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Colored dissolved organic matter in Tampa Bay, Florida

Marine Chemistry

By:
, , , ,
DOI: 10.1016/j.marchem.2006.12.007

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Abstract

Absorption and fluorescence of colored dissolved organic matter (CDOM) and concentrations of dissolved organic carbon (DOC), chlorophyll and total suspended solids in Tampa Bay and its adjacent rivers were examined in June and October of 2004. Except in Old Tampa Bay (OTB), the spatial distribution of CDOM showed a conservative relationship with salinity in June, 2004 (aCDOM(400) = − 0.19 × salinity + 6.78, R2 = 0.98, n = 17, salinity range = 1.1–32.5) with little variations in absorption spectral slope and fluorescence efficiency. This indicates that CDOM distribution was dominated by mixing. In October, 2004, CDOM distribution was nonconservative with an average absorption coefficient (aCDOM(400), ∼ 7.76 m-1) about seven times higher than that in June (∼ 1.11 m-1). The nonconservative behavior was caused largely by CDOM removal at intermediate salinities (e.g., aCDOM(400) removal > 15% at salinity ∼ 13.0), which likely resulted from photobleaching due to stronger stratification. The spatial and seasonal distributions of CDOM in Tampa Bay showed that the two largest rivers, the Alafia River (AR) and Hillsborough River (HR) were dominant CDOM sources to most of the bay. In OTB, however, CDOM showed distinctive differences: lower absorption coefficient, higher absorption spectral slopes, and lower ratios of CDOM absorption to DOC and higher fluorescence efficiency. These differences may have stemmed from (1) changes in CDOM composition by more intensive photobleaching due to the longer residence time of water mass in OTB; (2) other sources of CDOM than the HR/AR inputs, such as local creeks, streams, groundwater, and/or bottom re-suspension. Average CDOM absorption in Tampa Bay at 443 nm, aCDOM(443), was about five times higher in June and about ten times higher in October than phytoplankton pigment absorption, aph(443), indicating that blue light attenuation in the water column was dominated by CDOM rather than by phytoplankton absorption throughout the year.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Colored dissolved organic matter in Tampa Bay, Florida
Series title:
Marine Chemistry
DOI:
10.1016/j.marchem.2006.12.007
Volume
104
Issue:
1-2
Year Published:
2007
Language:
English
Publisher:
Elsevier
Contributing office(s):
Coastal and Marine Geology Program
Description:
12 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Marine Chemistry
First page:
98
Last page:
109
Number of Pages:
12
Country:
United States
State:
Florida
Other Geospatial:
Tampa Bay