# Presentation: 296449

## Mapping and Monitoring Submerged Aquatic Vegetation in Ichetucknee and Manatee Springs

**Raymond C. Kurz, Ph.D.**
- Phinla Sinphay
- Wendy Hershfeld
- Debra C. Woithe, Inc.
- Rob Mattson, SRWMD

## Project History

**Administered by SRWMD**
**Funded through grant from FDEP for Florida Springs Initiative**
**Component of baseline data collection (water quality, vegetation, flow) for springs – use to manage resource effectively **
**Assist with development of MFLs**
**Project began in February 2003, completed first phase in June 2003, second phase in June 2004**

## Objectives

**Phase 1 (2003)**
**Map SAV in Ichetucknee and Manatee Spring Runs**
**Monitoring (SAV, periphyton, canopy, physicochemical, light, flow)**
**SAV-associated Macroinvertebrate Sampling**
**Recreational Use Impact Assessment**
**Phase 2 (2004)**
**Remap high use areas in Ichetucknee Springs**
**Conduct shading analysis, flow, depth mapping**
**Conduct surface water quality sampling and additional macrophyte/periphyton sampling**

## Study Areas

## Mapping Methods

- March-May 2003 and 2004
- GPS in open canopy areas
- Transect mapping in heavily canopied areas (% coverage by species along 100 ft transects) – tied to GPS
- Used USGS DOQQ aerial as basemap
- Shoreline photointerpreted from aerial, widths verified using measuring tape
- Only SAV points mapped in Manatee Springs due to sparse coverage of SAV – points converted to polygons using field notes/sketches

## Mapping Methods

- Use of handheld computer linked with GPS hardware and GIS software
- ArcPad 6.0 (ESRI)
- PDOP < 6.0
- <5 m horizontal accuracy
- Target minimum map unit 30 sq. ft.
- QC checks for horizontal accuracy using known benchmark
- Overall map accuracy of 94%

## QC Check

***Suwannee River***

***Manatee Springs***

**Predominantly**
***Sagittaria kurziana***

***Manatee Springs***

## Manatee Springs

***No SAV***

*USFWS Caging Experiment*

***Manatee Springs***

## Ichetucknee Springs

## Ichetucknee State Park

- Headspring

- Rice Marsh

- Floodplain

## Slide 14

## Ichetucknee Springs

## Historical Change

***all 1979 values estimated– original mapping was performed by Dutoit via transect method, cutoff points for reaches were estimated**

## Remapping of High Use Areas (2004)

**Determine if SAV impacted by summer of 2003 recreational usage**
**Focus on shallow areas and exit/entry points**

## ShadingFlowDepth Mapping

- Field measurements at multiple transect locations
- Tree height
- Canopy cover
- Water depth
- Flow velocity

## Flow Velocity

## Depth

## Shading Analysis

- Spatial Analyst “hillshade” command

## SAV and Shade

## SAV – Depth/Flow/Shade Relationships

*Sagittaria* appears fairly independent of depth, flow, reach, or tree canopy shade
*Chara* has a positive trend of increasing coverage with increasing depth, flow and tree canopy shade
*Vallisneria* coverage appears to increase with increasing amounts tree canopy shade, while it is less strongly related to increasing depth and flow
*Zizania* only occurred in depths shallower than 1 m (typically emergent)

## Conclusions

- SAV in Manatee Springs likely varies seasonally due to river inundation, manatee grazing
- SAV in Ichetucknee Springs has increased dramatically since 1979 study
- Small loss in SAV cover (2%) between 2003 and 2004 high use areas, likely due to human activities (installation of new dock and safety cable across river) in lower reach
- Does not appear to be a strong relationship between SAV and canopy cover

- Questions?