Thursday, 2:30 PM in 555 AB (RICC)
(subject to change)
The NH Department of Environmental Services and the NH Estuaries Project are developing water quality criteria for nutrients to protect the declining eelgrass beds in the Great Bay Estuary (GBE). The traditional conceptual model for eelgrass loss from nitrogen enrichment and phytoplankton shading has proven difficult to apply to GBE because tides and resuspended sediments dominate this estuary. The nitrogen load to GBE (2,732 kg/day), even when normalized by the estuary surface area, volume, and/or flushing time, is typically higher than expected for the amount of eelgrass remaining. Due to high variability and small sample size of currently available data, statistical analysis of water quality grab samples and light attenuation is not able to detect significant factors controlling water clarity for any parameter except colored dissolved organic matter. To improve statistical power, in-situ sensors have been deployed on a moored buoy to measure light attenuation and water quality parameters every hour. The buoy observations as well as field observations by researchers are being used to formulate a new conceptual model for eutrophication in the GBE that will include variable light fields due to large tidal ranges, sediment resuspension during tidal cycles and wind events, and macroalgae growth.
