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Particulate organic carbon and nitrogen are measured from discrete bottle samples collected during CTD-rosette casts on Northeast U.S. Shelf Long-Term Ecological Research (NES-LTER) Transect cruises (ongoing since 2017). Sampling frequency is approximately seasonal. Samples were filtered and collected on combusted glass fiber filters, pelletized using ultra clean tin disks, and combusted using a Flash EA1112 CHN analyzer to calculate concentrations of particulate organic carbon and particulate organic nitrogen in micromoles per liter. Values are also reported as concentrations in micrograms per liter and carbon to nitrogen molar ratio. 

These data represent the abundance, biovolume, and biomass of prokaryotic and eukaryotic picoplankton and nanoplankton sampled continuously underway during Northeast U.S. Shelf Long-Term Ecological Research (NES-LTER) Transect cruises, ongoing since 2018. Samples were obtained with an Attune NxT Flow Cytometer sampling at approximately 2-min intervals from the underway science seawater. Cells were identified and enumerated from the flow cytometry data files based on their scattering, phycoerythrin (575 nm) and chlorophyll (680 nm) fluorescence signals. 

This dataset consists of primary production measurements based on uptake of carbon-13 added as 13C-bicarbonate during 24-h deckboard incubations of seawater. Sampling occurred on cruises along the Northeast U.S. Shelf Long Term Ecological Research (NES-LTER) Transect during summer, fall, and winter, starting in summer 2019. Net primary production (NPP) was determined from particulate organic carbon (POC) content and associated stable isotope enrichment. Three data tables are included: 1. Depth-specific primary productivity based on fractional light levels of the surface irradiance with reference to the profile of photosynthetically active radiation (PAR). 2. Integrated primary productivity. 3. Natural abundance POC. The tables derive from the raw data included as other entities. 

This dataset lists the inventory of physical samples from zooplankton net tows conducted on Northeast U.S. Shelf Long-Term Ecological Research (NES-LTER) Transect cruises, ongoing since 2017. The NES-LTER transect lies south of Martha’s Vineyard, Massachusetts. Dedicated NES-LTER cruises target summer and winter seasons, with samples collected in oblique tows with a bongo net fitted with 150 and 335 micron mesh nets, as well as a ring net with a 20 micron mesh net. Additional cruises along the NES-LTER Transect, including spring and fall cruises with the Ocean Observatories Initiative, collect samples in vertical tows using a ring net with 150 micron mesh net. Samples are shared with different labs for purposes including DNA metabarcoding, stable isotopes, and morphological identification. 

Zooplankton are sampled on Northeast U.S. Shelf Long-Term Ecological Research (NES-LTER) Transect cruises in summer and winter seasons in oblique tows with a bongo net equipped with two mesh sizes (335 micron and 150 micron). Tows are conducted at standard stations L1 to L11 along longitude 70 deg 53 min W extending southward from near Martha’s Vineyard, Massachusetts, to approximately 150 km offshore. Counts for taxa morphologically identified from the 335 micron net were provided by the Northeast Fisheries Science Center of the NOAA National Marine Fisheries Service. Counts were divided by volume and multiplied by depth sampled for abundance as per meter squared. The first version of this data package provides the abundance of 14 taxa from the 335 micron net for cruises in 2018 - 2020 in a described data table, as well as a supplemental table for the tow metadata. 

This package provides a concatenated table of events recorded on seasonal Transect cruises for Northeast U.S. Shelf Long-Term Ecological Research (NES-LTER). Events were recorded onboard with Rolling Deck to Repository (R2R) event logger (elog) software. Event listings include date, time, ship’s position, instrument, and action for use in physical sample cataloging and post-cruise data integration. Cruises include winter and summer cruises dedicated to NES-LTER, spring and fall cruises in collaboration with the Ocean Observatories Initiative (OOI), and additional fall cruises. 

The continuous underway fluorescence, induced by in vivo chlorophyll-a (Chl-a), of surface waters of the Northeast U.S. shelf is compared to discrete Chl-a samples for post-calibration, collected ship-board as part of the Northeast U.S. Shelf Long-Term Ecological Research (NES LTER). Chl-a values derived from the manufacturer-calibrated sensors (hereafter, “continuous fluorescence”) and collected continuously are often different from the precise Chl-a concentrations obtained from discrete, extracted samples. Moreover, underway fluorometers and manufacturer calibrations differ per cruise. Thus, post-calibration of the continuous fluorescence signals using discrete Chl-a measurements is essential to standardize and compare the high-resolution underway Chl-a data along cruise tracks. For six cruises aboard the R/V Endeavor between summer 2019 and summer 2021, 12 to 22 discrete samples were collected from the underway system to measure Chl-a concentrations. These discrete Chl-a concentrations were then compared, using simple linear regressions (Model I least square fit), to corresponding continuous fluorescence values recorded by the two independent fluorometers installed with the underway system. For each cruise a preferred fluorometer was identified based on the best fit of the linear regression between discrete Chl-a concentrations and continuous fluorescence values. The slope and the intercept of the linear regression were used to post-calibrate continuous fluorescence values into standardized and intercomparable Chl-a concentration. This data package includes a table for the underway discrete Chl-a values and a table for the 1-min post-calibrated continuous fluorescence values for the preferred underway fluorometer per cruise.