Embryonic exposure to environmentally relevant concentrations of PCB126 affect prey capture ability of Fundulus heteroclitus larvae

Early life stages from a marine fish species, Fundulus heteroclitus, were exposed to sublethal doses of 3,3',4,4',5 pentachlorobiphenyl (PCB126) to evaluate its effects on ecologically relevant responses: growth and behavior. A few hours after fertilisation, eggs were treated topically with PCB126 (2.5-50 pg egg?1). Four days post-hatching (dph), morphological changes (body length and malformations), spontaneous locomotor activity (active swimming speed, rate of travel, % inactivity), prey capture ability (Artemia franciscana nauplii) and whole body EROD activity were evaluated in larvae. Untreated larvae collected at 0.5, 1, 2, 3, 4 dph were also examined. PCB126 did not increase the mortality or malformation rates. Body length and spontaneous locomotor activity were altered only in larvae treated with the highest dose. Treatment with PCB126 caused a dose-responsive reduction in prey capture ability (rate of decline in the number of Artemia) and induction of EROD activity. The lowest observed effective dose for both of these responses was 5.0 pg PCB126 egg?1 or 5.0 TCDD-toxic equivalents pg g?1 egg, using a TCDD-toxic equivalent factor of 0.005 and an egg mass of 5 mg. Prey capture efficiency (number of Artemia captured per feeding strike) was reduced at ≥ 10.0 pg egg?1. In untreated developing larvae, prey capture ability and efficiency increased as post-hatching development progressed and EROD activity remained low. The pattern of behavioral responses observed in PCB126-exposed Fundulus larvae differed from that observed in less-developed larvae indicating that other mechanisms than retarded development were involved. Behavioral dysfunction was a more sensitive response to PCB126 than morphological alterations and it occurred at environmentally relevant concentrations.     

Exposure to environmentally relevant concentrations of different nonylphenol formulations in Japanese medaka.

The time course of exposure to p-nonylphenol (NP) from two different sources was compared to equivalent exposures of 17-beta-estradiol (E2) and a solvent control (ethanol; EtOH). Japanese medaka were exposed for 4 days to a nominal concentration of 20 micrograms/l of either NP-I (Schenectady International, Inc.), NP-II (Aldrich), or E2, and were then placed in untreated water for 5 days. Tissue samples were taken at two time points during the 4-day exposure and two time points during the 5 days following exposure. Liver homogenates were analyzed using a western blot to detect vitellogenin (VTG) and quantified by measuring the optical density for each lane. Preliminary results indicate that E2 significantly increased VTG staining above the level observed in EtOH-treated controls for both males and females. A two-way analysis of variance (ANOVA) indicates that NP from both sources, as well as E2, significantly increased VTG staining in males (ANOVA, n = 48, P < 0.001; Tukey pairwise tests, all P < 0.008). A significant increase in VTG was observed in E2-treated males and females the first day following transfer into toxicant-free water (two-way ANOVAs, both n = 48, P < 0.003; Tukey pairwise tests, all P < 0.019). If confirmed, this extended response observed for low-level exposures may represent a significant factor for sampling scenarios following pulsitile exposure.     

Variable wavelength absorption in detecting environmentally relevant PAHs by high-performance liquid chromatography

Twenty-three polycyclic aromatic hydrocarbons (PAHs) were analysed by reversed-phase high-performance liquid chromatography coupled with a variable wavelength absorption detector. Compounds not chromatographically resolved were individually quantified by using characteristic UV-VIS absorption maxima programmed over three runs during the chromatographic separation. Detection limits ranging from 0.1 to 1 ng g⁻¹ (dry weight) were found in the analysis of sediment core extracts.     

Achieving MPA effectiveness through application of responsive governance incentives in the Tubbataha reefs

The dynamic institutional arrangements, which characterized the past two decades of management in the Tubbataha Reefs Natural Park (TRNP), reflect flexibility and diversity in the use of governance incentives. At the initial stage, legal and knowledge incentives provided the main guidance in identifying the appropriate organizational structure to manage the Park and to establish its boundaries and jurisdictional limits. Knowledge incentives provided the added value of generating credible information that showed the significance of the Tubbataha Reefs and the positive impact of management actions. Communicating information to the public, as an interpretative incentive, supported greater recognition and influence at the national and international levels. During the middle stage, the use of economic incentives ensured that the Park management benefitted from tourism through user fees and that Cagayancillo Municipality received a fair share of benefits to partly compensate foregone income opportunities. The Tubbataha Trust Fund was created serving as a depository of revenue from grants and donations and included instituting fiscal management to encourage more partners and stakeholders to contribute. Presently, in the light of current issues and the recently passed TRNP Act, striking a balance between legal-economic-participative incentives takes precedence over interpretative and knowledge incentives which are in place and only need to be maintained.     

鲈鱼胆汁中芘及代谢产物含量与水体中芘含量的关系

运用GC—MS的方法和荧光分光光度法，研究鲈鱼分别暴露于0．1、1．0和10．0μg／dm^3质量浓度芘溶液中7d，水体中芘及其鲈鱼胆汁中芘和1-羟基芘含量的变化,实验结果显示：(1)鲈鱼对水体中的芘具有非常显著的去除作用。(2)随着芘暴露浓度的增大，鲈鱼对芘的代谢去除作用增强。(3)随着暴露时间的延长和芘暴露浓度的增大，胆汁的1-羟基芘浓度递增。(4)鲈鱼胆汁具有较高的芘浓度，对海水中的芘具有较强的富集作用。(5)鲈鱼胆汁的1-羟基芘及芘的浓度与水体芘浓度均具有很好的相关性，对于指示水体的芘污染程度具有一致性；可作为指示水体芘污染程度的生物标志物。     

Spatial and temporal variability in particle-bound pesticide exposure and their effects on benthic community structure in a temporarily open estuary

Spatial and temporal variations in particle-bound pesticide contamination, natural environmental variables, and benthic abundance were measured during the dry summer season within a temporarily open estuary (Lourens River). This study focused on the effect of particle-associated pesticides on the dynamics of the benthic community (including epi-benthic, hyper-benthic, and demersal organisms) by comparing two runoff events, differing in their change in pesticide concentration and environmental variables. The two chosen sites were situated within the upper and middle reaches of the estuary and differ significantly in salinity (p = 0.001), flow (p = 0.5), temperature (p < 0.001) and particulate organic carbon in the sediment (p < 0.001). Generally higher particle-bound pesticides were found in the upper reaches.     

Acetylthiocholine (ATC)--cleaving cholinesterase (ChE) activity as a potential biomarker of pesticide exposure in the Manila clam, Ruditapes philippinarum, of Korea

The acetylthiocholine (ATC) - cleaving cholinesterase (ChE) activity in Manila clam, which is widely distributed throughout the coastal environment of Korea, was assayed as a potentially useful biomarker of organophosphorous pesticides (OPs). A clear dose-response relationship was determined between inhibited ChE in adductor muscle of clams and four OPs (methidathion, chlorpyrifos, diazinon, IBP) which are heavily used OPs in Korea. The measured EC(50)-24?h values of methidathion, chlorpyrifos, diazinon, and IBP for Ruditapes philippinarum were 7.16?μg?l(-1), 0.34?mg?l(-1), 3.01?mg?l(-1), and 3.41?mg?l(-1), respectively. In field studies, ChE activity in Manila clams collected from 23 stations in the mid-western coastal region demonstrated spatial variation with statistical differences. These results suggest that ChE activity in R. philippinarum is a potential biomarker for assessing organophosphorous pesticide contamination in coastal environments.     

Errors in the retrieval of oceanic concentrations of optically active materials from multispectral sensor signals by observations through atmospheric layer

This paper presents an algorithm for retrieving the oceanic concentrations of optically active materials (OAMs)—phytoplankton, particulate matter, and dissolved organics—from signals of a multispectral sensor placed at an arbitrary height above the sea surface. The algorithm takes into account sensor noises (both photon (shot) and dark current). The joint distribution of the upwelling radiance and OAM spectra required for the algorithm is constructed using optical models of water and the oceanic atmosphere. A method based on correlations between inherent optical properties is proposed to improve the retrieval accuracy. The calculations showed that this method significantly increases the accuracy of OAM retrieval.     

Assessment of the governance system for the management of the East Sea-Jung dumping site,Korea through analysis of heavy metal concentrations in bottom sediments

As with many countries, the Korea government has made a variety of efforts to meet the precautionary principle under the London Convention and Protocol acceded in 1994 and 2009. However, new strategies for the suitable marine dumping of waste materials have since been developed. In this study, the distribution and contamination of heavy metals including Al, Fe, Mn, Li, Co, Cr, Ni, Cu, Zn, As, Cd, Pb and Hg in bottom sediments were analyzed and compared to various criteria in order to evaluate the effectiveness of the management of the East Sea-Jung (ES-Jung) dumping site by the Korea government. The results indicate that the average metal concentrations were significantly lower than Effects Range Low (ERL) values, and generally similar to or lower than the Threshold Effect Levels (TEL) from the Sediment Quality Guidelinces (SQGs). According to analyses of various metal contamination indexes (Enrichment Factor: EF, Pollution Load Index: PLI and the Index of Geoaccumulation: Igeo), most areas were found to be uncontaminated by heavy metals with the exception of several moderately contaminated stations (ESJ 33, 54, 64 and ESJR 20). Heavy metal concentrations in areas grouped as G1, G2, DMDA, N-Ref and S-Ref which showed similar characteristics between 2007-2013 and 2014, were compared. Unexpectedly, most concentrations in the northern reference area (N-Ref) were much higher than those in the actual dumping areas (G1 and G2), may be due to the influences from nearby cities to the west of the ES-Jung site, rather than from the dumping site itself. Additionally, heavy metal concentrations in the dredged material dumping area (DMDA) were found to be low although they have slightly increased over time and those in the southern reference area (S-Ref) were found to have gradually decreased with year. The concentrations of most metals in the East Sea-Jung dumping site were similar to or less than those in the Earth’s crust and approximately the same as those in continental sediments. As a result, this site can be considered as uncontaminated or slightly contaminated. This implies that the efforts made by the Korea government to manage and govern the dumping site through various policies, including ‘the focal point system’, ‘the responsibility zones system’ and ‘the principle of pollution causing party liability’, have been successful.     

Changes in the tissue concentrations and contents of calcium, copper and zinc in the shore crab Carcinus maenas (L.) (Crustacea: Decapoda) during the moult cycle and following copper exposure during ecdysis

The tissue concentrations and contents of calcium, copper and zinc were determined at different stages in the moult cycle of the shore crab Carcinus maenas. The crabs were dissected into the following tissues: the midgut gland, the gill, the ‘rest tissue’ (the latter defined as the left over tissue, i.e. muscles and exoskeleton), and the haemolymph, and analysed as such. One group of crabs was maintained in clean seawater. In these crabs, calcium was lost from haemolymph during premoult and apparently stored in the midgut gland. At ecdysis approximately 90% of the whole body calcium content was lost with the exuviae while the haemolymph calcium content doubled. During early postmoult calcium stored in the midgut gland was used in combination with calcium absorbed from the surrounding seawater for a rapid calcification of the new exoskeleton. Both the copper and zinc concentrations declined in the ‘rest tissue’ compartment during premoult. At ecdysis the haemolymph copper and zinc contents increased 35 and 86%, respectively, from premoult to the newly moult stage. At the same time, however, the copper and zinc haemolymph concentrations decreased. During postmoult, copper (25%) and zinc (45%) were lost from haemolymph and mainly excreted but a minor fraction (5–10%) was stored in the midgut gland.A second group of crabs was maintained in copper-contaminated seawater (0.1 mgl⁻¹) during ecdysis and postmoult. Following exposure of the animals to raised ambient levels of copper, the calcium and zinc contents of the midgut gland were reduced while the copper contents of the midgut gland and most other tissues were increased in comparison to crabs held in clean seawater.