Capability of space borne multispectral image for detecting discoloration in optically complex coastal waters.

Coastal pollutants, from harmful algal blooms, sewage and industrial discharges, pose severe risks to marine ecosystems and public health. Recently, Promenade Beach in Puducherry, Southeast-India, experienced reddish-brown water discoloration, suspected to result from either algal blooms or suspended matter. This study monitored the spatial extent and characteristics of the discoloration using Sentinel-2 satellite images from September to November 2023, with field observations and laboratory analyses. Analyses included measurements of chlorophyll-a (Chl-a), Total Suspended Matter (TSM), and the Normalized Difference Chlorophyll Index (NDCI) to differentiate between algal blooms and other pollutants. The satellite data indicated extents of discoloration, with high TSM concentrations (>45 g/m3) and negative NDCI values suggesting absence of algal blooms. No mortality of aquatic organisms was observed during this discoloration, indicating no deleterious impact on aquatic life. This approach highlights the importance of combining satellite technology with field data for effective coastal pollution monitoring, essential for protecting marine ecosystems.

Phylogenetic affiliation of Pedinomonas noctilucae and green Noctiluca scintillans nutritional dynamics in the Gulf of Mannar, Southeastern Arabian Sea.

The present investigation focused on studying the phylogenetic position of the green Noctiluca endosymbiont, Pedinomonas noctilucae, collected from the Gulf of Mannar, India. In this study, we re-examined the evolutionary position of this endosymbiotic algae using rbcL sequences. The phylogenetic analysis revealed that P. noctilucae is distantly related to the Pedinomonas species, and formed a monophyletic clade with Marsupiomandaceae. Based on the phylogenetic association of endosymbiont with Maruspiomonadales it was concluded that the endosymbiont belongs to an independent genus within the family Marsupiomonadaceae. At the site of the bloom, Noctiluca scintillans was found to exhibit a dense monospecific proliferation, with an average cell density of 27.l88 × 103 cells L-1. The investigation revealed that the green Noctiluca during its senescent phase primarily relied on autotrophic nutrition, which was confirmed by the presence of a high number of trophonts, vegetatively reproducing cells (1.45 × 103 cells L-1) and the absence of food vacuoles.

Soil contamination by brominated flame retardants in open waste dumping sites in Asian developing countries.

In Asian developing countries, large amounts of municipal wastes are dumped into open dumping sites each day without adequate management. This practice may cause several adverse environmental consequences and increase health risks to local communities. These dumping sites are contaminated with many chemicals including brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs). BFRs may be released into the environment through production processes and through the disposal of plastics and electronic wastes that contain them. The purpose of this study was to elucidate the status of BFR pollution in municipal waste dumping sites in Asian developing countries. Soil samples were collected from six open waste dumping sites and five reference sites in Cambodia, India, Indonesia, Malaysia, and Vietnam from 1999 to 2007. The results suggest that PBDEs are the dominant contaminants in the dumping sites in Asian developing countries, whereas HBCD contamination remains low. Concentrations of PBDEs and HBCDs ranged from ND to 180 µg/kg dry wt and ND to 1.4 µg/kg dry wt, respectively, in the reference sites and from 0.20 to 430 µg/kg dry wt and ND to 2.5 µg/kg dry wt, respectively, in the dumping sites. Contamination levels of PBDEs in Asian municipal dumping sites were comparable with those reported from electronic waste dismantling areas in Pearl River delta, China.

Perchlorate contamination of groundwater from fireworks manufacturing area in South India.

Perchlorate contamination was investigated in groundwater and surface water from Sivakasi and Madurai in the Tamil Nadu State of South India. Sensitive determination of perchlorate (LOQ = 0.005 µg/L) was achieved by large-volume (500 µL) injection ion chromatography coupled with tandem mass spectrometry. Concentrations of perchlorate were <0.005-7,690 µg/L in groundwater (n = 60), <0.005-30.2 µg/L in surface water (n = 11), and 0.063-0.393 µg/L in tap water (n = 3). Levels in groundwater were significantly higher in the fireworks factory area than in the other locations, indicating that the fireworks and safety match industries are principal sources of perchlorate pollution. This is the first study that reports the contamination status of perchlorate in this area and reveals firework manufacture to be the pollution source. Since perchlorate levels in 17 out of 57 groundwater samples from Sivakasi, and none from Madurai, exceeded the drinking water guideline level proposed by USEPA (15 µg/L), further investigation on human health is warranted.

Fertilizer induced nitrous oxide emissions from Vertisols and Alfisols during sweet sorghum cultivation in the Indian semi-arid tropics.

Nitrous oxide (N(2)O) emissions from Vertisols and Alfisols during sweet sorghum cultivation in the Indian semi-arid tropics were determined using a closed chamber technique during the rainy season (June-October) of 2010. The study included two treatments, nitrogen (N) at a rate of 90 kg/ha and a control without N fertilizer application. The N(2)O emissions strongly coincided with N fertilization and rainfall events. The cumulative N(2)O-N emission from Alfisols was 1.81 N(2)O-N kg/ha for 90 N treatment and 0.15 N(2)O-N kg/ha for the 0 N treatment. Similarly, the N(2)O-N emission from Vertisols was 0.70 N(2)O-N kg/ha for 90 N treatment and 0.09 N(2)O-N kg/ha for the 0 N treatment. The mean N(2)O-N emission factor for fertilizer induced emissions from the Alfisols was 0.90% as compared to 0.32% for Vertisols. Our results suggest that the N(2)O emissions are dependent on the soil properties. Therefore, the monitoring of N(2)O emissions from different agro-ecological regions, having different soil types, rainfall characteristics, cropping systems and crop management practices are necessary to develop comprehensive and accurate green house gas inventories.

Geographical distribution of non-PBDE-brominated flame retardants in mussels from Asian coastal waters.

Hexabromocyclododecanes (HBCDs), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), and decabromodiphenyl ethane (DBDPE) used as alternatives for polybrominated diphenyl ethers (PBDEs) are also persistent in the environment as PBDEs. Limited information on these non-PBDE brominated flame retardants (BFRs) is available; in particular, there are only few publications on environmental pollution by these contaminants in the coastal waters of Asia. In this regard, we investigated the contamination status of HBCDs, BTBPE, and DBDPE in the coastal waters of Asia using mussels as a bioindicator. Concentrations of HBCDs, BTBPE, and DBDPE were determined in green (Perna viridis) and blue mussels (Mytilus edulis) collected from the coastal areas in Cambodia, China (mainland), SAR China (Hong Kong), India, Indonesia, Japan, Malaysia, the Philippines, and Vietnam on 2003-2008. BTBPE and DBDPE were analyzed using GC-MS, whereas HBCDs were determined by LC-MS/MS. HBCDs, BTBPE, and DBDPE were found in mussels at levels ranging from <0.01 to 1,400, <0.1 to 13, and <0.3 to 22 ng/g lipid wt, respectively. Among the three HBCD diastereoisomers, α-HBCD was the dominant isomer followed by γ- and ß-HBCDs. Concentrations of HBCDs and DBDPE in mussels from Japan and Korea were higher compared to those from the other Asian countries, indicating extensive usage of these non-PBDE BFRs in Japan and Korea. Higher levels of HBCDs and DBDPE than PBDEs were detected in some mussel samples from Japan. The results suggest that environmental pollution by non-PBDE BFRs, especially HBCDs in Japan, is ubiquitous. This study provides baseline information on the contamination status of these non-PBDE BFRs in the coastal waters of Asia.

Monitoring temporal and spatial trends of legacy and emerging contaminants in marine environment: results from the environmental specimen bank (es-BANK) of Ehime University, Japan.

The Environmental Specimen Bank (es-BANK) for Global Monitoring at the Center for Marine Environmental Studies, Ehime University, Japan has more than four decades of practical experience in specimen banking. Over the years, es-BANK has archived specimens representing a wide range of environmental matrices, i.e. fishes, reptiles, birds, aquatic mammals, terrestrial mammals, human, soils, and sediments. The samples have been collected as part of the various monitoring programs conducted worldwide. The current review is a summary of selected studies conducted at the Center for Marine Environmental Studies, on temporal and spatial trends of legacy and emerging contaminants in the marine environment. One of the major conclusions drawn from the studies is that environmental problems are no more regional issues and, thus, environmental specimen banking should not be limited to national boundaries, but should have a global outlook.

Genomic evidence of intraspecific recombination in sugarcane mosaic virus.

The sugarcane mosaic virus (SCMV) of the genus potyvirus, which primarily affects maize, sugarcane, sorghum, abaca, and grasses, occurs worldwide and causes significant economic loss. Using the full genome sequences of SCMV and several recombination detection methods, in this study we report that recombination is the major driving force in the evolution and emergence of several new variants of SCMV. We reported eight highly significant (P < 0.001) recombination break points, majority of which are located within 6K1-VPg-NIaPro-NIb region, thus indicating a region for recombination hotspot. The observation of commonalities of same recombination events among the SCMV isolates between the countries (Spain and Mexico), and within the country (within China, and within Mexico), suggests common origin of the isolates in respective regions.

Trace elements and stable isotope ratios (delta(13)C and delta(15)N) in fish from deep-waters of the Sulu Sea and the Celebes Sea.

Trace elements (TEs) and stable isotope ratios (delta(15)N and delta(13)C) were analyzed in fish from deep-water of the Sulu Sea, the Celebes Sea and the Philippine Sea. Concentrations of V and Pb in pelagic fish from the Sulu Sea were higher than those from the Celebes Sea, whereas the opposite trend was observed for delta(13)C. High concentrations of Zn, Cu and Ag were found in non-migrant fish in deep-water, while Rb level was high in fish which migrate up to the epipelagic zone, probably resulting from differences in background levels of these TEs in each water environment or function of adaptation to deep-water by migrant and non-migrant species. Arsenic level in the Sulu Sea fish was positively correlated with delta(15)N, indicating biomagnification of arsenic. To our knowledge, this is the first study on relationship between diel vertical migration and TE accumulation in deep-water fish.

Spatial distribution of polybrominated diphenyl ethers and hexabromocyclododecanes in sediments from coastal waters of Korea.

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) were determined in surface sediments collected from 24 coastal locations in Korea. The concentrations of summation operatorPBDEs (defined as the sum of all targeted PBDE congeners except for BDE-209) and BDE-209 ranged from 0.05 to 32 ng g(-1) dry wt. and from 0.40 to 98 ng g(-1) dry wt., respectively. The PBDE congener compositions were dominated by BDE-209, which is in accordance with the consumption of decaBDE mixture in Korea. HBCD concentrations ranged from 0.39 to 59 ng g(-1) dry wt. Concentrations of PBDEs and HBCDs were found to be higher near locations with industrial complexes and harbors, associating these compounds to urbanization and industrialization. Significant positive correlations between PBDE and HBCD concentrations and organic carbon content in sediments imply the role played by organic matter in the contaminant transport and trapping in the aquatic environment.

Organohalogen compounds in deep-sea fishes from the western North Pacific, off-Tohoku, Japan: Contamination status and bioaccumulation profiles.

Twelve species of deep-sea fishes collected in 2005 from the western North Pacific, off-Tohoku, Japan were analyzed for organohalogen compounds. Among the compounds analyzed, concentrations of DDTs and PCBs (up to 23,000 and 12,400 ng/g lipid wt, respectively) were the highest. The present study is the foremost to report the occurrence of brominated flame retardants such as PBDEs and HBCDs in deep-sea organisms from the North Pacific region. Significant positive correlations found between delta(15)N ( per thousand) and PCBs, DDTs and PBDEs suggest the high biomagnification potential of these contaminants in food web. The large variation in delta(13)C (per thousand) values observed between the species indicate multiple sources of carbon in the food web and specific accumulation of hydrophobic organohalogen compounds in benthic dwelling carnivore species like snubnosed eel. The results obtained in this study highlight the usefulness of deep-sea fishes as sentinel species to monitor the deep-sea environment.

Contamination by trace elements at e-waste recycling sites in Bangalore, India.

The recycling and disposal of electronic waste (e-waste) in developing countries is causing an increasing concern due to its effects on the environment and associated human health risks. To understand the contamination status, we measured trace elements (TEs) in soil, air dust, and human hair collected from e-waste recycling sites (a recycling facility and backyard recycling units) and the reference sites in Bangalore and Chennai in India. Concentrations of Cu, Zn, Ag, Cd, In, Sn, Sb, Hg, Pb, and Bi were higher in soil from e-waste recycling sites compared to reference sites. For Cu, Sb, Hg, and Pb in some soils from e-waste sites, the levels exceeded screening values proposed by US Environmental Protection Agency (EPA). Concentrations of Cr, Mn, Co, Cu, In, Sn, Sb, Tl, Pb and Bi in air from the e-waste recycling facility were relatively higher than the levels in Chennai city. High levels of Cu, Mo, Ag, Cd, In, Sb, Tl, and Pb were observed in hair of male workers from e-waste recycling sites. Our results suggest that e-waste recycling and its disposal may lead to the environmental and human contamination by some TEs. To our knowledge, this is the first study on TE contamination at e-waste recycling sites in Bangalore, India.

Organohalogen contaminants in striped dolphins (Stenella coeruleoalba) from Japan: present contamination status, body distribution and temporal trends (1978-2003).

Organohalogen contaminants including PCBs, DDTs, CHLs, HCHs, HCB, PBDEs and HBCDs were determined in striped dolphins (Stenella coeruleoalba) found stranded at Gogo-shima (n=6, 2003) and collected from Taiji (n=15, 1978-1992) in Japan. All target compounds were significantly detected in all the specimens, indicating ubiquitous contamination of oceanic cetaceans in northwest Pacific Ocean. Examination of body distribution of organohalogens in the six specimens from Gogo-shima showed no significant difference in concentrations among the analyzed tissues, except for brain, which had lower levels possibly due to the existence of blood-brain barrier. For evaluating temporal trends, archived blubber samples of adult male stripped dolphins collected in 1978, 1979, 1986 and 1992 were analyzed. Concentrations of PCBs, DDTs and HCHs did not change significantly during 1978-2003. In contrast, remarkable increasing trends of PBDEs and HBCDs were observed, suggesting growing consumption in Japan and surrounding countries in recent years.

Trace elements and stable isotopes (delta13C and delta15N) in shallow and deep-water organisms from the East China Sea.

Trace elements (22) and stable isotope ratios (delta15N and delta13C) were analyzed in marine organisms from shallow (SW) and deep-water (DW) of the East China Sea to understand biomagnification and prey source of trace elements. In the benthic marine organisms from DW, delta15N values were negatively correlated with Ba, Cu, Ag, Mo, Sr, As, and Co concentrations. This may be due to the specific accumulation in lower trophic animals and/or the biodilution through the food web in DW. Relationships between delta15N and concentrations of Co, Cr, Bi, and Tl in fish and Ag, Bi, V, Hg, and Tl in crustaceans showed positive correlations, suggesting that trophic position was affecting the concentrations of those elements in phyla, with higher trophic animals retaining higher concentrations than the lower trophic animals. Positive correlations between delta13C and Rb were observed in marine organisms. Therefore, Rb may be a possible substitute of delta13C as tracer of prey source in the East China Sea although further investigation is required.

Brominated flame retardants in the environment of Asia-Pacific: an overview of spatial and temporal trends.

In this paper, we summarize spatial and temporal trends of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in coastal and marine biota, and further assess human exposure to these brominated flame retardants (BFRs) in Asia-Pacific. The review is based mainly on the studies that were conducted in our laboratory and utilized samples archived in the environmental specimen bank (es-BANK) of Ehime University, Japan. The studies suggest that the target BFRs are ubiquitous in the environment of Asia-Pacific. Examination of spatial trends reveals that concentrations of these contaminants are relatively high in samples from Korea, South China and Japan. In general, the magnitude of environmental contamination by PBDEs in Asia-Pacific, as well as human exposure to these contaminants, seem to be comparable to or slightly higher than in Europe, but lower than in North America. Evaluation of temporal trends in concentrations of BFRs in marine mammals from the coastal waters of Japan and China showed drastic increase during the last 30 years. These changes in BFR levels in samples from Japan were in line with trends in production/use of the commercial formulations. Since the withdrawal of some PBDE products from the Japanese market in the 1990s, concentrations of HBCDs appear to exceed those of PBDEs, reflecting increasing usage of HBCDs over PBDEs. The increasing environmental contamination by BFRs in Chinese coastal waters indicates that contamination by BFRs has already become evident, even in developing countries. In view of the rising environmental levels and the high consumption volume of BFRs in Asia, further efforts should be made to monitor environmental contamination by these chemicals in order to identify sources and reduce emissions.

Levels and body distribution of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in freshwater fishes from the Yangtze River, China.

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) were determined in muscle, liver and eggs of freshwater fishes from the lower reach of the Yangtze River, China. The present study is the first to report HBCD concentrations in the environment of China. The concentrations of PBDEs and HBCDs in muscle of freshwater fishes from the Yangtze River ranged from 18 to 1100ng/g and 12 to 330ng/g lipid weight (wt.), respectively. When compared with other regions of the world, the contamination of PBDEs in biota could be regarded as moderate, whereas contamination of HBCDs in biota was relatively high. The PBDE congener profiles in fishes of the present study were markedly different from those observed in freshwater and marine fishes from other regions of the world. In the present study, BDE-15, BDE-28 and BDE-47 were the predominant congeners in the fishes. This particular congener profile in fishes from the Yangtze River revealed that a specific commercial PBDE formulation (probably made in China) might have been used in the Yangtze River Delta region.

Asian Mussel Watch Program: contamination status of polybrominated diphenyl ethers and organochlorines in coastal waters of Asian countries.

Mussel samples were used in this study to measure the levels of polybrominated diphenyl ethers (PBDEs) and organochlorines (OCs) in the coastal waters of Asian countries like Cambodia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, the Philippines, and Vietnam. PBDEs were detected in all the samples analyzed, and the concentrations ranged from 0.66 to 440 ng/g lipid wt. Apparently higher concentrations of PBDEs were found in mussels from the coastal waters of Korea, Hong Kong, China, and the Philippines, which suggests that significant sources of these chemicals exist in and around this region. With regard to the composition of PBDE congeners, BDE-47, BDE-99, and BDE-100 were the dominant congeners in most of the samples. Among the OCs analyzed, concentrations of DDTs were the highest followed by PCBs > CHLs > HCHs > HCB. Total concentrations of DDTs, PCBs, CHLs, and HCHs in mussel samples ranged from 21 to 58 000, 3.8 to 2000, 0.93 to 900, and 0.90 to 230 ng/g lipid wt., respectively. High levels of DDTs were found in mussels from Hong Kong, Vietnam, and China; PCBs were found in Japan, Hong Kong, and industrialized/urbanized locations in Korea, Indonesia, the Philippines, and India; CHLs were found in Japan and Hong Kong; HCHs were found in India and China. These countries seem to play a role as probable emission sources of corresponding contaminants in Asia and, in turn, may influence their global distribution.

Isomer specific determination of hexabromocyclododecanes (HBCDs) in small cetaceans from the South China Sea--Levels and temporal variation.

A diastereoisomer (alpha, beta, and gamma) specific analytical method for measuring hexabromocyclododecanes (HBCDs) was developed using liquid chromatography-tandem mass spectrometry (LC-MS-MS). The method developed was applied to analyze blubber of small cetaceans to divulge the distribution and temporal variation of HBCDs in the Asian marine environment. HBCDs were detected in all the blubber samples of finless porpoises (Neophocaena phocaenoides) and Indo-Pacific humpback dolphins (Sousa chinensis) collected from the South China Sea during 1990-2001. Concentrations of HBCDs were higher in humpback dolphins (31-380 ng/g lipid) than in finless porpoises (4.7-55 ng/g lipid), which can be attributed to habitat differences. Average concentrations of alpha-HBCD in finless porpoises increased from 9.5 ng/g lipid in 1990 to 35 ng/g lipid in 2000/01. alpha-HBCD was predominant among the three isomers with some exceptions in finless porpoises collected in 1990. This is the first report on HBCDs contamination in marine mammals from Southeast Asia.

Adaptive evolution after duplication of penaeidin antimicrobial peptides.

Penaeidin antimicrobial peptides in penaeid shrimps are an important component of their innate immune system that provides immunity against infection caused by several gram-positive bacteria and filamentous fungal species. Despite the knowledge on the identification and characterization of these peptides in penaeid shrimps, little is known about the evolutionary pattern of these peptides and the underlying genetic mechanisms that maintain high sequence diversities in the penaeidin gene family. Based on the phylogenetic analyses and maximum likelihood-based codon substitution analyses, here we present the convincing evidence that multiple copies of penaeidins have evolved by gene duplication, and positive Darwinian selection (adaptive evolution) is the likely cause of accelerated rate of amino acid substitutions among these duplicated genes. While the average ratio of non-synonymous to synonymous substitutions (omega) for the entire coding region of both active domains is 0.9805, few codon sites showed significantly higher omega (3.73). The likelihood ratio tests that compare models incorporating positive selection (omega>1) at certain codon sites with models not incorporating positive selection (omega<1), failed to reject (p=0) the evidence of positive Darwinian selection. The rapid adaptive evolution of this gene family might be directed by the pathogens and the faster rate of amino acid substitutions in the N-terminal proline-rich and C-terminal cysteine-rich domains could be due to their direct involvement in the protection against pathogens. When the host expose to different habitats/environment an accelerated rate of amino acid substitutions in both the active domains may also be expected.

Spatial distribution and accumulation of brominated flame retardants, polychlorinated biphenyls and organochlorine pesticides in blue mussels (Mytilus edulis) from coastal waters of Korea.

Blue mussels (Mytilus edulis) from 20 locations along the coastal waters of Korea were analyzed to elucidate the characteristic distribution and contamination status of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), polychlorinated biphenyls (PCBs) and organochlorine pesticides. To our knowledge, this is the first study to report on the contamination status of HBCDs from Korea. PBDEs and HBCDs were found in mussels at levels ranging from 6.6 to 440 and from 6.0 to 500 ng/g lipid wt., respectively. Concentrations of PBDEs in mussels from Korea were higher or comparable to available data in mussels from other countries. Among the organochlorine compounds (OCs) analyzed, levels of PCBs and DDTs were the highest followed by CHLs, HCHs and hexachlorobenzene. For all the compounds, higher concentrations were found in mussels from southeastern coast of Korea. The present study shows the importance of mussels as bioindicators for monitoring contaminants in coastal waters.