Abundance and biomass of Hemiaulus on the Northeast U.S. Shelf from 2013 to 2023 determined by Imaging FlowCytobot.

These data include abundance and carbon concentration of the diatom Hemiaulus on the Northeast U.S. Shelf during 81 research cruises from 2013 to 2023 as part of Long-Term Ecological Research (NES-LTER). Abundances are determined from Imaging FlowCytobot (IFCB) deployed in three different sampling schemes: underway mode (sampling near-surface seawater) on NOAA EcoMon, HAB Cyst, and AMAPPS broadscale survey cruises from 2013 to 2023; in underway mode (sampling near-surface seawater) on NES-LTER transect cruises from 2017 to 2023, and in discrete mode (CTD rosette discrete samples from depth) on NES-LTER transect cruises. Results are based on machine learning image classification, with one data table provided per sampling scheme (broadscale underway, transect underway, and transect discrete). Hemiaulus data are provided in abundance per milliliter and micrograms of carbon per liter.