Current Status of Antifouling Biocides Contamination in the Seto Inland Sea, Japan.

A monitoring survey of antifouling biocides was conducted in the Harima Nada Sea and Osaka Bay of the Seto Inland Sea, Japan to assess contamination by organotin (OT) compounds and alternative biocides. The concentrations of tributyltin (TBT) compounds in surface water ranged from 1.0 to 2.

Toxicity and Environmental Risk Assessment of Polycarbamate and Its Main Components to Marine Algae and Crustaceans.

Polycarbamate is commonly used as an antifoulant coating on fishing nets in Japan. Although its toxicity to freshwater organisms has been reported, its toxicity to marine organisms is currently unknown. We conducted algal growth inhibition and crustacean immobilization tests to assess the effects of polycarbamate on marine organisms.

Integrated transcriptomic and metabolomic analyses reveal mechanism underlying higher resistance of the marine oligochaete Thalassodrilides cf. briani (Clitellata: Naididae) to heavy contamination of sediments with polycyclic aromatic hydrocarbons.

In some coastal areas, sediments are contaminated with various chemical compounds, causing significant threats to marine organisms. Therefore, the development of remediation techniques is important. Here, we focused on bioremediation using marine benthic animals such as aquatic oligochaetes.

Estimation of the uptake and gut retention of microplastics in juvenile marine fish: Mummichogs (Fundulus heteroclitus) and red seabreams (Pagrus major).

We investigated the impact of microplastics (MPs) on marine fish by estimating the uptake and retention by mummichogs (Fundulus heteroclitus) and red seabreams (Pagrus major) of MPs similar in size (≥0.25 mm) and composition (polyethylene) to MPs detected in fish intestines. Results revealed a correlation between MP concentrations in aquarium water and the content of MPs in the gastrointestinal tracts of exposed fish.

Ecological risk assessment of an antifouling biocide triphenyl (octadecylamine) boron in the Seto Inland Sea, Japan.

In this study, we derived the predicted no-effect concentrations (PNEC) for triphenyl (octadecylamine) boron (TPB-18) and investigated the occurrence of triphenylboranes (TPBs), including TPB-18, for ecological risk assessment in the Seto Inland Sea, Japan. We tested algal growth inhibition, crustacean immobilization, and reproductive toxicity and performed toxicity tests in fish to assess acute and chronic toxicity and generate the PNEC for TPB-18. The minimum toxicity value was 0.

Occurrence of neonicotinoids and fipronil in estuaries and their potential risks to aquatic invertebrates.

This study aimed to evaluate and qualify field-based potential risks of seven neonicotinoid and phenylpyrazole (fipronil) insecticides on aquatic invertebrates, including estuary-resident marine crustaceans. One hundred and ninety-three estuarine water samples, with salinity ranging from 0.5 to 32.

Physiological responses of eelgrass (Zostera marina) to ambient stresses such as herbicide, insufficient light, and high water temperature.

This study aimed to elucidate the biological responses of eelgrass (Zostera marina) to artificially induced stresses such as herbicide (Irgarol 1051, Irg) exposure, insufficient light, and high water temperature (27 ± 1.0 °C) by evaluating growth inhibition, photosynthetic activity, and metabolomic profiles. After 14 days, all treatments inhibited growth, but photosynthetic activity was only reduced in the Irg-exposed group.

Toxicity of the biocide polycarbamate, used for aquaculture nets, to some marine fish species.

We investigated toxic effects of the antifouling biocide polycarbamate (PC) on marine fish by conducting acute, early-life stage toxicity (ELS), and embryo toxicity tests. Mummichog (Fundulus heteroclitus) 96-h LC values for hatched larvae (body weight about 2.0 mg) and juveniles (660 ± 36 mg) were about 12 and 630 μg/L, respectively.

Detection and localization of the thyroid hormone receptor beta mRNA in the immature olfactory receptor neurons of chum salmon.

Thyroid hormone (TH) plays an important role in regulating multiple cellular and metabolic processes, including cell proliferation, cell death, and energy metabolism, in various organs and tissues of vertebrates. It is generally accepted that anadromous Pacific salmon ( spp.) imprint odorants from their natal stream during their seaward migration, and they then use olfaction to discriminate their natal stream during the spawning migration.

Development of a method to assess the ichthyotoxicity of the harmful marine microalgae Karenia spp. using gill cell cultures from red sea bream (Pagrus major ).

The present study reports the development of a method to investigate ichthyotoxicity of harmful marine microalgae using cultured red sea bream (Pagrus major) gill cells. The cultured gill cells formed adherent 1-2 layers on the bottom of the culture plate and could tolerate seawater exposure for 4 h without significant alteration in cell survival. The microalgae Karenia mikimotoi, Karenia papilionacea, K.

A hepatic metabolomics-based diagnostic approach to assess lethal toxicity of dithiocarbamate fungicide polycarbamate in three marine fish species.

The present study was performed to evaluate the toxic effect of the dithiocarbamate fungicide polycarbamate (PC) on the hepatic metabolic profiles of three marine fish species, red sea bream (Pagrus major), spotted halibut (Verasper variegatus), and marbled flounder (Pleuronectes yokohamae). First, juvenile fish were exposed to graded concentrations of PC for 96h; the 96-h LC values obtained were 22-29, 239-553, and 301-364µgL for red sea bream, spotted halibut, and marbled flounder, respectively, indicating that red sea bream possessed higher sensitivity to PC than the two benthic species. Second, the fish were exposed to lethal-equivalent concentration (H group) or sub-lethal (one-tenth of the H group concentrations; L group) for 24 and 96h and gas-chromatography based metabolomics approach was employed to explore the crucial biomarker metabolite associated with lethal toxicity.

Photo-induced toxicity and oxidative stress responses in Tigriopus japonicus exposed to nitro-polycyclic aromatic hydrocarbons and artificial light.

Photo-induced toxicity is an important phenomenon in ecotoxicology because sunlight reaches many organisms in their natural habitats. To elucidate whether sunlight enhances the toxicity of nitro-polycyclic aromatic hydrocarbons (nitro-PAHs), the acute toxicities of 10 nitro-PAHs and the related compound 1-nitropyrene (1-NP) to Tigriopus japonicus were assessed in darkness or under light conditions. In addition, the relationships among the toxicity of 1-NP to T.

Evaluation of bioremediation potential of three benthic annelids in organically polluted marine sediment.

This study aimed to evaluate the possible remedial effects of three marine benthic annelids on organically polluted sediments from the waters of Hatsukaichi Marina, Hiroshima, Japan. Two polychaetes, Perinereis nuntia and Capitella cf. teleta, and an oligochaete, Thalassodrilides sp.

Effect of taurine supplementation on hepatic metabolism and alleviation of cadmium toxicity and bioaccumulation in a marine teleost, red sea bream, Pagrus major.

This study was performed to unravel the mechanism of the beneficial action of taurine on marine teleost fish, red sea bream (Pagrus major), by analyzing the hepatic metabolism. Moreover, the ameliorative effects of the nutrient against cadmium toxicity and bioaccumulation were further evaluated. The fish were fed a diet containing 0 % (TAU0 %), 0.

Transcription of a novel P450 gene varies with some factors (pollutant exposure, temperature, time, and body region) in a marine oligochaete (Thalassodrilides sp.).

Cytochrome P450 (CYP) enzymes play important roles in the metabolism of exogenous compounds such as polycyclic aromatic hydrocarbons (PAHs). A novel, full-length CYP gene (CYP4V30) was identified in the oligochaete Thalassodrilides sp. CYP4V30 mRNA expression was studied in worms exposed to PAH-polluted (Σ16PAHs; 37441ng/g dry weight) or unpolluted (Σ16PAHs; 19ng/g dry weight) sediment.

Differences in the ability of two marine annelid species, Thalassodrilides sp. and Perinereis nuntia, to detoxify 1-nitronaphthalene.

Bioremediation is a promising method for remediating environmentally polluted water. We investigated the abilities of two benthic annelid species to biotransform 1-nitronaphthalene, a nitrated polycyclic aromatic hydrocarbon. We used an oligochaete, Thalassodrilides sp.

Spatial analysis of 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (Sea-Nine 211) concentrations and probabilistic risk to marine organisms in Hiroshima Bay, Japan.

We analyzed the spatial distribution of an antifouling biocide, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (Sea-Nine 211) in the surface water and sediments of Hiroshima Bay, Japan to determine the extent of contamination by this biocide. A quantitative estimate of the environmental concentration distribution (ECD) and species sensitivity distributions (SSDs) for marine organisms were derived by using a Bayesian statistical model to carry out a probabilistic ecological risk analysis, such as calculation of the expected potentially affected fraction (EPAF). The spatial distribution analysis supported the notion that Sea-Nine 211 is used mainly for treatment of ship hulls in Japan.

Reproductive toxicity of 1-nitronaphthalene and 1-nitropyrene exposure in the mummichog, Fundulus heteroclitus.

After pregnant mummichog were implanted with 1-nitronaphthalene or 1-nitropyrene via cholesterol pellet, we investigated the effects of the chemicals on embryo normality, hatchability and days to hatch of normal embryos, and growth and survival of hatched larvae from normal embryos of the implanted mummichog. Hatchability was the parameter most sensitive to the effects of both 1-nitronaphthalene and 1-nitropyrene. The 4-week lowest-observed-effect concentration (LOEC) of 1-nitronaphthalene, based on the actual concentrations in the eggs in the test, was 447 ng g(-1) wet wt.

Primary risk assessment of dimethyldithiocarbamate, a dithiocarbamate fungicide metabolite, based on their probabilistic concentrations in a coastal environment.

The primary ecological risk of dimethyldithiocarbamate (DMDC), a dithiocarbamate fungicide (DTC) metabolite, was evaluated based on their probabilistic environmental concentration distributions (ECDs) in the coastal environment, Hiroshima Bay, Japan. And their behavior and temporal trends was further considered. This is the first report of the identification of DMDC from environmental seawater and sediment samples.

Molecular cloning and gene expression of mummichog (Fundulus heteroclitus) Runx2 during embryogenesis.

In our previous study, we clarified the toxicity of 2,2'-dipyridyldisulfide [(PS)2], one of photodegradation products of a metal pyrithione that is used as an alternative antifouling paint biocides to organotin compounds in Japan. In early life stage toxicity tests, we exposed the mummichog, (Fundulus heteroclitus) to (PS)2, and the hatched larvae subsequently displayed notochord undulations and skeletal deformities ( Mochida et al., 2012 ).

Toxicity of degradation products of the antifouling biocide pyridine triphenylborane to marine organisms.

We evaluated the acute toxicities of the main degradation products of pyridine triphenylborane (PTPB), namely, diphenylborane hydroxide (DPB), phenylborane dihydroxide (MPB), phenol, and biphenyl, to the alga Skeletonema costatum, the crustacean Tigriopus japonicus, and two teleosts, the red sea bream Pagrus major and the mummichog Fundulus heteroclitus. DPB was the most toxic of the degradation products to all four organisms. The acute toxicity values of DPB for S.

Use of species sensitivity distributions to predict no-effect concentrations of an antifouling biocide, pyridine triphenylborane, for marine organisms.

We used species sensitivity distributions (SSDs) and a Bayesian statistical model to carry out a primary risk assessment for pyridine triphenylborane (PTPB) in Hiroshima Bay, Japan. We used SSDs derived from toxicity values, such as EC₅₀ and LC₅₀, obtained from this study and previous work to calculate hazardous concentrations that should protect 95% and 99% of species (HC₅ and HC₁) and demonstrated that the medians of the HC₅ and HC₁ were 0.78 and 0.

Induction of apoptosis in testis of the marine teleost mummichog Fundulus heteroclitus after in vivo exposure to the antifouling biocide 4,5-dichloro-2-n-octyl-3(2H)-isothiazolone (Sea-Nine 211).

4,5-dichloro-2-n-octyl-3(2H)-isothiazolone (Sea-Nine 211) has been widely used as an effective antifouling biocide. However, little is known about its reproductive toxicity in fish. Here we investigated testicular toxicity in a marine teleost, the mummichog Fundulus heteroclitus, after exposure to Sea-Nine 211 for 28 d.