Fish Community Assessment

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Fish Community Assessment of the Peace River
Tom Champeau, FFWCC-DFFM Bill Pouder,
FFWCC-DFFM Jeff Willitzer, FFWCC-DFFM Dave
Blewett, FFWCC-FWRI Phil Stevens, FFWCC-FWRI
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• Peace River Facts
• Flow begins at hypereutrophic
• Lake Hancock.
• 211 km in length.
• Drops 30 m from Central Florida
• Highlands to Charlotte Harbor.
• Average gradient of 0.2 m/km
• Average annual discharge of
• 32.7 m2/s.
• Drainage area is 5,959 km2.
• Upper basin mined for
• phosphate ore since 1900.
• Agricultural development
• throughout the basin.

PEACE RIVER
Photo credit NASA
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Homeland
Wauchula
Gardner
Nocatee
Photo credit NASA
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Map from FDEP, 2006
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Fish as Indicators of Biotic Integrity

• Sensitive to a wide range of environmental
  conditions.
• Long lived species measure time scale effects.
• Can evaluate ecological interactions over a range
  of life history phases.
• Possess economic value and stakeholder interest.

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What environmental factors can fish data evaluate?

• Water quality (Lake Hancock effects).
• Hydrological cycles (baseflow, MFLs).
• Structural habitat (woody debris, snags).
• Extreme events (hurricanes, droughts).
• Impact of invasive exotic fishes.
• Ecological role of marine species.

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Common snook (Centropomis undecimalis) are a
marine predator found in the Peace River
throughout the year.
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Relative abundance ( of fish/minute of
electrofishing) of common snook (Centropomis
undecimalis) in Peace River, 2004 2006. (From
Blewett et al. 2006)
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Blue tilapia, Oreochromis aureaThought to have
invaded Peace River 1963 - 68.
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Walking catfish, Clarias batrachusThought to
have invaded Peace River 1973 -77  
Photo credit USGS
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Vermiculated Sailfin Armored Catfish,
Pterygoplichthys disjunctivus Orinoco Sailfin
Armored Catfish, Pterygoplichthys
multiradiutusFirst documented in Peace River in
1992
Photo credit USGS
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• Brown Hoplo, Hoplosternum littorale
• First documented in Peace River in 2005

Photo credit USGS
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African jewelfish, Hemichromis letourneuxi First
documented in Peace River in 2005
Photo credit USGS
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Oriental weatherloach, Misgurnus
anguillicaudatusFirst documented in Peace River
bass stomach in 2008
Photo credit USGS
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Methods

• Used boat electrofishing.
• Mostly at night, some day.
• Four stations were selected.
• Clustered replicates of three
• ten-minute samples.
• Time measured as the total
• amount of time electricity is
• applied to the water.
• Fish were measured in total
• length, weighted, and released.
• Followed standardized protocol
• developed by Bass (1990) .

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Fish Community Metrics

• Relative abundance of fish/minute
• Relative biomass kg of fish/minute
• Percent abundance of exotic species
• Percent biomass of exotic species
• Species richness
• Shannon diversity
• Comparisons used Kruskal-Wallis/ANOVA at P lt 0.05

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Structural Riverine Habitat
Exposed roots
Woody debris and snags
Steep sand banks
Gentle banks
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Locations of Peace River fish community fish
sampling stations
Homeland
Wauchula

• Nocatee is influenced by
• tides but is freshwater.
• Narrow conductivity range.
• Sampling done during fall
• or winter within a narrow
• range of water levels to
• reduce sampling error.
• Sampled every year from
• 1983 to 1992.
• No sampling 1993 2003.
• Repeated protocol in 2005
• and 2006.

Gardner
Nocatee
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Objectives

• Update fish community database.
• Compare with historic data 1983 1992.
• Document number and composition of exotic fish
  species.
• Evaluate effects of 2004 hurricanes and prolonged
  hypoxia event (Stevens et al. 2006 Tomasko et
  al. 2006).

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Hurricane Charley - August 13, 2004
Photo credit National Weather Service
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17.2 feet on 08 Sept
Duration of hypoxia (lt2.0 mg/l from Tomasko et
al. 2006)
Francis
Jeanne
11 feet Flood Stage
Charley
Flow data from USGS
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If hypoxic flooding reduced native fish
abundance, will exotics adapted for such
conditions dominate?
Photo credit NASA
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Relative abundance (median number of fish
collected per minute of electrofishing) of native
and exotic fish for all Peace River
stations,1983-2006.
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Comparison of mean exotic and native fish
abundance with standard errors for historic
period (1983-1992) and recent years (2005 and
2006).
2005 vs 2006 Exotic P0.002
Total P0.04 Exotic P0.04
Total P0.01
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Relative biomass (median kg of fish collected per
minute of electrofishing) of native and exotic
fish for all Peace River stations,1983-2006.
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Comparison of mean exotic and native fish biomass
with standard errors for historic period
(1983-1992) and recent years (2005 and 2006).
2005 vs 2006 Total P0.018
Total P0.0002 Exotic P0.001
Exotic P0.01
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Median species richness and Shannon diversity for
all Peace River stations,1983-2006.
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Comparison of mean species richness and diversity
with standard errors for historic period
(1983-1992) and recent years (2005 and 2006).
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Species Composition - AbundanceTop five species
mean percent composition and (SE)
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Species Composition Comparison(Two-dimensional
nonmetric scaling ordination and similarity
percentages analysis)
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Species Composition by Year (Two-dimensional
nonmetric scaling ordination and similarity
percentages analysis)
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Results Summary

• Abundance higher than historic mean in 2005 and
  2006.
• Five new exotics since 1990.
• Exotic abundance higher in 2006.
• Biomass higher than historic mean in 2006.
• Exotic biomass higher in 2005 and 2006.
• Richness and diversity not significantly
  different from historic means.

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Results Summary

• No native extirpations documented.
• During Spring 2005, 32 species collected but
  community was dominated by Gambusia holbrooki
  (49).
• By 2006, abundance composition for many species
  similar to historic levels, except
  Pterygoplichthys sp. that were most abundant
  (21).
• Hurricane effects?? Do not know what fish
  community was in 2004. Floods followed by
  extended drought.

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How can fish community data help support future
river/watershed management?

• Exotic fish evaluations, changes in community
  structure.
• Biotic integrity of Horse Creek and Charlie
  Creek.
• Lake Hancock discharge to support base flow in
  upper river.
• Long-term data to evaluate MFL (State Wildlife
  Grant/SWFWMD funding 2007 2010).
• Fish community response to flood and drought.
• Status of sport fishery.
• Ecological role of snook and their habitat
  requirements/preferences.
• Provide information about fish community to
  stakeholders and decision-makers.

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Literature Cited

• Bass, D. G., Jr. 1990. Monitoring Floridas
  riverine fish communities. Florida Scientist,
  53(1) 1-10.
• Blewett, D., P. W. Stevens, T. R. Champeau, and
  R. G. Taylor. 2006. Abundance of common snook,
  Centropomus undecimalis, in three southwest
  Florida rivers Implications for overwintering.
  Florida Wildlife Research Institute, Florida Fish
  and Wildlife Conservation Commission. Port
  Charlotte, Florida.
• Stevens, P. W., D. A. Blewett, and J. P. Casey.
  2006. Short-term effects of a low dissolved
  oxygen event of estuarine fish assemblages
  following the passage of Hurricane Charley.
  Estuaries and Coasts, 29(6a) 997-1003.
• Tomasko, D. A., C. Anastasiou, and C. Kovach.
  2006. Dissolved oxygen dynamics in Charlotte
  Harbor and its contributing watershed, in
  response to Hurricanes Charley, Frances, and
  Jeanne-impacts and recovery. Estuaries and Coasts
  29(6a) 932 938.