Update on the Ecological Model Jamie Vaudrey, James Kremer (UCONN) Mark Brush (VIMS), Dave Ullman (URI) CHRP October 8, 2009

& basis for formulations: (excluding macroalgae...) Processes of the model & basis for formulations: (excluding macroalgae...) Temp, Light, Boundary Conditions Chl, N, P, Salinity O2 coupled stoichiometrically Productivity Physics Surface layer - - - - - - - - - Deep layer Bottom sediment BZI Phytoplankton D O 2 mixing flushing Atmospheric Photic zone heterotrophy Flux to bottom deposition N P . N ƒ[Chl] ƒ(Chl10d) BRIEF REVIEW Jim Kremer’s version of the conceptual model. The text in blue is a clue to the basis for the formulation, e.g. benthic SOD (“Benthic heterotrophy” is a function of accumulated organic matter and temperature). In CHRP we track C, N & P in the water and organic matter. It is referred to as “simplified” because only the primary ecological processes related to estuarine eutrophication were parameterized and the physical framework comprised only surface and bottom layers of 15 boxes (= 30 model elements) Sediment Land-use organics N P Benthic heterotrophy Denitri- fication ƒ(OM,T) % . 2

Brown, CTD Surveys salinity oxygen Buoy Network salinity oxygen chlorophyll Nutrient Stations DIN DIP

July 6, 2006 box-wide average higher than buoy data

box-wide data may be high, except for box 3

Sometimes, the box-wide average will be better (less of a gradient in boxes)

In some cases, box-wide average should be right on.

Data not final – preliminary results

Data not final – preliminary results

Data not final – preliminary results

Data not final – preliminary results

Data not final – preliminary results

Data not final – preliminary results

Data not final – preliminary results

Data not final – preliminary results

Area = fraction of inflow due to source Use the exchange data to identify sources. Bay Model River Area = fraction of inflow due to source Data not final – preliminary results

Area = fraction of inflow due to source Greenwich Bay – sources are from neighboring elements. Bay Model River Area = fraction of inflow due to source Data not final – preliminary results

Source data for Greenwich Bay – information on which elements contribute to flux in. Data not final – preliminary results

Box 3 Current Conditions N reduced 50% Phytoplankton surface bottom Nitrogen N reduced 50% Varying N input – surface bottom Oxygen

Application of Model Results Determine largest sources of input. What controls the ecology in elements? Additional Model Scenarios Varying N input. Additional ROMS runs, varying meteorological conditions. Conclusions