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The three contiguous National Estuary Programs of southwest Florida, along with partners from six coastal counties, have developed a tidal creek water quality assessment framework to help prioritize natural resource investigations across a large population of tidal creeks between Tampa Bay and Estero Bay, Florida. The assessment framework is based on outcomes of a multidisciplinary study and includes a nutrient based report card that characterizes nutrient conditions relative to regional numeric nutrient criteria developed for contributing freshwater streams, identification of site-specific water quality indicators of tidal creek condition, and an online open science dashboard to display the assessment framework and provide access to all information relevant to its implementation. Application of the assessment framework has provided an actionable list of southwest Florida tidal creeks prioritized for further research and potential management action along with a host of site-specific indicator results that provide insights into drivers of tidal creek condition. The open science dashboard provides a platform for dissemination of this information in a readily accessible and reproducible format and a means to incorporate new data and indicators as they become available. Local resource managers are in need of tools to help prioritize natural resource investigations and management actions that achieve the greatest resource benefit with limited available resources. This assessment framework informs these efforts and builds capacity for future research to identify and refine management tools for these creeks where management resources, data, and sentinel biological response endpoints are limited. [ABSTRACT FROM AUTHOR]

Abstract: Eutrophication of surface water is a worldwide concern. Sediments may play an important role in buffering phosphorus (P) concentration in the overlying water column. However, information on the spatial variation of sediment P availability as affected by agricultural water discharge and hydrological conditions is limited. In this study river sediments were sampled in spring, summer, fall and winter, respectively from seven locations along a main tributary (Ten Mile Creek, TMC), which receives surface runoff water from agricultural lands and discharges into the Indian River Lagoon, south Florida, USA, and analyzed for P availability. Simultaneously, hydrological variables were measured on the spot and river water samples were collected for analyses of water quality. The results demonstrated that available P in the sediments of TMC as measured by several commonly used extraction procedures had a large spatial variation. The downstream locations had a greater amount of available P in the sediments than the upstream locations, which is attributable to the settlement of finer particles due to slower water flow and increased influence from salt water in the downstream locations where the fresh river water gradually mixed with salt water from the Indian River Lagoon. Phosphorus availability in the sediments appeared to be related to P sorption by iron and aluminum oxides and the competition for adsorbing sites between SO4 2− and PO4 3−. This spatial variation of P availability agrees with the elevation of chlorophyll a (Chla) in overlying water body in the downstream locations of TMC, indicating that the internal P source plays an important role in triggering an algal boom in surface water systems. [ABSTRACT FROM AUTHOR]

Localized declines in coral condition are commonly linked to land-based sources of stressors that influence gradients of water quality, and the distance to sources of stressors is commonly used as a proxy for predicting the vulnerability and future status of reef resources. In this study, we evaluated explicitly whether proximity to shore and connections to coastal bays, two measures of potential land-based sources of disturbance, influence coral community and population structure, and the abundance, distribution, and condition of corals within patch reefs of the Florida Reef Tract. In the Florida Keys, long-term monitoring has documented significant differences in water quality along a cross-shelf gradient. Inshore habitats exhibit higher levels of nutrients (DIN and TP), TOC, turbidity, and light attenuation, and these levels decrease with increasing distance from shore and connections to tidal bays. In clear contrast to these patterns of water quality, corals on inshore patch reefs exhibited significantly higher coral cover, higher growth rates, and lower partial mortality rates than those documented in similar offshore habitats. Coral recruitment rates did not differ between inshore and offshore habitats. Corals on patch reefs closest to shore had well-spread population structures numerically dominated by intermediate to large colonies, while offshore populations showed narrower size-distributions that become increasingly positively skewed. Differences in size–structure of coral populations were attributed to faster growth and lower rates of partial mortality at inshore habitats. While the underlying causes for the favorable condition of inshore coral communities are not yet known, we hypothesize that the ability of corals to shift their trophic mode under adverse environmental conditions may be partly responsible for the observed patterns, as shown in other reef systems. This study, based on data collected from a uniform reef habitat type and coral species with diverse life-history and stress–response patterns from a heavily exploited reef system, showed that proximity to potential sources of stressors may not always prove an adequate proxy for assigning potential risks to reef health, and that hypothesized patterns of coral cover, population size–structure, growth, and mortality are not always directly related to water quality gradients. [Copyright &y& Elsevier]

Current meter and water level data from two tidal channels in the Florida Keys are combined with acoustic Doppler profiler data to quantify tidal, low-frequency and long-term mean volume transport between Hawk Channel, on the Atlantic side of the Keys, and Florida Bay, on the Gulf side. Current meters in Long Key Channel and the Seven Mile Bridge channels were maintained for time periods of 279 and 259 days, respectively. During each study, shorter current records were obtained from additional study sites for channel calibration. In Long Key Channel, the combination of tidal and nontidal forcing produces inflows and outflows that occasionally exceed 8000 and −9000 m3 s−1, respectively. Maximum inflows and outflows through the Seven Mile Bridge channels can exceed 10,000 and −13,000 m3 s−1, respectively. The residual tidal transport through Long Key Channel is 27.7 m3 s−1 into Florida Bay, while the residual transport through the Seven Mile Bridge channels is −177.5 m3 s−1 into Hawk Channel. In Long Key Channel, the mean total transport from October 21, 1997 to July 27, 1998 was an outflow of −392 m3 s−1. The mean total transport in Seven Mile Bridge Channel from October 22, 1998 to July 8, 1999 was an outflow of −454 m3 s−1. Spectral analysis of volume transport and wind-stress quantifies low-frequency wind-forced exchanges. The Long Key Channel transport time series is highly correlated with wind stress over all time scales in excess of 3.5 days. High coherences were restricted to periodicities of 1–7 days in the Seven Mile Bridge channels. In both channels, highest correlation occurs when the along-channel axis lies 55° to the right of the wind-stress vector. [Copyright &y& Elsevier]