Species delimitation in the green algal genus Codium (Bryopsidales) from Korea using DNA barcoding

Codium, one of the largest marine green algal genera, is difficult to delimit species boundary accurately based on morphological identification only. DNA barcoding is a powerful tool for discriminating species of seaweeds. The plastid elongation factor TU(tuf A) is considered as maker to perform DNA barcoding of green algal species than rbc L gene due to universality and rapid evolution rate. We conducted DNA barcoding application to Codium specimens from the Jeju Island, Korea to overcome the limit of morphological identification and to confirm the species diversity. As a result of applying tuf A marker, we newly generated fifty-five tuf A barcodes to resolve eight species. Tuf A marker exhibited 6.1%–21.8% interspecific divergences, wider than the gap of rbc L exon 1,3.5%–11.5%. Molecular analysis of rbc L exon 1 sequences of Codium revealed eight distinct species like tuf A analysis separated in five phylogenetic groups. DNA barcoding of the genus Codium using tuf A marker is more helpful to overcome the limit of morphological identification, and this is more potential to reveal cryptic species and to resolve the relationships among subspecies than rbc L analysis alone. The complement of tuf A barcoding and rbc L analyses including morphology for the genus Codium in the northwestern Pacific will give much more reliable achievement for discovering species diversity and resolving the phylogenetic relationships.     

Simulation of the extreme waves generated by typhoon Bolaven (1215) in the East China Sea and Yellow Sea

Record-breaking high waves occurred during the passage of the typhoon Bolaven (1215) (TYB) in the East China Sea (ECS) and Yellow Sea (YS) although its intensity did not reach the level of a super typhoon. Winds and directional wave measurements were made using a range of in-situ instruments mounted on an ocean tower and buoys. In order to understand how such high waves with long duration occurred, analyses have been made through measurement and numerical simulations. TYB winds were generated using the TC96 typhoon wind model with the best track data calibrated with the measurements. And then the wind fields were blended with the reanalyzed synoptic-scale wind fields for a wave model. Wave fields were simulated using WAM4.5 with adjustment of C_d for gust of winds and bottom friction for the study area. Thus the accuracy of simulations is considerably enhanced, and the computed results are also in better agreement with measured data than before. It is found that the extremely high waves evolved as a result of the superposition of distant large swells and high wind seas generated by strong winds from the front/right quadrant of the typhoon track. As the typhoon moved at a speed a little slower than the dominant wave group velocity in a consistent direction for two days, the wave growth was significantly enhanced by strong wind input in an extended fetch and non-linear interaction.     

Demersally drifting invertebrates from Kongsfjorden,Svalbård (Arctic Ocean)–a comparison of catches from drift-pump and drift-nets

Demersally drifting organisms were collected at Ny Ålesund (Svalbård–Arctic Ocean) to study the taxon composition and relative abundances in the Arctic summer. Catch potentials of two collection devices for demersal drift were compared. A lowvolume submersible drift-pump and a drift-net unit were employed for the collection of demersally drifting biota, particularly for shallow aquatic habitats. With the exception of Appendicularia, Chaetognatha, Coelenterata, and Ctenophora, which were damaged at times, the pump catches were in good condition and sufficient for identification and quantification of less mobile fauna. A comparison of the two devices revealed that the drift-pump collected more specimens than the drift-net. However, the drift-net may have caused an underestimation of the abundances of invertebrates. No differences in identified taxon number and indices of richness, evenness and diversity were found. However, the proportion of invertebrate animals in the two devices was different for the three groups: zooplankton, macrofauna and meiofauna. At Svalbård, zooplankton, larvae of macrofauna, and meiofauna were successfully collected by the two collecting devices. However, the catchibility of the two devices in collecting various invertebrate taxa was different and, therefore, a sound ‘Device Effect’ was revealed.     

Meteorites at Meridiani Planum provide evidence for significant amounts of surface and near‐surface water on early Mars

Abstract– Six large iron meteorites have been discovered in the Meridiani Planum region of Mars by the Mars Exploration Rover Opportunity in a nearly 25 km‐long traverse. Herein, we review and synthesize the available data to propose that the discovery and characteristics of the six meteorites could be explained as the result of their impact into a soft and wet surface, sometime during the Noachian or the Hesperian, subsequently to be exposed at the Martian surface through differential erosion. As recorded by its sediments and chemical deposits, Meridiani has been interpreted to have undergone a watery past, including a shallow sea, a playa, an environment of fluctuating ground water, and/or an icy landscape. Meteorites could have been encased upon impact and/or subsequently buried, and kept underground for a long time, shielded from the atmosphere. The meteorites apparently underwent significant chemical weathering due to aqueous alteration, as indicated by cavernous features that suggest differential acidic corrosion removing less resistant material and softer inclusions. During the Amazonian, the almost complete disappearance of surface water and desiccation of the landscape, followed by induration of the sediments and subsequent differential erosion and degradation of Meridiani sediments, including at least 10–80 m of deflation in the last 3–3.5 Gy, would have exposed the buried meteorites. We conclude that the iron meteorites support the hypothesis that Mars once had a denser atmosphere and considerable amounts of water and/or water ice at and/or near the surface.     

Down-scaled regional ocean modeling system (ROMS) for high-resolution coastal hydrodynamics in Korea

A down-scaled operational oceanographic system is developed for the coastal waters of Korea using a regional ocean modeling system(ROMS).The operational oceanographic modeling system consists of atmospheric and hydrodynamic models.The hydrodynamic model,ROMS,is coupled with wave,sediment transport,and water quality modules.The system forecasts the predicted results twice a day on a 72 h basis,including sea surface elevation,currents,temperature,salinity,storm surge height,and wave information for the coastal waters of Korea.The predicted results are exported to the web-GIS-based coastal information system for real-time dissemination to the public and validation with real-time monitoring data using visualization technologies.The ROMS is two-way coupled with a simulating waves nearshore model,SWAN,for the hydrodynamics and waves,nested with the meteorological model,WRF,for the atmospheric surface forcing,and externally nested with the eutrophication model,CE-QUAL-ICM,for the water quality.The operational model,ROMS,was calibrated with the tidal surface observed with a tide-gage and verified with current data observed by bottom-mounted ADCP or AWAC near the coastal waters of Korea.To validate the predicted results,we used real-time monitoring data derived from remote buoy system,HF-radar,and geostationary ocean color imager(GOCI).This down-scaled operational coastal forecasting system will be used as a part of the Korea operational oceanographic system(KOOS) with other operational oceanographic systems.     

Distribution of dinoflagellate cysts in Yellow Sea sediments

To investigate the distribution,abundance,and species composition of dinoflagellate cysts in the Yellow Sea,surface sediment samples were collected at 37 sites,including the Korean dump site.Twenty-one dinoflagellate cyst taxa were identified,with the assemblages dominated mainly by Spiniferites bulloideus,Operculodinium centrocarpum,and cyst of Alexandrium catenella/tamarense type.A high frequency of O.centrocarpum in the Yellow Sea was observed for the first time,and it is likely that this can be attributed to the dynamics of the Yellow Sea Cold Water Mass and the Changjiang(Yangtze) River runoff.Total cyst concentrations ranged from 23 to 48 442 cysts/g dry weight,and high cyst concentrations were recorded adjacent to the dumping site.This result suggests that anthropogenic activities such as ocean dumping stimulate the growth of dinoflagellates in the Yellow Sea,which in turn leads to high levels of dinoflagellate cyst production.     

Effects of natural and calcined oyster shells on Cd and Pb immobilization in contaminated soils

In Korea, soils adjacent to abandoned mines are commonly contaminated by heavy metals present in mine tailings. Further, the disposal of oyster shell waste by oyster farm industries has been associated with serious environmental problems. In this study, we attempted to remediate cadmium (Cd)- and lead (Pb)-contaminated soils typical of those commonly found adjacent to abandoned mines using oyster shell waste as a soil stabilizer. Natural oyster shell powder (NOSP) and calcined oyster shell powder (COSP) were applied as soil amendments to immobilize Cd and Pb. The primary components of NOSP and COSP are calcium carbonate (CaCO₃) and calcium oxide (CaO), respectively. X-ray diffraction, X-ray fluorescence and scanning electron microscope analyses conducted in this study revealed that the calcination of NOSP at 770°C converted the less reactive CaCO₃ to the more reactive CaO. The calcination process also decreased the sodium content in COSP, indicating that it was advantageous to use COSP as a liming material in agricultural soil. After 30 days of incubation, we found that the 0.1 N HCl-extractable Cd and Pb contents in soil decreased significantly as a result of an increase in the soil pH and the formation of metal hydroxides. COSP was more effective in immobilizing Cd and Pb in the contaminated soil than NOSP. Overall, the results of this study suggest that oyster shell waste can be recycled into an effective soil ameliorant.     

Effects of biochar, cow bone, and eggshell on Pb availability to maize in contaminated soil irrigated with saline water

Toxicity of heavy metals adversely affects environment and human health. Organic materials derived from natural matters or wastes have been applied to soils to reduce the mobility of contaminants such as heavy metals. However, the application of cow bone powder (CB), biochar (BC), and eggshell powder (ES) is rarely investigated for the reduction of Pb bioavailability in soils irrigated with saline water. The objective of this study was to assess the effectiveness of CB, BC, and ES additions as immobilizing substances on Pb bioavailability in shooting range soil irrigated with deionized and saline water. Each additive of CB, BC, and ES at 5 % (w/w) was mixed with soils and then the deionized and saline water were irrigated for 21 days. With deionized water irrigation, the soils treated with CB, BC, and ES exhibited higher pH when compared with saline water irrigation. With saline water irrigation, the electrical conductivity, water-soluble anions, and cations were significantly increased in soils treated with CB, BC, and ES. The water-soluble Pb in soils treated with CB, BC, and ES was significantly decreased with saline water irrigation. On the other hand, the water-soluble Pb in soil treated with CB was increased with deionized water irrigation. Only BC with saline water irrigation decreased the Pb concentration in maize shoots.     

Strategically Locating Wildlife Crossing Structures for Florida Panthers Using Maximal Covering Approaches

Crossing structures are an effective method for mitigating habitat fragmentation and reducing wildlife‐vehicle collisions, although high construction costs limit the number that can be implemented in practice. Therefore, optimizing the placement of crossing structures in road networks is suggested as a strategic conservation planning method. This research explores two approaches for using the maximal covering location problem (MCLP) to determine optimal sites to install new wildlife crossing structures. The first approach is based on records of traffic mortality, while the second uses animal tracking data for the species of interest. The objective of the first is to cover the maximum number of collision sites, given a specified number of proposed structures to build, while the second covers as many animal tracking locations as possible under a similar scenario. These two approaches were used to locate potential wildlife crossing structures for endangered Florida panthers (Puma concolor coryi) in Collier, Lee, and Hendry Counties, Florida, a population whose survival is threatened by excessive traffic mortality. Historical traffic mortality records and an extensive radio‐tracking dataset were used in the analyses. Although the two approaches largely select different sites for crossing structures, both models highlight key locations in the landscape where these structures can remedy traffic mortality and habitat fragmentation. These applications demonstrate how the MCLP can serve as a useful conservation planning tool when traffic mortality or animal tracking data are available to researchers.