Date of Award

Spring 2011

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Environmental Engineering - (Ph.D.)

Department

Civil and Environmental Engineering

First Advisor

Lisa Axe

Second Advisor

Liping Wei

Third Advisor

Eliza Zoi-Heleni Michalopoulou

Fourth Advisor

Priscilla Nelson

Fifth Advisor

Thomas J. Olenik

Abstract

The New York / New Jersey (NY/NJ) coastal area is one of the most productive regions around the world and a major natural and scenic resource for New York and New Jersey. As a result of excessive nutrient loading in the water, algal blooms have been observed since 1950’s. The NY/NJ coastal area includes the NY/NJ Bight and the NY/NJ Harbor Estuary, and in the former, brown tides (Aureococcus anophagefferens) were first observed in 1985 becoming a more serious water quality problem over the last 25 years. The influence of micronutrients, namely trace metals, on A. anophagefferens that are widespread in coastal waters is not as well understood. Growth rate and bioaccumulation from exposure to trace metals demonstrated that nickel promoted brown tide growth and that the occurrence of the blooms may significantly influence the fate of cadmium and zinc. On the other hand, in the NY/NJ Harbor Estuary diatom and dinoflagellate blooms dominate the area. Rapid assessment of alga blooms is critical in maintaining coastal waters and remote sensing is an effective tool for monitoring. To improve the accuracy of its application in the NY/NJ Harbor Estuary and to build a bio-optical database, in situ samples were collected from August 2008 to June 2009. Absorption spectra revealed contributions of 47 ± 18% color dissolved organic matter (CDOM), 18 ± 6% non-algal particles (NAP), and 35 ± 16% phytoplankton. The narrow variation in the NAP contribution demonstrates that it can be conveniently subtracted from the total absorption. Furthermore, analysis showed that organics dominated the NAP spectra; in situ sources with minor terrigenous inputs dominated CDOM spectra; and, diatom and dinoflagellate governed phytoplankton contributions. The combination of pigment distribution analysis and package effect estimation indicates that cell size was a significant factor accounting for variability observed in the specific absorption coefficient. Overall, the obtained biooptical characteristics, including the specific absorption coefficient and slopes of CDOM and NAP spectra, facilitate application of remote sensing models for water quality monitoring of the NY/NJ Harbor Estuary.

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