Biogeochemical Controls on Pelagic Respiration Rates in Long Island Sound

Respiration rates of surface and bottom waters were measured across 10 stations in Long Island Sound (LIS) throughout five cruises spanning June, July, August, September, and November 2019. The dissolved oxygen concentration was measured continuously over five-hour dark incubation periods using Vernier GoDirect Optical Dissolved Oxygen probes. Dissolved oxygen was also measured discretely on dark incubated samples over the following five days. In addition to dissolved oxygen, dissolved and particulate organic carbon, dissolved inorganic carbon, total and particulate nitrogen, and nutrients were also measured to constrain the entirety of the respiration equation. Total alkalinity, pH, pCO₂, and gross primary productivity were also measured on surface samples only. Respiration is an important factor leading to hypoxic conditions in eutrophic water bodies such as LIS, but the parameters most affecting this process in LIS have not yet been constrained. This study compares the measured biogeochemical parameters to the observed respiration rates to elucidate the important controls on respiration in LIS. These data will be used to inform a new ecosystem model of LIS.