Transport through Tavernier Creek: a primary flushing pathway for Northeast Florida Bay

Abstract

Current meter data from a 411-day study are used to characterize the movement of water through Tavernier Creek, a tidal channel in the Upper Florida Keys that connects northeastern Florida Bay with the narrow continental shelf on the Atlantic Ocean side of the Keys. The record reveals active tidal and nontidal exchanges. Strongest flood and ebb current speeds commonly reach 50 cm s⁻¹. Low-frequency exchanges are highly coherent with the across-shelf component of local wind stress over time scales in excess of 2.5 days. Bay-shelf exchanges are investigated in four ways. Current measurements made while a drogue was tracked from one end of the creek to the other provide a relationship that can be applied to the time series of current meter data. Results suggest that ocean water reaches the bay end of the creek on 92% of the floods, and bay water reaches the ocean end on 94% of the ebbs. The Eulerian tidal excursion calculated from the amplitude of the M ₂ tidal constituent is 1.42 times the length of the channel, and half-tidal cycle Eulerian displacements are commonly 1.5 times the length of the channel. Salinity measurements over a 165-day period document the arrival of bay and ocean water at a study site at about the midpoint of Tavernier Creek. Results suggest that the creek becomes completely flushed after about 450,000 m³ of water have entered from either end. Histograms of ebb and flood volume transports indicate that half-tidal cycle transports are commonly between 800,000 and 1,100,000 m³. The long-term movement of water through Tavernier Creek is a net outflow from Florida Bay. Results support the idea that Tavernier Creek serves as an effective conduit for exchanging bay and ocean water, and especially for draining the northeast corner of Florida Bay.