Water quality data and Olympia oyster abundance counts from depth-specific sampling collected by boat in Fidalgo Bay, WA, during July 2017 (NCEI Accession 0278463)

Acquisition Description:
We measured larval abundance, chlorophyll-a, temperature, and salinity from four depths at one location in Fidalgo Bay, WA, by boat each day from July 11 to July 14, 2017. Each day, we completed eleven sampling events. During each sampling event, we collected samples from four depths in the water column: surface (0.5 m below surface), bottom (0.5 m above seafloor), and two mid-depth samples, which evenly split the depth between surface and bottom samples. We planned each sampling event to begin at specific times relative to the predicted low tide with the goal of collecting approximately equal numbers of samples during ebb and flood tide.

To collect each larval sample, we used a modified bilge pump to filter 100-liters of water from our targeted depths through a 102-µm mesh plankton net to ensure retention of Olympia oyster larvae. Each sample was stored on ice while in the field and then preserved in 70% ethanol. At the end of filtering each 100-L sample, we collected 60-ml of bulk seawater from the pump for measurement of chlorophyll-a. We filtered the 60-ml of seawater through a glass microfiber filter (WhatmanTM GF/F). The foil-wrapped filters were held on ice in the field and then stored them at -80°C for later extraction. We measured chlorophyll-a concentration from each filtered sample by extracting the chlorophyll-a pigment using 90% acetone for 24 hours in the dark at -20°C and then reading fluorescence of each sample with a Turner Trilogy Fluorometer (Parsons et al. 1984; Welschmeyer 1994). We also programmed a Hach Environmental Company HydroLab DS5 water quality multiprobe instrument to collect temperature and salinity measurements at the same times and depths as our pump sampling. A Hach Hydras 3 Pocket instrument enabled us to calibrate, program, and retrieve data from the HydroLab.

This dataset includes unprocessed data and simple data calculations accomplished with R (Version 3.3.2).

We programmed a Nortek 1MHz Aquadopp acoustic Doppler current profiler (ADCP) to record velocity measurements in 0.3 meter vertical bins every 60 seconds. We then attached the ADCP instrument with sensors facing skyward to steel cross-bar frame and deployed it on the seafloor in Fidalgo Bay’s main channel for four days. We utilized Nortek AS software AquaPro version 1.27 to program and retrieve current velocity data from the Aquadopp instrument. This dataset includes these raw unprocessed data.