A bstract The venerid clam(M actra veneriformis Reeve 1854) is one of the main cultured bivalve species in intertidal and shallow subtidal ecosystems along the west coast of Korea. To understand the effects of ocean a...A bstract The venerid clam(M actra veneriformis Reeve 1854) is one of the main cultured bivalve species in intertidal and shallow subtidal ecosystems along the west coast of Korea. To understand the effects of ocean acidifi cation on the early life stages of Korean clams, we investigated shell growth and abnormality rates and types in the D-shaped, umbonate veliger, and pediveliger stages of the venerid clam M. veneriformis during exposure to elevated seawater pCO_2. In particular, we examined abnormal types of larval shell morphology categorized as shell deformations, shell distortions, and shell fi ssures. Specimens were incubated in seawater equilibrated with bubbled CO_2-enriched air at(400±25)×10^(-6)(ambient control),(800±25)×10^(-6)(high pCO_2), or(1 200±28)×10^(-6)(extremely high pCO_2), the atmospheric CO_2 concentrations predicted for the years 2014, 2084, and 2154(70-year intervals; two human generations), respectively, in the Representative Concentration Pathway(RCP) 8.5 scenario. The mean shell lengths of larvae were signifi cantly decreased in the high and extremely high pCO_2 groups compared with the ambient control groups. Furthermore, under high and extremely high pCO_2 conditions, the cultures exhibited signifi cantly increased abundances of abnormal larvae and increased severity of abnormalities compared with the ambient control. In the umbonate veliger stage of the experimental larvae, the most common abnormalities were shell deformations, distortions, and fi ssures; on the other hand, convex hinges and mantle protuberances were absent. These results suggest that elevated CO_2 exerts an additional burden on the health of M. veneriformis larvae by impairing early development.展开更多
Predicting the spatial distribution of soil moisture is an important hydrological question. We measured the spatial distribution of surface soil moisture (upper 6 cm) using an Amplitude Domain Reflectometry sensor at ...Predicting the spatial distribution of soil moisture is an important hydrological question. We measured the spatial distribution of surface soil moisture (upper 6 cm) using an Amplitude Domain Reflectometry sensor at the plot scale (2 × 2 m) and small catchment scale (0.84 ha) in a temperate forest. The spatial variation of soil water content was higher during dry conditions than that during wet conditions. Results indicated 3.1 samples at the plot scale were sufficient to estimate mean soil water content when the precision was 0.1. Soil water content increased with increasing topographic index (TI) and soil-topographic index (STI) at the small catchment scale. The correlation between soil water content and TI was higher than that between soil water content and STI. This suggests that topography is more important for estimating surface soil moisture than soil depth as formation of surface soil moisture occurs at ≤6 cm.展开更多
Global regulations and many regional and national controls restrict the use of substances that exhibit the potential for environmental persistence and long-range transport.Nevertheless,many current-use pesticides(CUPs...Global regulations and many regional and national controls restrict the use of substances that exhibit the potential for environmental persistence and long-range transport.Nevertheless,many current-use pesticides(CUPs)continue to be newly discovered in remote regions,including the Arctic.The present review serves as an update,summarizing newly available information for CUPs in the Arctic environment and biota published from 2010 to 2018.Since 2010,at least seven new CUPs have been measured in Arctic media:2-methyl-4-chlorophenoxyacetic acid(MCPA),metribuzin,pendimethalin,phosalone,quizalofop-ethyl,tefluthrin and triallate.Considering the large number of pesticides in current use,the number measured in the Arctic is very limited,however,modelling studies have identified additional CUPs as potential Arctic contaminants that have yet to be investigated in the Arctic.Owing to their recent detection,reports of CUPs in the Arctic are limited,but growing.CUPs have been reported in a wide range of abiotic Arctic matrices,including air,snow,ice,freshwater and seawater,indicating their capacity for long-range atmospheric transport,however,concentrations are generally low in comparison to legacy pesticides and other persistent organic pollutants(POPs).Recent food-web studies indicate CUPs can enter Arctic terrestrial and marine food chains,however,in contrast to POPs,the highest concentrations of many CUPs were found in lower trophic-level organisms,and the lowest concentrations detected in animals at the highest trophic levels(i.e,ringed seals,polar bear,caribou,and wolves)indicating significant trophic dilution.The detection of CUPs in the remote Arctic ecosystem reinforces the need for continued monitoring of both known and potential Arctic pollutants to prevent impacts on human and environmental health as the global arsenal of pesticides used in agriculture continuously changes.展开更多
基金Supported by the Korea Polar Research Institute(Nos.PE14150,PM15040)
文摘A bstract The venerid clam(M actra veneriformis Reeve 1854) is one of the main cultured bivalve species in intertidal and shallow subtidal ecosystems along the west coast of Korea. To understand the effects of ocean acidifi cation on the early life stages of Korean clams, we investigated shell growth and abnormality rates and types in the D-shaped, umbonate veliger, and pediveliger stages of the venerid clam M. veneriformis during exposure to elevated seawater pCO_2. In particular, we examined abnormal types of larval shell morphology categorized as shell deformations, shell distortions, and shell fi ssures. Specimens were incubated in seawater equilibrated with bubbled CO_2-enriched air at(400±25)×10^(-6)(ambient control),(800±25)×10^(-6)(high pCO_2), or(1 200±28)×10^(-6)(extremely high pCO_2), the atmospheric CO_2 concentrations predicted for the years 2014, 2084, and 2154(70-year intervals; two human generations), respectively, in the Representative Concentration Pathway(RCP) 8.5 scenario. The mean shell lengths of larvae were signifi cantly decreased in the high and extremely high pCO_2 groups compared with the ambient control groups. Furthermore, under high and extremely high pCO_2 conditions, the cultures exhibited signifi cantly increased abundances of abnormal larvae and increased severity of abnormalities compared with the ambient control. In the umbonate veliger stage of the experimental larvae, the most common abnormalities were shell deformations, distortions, and fi ssures; on the other hand, convex hinges and mantle protuberances were absent. These results suggest that elevated CO_2 exerts an additional burden on the health of M. veneriformis larvae by impairing early development.
文摘Predicting the spatial distribution of soil moisture is an important hydrological question. We measured the spatial distribution of surface soil moisture (upper 6 cm) using an Amplitude Domain Reflectometry sensor at the plot scale (2 × 2 m) and small catchment scale (0.84 ha) in a temperate forest. The spatial variation of soil water content was higher during dry conditions than that during wet conditions. Results indicated 3.1 samples at the plot scale were sufficient to estimate mean soil water content when the precision was 0.1. Soil water content increased with increasing topographic index (TI) and soil-topographic index (STI) at the small catchment scale. The correlation between soil water content and TI was higher than that between soil water content and STI. This suggests that topography is more important for estimating surface soil moisture than soil depth as formation of surface soil moisture occurs at ≤6 cm.
基金We thank the Arctic Monitoring and Assessment Programme(AMAP)and the national programs in circumpolar countries for their funding and support of this work.We are especially grateful to Simon Wilson,Cynthia de Wit,and the numerous reviewers that were a part of this process.We are thankful to the northern communities in circumpolar regions for their cooperation and collection of biological samples that yielded much of the data reviewed here.We also thank Canada's Northern Contaminants Program(NCP)for providing air data from the station of Alert.The Danish contribution to the AMAP assessment report(Katrin Vorkamp and Frank Riget)was supported by the Danish Environmental Protection Agency,under the Cooperation for Environment in the Arctic(DANCEA),grants no.MST-112-191 and MST-113-00082.
文摘Global regulations and many regional and national controls restrict the use of substances that exhibit the potential for environmental persistence and long-range transport.Nevertheless,many current-use pesticides(CUPs)continue to be newly discovered in remote regions,including the Arctic.The present review serves as an update,summarizing newly available information for CUPs in the Arctic environment and biota published from 2010 to 2018.Since 2010,at least seven new CUPs have been measured in Arctic media:2-methyl-4-chlorophenoxyacetic acid(MCPA),metribuzin,pendimethalin,phosalone,quizalofop-ethyl,tefluthrin and triallate.Considering the large number of pesticides in current use,the number measured in the Arctic is very limited,however,modelling studies have identified additional CUPs as potential Arctic contaminants that have yet to be investigated in the Arctic.Owing to their recent detection,reports of CUPs in the Arctic are limited,but growing.CUPs have been reported in a wide range of abiotic Arctic matrices,including air,snow,ice,freshwater and seawater,indicating their capacity for long-range atmospheric transport,however,concentrations are generally low in comparison to legacy pesticides and other persistent organic pollutants(POPs).Recent food-web studies indicate CUPs can enter Arctic terrestrial and marine food chains,however,in contrast to POPs,the highest concentrations of many CUPs were found in lower trophic-level organisms,and the lowest concentrations detected in animals at the highest trophic levels(i.e,ringed seals,polar bear,caribou,and wolves)indicating significant trophic dilution.The detection of CUPs in the remote Arctic ecosystem reinforces the need for continued monitoring of both known and potential Arctic pollutants to prevent impacts on human and environmental health as the global arsenal of pesticides used in agriculture continuously changes.
