Normalized Foraminiferal Data for Chincoteague Bay and the Marshes of Assateague Island and the Adjacent Vicinity, Maryland and Virginia- Fall 2014

Estuarine grab samples (denoted with a “G”) were collected in the field using a petite Ponar sediment sampler in the spring (March 26–April 4) and fall (October 21–30) of 2014. During the same time periods, surface samples (denoted with an “S”) were collected on land from marsh and sandy over-wash environments . At each sample location, the top one centimeter (cm) of undisturbed surface material was subsampled for two (replicate) foraminiferal samples of approximately 25 milliliters (mL) using either a spatula or scoopula and placed in two graduated centrifuge tubes (denoted with “a” and “b”). All surface samples were preserved in the field using 90% ethanol mixed with Rose Bengal stain within hours of collection in order to distinguish between live (and recently live) and dead foraminifera (modified from Walton, 1952). Each centrifuge tube was shaken twice daily for at least two weeks prior to lab processing.

Following a two-week staining period, foraminiferal sample volumes were recorded from the centrifuge tube they were stored in. Once recorded, samples were washed over a 63- and 850-micron (µm) sieve in order to remove ethanol, clay material, and to separate out large organics (Schonfeld and others, 2012). In some cases, multiple washes were necessary to remove all clay aggregates. Once dry, some of the samples with a high sand content were processed using sodium polytungstate in order to concentrate foraminifera (Munsterman and Kerstholt, 1996). Prior to picking, samples were dry sieved over 125 and 250 µm sieves in order to create four splits; 63–125, 125–250, 250–850, and >850 µm and vialed separately. For picking, the 125–250 and 250–850 size fractions for each sample were split into equal parts using a microsplitter and spread evenly over a hole punched, gridded picking tray. Entire splits were picked until approximately 200 foraminiferal specimens were acquired to enable the calculation of foraminiferal densities. At least one sample was picked from each spring site whereas only a select few samples collected in the fall and from the offshore sites were picked for contrast while attempting to choose sites that vary geographically. Foraminiferal identifications were made by making comparisons with published literature. The foraminiferal data presented in this publication include raw count data and volumetrically normalized (25 mL) specimen counts.

Added keywords section with USGS persistent identifier as theme keyword.