Concentrations of trace metals (Zn, Cr, Cu, V, Cd and Pb), total organic carbon (TOC), black carbon (BC) and their granulometry were examined in 25 surface sediment samples from the northern Bering Sea, Chukchi Sea and adjacent areas. Trace metal concentrations in the sediments varied from 21.06–168.21mgkg⁻¹ for Zn, 8.91–46.94mgkg⁻¹ for Cr, 2.69–49.39mgkg⁻¹ for Cu, 32.46–185.54mgkg⁻¹ for V, 0.09–0.92mgkg⁻¹ for Cd, and 0.95–15.25mgkg⁻¹ for Pb. The geoaccumulation index (Igₑₒ) indicated that trace metal contamination (Zn and Cd) existed in some stations of the study area. The distribution of grain size plays an important role in influencing the distribution of trace metals (Zn, Cr, Cu, V, and Pb) in sediments from the Chukchi Sea and adjacent areas.

The implementation of the Marine Strategy Framework Directive (MSFD) is directing European marine research towards the coordinated and integrated assessment of sea environmental status, following the ecosystem-based approach. The MSFD uses a set of 11 descriptors which, together, summarise the way in which the whole system functions. As such, the European Commission has proposed an extensive set of indicators, to assess environmental status. Hence, taking account of the large amount of data available for the Basque coast (southern Bay of Biscay), together with a recent proposal for assessment within the MSFD, an integrated environmental status assessment approach is developed (for the first time) in this contribution. The strengths and weaknesses of the method, combined with proposals from the MSFD, are discussed.

The radionuclides ²¹⁰Po and ²¹⁰Pb were examined to trace the cycling of particulate organic carbon (POC) and particulate organic nitrogen (PON) in the Zhubi coral reef lagoon. The net export flux of POC to the open sea is 14mgCm⁻²d⁻¹. However, the net exchange of PON has not yet been observed. On average, the vertical export fluxes in the lagoon of POC and PON, as derived from ²¹⁰Po/²¹⁰Pb disequilibria, are 43mgCm⁻²d⁻¹ and 13.8mgNm⁻²d⁻¹, respectively. The deficit of ²¹⁰Po relative to ²¹⁰Pb in particulate matter provides evidence for the degradation of particulate organic matter. According to the mass balance budgets, 310mgCm⁻²d⁻¹ and 121mgNm⁻²d⁻¹ were recycled into dissolved fractions. Based on a first-order kinetics model, the degradation rate constants of POC and PON are 0.28 and 0.30m⁻¹, respectively. Thus, ²¹⁰Po and ²¹⁰Pb can quantify the cycling of carbon and nitrogen in this coral lagoon.

Considerable debate surrounds the sources of oxygenated polybrominated diphenyl ethers (O-PBDEs) in wildlife as to whether they are naturally produced or result from anthropogenic industrial activities. Natural radiocarbon (¹⁴C) abundance has proven to be a powerful tool to address this problem as recently biosynthesized compounds contain contemporary (i.e. modern) amounts of atmospheric radiocarbon; whereas industrial chemicals, mostly produced from fossil fuels, contain no detectable ¹⁴C. However, few compounds isolated from organisms have been analyzed for their radiocarbon content. To provide a baseline, we analyzed the ¹⁴C content of four O-PBDEs. These compounds, 6-OH-BDE47, 2′-OH-BDE68, 2′,6-diOH-BDE159, and a recently identified compound, 2′-MeO-6-OH-BDE120, were isolated from the tropical marine sponges Dysidea granulosa and Lendenfeldia dendyi. The modern radiocarbon content of their chemical structures (i.e. diphenyl ethers, C₁₂H₂₂O) indicates that they are naturally produced. This adds to a growing baseline on, at least, the sources of these unusual compounds.

This ten-year study examined the morphological, physiological, and ecological characteristics of coral growth anomalies on Acropora cytherea on Amuro Island, Okinawa, Japan. The objectives of the study were to assess whether the growth anomalies, identified as diffuse disruptions on the skeleton: (i) were more prevalent on large colonies than on small colonies, (ii) were more common near the center of the colonies than peripherally, (iii) affected colony growth and mortality, and (iv) affected coral-colony fecundity and photosynthetic capacity. We hypothesized that the growth anomalies were signs of the onset of aging. The growth anomalies were more prevalent on colonies >2m diameter, and were concentrated near the central (older) portions of the colonies. The growth anomalies were also associated with reduced productivity and dysfunctional gametogenesis. Still, the growth anomalies did not appear to affect colony survival. The contact experiments showed that the growth anomalies were not contagious, and were most likely a sign of aging that was exacerbated by thermal stress.

A survey on the Partially Extracted Trace Metals (PETMs) concentration (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd) in beach sediments is reported for the first time from 57 different locations in Chennai Metropolitan City of Southeast coast of India. The concentration of PETMs suggests that they are mainly concentrated with organic matter in the crowded part of the industrial regions in the beaches from the northern part rather than the tourist beaches in the southern part of the city. The comparison on enrichment of trace metals indicates higher values of Pb, Ni in the beaches than lowest effect level (LEL) and effects range low (ERL) than the tourist beaches.

This biomonitoring study presents the spatial and temporal distributions of heavy metals in the soft tissues of a major fouling species Amphibalanus amphitrite living on hard substrate at different sites along the eastern Aegean coast. A. amphitrite has been chosen as a strong candidate for monitoring heavy metals. Sediment and seawater samples were also collected to detect their metal contents in order to gain more information on the environmental conditions and possible bioaccumulation patterns. The physico-chemical characteristics of sampling stations have been measured in order to characterize the sampling area. The order of metal concentrations in barnacles, sediment and seawater decreased in the following order Cu>Fe>Zn>Mn>Cd>Cr>Pb>Hg, Fe>Mn>Zn>Cu>Pb>Cr>Hg>Cd and Fe>Zn>Mn>Cu>Pb>Cr>Cd>Hg, respectively. These results showed that barnacles accumulate Cu in a higher degree than both sediment and seawater. Moreover, metal concentrations in barnacle have the potential for use in any future regulatory framework monitoring and eventually controlling ambient metal pollution levels.

Oryzias melastigma, also called O. dancena, is becoming a very useful model for estuarine and marine ecotoxicity studies. With O. melastigma being adopted by ILSI Health and Environmental Science Institute (HESI) for embryo toxicity testing, improved knowledge of biomarker based embryonic development becomes especially important for mechanism-based toxicity evaluations. Using whole mount in situ hybridization and immunostaining techniques together with widely used molecular markers, this study describes the molecular development of marine medaka embryos, focusing on the brain, eye, heart, pectoral fin, pancreas, liver, muscle and neuron system. These organs are targets of environmental pollutants that disrupt normal embryonic development in medaka and other fish.

It has been well known that oil spills cause serious problems in the aquatic organisms. In particular, some species of teleosts, which develop on the sea surface thought to be affected by heavy oil (HO). During the embryogenesis, the nervous system is constructed. Therefore, it is important to study the toxicological effects of HO on the developing neurons. We exposed HO to eggs of Japanese flounder (Paralichthys olivaceus) and investigated the neural disorder. In larvae exposed by HO at the concentration of 8.75mg/L, the facial and lateral line nerves partially entered into the incorrect region and the bundle was defasciculated. Furthermore, in the HO-exposed larvae, Sema3A, a kind of axon guidance molecule, was broadly expressed in second pharyngeal arch, a target region of facial nerve. Taken together, we suggested the possibility that the abnormal expression of Sema3A affected by HO exposure causes disruption of facial nerve scaffolding.

The effects of polychlorinated biphenyls (PCBs) on liver function and their differences between sexes were analyzed in Japanese medaka (Oryzias latipes) exposed to PCB126 or Kanechlor-400 (KC-400) using microarray. PCB exposure induced vitellogenin 1 expression in female medaka while suppressing choriogenin genes, which suggests that the effects of PCBs on estrogen-responsive genes do not occur directly through an estrogen receptor-mediated pathway. Reduction of androgen receptor alpha expression was also observed, and the gene expression pattern in PCB-exposed males changed to become more similar to that of females. Furthermore, changes in glycolysis-related genes indicate that PCB exposure might enhance glucose production via gluconeogenesis in the liver of medaka. Taken together, our results suggest that PCBs disrupt the endocrine system, especially androgen function, and may have the potential to cause demasculinizing effects. Additionally, induction of gluconeogenesis might be a response to maintain glucose levels consumed as a result of PCB exposures.