Culturing the solitary ascidian Phallusia nigra in closed and open water systems for tropical environmental research

Ocean warming ameliorates the negative effects of ocean acidification on Paracentrotus lividus larval development and settlement

海洋酸化和全球变暖对贝类生理生态的影响研究进展

고랑가리비의 산란을 유도하고 수정난의 발생과 유생의 성장과정을 조사하였다. 산란자극 방법으로 광 자극, 간출 자극, 온도 자극, 그리고 간출 후 온도자극을 수온 <TEX>$16{\pm}0.5^{\circ}C$</TEX>에서 각각 실시하였다. 광 자극은 암컷 1마리당 700-900천개, 온도 자극은 700-800천개로 적은 산란량을 보인 반면 간출 자극은 700-1,200천개로 높았으며 간출 자극 후 온도자극이 1,000-1,500천개로 가장 높은 산란량을 보였다. 수정율에 있어 광 자극은 암컷 1마리당 71.7%, 온도자극은 73.4%, 간출 자극이 73.6%이었으며 간출 자극 후 온도자극은 76.3%로 가장 높았으나 자극방법에 따른 수정율의 유의적인 차이는 없었다. 수정란부터 D상 유생으로의 수온별 발생과정을 조사하기 위하여 비이커에 ml당 1,000개의 수정란을 수용하고 각각 <TEX>$8^{\circ}C$</TEX>, <TEX>$12^{\circ}C$</TEX>, <TEX>$16^{\circ}C$</TEX>, <TEX>$20^{\circ}C$</TEX> 및 <TEX>$24^{\circ}C$</TEX>에서 D상 유생으로 발생하는 생존율을 광학현미경을 사용하여 30분 간격으로 관찰한 결과, <TEX>$8^{\circ}C$</TEX>와 <TEX>$24^{\circ}C$</TEX>의 실험군이 4.1%와 3.2%로 생존율이 낮은 편이었으며 <TEX>$16^{\circ}C$</TEX>에서 32.7%로 가장 높은 생존율을 보여주었다. 수정란의 크기는 <TEX>$72{\pm}2.1{\mu}m$</TEX>, 담륜자 유생은 <TEX>$103{\pm}3.8{\mu}m$</TEX>, D상 유생은 <TEX>$129{\pm}10.4{\mu}m$</TEX>, 각정기 유생은 <TEX>$145{\pm}16.8{\mu}m$</TEX>, 후기 유생은 <TEX>$197{\pm}13.6{\mu}m$</TEX>이었으며 528시간 후에 각장 <TEX>$245{\pm}15.8{\mu}m$</TEX>의 초기 부착종묘로 성장하였다. The development of swift's scallop Chlamys swiftii, reared in the laboratory, has been examined through the investigation of morphological characteristics in fertilized egg, larvae and juvenile. Eggs were fertilized with a dilute sperm solution to improve the survival of fertilized eggs. Developing larvae were maintained at a temperature of <TEX>$16{\pm}0.5^{\circ}C$</TEX> and salinity concentration of 33 ppt. We have investigated the fertilization rates and egg number spawned at several stimulating conditions such as sunlight exposure, air dry, seawater temperature rise (<TEX>$5^{\circ}C$</TEX>) and seawater temperature rise (<TEX>$5^{\circ}C$</TEX>) after exposure of air dry for spawning induction of swift's scallop Chamys swiftii. Stimulation treated with sunlight exposure and seawater temperature rise (<TEX>$5^{\circ}C$</TEX>) have shown the spawning number of 700,000-900,000 and 700,000-800,000 per individual, respectively while stimulation treated with seawater temperature rise (<TEX>$5^{\circ}C$</TEX>) after exposure of air dry have shown the high spawning number of 1,000,000-1,500,000 per individual. Survival rate of D-shaped larvae of swift's scallop put into the different seawater temperatures of <TEX>$8^{\circ}C$</TEX>, <TEX>$12^{\circ}C$</TEX>, <TEX>$16^{\circ}C$</TEX>, <TEX>$20^{\circ}C$</TEX> and <TEX>$24^{\circ}C$</TEX> has been 4.1%, 11.6%, 32.7%, 18.6% and 3.2%, respectively. Fertilized eggs with the diameter of <TEX>$72{\mu}m$</TEX> developed into trochophore larvae of <TEX>$103{\pm}3.8{\mu}m$</TEX> shortly after 35 hours and to D larvae of <TEX>$129{\pm}10.4{\mu}m$</TEX> shell length within 72 hours. It took 336 hours to become initial Umbo-stage larva of <TEX>$145{\pm}16.8{\mu}m$</TEX> shell length. Post larvae, which have been <TEX>$197{\pm}13.6{\mu}m$</TEX> shell length, spontaneously have settled in the attachment substances. It have required 528 hours from fertilized eggs to early attached juvenile to become initial juvenile size of <TEX>$245{\pm}15.8{\mu}m$</TEX> shell length.

Meridional heat transport of the western Pacific boundary current (the Kuroshio Current) is one of the key factors in global climate change. This current is important because it controls the temperature gradient between low latitudes and the North Pacific and so significantly influences mid-latitude atmosphere-ocean interactions. Here we reconstruct changes in hydrological conditions within the mid-latitude mainstream of the Kuroshio Current based on faunal analysis of planktonic foraminifera in core DSDP 296 from the Northwest Pacific Ocean. This approach enabled us to deduce evolutionary processes within the Kuroshio Current since the Pliocene. A total of 57 species in the coarser section (> 150 µm) were identified; results indicate that planktonic foraminiferal faunal evolution has mainly been characterized by three major stages, the first of which comprised mixed-layer warm-water species of Globigerinoides ruber which first appeared between 3.5 and 2.7 Ma and then gradually increased in content. Percentages of another warm-water species of G. conglobatus also gradually increased in number over this interval. Variations in warm-water species indicate a gradual rise in sea surface temperature (SST) and imply initiation of Kuroshio Current impact on the Northwest Pacific Ocean since at least 3.5 Ma. Secondly, over the period between 2.7 and 2.0 Ma, thermocline species of Globigerina calida , Neogloboquadrina humersa , Neogloboquadrina dutertrei , and Pulleniatina obliquiloculata started to appear in the section. This fauna was dominated by G. ruber as well as increasing G. conglobatus contents. These features imply a further rise in SST and its gradually enhanced influence on thermocline water, suggesting strengthening of the Kuroshio Current since 2.7 Ma. Thirdly, between 2.0 Ma and present, increasing contents of thermocline species (i.e., G. calida , N. dutertrei and P. obliquiloculata ) indicate a gradual rise in seawater temperature at this depth and also imply more intensive Kuroshio Current during this period. On the basis of comparative records from cores ODP 806 and DSDP 292 from the low latitude Western Pacific, we propose that initiation of the impact of the Kuroshio Current in the Northwest Pacific and it subsequent stepwise intensifications since 3.5 Ma can be closely related to the closure and restriction of the Indonesian and Central American seaways as well as variations in the Western Pacific Warm Pool (WPWP) and equatorial Pacific region.

Dermatan sulfate obtained from the Phallusia nigra marine organism is responsible for antioxidant activity and neuroprotection in the neuroblastoma-2A cell lineage

Marine ferromanganese polymetallic crusts and nodules are an important mineral resource widely distributed on the seafloor. They are regarded as strategic reserve resources and have attracted much attention. During the mineralization process, the iron-manganese oxide/hydroxide colloids generated by the oxidation of Fe2+ and Mn2+ in the ambient seawater adsorb metal ions and oxidize the metal ions to a high valence state or form metal complexes to be enriched in iron-manganese minerals. They grow slowly at a rate of several mm/Myr, recording and preserving important information on paleo-ocean and paleoclimate changes. They are ideal objects and response media for studying global ocean evolution and environmental changes and are also helpful in exploring the source-sink process of marine substances. Therefore, based on the precise chronology of polymetallic crusts and nodules from the South China Sea (SCS), this study used in-situ Pb isotope analysis technology to analyze the variation characteristics of Pb isotope composition of polymetallic crusts and nodules, to reveal the growth and mineralization history and environmental evolution of crusts and nodules in the study area.&amp;#160;The results show that: (1) The growth ages of SCS polymetallic crusts and nodules are about 1.16-3.46 Ma and an average growth rate of 3.19-6.07 mm/Myr using the 10Be/9Be isotope method. (2) The Pb isotope characteristics of SCS polymetallic crusts and nodules are related to their growth area: the Pb source of crusts and nodules growing in the northern SCS is mainly affected by the input of terrigenous materials; the crusts and nodules growing in the central SCS are less affected by terrigenous materials and are gradually affected by the weathering/alteration of seamount substrates and the input of volcanic activities. (3) Through the coupling of the mineralization chronology framework of SCS polymetallic crusts and nodules with the Pb isotope compositions of their profiles, it is found that the rapid formation and large-scale expansion of the northern hemisphere ice sheet around 3.5 Ma caused the deep water of the SCS to become extremely oxidized, thus promoting the mineralization of SCS crusts and nodules. The tectonic activities in the SCS since 2.8 Ma have had a greater impact on the SCS polymetallic crusts and nodules. Events such as the closure of the Lehe Waterway and the successive closure of the Taitung Waterway have led to the strengthening of the closure of the SCS, the lack of ventilation, and the reduction of oxidation of the seawater, which has slowed the growth rate of polymetallic crusts and nodules. In addition, the uplift of Taiwan and the subsidence of the northern SCS have led to an increase in the input of terrigenous materials, which has led to a decrease in the content of metal elements in the mineralization of polymetallic crusts and nodules. Therefore, the mineralization of SCS polymetallic crusts and nodules is subject to joint control of the tectonic evolution of the SCS and changes in the marine environment such as global climate change.

Using particle tracking and genetic approaches to infer population connectivity in the deep-sea scleractinian coral Deltocyathus magnificus in the South China sea

The aim of this article is a comprehensive review of Papal Encyclicals in the context of global environmental and climatic change, against the backdrop of the activity of multinational institutions. The Encyclicals look to the future in teaching the faithful, in a manner which indicates that they are part of a goal-oriented policy, both in terms of scientific research, and concrete economic, social, and geopolitical activity. Attention has also been paid to the relationship between the activity of humankind, and global environmental change, particularly of the biotic and climatic variety. If this aggressive anthropogenic activity cannot be deemed responsible for initiating global warming, it may certainly be seen to have “encouraged” it. The impulses behind sustainable development, as well as the instruments of its implementation, and the inspiration behind the idea, have also been discussed. The achievement of this goal, necessitating the balancing of anthropological aspirations and the long-term security of the environment are also referenced in the Encyclicals.

Vibrio harveyi is an emerging pathogen that causes mass mortality in a wide variety of marine animal species; however, it is still unclear which environmental determinants correlate V. harveyi dynamics and the bacterium-mediated death of marine animal life. We conducted a correlation analysis over a 5-year period (2003-2007) analysing the following data: V. harveyi abundance, marine animal mortality and environmental variables (seawater temperature, salinity, pH, chlorophyll a, rainfall and total viable bacterial counts). The samples were collected from a coastal area in northern Japan, where deaths of a marine gastropod species (Haliotis discus hannai) have been reported. Our analysis revealed significant positive correlations between average seawater temperature and average V. harveyi abundance (R = 0.955; P < 0.05), and between average seawater temperature and V. harveyi-mediated abalone death (R = 0.931; P < 0.05). Based on the regression model, n degrees C rise in seawater temperature gave rise to a 21(n)-fold increase in the risk of mortality caused by V. harveyi infection. This is the first report providing evidence of the strong positive correlation between seawater temperature and V. harveyi-mediated death of marine species.

Ocean acidification (OA) and warming related to the anthropogenic increase in atmospheric CO2 have been shown to have detrimental effects on several marine organisms, especially those with calcium carbonate structures such as corals. In this study, we evaluate the response of two Mediterranean shallow-water azooxanthellate corals to the projected pH and seawater temperature (ST) scenarios for the end of this century. The colonial coral Astroides calycularis and the solitary Leptopsammia pruvoti were grown in aquaria over a year under two fixed pH conditions, control (8.05 pHT units) and low (7.72 pHT units), and simulating two annual ST cycles, natural and high (+3 °C). The organic matter (OM), lipid and protein content of the tissue and the skeletal microdensity of A. calycularis were not affected by the stress conditions (low pH, high ST), but the species exhibited a mean 25 % decrease in calcification rate at high-ST conditions at the end of the warm period and a mean 10 % increase in skeletal porosity under the acidified treatment after a full year cycle. Conversely, an absence of effects on calcification and skeletal microdensity of L. pruvoti exposed to low-pH and high-ST treatments contrasted with a significant decrease in the OM, lipid and protein content of the tissue at high-ST conditions and a 13 % mean increase in the skeletal porosity under low-pH conditions following a full year of exposure. This species-specific response suggests that different internal self-regulation strategies for energy reallocation may allow certain shallow-water azooxanthellate corals to cope more successfully than others with global environmental changes.

Phallusia nigra, a solitary ascidian, has no epibionts on the surface of tunic. Moreover, the tunic contains sulfuric acid. The pH inside the tunic was about 1 as measured with a needle-tip pH electrode, and the pH at the tunic surface was 4–5 as measured with a flat-surfaced pH electrode. The surface pH decreased to 2 when the tunic surface was gently wiped with tissue paper. Thus, the tunic seems to release acid in response to mechanical stimuli. The time course of the pH recording showed that the acidity is stable at pH 1–2 for more than five minutes after the needle-tip electrode is inserted, so neutralization of tunic acid with seawater would not occur rapidly. The acid is contained in highly vacuolated cells (tunic bladder cells), and most of these cells are located beneath the tunic surface (Stoecker, 1978; Hirose, 1999). The major anion in the tunic acid was sulfuric acid, and the SO42−/Cl− ratio was 4.63. In histological sections, the vacuolar lumen appear to occupy 25% of the total tuni...

Gravity-driven biomimetic membrane (GDBM): An ecological water treatment technology for water purification in the open natural water system

Anthropogenic multipollutant input to the offshore South China Sea

The solitary ascidian Microcosmus exasperatus is globally distributed in tropical and sub-tropical waters. In the Mediterranean it is considered an invasive species introduced through the Suez Canal, with a restricted distribution in the eastern basin. In order to understand the potential of this species to establish sustainable communities at additional sites in the Mediterranean, we studied its reproduction cycle over a 2-year period in relation to seawater temperature and chlorophyll-a data. Although M. exasperatus reproduces seasonally, with significantly greater activity in summer and early fall, mature oocytes occur throughout the year, suggesting multiple spawning periods. We found that reproductive effort significantly correlated with seawater temperature, while chlorophyll-a showed a low and insignificant explanatory power. A combined regression model of both parameters yielded the highest explained variance, suggesting a synergic effect of these two factors. Such a prolonged reproductive activity period enables repeated recruitment events. In view of the anticipated rise in seawater temperature, we predict that this species will gradually expand its distribution further across the Mediterranean.

The role of ecological divergence in speciation between intertidal and subtidal Scoloplos armiger (Polychaeta, Orbiniidae)