the presence of any xenobiotic, both fertilization and early development could be used as a biological indicator for a rapid bioassay to monitor marine pollution. The percentage of successful fertilization and early development was comparatively higher at the reference site (Neelangarai) and in the seawater samples collected from Marina. The physicochemical characteristics of the seawater from these sampling stations corroborated the findings of this investigation. Our results showed that H. elegans gametes were highly sensitive to any contaminant present in the seawater, and confirmed previous findings that this polychaetae can be routinely used as a test organism for ecotoxicological bioassays in tropical and subtropical regions.

Toxic metal pollution and ecological risk assessment in water and sediment at ship breaking sites in the Bay of Bengal Coast, Bangladesh

Quantification of four toxic metals (As, Cr, Cd, and Pb) in water and sediments at the Sitakunda ship breaking area in Bangladesh was studied. Along with this, sediment quality and ecological risk were evaluated for the metal intrusion to the study area. A total sample number of 120 (water; n = 60 and sediment; n = 60) were analyzed for both winter and summer seasons using atomic absorption spectrophotometer (AAS). The trace metal concentration in both water and sediment showed decreasing trend as follows; Cr (mean-W: 0.118 mg/L; mean-S:121.87 mg/kg) > Pb (mean-W: 0.064 mg/L; mean-S: 65.31 mg/kg) > As (mean-W: 0.03 mg/L; mean-S: 32.53 mg/kg) > Cd (mean-W: 0.004 mg/L; mean-S: 4.81 mg/kg). However, in both segments, the concentrations of the toxic metals exceeded the recommended acceptable limits. As and Cd showed significant variation (water and sediment) between the seasons, while Pb and Cr had no seasonal impact. Metal pollution index (MPI) and contamination factor (CF) was evaluated and revealed that the study area exhibited the critical score of water quality (MPI > 100). The cumulative effect of the metal concentrations was high (CI > 3). The assessed mean geoaccumulaiton index (I_geo) revealed that the study area was moderate to strongly polluted except for Cr. According to the contamination factor (CF), the sediment samples were moderate to highly contaminated by Cd, Pb, and As. Moreover, the explored range of pollution load index (PLI) in all sampling sites in the ship breaking region was from 1.75 to 3.10, suggesting that the sediment in the study area was highly polluted by heavy metals (PLI > 1). The risk index and the potential ecological risk index (PERI) suggested that the study area was at high risk due to metals pollution. Therefore, it is obligatory to maintain some crucial efforts for the betterment of the surrounding environment near the investigated sites.

New normal baseline data during nationwide lock down due to Covid 19 pandemic in the world's largest ship recycling yard at Alang, India

A detailed study to generate the new normal baseline data has been carried out during nationwide lockdown (May 12 to May 16, 2020) covering sampling for ambient air, coastal water, coastal sediments, fish and bioaccumulation of heavy metals, in an around Alang, the world's biggest ship recycling yard. The lockdown data were compared with 2018 and 2019 observed data. PM10 values during lockdown were reduced by 3.75 to 4.5 times as compared with previous 2 years. Similarly, four-fold reduction of PM2.5 and SPM values was observed during lockdown. The gaseous pollutants like NO2 and O3 are within safe limit. Overall air quality index (AQI) improved significantly during lockdown. Similarly, there was drastic reduction in the majority of the nutrient parameters in the coastal water. Different heavy metal concentration in the coastal sediments samples also showed strong reduction during lockdown sampling in comparison with other two sampling. This proves that the coastal environment has its efficient self-cleaning potentials if there is considerable reduction in the anthropogenic as well as industrial activities. Diversity of phytoplankton and zooplankton also increased. The results were validated using statistical techniques like analysis of variance and least significance difference (LSD).

Boating- and Shipping-Related Environmental Impacts and Example Management Measures: A Review

Boating and shipping operations, their associated activities and supporting infrastructure present a potential for environmental impacts. Such impacts include physical changes to bottom substrate and habitats from sources such as anchoring and mooring and vessel groundings, alterations to the physico-chemical properties of the water column and aquatic biota through the application of antifouling paints, operational and accidental discharges (ballast and bilge water, hydrocarbons, garbage and sewage), fauna collisions, and various other disturbances. Various measures exist to sustainably manage these impacts. In addition to a review of associated boating- and shipping-related environmental impacts, this paper provides an outline of the government- and industry-related measures relevant to achieving positive outcomes in an Australian context. Historically, direct regulations have been used to cover various environmental impacts associated with commercial, industrial, and recreational boating and shipping operations (e.g., MARPOL). The effectiveness of this approach is the degree to which compliance can be effectively monitored and enforced. To be effective, environmental managers require a comprehensive understanding of the full range of instruments available, and the respective roles they play in helping achieve positive environmental outcomes, including the pros and cons of the various regulatory alternatives.

Whole transcriptome-based miRNA-mRNA network analysis revealed the mechanism of inflammation-immunosuppressive damage caused by cadmium in common carp spleens

Cadmium (Cd) is a well-known environmental pollutant and can damage fish. MicroRNAs (miRNAs) can involve in inflammation and immunosuppression. However, the mechanisms of miRNAs are still unclear in common carp (Cyprinus carpio L.) treated by Cd. In current study, 54 juvenile common carp were randomly divided into the control group and the Cd group (0.26 mg L^-1 Cd) and were cultured for 30 days. The results revealed inflammatory damage in the spleens of common carp after Cd exposure using morphological construction. There were 23 differentially expressed miRNAs including 17 up-regulated differentially expressed miRNAs (miR-1-4-3p, miR-7-1-5p, miR-7-2-5p, miR-10-43-5p, miR-34-3-5p, miR-128-4-3p, miR-128-5-3p, miR-132-2-5p, miR-132-6-5p, miR-216-3-5p, miR-216-4-5p, miR-375-2-3p, miR-375-4-3p, miR-375-5-3p, miR-375-7-3p, miR-375-8-3p, and miR-724-5p) and 6 down-regulated differentially expressed miRNAs (miR-9-6-5p, miR-25-9-3p, miR-31-3-5p, miR-31-12-5p, miR-103-5-5p, and miR-122-1-3p). The 23 miRNAs regulated 2022 target mRNAs. There were 10 pathways and 9 annotation clusters on 2022 target mRNAs using KEGG and GO analysis, respectively. Among them, 5 pathways (NF-κB signaling pathway, Jak-STAT signaling pathway, MAPK signaling pathway, Th1 and Th2 cell differentiation, and Toll-like receptor signaling pathway) and 7 GO terms (negative regulation of immune system process, T cell mediated immunity, regulation of immune response, inflammatory response, positive regulation of inflammatory response, regulation of inflammatory response, and inflammasome complex) were associated with inflammatory response and immunosuppression. miR-375-4-3p, NF-κB, COX-2, PTGES, and IL-4/13A increased and miR-31-12-5p, miR-9-6-5p, MMP9, IL-11, SPI1, and T-Bet decreased using transcriptome sequencing and RT-qPCR in Cd-treated common carp spleens, which revealed that our results were reliable. Our data indicated that miRNAs mediated inflammation-immunosuppressive injury caused by Cd in common carp spleens using whole transcriptome-based miRNA-mRNA network analysis. Our study provided new insights into the toxicology of Cd exposure.

Assessing Energy-Based CO2 Emission and Workers’ Health Risks at the Shipbreaking Industries in Bangladesh

The study represents the estimation of energy-based CO2 emission and the health risks of workers involved in the shipbreaking industries in Sitakunda, Bangladesh. To calculate the carbon emission (CE) from three shipbreaking activities, i.e., metal gas cutting (GC), diesel fuel (FU) and electricity consumption (EC), we used the Intergovernmental Panel on Climate Change (IPCC) guidelines and Environmental Protection Agency (EPA)’s Emission and Generation Resource Integrated Database (eGRID) emission factors. Moreover, the geographic weighted regression (GWR) model was applied to assess the contribution of influencing factors of CE throughout the sampling points. To assess the workers’ health condition and their perceptions on environmental degradation, a semi-structured questionnaire survey among 118 respondents were performed. The results showed that total CO2 emissions from GC were 0.12 megatons (MT), 11.43 MT, and 41.39 MT for daily, monthly, and yearly respectively, and the values were significantly higher than the surrounding control area. Emissions from the FU were estimated as daily: 0.85 MT, monthly: 1.92 MT, and yearly: 17.91 MT, which were significantly higher than EC. The study also revealed that workers were very susceptible to accidental hazards especially death (91%), and pollution (79%). Environmental consequences and health risks of the workers in shipbreaking industry warrant more attention nationally and internationally at the industry-level.

Ship breaking or scuttling? A review of environmental, economic and forensic issues for decision support

In a globalized world, the world trade fleet plays a pivotal role in limiting transport costs. But, the management of obsolete ships is an acute problem, with most Ship Recycling Facilities (SRF) situated in developing countries. They are renowned for their controversial work and safety conditions and their environmental impact. Paradoxically, dismantlement is paid for by the shipowners in accordance with international conventions therefore it is more profitable for them to sell off ships destined for scrapping. Scuttling, the alternative to scrapping, is assessed in the present review to compare the cost/benefit ratios of the two approaches. Although scrapping provides employment and raw materials - but with environmental, health and safety costs - scuttling provides fisheries and diving tourism opportunities but needs appropriate management to avoid organic and metal pollution, introduction of invasive species and exacerbation of coastal erosion. It is also limited by appropriate bottom depth, ship type and number. The present review inventories the environmental, health, safety, economic, and forensic aspects of each alternative.

Collection of mullet fish (Mugil cephalus) from west coast of India: evaluation of its quality with relation to food safety

The present study focuses on bacterial and selected heavy metal contaminations of economically important mullet fish (Mugil cephalus) collected from West coast of Gujarat, India. Molecular identification using 16S rRNA sequencing revealed the presence of Aeromonas veronii, A. mollusorum, A. cavae, A. bivalvum, and V.alginolyticus in the gill and the intestine along with some other non-pathogenic bacteria. Pathogenicity of different Aeromonas species was confirmed by hemolysin assay. Apart from pathogenicity, multidrug resistance pattern was also reported against some commonly used antibiotics. Heavy metal analysis of different parts such as ventral and dorsal muscles as well as gills of M. cephalus revealed maximum concentration of Pb (24.08 ± 4.40 mg/kg), Cd (8.25 ± 3.04 mg/kg), and Cu (33.67 ± 5.34 mg/kg), which were higher than the permissible limit. To the best of our knowledge, this is the first study analyzing different heavy metals and associated bacteria in M. cephalus fish in India. Further, the distribution of heavy metals in M. cephalus fish from other countries was also compared.

Lead distribution in coastal and estuarine sediments around India

This study describes the geochemical distribution of lead (Pb) and identifies the critical factors that significantly control Pb distribution and speciation in coastal and estuarine sediments around India by using published data from the literature. Crustal sources influence the abundance of Pb in coastal sediment from the south-east and central-west coast of India. Parts of north-east, north-west, and south-west coast of India were polluted by Pb. Distribution of Pb in sediments, from the north-east and north-west coasts of India, were controlled by Fe-Mn oxyhydroxide mineral phases of the sediments. However, organic carbon (OC) seemed to be a dominant factor in controlling the distribution of Pb in sediments from the central-east and south-west coasts of India. The outcome of this study may help in decision-making to predict the levels of Pb from natural and anthropogenic sources and to control Pb pollution in coastal and estuarine sediments around India.

Magnetic characteristics of sediment grains concurrently contaminated with TBT and metals near a shipyard in Busan, Korea

Bottom sediments near shipyards are often susceptible to receiving accidental spills of TBT and metals or their degradation products from hull scraping of antifouling system paints applied prior to 2008, when the AFS Convention 2001 was not in force. We investigated TBT and metal contamination of sediments near the shipyards of a small marina located in Busan, Korea and found that they were highly contaminated with TBT, Cu, and Zn. To better understand the environmental impacts and to make an optimal remediation plan, we characterized individual antifouling fragments in terms of metal and TBT contents, magnetic properties, and grain-size. Coarse-sized individual antifouling fragments exhibited simultaneously high levels of TBT, metals and high magnetic susceptibility, and appeared to be a major source of pollution in the sediment. Therefore, magnetic separation in combination with size-separation appears to be a cost-effective remediation method to remove the TBT and metals from contaminated shipyard sediments.

Cancer incidence of Taiwanese shipbreaking workers who have been potentially exposed to asbestos

BACKGROUND

Shipbreaking remains one of the most dangerous jobs worldwide. Shipbreaking workers are exposed to many hazardous chemicals, especially asbestos. Unfortunately, long-term follow-up studies of cancer incidence patterns in shipbreaking workers are lacking. This study examines whether there is an increased risk of cancer among male shipbreaking workers over a 24-year follow-up period.

METHODS

4155 male shipbreaking worker's information was retrospectively collected from Kaohsiung's Shipbreaking Workers Union database from 1985. The study cohort was linked to the Taiwan Cancer Registry from 1985 to 2008 for new cancer cases. The expected number of cancers for shipbreaking workers was calculated by using the age (5-year intervals) and calendar time-specific annual rates of cancer incidence with reference to the general population of Taiwan from 1985 to 2008. Standardized incidence ratios (SIRs) were calculated as relative risk estimates. The hazard ratio (HR) for cancer was calculated for the shipbreaking workers with Total Exposure Potential Scores for asbestos.

RESULTS

After consideration of a 5-year latency period, an elevated incidence of overall cancer (N=368; SIR=1.13 (1.01-1.25)), oral cavity cancer (N=83; SIR=1.99 (1.58-2.46)), and trachea, bronchus, and lung cancers (N=53; SIR=1.36 (1.02-1.78)) was found among male shipbreaking employees. Moreover, mesothelioma cases were found in those who had the occupation of flame cutter. The high asbestos exposure group was associated with an increased SIR of developing overall cancer and oral cancer, whether we considered a 5-year or 10-year latency period.

CONCLUSION

Asbestos-related diseases, including lung cancer and mesothelioma, were seen in excess in these shipbreaking workers and some cases appeared to have a dose-dependent relationship. Preventative measures among male shipbreaking workers should be researched further.

Biodegradation of phenanthrene in bioaugmented microcosm by consortium ASP developed from coastal sediment of Alang-Sosiya ship breaking yard

A phenanthrene-degrading bacterial consortium (ASP) was developed using sediment from the Alang-Sosiya shipbreaking yard at Gujarat, India. 16S rRNA gene-based molecular analyses revealed that the bacterial consortium consisted of six bacterial strains: Bacillus sp. ASP1, Pseudomonas sp. ASP2, Stenotrophomonas maltophilia strain ASP3, Staphylococcus sp. ASP4, Geobacillus sp. ASP5 and Alcaligenes sp. ASP6. The consortium was able to degrade 300 ppm of phenanthrene and 1000 ppm of naphthalene within 120 h and 48 h, respectively. Tween 80 showed a positive effect on phenanthrene degradation. The consortium was able to consume maximum phenanthrene at the rate of 46 mg/h/l and degrade phenanthrene in the presence of other petroleum hydrocarbons. A microcosm study was conducted to test the consortium's bioremediation potential. Phenanthrene degradation increased from 61% to 94% in sediment bioaugmented with the consortium. Simultaneously, bacterial counts and dehydrogenase activities also increased in the bioaugmented sediment. These results suggest that microbial consortium bioaugmentation may be a promising technology for bioremediation.

Trace metals pollution in seawater and groundwater in the ship breaking area of Sitakund Upazilla, Chittagong, Bangladesh

This study reveals potential accumulation of trace metals in the sea and groundwater due to ship breaking activities which take place along the Bay of Bengal in Sitakund Upazilla, Chittagong, Bangladesh. When compared with WHO and Bangladesh domestic standards for water quality, it is revealed that seawater was strongly polluted by Fe and Hg, moderately by Mn and Al, and slightly by Pb and Cd. Groundwater was strongly polluted by Fe, Pb and Hg, moderately by Mn and Al, and slightly by As. Trace element concentrations of all seawater samples exceeded the average concentration of elements in the Earth's seawater. The application of Principal Components Analysis identified two sources of pollution-marine and ship breaking. The mechanism of groundwater pollution inferred that if seawater is polluted, nearby groundwater is also polluted with trace metals due to the influence of seawater intrusion.

Geochemical and geo-statistical assessment of selected heavy metals in the surface sediments of the Gorgan Bay, Iran

We investigated heavy metal concentrations of zinc (Zn), copper (Cu), chromium (Cr), and lead (Pb), their spatial distribution and enrichment factor index in surface sediments of the Gorgan Bay. Sediment Quality Guidelines were also applied to assess adverse biological effects of these metals. Heavy metals were determined by inductively coupled plasma-mass spectroscopy (ICP-MS). The results indicated mean concentrations (ppm) of heavy metals were (mean±S.D.) Pb: 11.5±4.88, Cu: 18±8.83, Zn: 42±22.15 and Cr: 32±15.19. Based on Enrichment index, the Gorgan Bay is a low-enriched to non-enriched bay. Heavy metal contents were lower than the standard limits of PEL, ERL, and ERM that reveal no threatening influence of the metals in the Bay.

Polycyclic aromatic and aliphatic hydrocarbons pollution at the coast of Aliağa (Turkey) ship recycling zone

Aliağa Bay is one of the most important maritime zones of Turkey where shipping activity, shipbreaking industry, steel works and petrochemical complexes exist together. Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons in sediment of the Aliağa Bay were investigated to evaluate an environmental risk assessment from PAHs contamination in 2009-2010. Aliphatic and PAHs diagnostic ratios were showed to be mainly petroleum-originated and pyrolitic contaminations, respectively. The TEL/PEL analysis suggests that Aliağa sediments were likely to be contaminated by acutely toxic PAH compounds.

Heavy metals contamination levels at the Coast of Aliağa (Turkey) ship recycling zone

Aliağa Bay is one of the most important maritime zones of Turkey where shipping activity, shipbreaking industry, steel works and petrochemical complexes exist together. Concentrations of heavy metals and organic carbon in sediment of the Aliağa Bay were investigated to evaluate an environmental risk assessment from metals contamination in 2009-2010. Comparison of the metal concentrations with average shale and Mediterranean background levels revealed that most of the samples from the Aliağa were polluted with Hg, Cd, Pb, Cr, Cu, Zn, Mn and Ni. It was found that Hg, Pb, Cu, Zn and Ni levels in Aliağa Bay exceeded the PEL values. Sediments, contaminated with Pb, Cr, Cu, Zn and Ni were considered as heavily polluted per the SQG.

Adaptation of microalgae to a gradient of continuous petroleum contamination

In order to study adaptation of microalgae to petroleum contamination, we have examined an environmental stress gradient by crude oil contamination in the Arroyo Minero River (AMR), Argentina. Underground crude oil has constantly leaked out since 1915 as a consequence of test drilling for possible petroleum exploitation. Numerous microalgae species proliferated in AMR upstream of the crude oil spill. In contrast, only four microalgal species were detected in the crude oil spill area. Species richness increases again downstream. Microalgae biomass in the crude oil spill area is dominated by a mesophile species, Scenedesmus sp. Effects of oil samples from AMR spill on photosynthetic performance and growth were studied using laboratory cultures of two Scenedesmus sp. strains. One strain (Se-co) was isolated from the crude oil spill area. The other strain (Se-pr) was isolated from a pristine area without petroleum contamination. Crude oil has undetectable effects on Se-co strain. In contrast crude oil rapidly destroys Se-pr strain. However, Se-pr strain can adapt to low doses of petroleum (≤ 3% v/v total hydrocarbons/water) by means of physiological acclimatization. In contrast, only rare crude oil-resistant mutants are able to grow under high levels of crude oil (≥ 10% v/v total hydrocarbons/water). These crude oil-resistant mutants have arisen through rare spontaneous mutations that occur prior to crude oil exposure. Species richness in different areas of AMR is closely connected to the kind of mechanism (genetic adaptation vs. physiological acclimatization) that allows adaptation. Resistant-mutants are enough to assure the survival of microalgal species under catastrophic crude oil spill.

In situ heavy metals (copper, lead and cadmium) in different plankton compartments and suspended particulate matter in two coupled Mediterranean coastal ecosystems (Toulon Bay, France)

We monitored the concentrations of copper, lead and cadmium in seawater, in suspended particulate matter (SPM) and in bacteria, phyto- and zooplankton communities separated from abiogenic particles, over a one year cycle in two coupled Mediterranean coastal ecosystems (Little Bay (LiB) and Large Bay (LaB)). Metals were present in seawater in the order Cu>Pb>Cd in both bays and showed important variations within the same month than among months. In LiB, their concentrations were between 0.62 and 2.82 microg Cu l(-1), 0.16 and 19 microg Pb l(-1) and 0.007 and 0.14 microg Cd l(-1), respectively, whereas in LaB, they were between 0.23 and 2.11 microg Cu l(-1), 0.09 and 0.76 microg Pb l(-1) and not detected and 0.65 microg Cd l(-1). SPM play an important role on metal adsorption, especially for copper. Bioaccumulation factors showed that bacteria and phytoplankton accumulate metals whereas zooplankton tends to biodiminish them in the plankton food web.

Effluent toxicity test using developmental stages of the marine polychaete Hydroides elegans

The US Environmental Protection Agency (USEPA) has established a suite of methods that use coastal invertebrate species as bioassay organisms to test industrial and domestic effluent as well as coastal waters for potential toxicity. Although these methods are used globally, the potential of such toxicity tests has not been adequately explored for Asian coastal waters. This study describes bioassay utilizing the gametes of Hydroides elegans to monitor coastal water quality and is based on the sensitivity of H. elegans embryo and larva to different concentrations of effluents and water samples collected from different regions of east coast of India. Among the water samples collected from different regions, seawater from Ennore station showed decrease in percentage of development, and 25% effluent concentration led to development arrest of H. elegans embryos. The different morphological effects produced by effluents clearly reflect the defect in early differentiation of embryonic cells. Since fertilization can be inhibited in the presence of any xenobiotic, both fertilization and early development can be used as a biological indicator for a rapid bioassay to monitor pollution. Toxicity tests utilizing early life stages of H. elegans are suitable for the assessment of effects produced by low levels of pollutants due to their high sensitivity to various contaminants relative to other marine species and also due to the relative simplicity of the bioassay.

Comparison of heavy metal toxicity in life stages (spermiotoxicity, egg toxicity, embryotoxicity and larval toxicity) of Hydroides elegans

A toxicity test was developed to examine the effects of heavy metal contaminants on the early life stages of the marine polychaete. We have studied the effects of metals on fertilization and early development of marine polychaete Hydroides elegans. These heavy metals have often been found in polluted ground and water near industrial discharges, and have therefore been detected from time to time in the food chain. They have been reported to alter various reproduction functions in various animals including marine populations. The toxic effect of mercury, cadmium, lead, nickel and zinc on sperm viability, fertilization, embryogenesis and larvae of H. elegans was examined. We observed that the rate of fertilization decreased when the sperm was incubated with heavy metals. Treatment of eggs with each metal did not prevent fertilization, but delayed or blocked the first mitotic divisions, and altered early embryonic development. All these effects were observed at relatively high concentrations. However, bio-accumulation in sediments and aquatic organisms have been reported. Polychaete eggs may then be in contact with very high concentrations of these heavy metals in areas where these metals are not handled or stocked properly, and then develop into abnormal embryos. In addition to bivalves and sea-urchins, polychaete embryos can provide biological criteria for seawater quality standards taking into account the sensitivity of the invertebrates and their contribution in detection of harmful chemicals with no marked effect on the species. Our results indicate that the early development of H. elegans is highly sensitive to heavy metals and this polychaete can be routinely employed as a test organism for ecotoxicity bioassays in tropical and subtropical regions.

Effects of Cd(II) and cu(II) on microbial characteristics in 2-chlorophenol-degradation anaerobic bioreactors

The effects of Cd2+ and Cu2+ at 300 mg/L on anaerobic microbial communities that degrade 2-cholorophenol (2-CP) were examined. Based on the polymerase chain reaction (PCR) of 16S rDNA, bacterial community diversity and archaeal community structure were analyzed with denaturing gradient gel electrophoresis (DGGE) and cloning, respectively. Degradation capabilities of the anaerobic microbial community were drastically abated and the degradation efficiency of 2-CP was reduced to 60% after shock by Cu2+ and Cd2+, respectively. The bacterial community structure was disturbed and the biodiversity was reduced after shock by Cu2+ and Cd2+ for 3 d. Some new metal-resistant microbes which could cope with the new condition appeared. The sequence analysis showed that there existed common Archaea species in control sludge and systems when treated with Cu2+ and Cd2+, such as Methanothrix soehngenii, Methanosaeta concilii, uncultured euryarchaeote, and so on. Both the abundance and diversity of archaeal species were altered with addition of Cd2+ and Cu2+ at high concentration. Although the abundance of the predominant archaeal species decreased with Cd2+ and Cu2+ addition for 3 d, they recovered to some extent after 10 d. The diversity of archaeal species was remarkably reduced after recovery for 10 d and the shift in archaeal composition seemed to be irreversible. The 2-CP-degradation anaerobic system was more sensitive to Cu2+ than Cd2+.

Seasonal distribution and contamination levels of total PHCs, PAHs and heavy metals in coastal waters of the Alang-Sosiya ship scrapping yard, Gulf of Cambay, India

Alang-Sosiya situated on the Gulf of Cambay is one of the largest ship breaking yard in the world. The seasonal distribution and contamination levels of dissolved and/or dispersed total petroleum hydrocarbons (PHCs), total polycyclic aromatic hydrocarbons (PAHs) and heavy metals in seawater during high tide are investigated. The concentrations of petroleum hydrocarbons and heavy metals are higher in the winter than in the monsoon and summer. The concentrations of total PHCs and PAHs are about three times higher in the winter and two times in the monsoon or summer at Along-Sosiya and about twice in all seasons at two stations one on either side 5 km away from it as compared to the reference station at Mahuva, 60 km away towards the south. Further, the levels of PHCs are correlated with salinity and compared with those of other regions. The concentration of all metals is the highest in the winter season followed by the monsoon and summer. We carried out the quantitative analysis of the possible relationships among 13 variables such as Al, Fe, Pb, Mn, Cu, Zn, Cd, Cr, Co, pH, NO3-, NO2 and PO4(3-).

Abundances, depositional fluxes, and homologue patterns of polychlorinated biphenyls in dated sediment cores from the Pearl River Delta, China

Despite the recent efforts to investigate the distribution and fate of persistent organic pollutants in the tropical and subtropical regions of Asia, very little was known about the temporal change of polychlorinated biphenyls (PCBs) in the environmental ecosystem of China. In this study, three dated sediment cores collected from the Pearl River Delta of southern China were analyzed for a large suite of PCB congeners, from which the temporal profiles of PCB abundances, fluxes, and homologue patterns were constructed. The sedimentary inventories of total PCBs at the sampling sites ranged from 480 to 1310 ng/cm2, at the low end of the worldwide figures. Although production and use of PCBs have been banned or highly restricted in China since the early 1980s, the fluxes of total PCBs continued to increase in the Pearl River Delta sediments. There was a concurrent increase of PCB fluxes and gross domestic product per capita in the region from 1980 to 1997, and a decline of agricultural land use was evident at the same time. Apparently, large-scale land transform since the early 1980s as well as emissions from the PCB-containing electrical equipments were responsible for the sharp rise of PCB fluxes in the recent sediments. The difference in the PCB homologue patterns from 1940 to the mid-1970s was probably indicative of the different timelines of PCB usage in Macao/Hong Kong and mainland China and the differenttypes of technical PCBs commercially used. PCBs were detectable in sediments deposited well before the time frame when production of PCBs began (before 1930) and were relatively enriched in the less chlorinated homologue groups (3Cl and 4Cl PCBs), suggesting the downward mobility of lightly chlorinated PCB congeners in the sediment column.

Distribution, enrichment and accumulation of heavy metals in coastal sediments of Alang-Sosiya ship scrapping yard, India

Since its inception in 1982, the Alang-Sosiya yard has become the largest ship scrapping works in the world. Several hundreds of ships arrive every year. The degree of heavy metal contamination has been studied in bulk and fine sediments from the intertidal zone of this ship scrapping yard, two stations, one on either side at 5 km distance and one reference station 60 km distance near Mahuva, towards the south. The samples have been subjected to a total digestion technique and analysed for elements: Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, Zn and Al, and %TOC. The absolute metal concentrations reflected variations in BF and FF sediment samples with organic matter content. Enrichment factors (EF) and geoaccumulation indices (Igeo) have been calculated and the relative contamination levels are assessed at these sites. At Alang-Sosiya, the enrichment of heavy metals has been observed to be relatively high.

Tolerance and accumulation of hexavalent chromium by two seaweed associated aspergilli

Marine seaweed (Eucheuma sp.) associated strains of Aspergillus flavus and Aspergillus niger were tested for their Cr(VI) tolerance. Both the isolates showed luxuriant growth in different concentrations of Cr(VI), i.e., 25, 50 and 100 ppm. There was no marked variation in the dry weight of control and test isolates, which indicated that both the isolates can tolerate a wide range of hexavalent chromium and their application for bioremediation purpose can be envisaged as XRF data revealed both the isolates accumulated more than 25% of the chromium supplied. A. flavus invariably exhibited higher accumulation potential.

Quantification and classification of ship scraping waste at Alang-Sosiya, India

Alang-Sosiya located on the Western Coast of Gulf of Cambay, is the largest ship recycling yard in the world. Every year on average 365 ships having a mean weight (2.10x10(6)+/-7.82x10(5) LDT) are scrapped. This industry generates a huge quantity of solid waste in the form of broken wood, rubber, insulation materials, paper, metals, glass and ceramics, plastics, leather, textiles, food waste, chemicals, paints, thermocol, sponge, ash, oil mixed sponges, miscellaneous combustible and non-combustible. The quantity and composition of solid waste was collected for a period of three months and the average values are presented in this work. Sosiya had the most waste 15.63 kg/m(2) compared to Alang 10.19 kg/m(2). The combustible solid waste quantity was around 83.0% of the total solid waste available at the yard, which represents an average weight of 9.807 kg/m(2); whereas, non-combustible waste is 1.933 kg/m(2). There is not much difference between the average of total solid waste calculated from the sampling data (96.71 MT/day) and the data provided by the port authorities (96.8 MT/day).

Fouling and ships' hulls: how changing circumstances and spawning events may result in the spread of exotic species

Organisms fouling ships' hulls are continually in transit worldwide. Although effective antifouling paints incorporating organotins have considerably reduced fouling biomass these paints have a limited period of effectiveness, which may be less than the ships' inter-docking period, depending on sea temperature and abrasion. Vessels immersed over several years can allow fouling communities to develop and spread beyond their native distribution. This process of establishment is not fully understood. This review proposes that short rapid turn-around of vessels with mature attached biota can result in synchronized spawnings and production of sufficient zygotes to form a founder population. Spawning may be induced by changes in temperature or salinity on entry into a port, according to season. The diversity of taxa in transit on ships' hulls includes commercial molluscs, which have the potential to transmit their diseases or pests to port regions. Several factors may act in the further enhancement of exotic species establishment including changes of in-port berthing regions to more marine conditions. Ships today are generally larger, and faster, and have a high frequency of port visits thereby increasing the number of spawning opportunities, perhaps with a larger inoculum size. With trade expansion, new trading routes, political events and changes in climate, new pathways for invasion will emerge. Greater controls on industrial discharges, improved treatments of urban wastes and better management of waste runoff into rivers as well as a phasing out of organotin antifoulants will mean a reduced toxicity in port regions. This may enable a smaller inoculum to colonize by creating opportunities for establishment not present in the previous 25 years. Some invaders will have unwanted consequences for the environment, economies and human health.