Mt. Hope Bay sediment and martian regolith simulant nutrient flux impact on algal and diatoms oxygen production | Poster Board #1042

Available sediment nutrient anions (NO2-, NO3-) and cations (Cu2+, Fe3+, Zn3+, Ni2+) fluxes play an essential role in the growth of primary producers like algae (Tisochrysis lutea) and diatoms (Thallassiosira weissfloggi). Marine sediment samples collected in Mt. Hope Bay, RI, and three commercially available Martian regolith simulants were characterized for their nutrient fluxes into DI, sterilized seawater, and raw seawater. The research further investigated the impact of these sediment fluxes as a substrate surface upon algae and diatom growth, in-situ oxygen production, pH, labile metal ions, nitrate, and nitrite concentrations in light and dark BOD microcosms. Dissolved oxygen concentrations were determined by the fluorescence-quenching probe, spectropolarimetric HACH® spot tests determined the suite of nutrients, and the concentration of metal cations was determined by ICP OES from filtered samples. The concertation of free nitrogen anions was found lower in the dark BODs' more acidic water columns. To further address the mineral fluxes from natural samples they were decarboned (500oC) and decarbonated (1000oC) on ignition in a furnace to contrast the regolith simulant. No impact was observed from the various underlying substrate environments on biological oxygen production from either algal or diatom growth over seven days. Trace metals were more labile from the regolith samples and the decarboned marine sediment samples notably Co and Fe ions.