Dataset: Pigment concentration data for mesocosm incubation experiment simulating a phytoplankton bloom in Chesapeake Bay August 2021

The mesocosm experiment was performed in August 2021 on the R/V Hugh Sharp, cruise HRS2110, at a station near the mouth of Chesapeake Bay. Surface water (2–5 m) was collected from the study site (37.27o N, 76.09o W), located near the mouth of the bay. Incubation medium was prepared by pumping surface water (~5 m) directly from the sample site through a series of nylon mesh and glass fiber filters, ending with a 0.3 μm filter, using a double diaphragm pump into three 24-L translucent polycarbonate (PC) carboys. Surface water inoculum was collected using a rosette system with 12–L Niskin bottles and a CTD profiler from 2–4 m depth and pre–filtered through 210 μm nylon mesh before being added to the mesocosms to produce a 10 % inoculation. Carboys were incubated for eight days in an on–deck water bath, using a seawater flow–through system drawn from surface water and a plastic screen shade covering to keep incubation temperature and light similar to in situ conditions. 

Samples for pigment analysis were collected twice daily at 12:00 and 18:00 starting on day 2. Duplicate samples (100–400 mL) were filtered onto pre–combusted (500o C for ~5 h) 0.3 μm 25 mm GF-75 filters using pigment-dedicated filter-holders. Filters were stored individually at -80o C. Pigment samples were analyzed by High Performance Liquid Chromatography (HPLC) (Pinckney et al., 1996, 2001).