5th UF Water Institute Symposium Abstract

Submitter's Name Nelson Anderson
Session Name Poster Session - Springs & Rivers
Poster Number 37
Author(s) Nelson Anderson,  University of Florida (Presenting Author)
  Matthew Cohen,  University of Florida
  Robert Hensley, University of Florida
  Lawrence Korhnak, University of Florida
  High Resolution Lotic Limitation Assessment Through the Use of In-Situ Mesocosms
  The determination of limiting nutrients in a lotic system normally requires a reach scale or ex-situ assessment. A reach scale experiment can find limitation for the system as a whole, but fails to discern fine scale spatial heterogeneity present due to differing types and densities of photosynthetic benthic coverages. Ex-situ experiments do not include field conditions, potentially giving an inaccurate representation. By using an in-situ mesocosm, solutes can be experimentally altered over a small portion of river bottom. By measuring GPP and biomass accretion in optically clear mesocosms, limitation can be determined for different species of benthic life over varying locations and conditions. . Here we present GPP and biomass responses of Sagittaria, algae, and bare substrate in Rainbow River, a major Florida karst spring fed river. Limitation was assessed on the basis of nitrogen, phosphorus, and iron additions, including all co-limitation possibilities. Results are expected to show iron limitation due to near absent surface water concentrations. This high resolution limitation data can be used to manage targeted nuisance species.