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ABSTRACT: We assessed effects of groundwater pumping to elevate lake levels on lake water chemistry and fish population metrics at seven
Florida lakes. Following groundwater pumping, lake level fluctuation was reduced and lake water samples increased in mean
pH, total alkalinity, total phosphorus, chloride and Secchi depth compared to historical means, indicating a close resemblance
to the chemistry of aquifer water in the region. Fish community metrics from the augmented lakes were compared to 36 non-augmented
lakes in Florida. The mean values for catch per unit effort, species richness and biomass of harvestable fishes, determined
by electrofishing, were lower in augmented lakes compared to non-augmented lakes. Canonical correspondence analysis (CCA)
indicated a high probability of a low abundance of individual species in augmented lakes compared to a majority of non-augmented
lakes. The augmented lake with the lowest pumping rate exhibited less of a shift in limnological variables from historical
values, and had fish population characteristics more closely resembling those of non-augmented lakes. Thus, reduced volumes
of groundwater introduction could lower impacts to limnological and fish population characteristics. Augmentation allows for
lakes to be utilized for recreational activities, and without augmentation some lakes in central Florida would likely go dry
due to groundwater withdrawals for water supply. Therefore, allowing more natural water level fluctuations and possible reductions
in total pumpage are recommended to reduce impacts to limnological and fish population characteristics, while still allowing
sufficient groundwater pumping to preserve lake habitats.
Hydrobiologia 04/2012; 556(1):279-294. · 1.78 Impact Factor
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North American Journal of Fisheries Management 08/2008; 28(4):1132-1137. · 0.94 Impact Factor
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ABSTRACT: Hydrological variables have influenced fish recruitment in lakes, reservoirs and rivers. We evaluated how annual and seasonal hydrological variables were related to year-class strength (i.e., residuals from catch curves) of sportfish across eight Florida waterbodies (four rivers and four lakes). Multiple regression equations computed for black bass Micropterus spp. were combined across rivers and year-class strength was negatively related to spring median flow rates and in some cases positively related to winter median flow rates (all p0.10). Conversely, Lepomis spp. residuals combined from the rivers indicated that year-class strength was positively related to median flow rates in the fall prior to spawning and negatively related to post-spawn fall median flow rates (all p0.10). Fish recruitment combined across lakes were not related to water levels in this study, although within lake relationships did occur in some instances. Ecological implications of this work include regulations such as minimum flows and levels (MFLs) regarding sportfish species. Impacts of hydrology on year-class strength of sportfish were stronger in rivers than in lakes for these Florida systems. High flows at least once every 3years in the fall may allow inundation of floodplain habitat, providing favorable environmental conditions for Lepomis spp. reproduction. Setting MFLs during periods of drought (i.e., 3years or more) should consider impacts to short-lived species such as Lepomis spp.
Hydrobiologia 12/2004; 532(1):193-207. · 1.78 Impact Factor
