The Distribution and Seasonal Variation of Dissolved Trace Metals in Florida Bay and Adjacent Waters

Florida Bay is a shallow carbonate estuary in South Florida. It receives fresh
waters from the Everglades that contribute a number of metals to the Bay. The
Bay is the largest estuary in Florida with nearly pristine conditions. In this
paper we report the first extensive study of trace metals in the Bay. The
seasonal distributions of trace metals (Sc, V, Cr, Co, Cu, Fe, Pb, Mn, Ni and
Al) were determined on surface waters in Florida Bay and adjacent waters. The
measurements in the Bay were made from May 2000 to May 2001, and the adjacent
waters were sampled in September 2000 and May 2002. Most of the dissolved trace
metals exhibited their maximum concentrations in summer, except Al and Pb that
did not show any seasonal variability. The seasonal variations of the metals
are related to the influx of fresh water from runoff and rainfall. The lowest
concentrations are found during the dry season in the winter and the highest
during the wet season in the summer. Several metals (V, Mn, Al, Sc, Fe, Co, Ni
and Cr) exhibited their highest concentrations in the western zone of the Bay.
The western Bay waters are influenced by Gulf of Mexico waters, which carry
metals coming from Barron, Broad and Shark rivers. These rivers are affected by
agricultural runoff from North Florida. The Shark River always exhibited high
concentrations of V, Mn, Al, Sc, Co and Cr. Other possible influences in the
western and north-central zone of the Bay are from Flamingo Center, the creeks
of Taylor Slough and the mangrove fringe of the Everglades. High concentrations
of Al, Co, Ni, Cr, Cu, Fe, and Pb were detected in the eastern zone. The high
values found in the northeast are influenced by Taylor Slough runoff and in the
southeast by Key Largo, Tavernier Marina and the drainage from the main highway
(US1) on Tavernier Key. The minimum concentrations for most of the metals were
found in areas near the Key channels that exchange waters between Florida Bay
and the Atlantic Ocean (Gulf Stream). The adjacent waters in the Atlantic side
including the Gulf Stream waters showed very low concentrations for all the
metals studied except for V. In the Bay correlations were found: 1)V with
salinity and Al and; 2) Sc with Si. Most of the other metals did not show any
strong correlations with nutrients or salinity. Florida Bay is thus not a
typical estuary due to it unique structure of its mud banks and multiple inputs
of metals from the mangrove fringe in the north. To show the Distribution and
Seasonal Variation of Dissolved Trace Metals in Florida Bay and Adjacent
Waters.

Spatial Data Organization Information -
Indirect Spatial Reference: Unknown
Direct Spatial Reference: Point Spatial
Reference Information -
Horizontal Coordinate System Definition - Geodetic Model