Carbonate preservation in marine sediments

Observations of carbonate preservation in marine sediments have long been used to infer changes in ocean circulation or biogenic production. When combined with measures of organic carbon rain and calcite accumulation rates, quantitative estimates of changes in preservation can reveal variation in biogenic fluxes, the org. C to calcite flux ratio and saturation state of bottom waters. Here we develop quantitative dissolution proxies for mid to higher latitudes based on foraminiferal test fragmentation. Examining surface sediments, we find that fragmentation in G. bulloides and G. truncatulinoides is linear with increasing seabed dissolution rate and can be used to quantify changes in carbonate preservation. G. truncatulinoides shows a constant relationship of fragmentation to dissolution. However, we observe that, although linear to dissolution rate, the fragmentation in G. bulloides depends on which morphotype is present. Other species, such as G. inflata, have complex responses to increasing dissolution and are less direct preservation indicators.

Selective mortality associated with variation in CO2 tolerance in a marine fish

Predicted future CO2 levels can affect reproduction, growth, and behaviour of many marine organisms. However, the capacity of species to adapt to predicted changes in ocean chemistry is largely unknown. We used a unique field-based experiment to test for differential survival associated with variation in CO2 tolerance in a wild population of coral-reef fishes. Juvenile damselfish exhibited variation in their response to elevated (700 µatm) CO2 when tested in the laboratory and this influenced their behaviour and risk of mortality in the wild. Individuals that were sensitive to elevated CO2 were more active and move further from shelter in natural coral reef habitat and, as a result, mortality from predation was significantly higher compared with individuals from the same treatment that were tolerant of elevated CO2. If individual variation in CO2 tolerance is heritable, this selection of phenotypes tolerant to elevated CO2 could potentially help mitigate the effects of ocean acidification.

Annotated record of the detailed examination of Mn deposits from DSDP Site 160, Leg 16 (Cores 16-160-1, 16-160-2 and 16-160-3)

DSDP 160 forms part of a series of sites in the eastern equatorial Pacific on the west flank of the East Pacific Rise. Earlier legs of the Deep Sea Drilling Project, in particular Legs 5 and 9, have reported sediments rich in oxides of iron and perhaps other transition metals just above basement in the eastern Pacific. These occurrences roughly define a broad zone on the west flank of the rise. Site DSDP 160 lies on this trend and were selected by the Pacific Site Selection Panel to test the extent of such deposits.

Supplemental Data - Bioremediation of polluted air from an industrial plant using rotating biofilter reactor-based technology

Two microbial isolates (HDB, Hydrogen-Degrading Bacteria) obtained from industrial wastewater were inoculated into the rotating biofilter reactor 'Biowheel 2.0' and tested for the ability to purify gaseous flows containing benzene and non-methane volatile organic compounds (NMVOCs) released at an industrial plant. Different classes of gaseous flow were tested, namely 'cold box', 'in shell', and 'mix', all of them associated with the industrial process of 'mold-casting'. A significant increase in Removal Efficiency (RE) was recorded for benzene and NMVOCs in the inoculated 'Biowheel 2.0' biofilter, compared to uninoculated control. For each type of gaseous flow, odor impact was evaluated in the inlet and outlet flows at the industrial plant, using the test panel method and electronic nose technology. A significant drop in the amount of Olfactometric Units (O.U.) m-3 occurred in the gaseous flows treated with the bacterial consortium. The reported data demonstrate the ability of the consortium to degrade hydrocarbons, revealing its potential for bioremediation of polluted air emissions occurring at industrial plants.