Applying Downscaled Global Climate Model Data to a Groundwater Model of the Suwannee River Basin, Florida, USA

Swain, Eric D.; Davis, J. Hal

doi:10.4236/ajcc.2016.54037

Cited by 6 publications

(4 citation statements)

References 17 publications

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“…In many river basins in the USA, river discharge per unit rainfall has increased in recent decades due to watershed changes, such as conversion from forest to agriculture or increase in impervious surfaces. In the Suwannee River, discharge has declined per unit rainfall possibly due to increasing human use of surface and groundwater (Seavey et al 2011) and changing climate (Swain and Davis 2016). Resulting decreased groundwater levels can impact human users in this region (Saetta et al 2015), but ecosystem impacts are unknown.…”

Section: Trends In Oyster Populations In the Gulf Of Mexicomentioning

confidence: 99%

Trends in Oyster Populations in the Northeastern Gulf of Mexico: An Assessment of River Discharge and Fishing Effects over Time and Space

et al. 2020

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Within the Big Bend region of the northeastern Gulf of Mexico, one of the least developed coastlines in the continental USA, intertidal and subtidal populations of eastern oyster Crassostrea virginica (hereafter referred to as "oyster") are a critical ecosystem and important economic constituent. We assessed trends in intertidal oyster populations, river discharge, and commercial fishing activity in the Suwannee River estuary within the Big Bend region using fisheries-independent data from irregular monitoring efforts and publicly available environmental data. We used generalized linear models to evaluate counts of oysters from line-transect surveys over time and space. We assessed model performance using simulation to understand potential bias and then evaluated whether these counts were related to freshwater inputs from the Suwannee River and commercial oyster fishing effort and landings at different time lags. We found that intertidal oyster counts have declined over time and that most of these declines are found in inshore intertidal oyster bars, which are becoming degraded. We also found a significant relationship between oyster counts and a 1-year lag on mean daily Suwannee River discharge, but including commercial fishery trips or landings did not improve model fit. It is unclear whether declines in intertidal oyster bars are offset by formation of new oyster reefs elsewhere. These results quantify rapid declines in intertidal oyster reefs in a region of coastline with high conservation value that can be used to inform ongoing and proposed restoration projects in the region.

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Section: Trends In Oyster Populations In the Gulf Of Mexicomentioning

confidence: 99%

Trends in Oyster Populations in the Northeastern Gulf of Mexico: An Assessment of River Discharge and Fishing Effects over Time and Space

et al. 2020

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“…Its rivers and tributaries generally have a free‐flowing hydrologic regime and are not impeded by major reservoir impoundments or dams. Hydrology of the watershed is therefore largely determined by basin geomorphology and geology, climate, and water and land‐use practices (Bales et al, 2006; Swain & Hal Davis, 2016). The Suwannee River discharges into Suwannee Sound through two diverging branches, East Pass (EP) and West Pass (WP; Figure 2), with additional inflows through interconnected tidal floodplain creeks and groundwater (Grubbs & Crandall, 2007; Light et al, 2002).…”

Section: Methodsmentioning

confidence: 99%

Quantifying uncertainty in coastal salinity regime for biological application using quantile regression

et al. 2023

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Salinity regimes in coastal ecosystems are highly dynamic and driven by complex geomorphic and hydrological processes. Estuarine biota are generally adapted to salinity fluctuation, but are vulnerable to salinity extremes. Characterizing coastal salinity regime for ecological studies therefore requires representing extremes of salinity ranges at time scales relevant to ecology (e.g., daily, monthly, and seasonally). Here, we propose a framework for modeling coastal salinity with these overall goals: (1) quantify uncertainty in salinity associated with important terrestrial and oceanographic drivers, (2) examine time scales of salinity response to river streamflow events, and (3) predict salinity continuously over space at key time scales. Salinity is modeled as quantile surfaces related to river discharge, tidal dynamics, wind, and spatial location, applied to Suwannee Sound estuary, FL, USA, where salinity has been monitored spatially since 1981. Each quantile level is regressed independently, and together they comprise a distribution of salinity uncertainty across space, with upper and lower quantiles describing salinity extremes. Effects of physical drivers on salinity are compared through four base models with various combinations of tide and wind variables, each including spatial coordinates and a single streamflow metric (in cubic meters per second). Multiple time scales of streamflow are considered by taking means across various periods, from 1 to 12 days, and at various lagged intervals prior to salinity sample, totaling 144 streamflow metrics. We found that the Suwannee coastal salinity regime is dynamic at multiple time scales and varies nonlinearly across space from the river effluence outward. Salinity increases nonlinearly with decreasing river flow rates below 200 m 3 /s, most prominently in the lower quantiles of salinity (τ = 0.05-0.25). Wind appears to have a stronger influence on salinity than astronomic tides for this estuary. The regression approach developed here can be applied to any coastal system that has sufficient spatial and temporal monitoring coverage to capture multiple flood and drought events.

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“…Since 1975, human population growth in the region has been considerable and the impacts of this population growth may be seen in the increase in irrigation intensive agricultural (see Marella et al, 2016). Regarding climatic impacts, changes in both precipitation and evapotranspiration have been projected for the area, which will likely impact discharge (Swain and Davis, 2016;Neupane et al, 2019). Swain and Davis (2016) estimated a ∼5% increase in evapotranspiration between the years 2039 and 2069, and Neupane et al (2019) forecasted a 12% increase for the 2080s under a high emissions scenario.…”

Section: Introductionmentioning

confidence: 99%

“…Regarding climatic impacts, changes in both precipitation and evapotranspiration have been projected for the area, which will likely impact discharge (Swain and Davis, 2016;Neupane et al, 2019). Swain and Davis (2016) estimated a ∼5% increase in evapotranspiration between the years 2039 and 2069, and Neupane et al (2019) forecasted a 12% increase for the 2080s under a high emissions scenario. The latter authors also estimated a decrease of 13% in mean discharge for the Suwannee with a 25.1% decrease during summer when anthropogenic water demands are high.…”

Section: Introductionmentioning

confidence: 99%

Exploring Impacts of River Discharge on Forage Fish and Predators Using Ecopath With Ecosim

2021

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The ecology of estuaries is shaped significantly by the extent of freshwater discharge which regulates abiotic processes and influences overall biological productivity. The Suwannee River Estuary of Florida’s Big Bend Coastline has historically been a productive and diverse estuarine ecosystem supported by significant freshwater inputs from the Suwannee River. In recent years, significant changes in land use and climatic conditions have resulted in lower discharges from the Suwannee. Our objectives were to explore the impact of freshwater inputs from the Suwannee River on the estuarine forage fish and sportfish communities downstream. We built a trophic-dynamic food web model in Ecopath with Ecosim to simulate different levels of discharge and evaluate how changes in discharge (drought and floods) would influence the trophic structure of the food web. Using the fitted model, we applied a series of different short-term and long-term flow projections under different climatic scenarios to evaluate impacts on fish functional groups and sportfish biomass. Simulations suggested that ecological production was more influenced by drought conditions than flood conditions. In our short-term scenarios, the drought simulations produced biomass changes that were approximately twice as substantial as the flood scenarios. When making comparisons to other published EwE models, we generally observed smaller changes in biomass production. Although this model focused on the influence of bottom-up effects, we observed strong top-down control of snook (Centropomus undecimalis) on the system. Several functional groups were particularly sensitive to changes in snook abundance which included spotted seatrout (Cynoscion nebulosus), sand seatrout (C. arenarius), and other members of the family Sciaenidae. Because snook have recently colonized the estuary, likely as a result of warmer winter temperatures, this finding has implications for climate change and natural resource management.

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Applying Downscaled Global Climate Model Data to a Groundwater Model of the Suwannee River Basin, Florida, USA

Cited by 6 publications

References 17 publications

Trends in Oyster Populations in the Northeastern Gulf of Mexico: An Assessment of River Discharge and Fishing Effects over Time and Space

Trends in Oyster Populations in the Northeastern Gulf of Mexico: An Assessment of River Discharge and Fishing Effects over Time and Space

Quantifying uncertainty in coastal salinity regime for biological application using quantile regression

Exploring Impacts of River Discharge on Forage Fish and Predators Using Ecopath With Ecosim

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