N2O, 15N2, 15N tissue tracer in oyster aquariums (Oyster Reef N2O Emission project) on 2017-12-31 (NCEI Accession 0292012)

Acquisition Description:
Three 9.45L aquariums contained twelve 7-cm long oysters pre-exposed to 15 N labeled phytoplankton (OA1, OA2, OA3,) and three aquariums had no oysters and served as controls (CA1, CA2, CA3). These aquariums were filled with 0.1micron filtered seawater and a small circulation pump was added. N 2 O, 15 N, and oxygen were measured initially and then aquariums sealed until oxygen had depleted to 2mgL -1 . Oysters were then harvested for their gill/mantle tissue (meat) and digestive tissue (digestive) over a period of time.

Oxygen was measured insitu using an oxygen probe. Water samples for N 2 O analysis were collected with a peristaltic pump through a syringe needle directly into 12 ml exetainer that had been flushed with N 2 and preserved with KOH to a pH above 12. Approximately six ml sample was collected. N 2 O concentrations in the headspace were measured on a GC-ECD. Water samples for 15N2 samples were collected with a peristaltic pump through a syringe needle directly into 30 ml serum bottles that had been flushed with He and preserved with KOH to a pH above 12. Approximately eight ml sample was collected. 15 N 2 was analyzed by GC - Isotope Ratio Mass Spectrometry (IRMS). Oyster tissue 15 N samples were collected from the aquariums from dissections. 15 N was analyzed on a elemental analyzer (EA) coupled with an IRMS.