Acidification of subsurface coastal waters enhanced by eutrophication

US EPA; NSF; NASA; National Natural Science Foundation of China; National Basic Research Program of China; National Science Council of the Republic of ChinaHuman inputs of nutrients to coastal waters can lead to the excessive production of algae, a process known as eutrophication. Microbial consumption of this organic matter lowers oxygen levels in the water(1-3). In addition, the carbon dioxide produced during microbial respiration increases acidity. The dissolution of atmospheric carbon dioxide in ocean waters also raises acidity, a process known as ocean acidification. Here, we assess the combined impact of eutrophication and ocean acidification on acidity in the coastal ocean, using data collected in the northern Gulf of Mexico and the East China Sea-two regions heavily influenced by nutrient-laden rivers. We show that eutrophication in these waters is associated with the development of hypoxia and the acidification of subsurface waters, as expected. Model simulations, using data collected from the northern Gulf of Mexico, however, suggest that the drop in pH since pre-industrial times is greater than that expected from eutrophication and ocean acidification alone. We attribute the additional drop in pH-of 0.05 units-to a reduction in the ability of these carbon dioxide-rich waters to buffer changes in pH. We suggest that eutrophication could increase the susceptibility of coastal waters to ocean acidification

An insight on the speciation and genetical imprint of bicarbonate ion in the groundwater along K/T boundary, South India

Groundwater stored in sand, clay, and underground rocks that act as huge aquifers of water have been vastly explored by human civilization for drinking and irrigation purposes. This underlying sand, clay, and rocks greatly influence the chemistry of groundwater by fluctuation in various concentrations of ions. The geochemistry of Ariyalur region was studied by taking 142 samples in both Pre monsoon (PRM) and Post monsoon (POM) seasons. Analysis for crucial cations and anions like K+, Na+, F-, Cl-, HCO3-, Mg2+, Ca2+, SO42-, PO43-, NO3-, and H4SiO4and the physico-chemical variables like pH, total dissolved solid (TDS), and electrical conductivity (EC) were carried out to understand the suitability of groundwater. From all these information, Piper-plot has been used to analyze the water type in both the seasons. The study revealed that in both the seasons, HCO3-covers the major factors followed by H2CO3which are responsible for the change of chemistry of groundwater and proved its importance in the study area. Hence to determine the relationship of HCO3-with other ions, various charts were used. To obtain the origin of this HCO3-and reactions related to it, correlation of different species like HCO3, CaHCO3, MgHCO3, NaHCO3, CaCO3, MgCO3, NaCO3, and H2CO3were analyzed along with major physico-chemical variables like pH and logpCO2. The factor analysis for these species revealed the processes and reactions taking place in the study area. The contour diagrams for all the species in both the season has revealed the origin of HCO3-and dissolution by comparing lithology and geology of the study area

Advantages and Applications of Cryopreservation in Fisheries Science

Cryopreservation is a long-term storage technique to preserve the biological material without deterioration for extended period of time at least several thousands of years. The ability to preserve and store both maternal and paternal gametes provides a reliable source of fish genetic material for scientific and aquaculture purposes as well as for conservation of biodiversity. Successful cryopreservation of fish sperm have been achieved for more than 200 fish species and many fish species have been adequated for the purpose of cryobanking. Cryopreservation of fish embryo is not viable, mainly because of the same limitations as in fish oocytes, i.e., high chilling sensitivity and low membrane permeability. However, cryopreservation of isolated embryonic cells is another option for preserving both maternal and paternal genome. In this paper, an overview of the current state of aquatic species is followed by a discussion on the sperm, embryos, oocytes and embryonic cells - blastomeres