Document Type

Honors Thesis

Publication Date

Winter 12-2017


Predicting benthic light fields in the Damariscotta River Estuary (DRE) allows us to evaluate optimal microphytobenthos habitat, and determine the most the productive regions of the DRE. A model was created using instantaneous photosynthetically active radiation (PAR) to predict the spatial distribution of sufficient light fields for primary production along the benthos of the estuary. PAR was collected at six stations oriented N- S along the DRE during late September in 2016 and 2017. Calculated at each station was Z1%, experimental and model diffuse coefficients of light (Kd), and the optimal light level depth for microphytobenthos production. Light fields were extrapolated between stations over bathymetric data of the DRE. Optimal light fields for microphytobenthos primary production are present along the edges of the entire DRE, and above 43.91o N. Light only reaches the benthos at the head of the estuary, and more light penetrated the water column in 2017. Light attenuates as a function of the concentration of scattering and absorbing agents, and spectral quality has a direct relationship with depth.