CTD cast and bottle data from a collaborative Chukchi Sea research cruise on R/V Norseman II, October 2020

This dataset contains temperature and salinity data collected in the Chukchi Sea during the 5-20 October, 2020 collaborative ecosystem research cruise on R/V Norseman II. The dataset consists of bottle and CTD data. The goal of the fall DBO cruise on the Norseman II was to evaluate ecosystem status and change at the Distributed Biological Observatory (DBO) time series sites, to deploy a mooring and sediment trap at the M8 site in the northern Bering Sea (DBO1 region), and to turn around the Chukchi Ecosystem Observatory (CEO) mooring array in the NE Chukchi Sea (DBO4 region). The DBO fall cruise was a consortium of funded projects from the National Oceanic and Atmospheric Administration (NOAA), the North Pacific Research Board (NPRB), National Ocean Partnership Program (NOPP), Arctic Marine Biodiversity Observing Network (AMBON), and Alaska Ocean Observing System (AOOS), focused on benthic sampling as well as water column measurements. The cruise departed from Nome, Alaska with a limited scientific team participating for the planned water column and sediment sampling on the five DBO transect lines in the northern Bering and Chukchi Seas and mooring turnaround. A new sediment trap was deployed at the M8 site that is a collaborative project between Jackie Grebmeier (UMCES) and Phyllis Stabeno and Calvin Mordy (NOAA/EcoFOCI) through a NPRB funded project led by Catherine Lalande (Université Laval). In addition, we deployed a M8 mooring for Phyllis Stabeno (NOAA EcoFOCI). The cruise also turned around a mooring/sediment trap array at the Chukchi Ecosystem Observatory (CEO) in the NE Chukchi Sea that led by Seth Danielson (University of Alaska Fairbanks (UAF)/NPRB/AOOS). Collaboration occurred through AMBON supported eDNA collections with Matt Galaska (UW/NOAA) as well as cross-data evaluation through the NOAA Arctic Research Program water column and benthic DBO data collections, and the Alaska Harmful Algal Bloom (HAB) network for sediment and dominant macrofaunal studies. The scientific team included personnel from: UMCES (4) and UAF (4), totaling 8 scientists (maximum due to berthing limitations associated with for COVID-19 safety protocol negotiated by Service Vessels of Alaska, the vessel owner) following a required quarantine in Anchorage prior to a charter flight to Nome, Alaska to fully isolate the scientific team from possible viral infection sources. The shipboard sampling included CTD/rosette sampling for temperature, salinity, and vertical water column sampling for other water column indicators. The CTD was deployed at all DBO stations and the two mooring sites (M8 in DBO1 region and CEO in the DBO4 region). We will collect water for chlorophyll, phytoplankton taxonomy, nutrients, oxygen-18/16 ratios, eDNA, zooplankton, van Veen grab deployments for macrofauna (population studies) and sediments (carbon content, grain size, HABS), and a single HAPS core deployment for collection of undisturbed sediment cores for carbon cycling experiments at select stations. A seabird observer on the bridge will complete the core DBO standard activities.