Understanding the cause of low dissolved oxygen in Cape Cod Bay and initiating a hypoxia warning system for the lobster fishery

Bottom hypoxia was observed in late summer 2019 and 2020 in southern Cape Cod Bay, resulting in significant benthic mortality of lobsters, scallops and some fish species. To investigate and better understand what caused this unprecedented hypoxia, these data were collected with funding the NOAA Sea Grant American Lobster Initiative . Data consist of vertical profiles collected with a CTD equipped with dissolved oxygen sensor, chlorophyll fluorometer and optical backscatter sensor. Data collection focused on late summer when physical conditions conducive to hypoxia are most common and included 2020, 2021, 2022, and 2023.