Utilization of Benthic Invertebrates as Salinity Indicators Utilization of Benthic Invertebrates as Salinity Indicators in South Florida Rivers, in South Florida Rivers,

Lessons from the Peace and Alafia RiversLessons from the Peace and Alafia Rivers

Jim Culter

Mote Marine Laboratory

November 2013November 2013Caloosahatchee Science Caloosahatchee Science

WorkshopWorkshop

ObjectivesObjectives Peace & Alafia River Projects, Large & Intensive Determine benthic components that will have greatest utility

for a possible long-term monitoring program. Species, communities, habitats or strata.

Evaluate relationships between the distribution and abundance of important benthic components and salinity.

Conclusions Transferrable to Caloosahatchee River?

WhenWhenPeace River November 1998 end of wet season, January 1999 winter dry season, March 1999 spring dry season, April 1999 spring very dry season June 1999 end of dry season.Alafia River May 1999May 1999 very low flowvery low flow September 2001September 2001 end normal wet seasonend normal wet season

Peace River – “Healthy River”Peace River – “Healthy River” Mollusk survey – 61 sites, 2 visitsMollusk survey – 61 sites, 2 visits

• 17,000 specimens17,000 specimens Infauna – 12 defined areas, 1,450 samplesInfauna – 12 defined areas, 1,450 samples

• 4 zones intertidal / subtidal + 3 creeks + 1 SAV site4 zones intertidal / subtidal + 3 creeks + 1 SAV site• 5 visits – 1 wet season, 4 dry season5 visits – 1 wet season, 4 dry season• Each area – 10 cores, 10 sweep nets, 1AS/kmEach area – 10 cores, 10 sweep nets, 1AS/km• + 120 sediment samples for granulometry+ 120 sediment samples for granulometry• 60,936 benthic specimens60,936 benthic specimens• 314 species314 species

Level of EffortLevel of Effort

Alafia River – “Impaired River”Alafia River – “Impaired River” Molluscs – 37 sites, 2 visits, 20 speciesMolluscs – 37 sites, 2 visits, 20 species Infauna – 17 defined areas, 298 samplesInfauna – 17 defined areas, 298 samples

• 2 Hillsborough Bay locations, 15 River locations2 Hillsborough Bay locations, 15 River locations• 2 visits – 1 wet season, 1 dry season2 visits – 1 wet season, 1 dry season• Each area – 7 grabs & 2 sweep nets per seasonEach area – 7 grabs & 2 sweep nets per season• 120 sediment samples for granulometry120 sediment samples for granulometry• 16,266 benthic specimens16,266 benthic specimens• 222 species dry season, 132 species wet season222 species dry season, 132 species wet season

Level of EffortLevel of Effort

Level of Effort – 1994-1995Level of Effort – 1994-1995

Caloosahatchee River – “Impaired River”Caloosahatchee River – “Impaired River” Infauna – 4 locations, 12 sample periodsInfauna – 4 locations, 12 sample periods 192 samples192 samples 219 species identified from 26,269 organisms219 species identified from 26,269 organisms

Biologically Relevant Salinity Zones (NOAA)Biologically Relevant Salinity Zones (NOAA)used for strata for Peace River studyused for strata for Peace River study

Zone IZone I ≤≤ 0.5 PSU 0.5 PSU freshwaterfreshwater Zone IIZone II > 0.5 to > 0.5 to ≤≤ 8.0 8.0 Zone IIIZone III > 8.0 to > 8.0 to ≤≤ 16.0 16.0 Zone IVZone IV > 16.0 PSU estuarine > 16.0 PSU estuarine

Peace River Zone CharacteristicsPeace River Zone Characteristics

Alafia RiverAlafia River

-82.44 -82.42 -82.40 -82.38 -82.36 -82.34 -82.32 -82.30 -82.2827.84

27.86

27.88

Total Taxa - Dry Season

-82.44 -82.42 -82.40 -82.38 -82.36 -82.34 -82.32 -82.30 -82.2827.84

27.86

27.88

Total Taxa - Wet Season60402010

60402010

Alafia RiverAlafia River

-82.44 -82.42 -82.40 -82.38 -82.36 -82.34 -82.32 -82.30 -82.2827.84

27.86

27.88 Total Amphipods per River km - Dry Season

-82.44 -82.42 -82.40 -82.38 -82.36 -82.34 -82.32 -82.30 -82.2827.84

27.86

27.88 Total Amphipods per River km - Wet Season

700030001000100

700030001000100

Millions

Millions

Alafia RiverAlafia River

-82.44 -82.42 -82.40 -82.38 -82.36 -82.34 -82.32 -82.30 -82.2827.84

27.86

27.88 Total Mysids per River km - Dry Season

-82.44 -82.42 -82.40 -82.38 -82.36 -82.34 -82.32 -82.30 -82.2827.84

27.86

27.88 Total Mysids per River km - Wet Season

60030010010

60030010010

Millions

Millions

Alafia River Taxa Alafia River Taxa ranked by ranked by

abundance vs. abundance vs. weighted center weighted center

of salinity.of salinity.

Salinity

0 5 10 15 20 25

Ran

k of

Abu

ndan

ce

0

20

40

60

80

100

120

140

Common

Rare

Alafia RiverAlafia River

R iv e r K ilo m e te r

0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7

Riv

er A

rea

(ha)

at -

0.12

m E

leva

tion

NG

VD

0

1

2

3

4

5

6Alafia RiverAlafia RiverArea Area

downstream to downstream to upstream.upstream.

Caloosahatchee Caloosahatchee River SubstrateRiver SubstrateDial Cordy and Associates, Dial Cordy and Associates,

Inc. 2012Inc. 2012

ObservationsObservations Benthic fauna – species rich & abundantBenthic fauna – species rich & abundant Life history details for most species sparseLife history details for most species sparse Epifaunal transients very important to fisheriesEpifaunal transients very important to fisheries Seasonal movement upstream importantSeasonal movement upstream important

Observations, continued.Observations, continued. Intertidal river habitat is importantIntertidal river habitat is important Rare taxa important? But not useful…Rare taxa important? But not useful… Abundant taxa too plastic?Abundant taxa too plastic? High spatial and sample varianceHigh spatial and sample variance

Large sample numbers needed to detect differences Large sample numbers needed to detect differences

Molluscs (other than oysters)Molluscs (other than oysters) Point in time collection Point in time collection ≠≠ species spatial domain. species spatial domain. 70% more species in Peace than Alafia70% more species in Peace than Alafia**..

Observations, continued.Observations, continued.

Molluscs (other than oysters)Molluscs (other than oysters) Point in time collection Point in time collection ≠≠ species domain species domain 70% more species in Peace than Alafia70% more species in Peace than Alafia**

Crustaceans – mobile species “keystone”Crustaceans – mobile species “keystone” Sedentary species worms etc. record of recent Sedentary species worms etc. record of recent

past conditionspast conditions It’s Complicated – few simple effective toolsIt’s Complicated – few simple effective tools

EndEnd