Preliminary Report on the Distribution of Modern Fauna and Flora

at selected sites in North-central and North-eastern Florida Bay

by

G.L. Brewster-Wingard, S.E. Ishman, L.E. Edwards, and D.A. Willard

U.S. Geological Survey, Reston, VA

Open-File Report 96-732

This report is preliminary and has not been reviewed for conformity with U.S. Geological

Survey editorial standards or with the North American Stratigraphic Code. Any use of

trade, product, or firm names is for descriptive purposes only and does not imply

endorsement by the U.S. Government

1996
TABLE OF CONTENTS

Introduction

Acknowledgments

Methods of Investigation

Collection of the Samples

Benthic Foraminifera and Molluscs

Pollen and Dinocysts

Analysis and Discussion of the Biotic Components

Benthic Foraminifers

Molluscs

Dinocysts

Pollen

Summary

References Cited

FIGURES

1. Map of sampling localities

2. Salinity measurements at each site

3. Regression plots of selected species of benthic foraminifera

4. Q-mode cluster analysis of molluscan assemblages 

5. Histogram of dinocysts assemblages

6. Pie diagrams of select pollen distributions

TABLES

1. Localities and sample descriptions

2. Percent abundance of benthic foraminifera

3. Percent abundance of molluscs

4. Salinity values for molluscs

5. Percent abundance of dinocysts

6. Percent abundance of pollen
1

INTRODUCTION

The passage of the Everglades Forever Act in 1994 and the mandate that the

Everglades ecosystem be restored to its “natural state” has focused scientific attention on

the southern Florida ecosystem. An essential part of the restoration is to determine the

history of the ecosystem prior to significant human alteration and to separate natural

variability in the ecosystem from human-induced change. The U.S. Geological Survey

(USGS), in cooperation with National Oceanic and Atmospheric Administration (NOAA),

South Florida Water Management District (SFWMD), the National Park Service (NPS),

and the Army Corps of Engineers (ACOE), among others, is conducting research to

provide information on the distribution of fauna and flora throughout the Everglades

ecosystem over the last 150-200 years. This report is produced by the Ecosystem History

of South Florida component of the U.S. Geological Survey’s Ecosystem Program, and is

one of a series of USGS Open-File Reports on the distribution of biogenic components in

sediments sampled from the south Florida region.

Florida Bay is an integral part of the Everglades ecosystem. It constitutes 850

square miles of water within Everglades National Park and has been the subject of much

concern in recent decades. Sea-grass die-offs, algal blooms, declining numbers of fish,

shellfish, and sponges have been issues of public concern (Lodge, 1994, p. 182-185). The

primary question is to what degree do these changes represent natural variation within the

ecosystem versus human-induced change. A series of sediment cores from Florida Bay is

being examined (Wingard, et al, 1995; Ishman, et al, 1996) to determine the changes that

have occurred over the last 150-200 years. The fauna and flora present in these cores are

used to interpret the biological, physical, and chemical parameters of the environment at

different intervals in the past. In order to interpret the significance of the down-core fauna

and flora more accurately, it is important to understand the distribution, salinity, and

substrate preferences and tolerances of the modern fauna and flora. Thus, we have

established 19 monitoring sites in Florida Bay that are sampled twice per year in February

and July, to determine seasonality. This report includes data from 13 sites sampled in

1995 located in the north-central and northeastern portions of Florida Bay (Figure 1;

Table 1).

ACKNOWLEDGMENTS

We would like to thank our colleagues at South Florida Water Management

District, National Oceanic and Atmospheric Administration, and Everglades National Park

for their cooperation and assistance in this investigation. The Keys Marine Lab, Florida

Institute of Oceanography, Long Key, FL provided the facilities, boats, and personnel to

assist us in the collection of the samples. We have benefited from discussions with

William Lyons, Florida Marine Research Institute, St. Petersburg, FL; Robert Halley,

Charles Holmes, and Gene Shinn, U.S. Geological Survey, St. Petersburg, FL; and .

Thomas M. Scott, Florida Geological Survey, Tallahassee, FL. Our reviewers, Harry
20

JOHN PENNEKAMP

CORAL REEF

STATE PARK

ONAL

1

8

1

3

4 5 9

11

2
Table 1: Localities and sample descriptions

Biota Analyzed SALINITY

for this report GPS Data (ppt)

 Site #

Location

 Month Sampled

Sample 

Description

 Forams Molluscs Dinocysts Pollen

LATITUDE LONGITUDE

 Error +/- FT

Top

Bottom

DEPTH 

(ft.)

BOTTOM 

CONDITIONS GENERAL AREA

1 Shell creek -mouth Feb

Bag - NE of 

channel X N 25 12.430 W 80 29.226 96 24 25 1

Mud with Thalassia, 

some eel grass

Mouth of creek flowing 

from Long Sound; 

surrounded by 

Mangroves.

1 Shell creek -mouth Feb

Push core - SW 

of channel X N 25 12.430 W 80 29.226 96 24 25 2 Shelly lag with eel grass

Mouth of creek flowing 

from Long Sound; 

surrounded by 

Mangroves.

1 Shell creek -mouth July

Push core - SW 

of channel X N 25 12.398 W 80 29.252 350 9 10 2.5 Shelly lag with eel grass

Mouth of creek flowing 

from Long Sound; 

surrounded by 

Mangroves.

2 Trout creek H2O station Feb

2 Bags - 10 yrds 

off island X N 25 12.719 W 80 32.014 93 9 9 2.5

Mix of mud, shell lag, 

root material; scattered 

eel grass but not 

healthy

10 yards off mangrove 

island near mouth of Trout 

Creek at water monitoring 

station.

2 Trout creek H2O station July

Push core - 10 

yrds off island X N 25 12.782 W 80 32.006 151 0 0 2.7

Soft mud with some 

shell material. 

Scattered eel grass - 

not healthy.

10 yards off mangrove 

island near mouth of Trout 

Creek at water monitoring 

station.

3 Duck key H2O station Feb

Bag - inlet in 

mangroves X N 25 10.797 W 80 29.375 108 25 25 1

Firm mud, very sparse 

eel grass.

Southern end of 

mangrove island in center 

of basin away from any 

mud banks or other 

islands.

3 Duck key H2O station July

Push core - inlet 

in mangroves X N 25 10.789 W 80 29.368 97 12 11 1

Firm mud, very sparse 

eel grass.

Southern end of 

mangrove island in center 

of basin away from any 

mud banks or other 

islands.

4 Northern Nest key Feb

Bag - side of 

bank X N 25 08.724 W 80 30.563 102 26 26 2

Soft, muddy, Thalassia 

covered (70-80%); 

sparse eel

Mud Bank at southrn end 

of northern mangrove 

island in center of basin.
Table 1: Localities and sample descriptions

Biota Analyzed SALINITY

for this report GPS Data (ppt)

 Site #

Location

 Month Sampled

Sample 

Description

 Forams Molluscs Dinocysts Pollen

LATITUDE LONGITUDE

 Error +/- FT

Top Bot-tom

DEPTH 

(ft.)

BOTTOM 

CONDITIONS GENERAL AREA

5 Porjoe key - s. mudbank Feb

Bag - edge of 

bank X N 25 08.157 W 80 28.352 90 27 28 1.5

Very soft mud 

with nearly 100% 

cover - eel grass 

or algae

To west of Little 

Buttonwood Sound on 

eastern edge of basin. 

Well developed mud bank 

on southern end of keys.

5 Porjoe key - s. mudbank July

Push core - 

edge of bank X

No GPS 

reading 17 18 2.5

Fairly firm mud 

with Thalassia 

covering

To west of Little 

Buttonwood Sound on 

eastern edge of basin. 

Well developed mud bank 

on southern end of keys.

6 Butternut key H2O station Feb 2 push cores X N 25 05.207 W 80 31.157 93 31 31 3

Firm bottom with 

layers of peat and 

coarse sediment

Mangrove island; 

samples from ne side of 

western tip of island. 

Basin lies to the west - 

open water. A long mud 

bank is present to the 

east of the island.

6 Butternut key H2O station Feb Bag X N 25 05.207 W 80 31.157 93 31 31 2

Coarse sediment 

overlying peats 

and clay.

Mangrove island; 

samples from ne side of 

western tip of island. 

Basin lies to the west - 

open water. A long mud 

bank is present to the 

east of the island.

7 Bottle key SE mudbanks Feb Bag - grass X N 25 03.724 W 80 33.504 117 28 29 1.5

Thalassia bed on 

very soft mud; 

patchy.

String of mangrove 

islands. Very shallow 

flats with lots of juvenile 

mangroves.

7 Bottle key SE mudbanks Feb

Push core - 

grass X N 25 03.724 W 80 33.504 117 28 29 1.5

Thalassia bed on 

very soft mud; 

patchy.

String of mangrove 

islands. Very shallow 

flats with lots of juvenile 

mangroves.
Table 1: Localities and sample descriptions

Biota Analyzed SALINITY

for this report GPS Data (ppt)

 Site #

Location

 Month Sampled

Sample 

Description

 Forams Molluscs Dinocysts Pollen

LATITUDE LONGITUDE

 Error +/- FT

Top

Bottom

DEPTH 

(ft.)

BOTTOM 

CONDITIONS GENERAL AREA

Mouth of creek flowing 

7 Bottle key SE mudbanks Feb Bag - mud X N 25 03.724 W 80 33.504 117 28 29 1.5

Very soft mud with no 

vegetation on surface; 

patchy.

String of mangrove 

islands. Very shallow flats 

with lots of juvenile 

mangroves.

7 Bottle key SE mudbanks July

Push core - high 

on bank, mud X N 25 03.911 W 80 33.020 83 23 23 1

Soft mud with sparse 

eel grass. 

String of mangrove 

islands. Very shallow flats 

with lots of juvenile 

mangroves.

8 Little Madeira Bay mouth Feb

Push core - bar 

to w of east 

island X X N 25 10.497 W 80 37.926 102 17.5 21 1

Substrate relatively firm - 

sparse Thalassia cover, 

dead algae.

Mouth of Bay which Taylor 

Creek feeds into. 2 small 

mangrove islands on 

either side of mouth. 

8 Little Madeira Bay mouth Feb

Bag - bar to w of 

east island X X N 25 10.497 W 80 37.926 102 17.5 21 1

Substrate relatively firm - 

sparse Thalassia cover, 

dead algae.

Mouth of Bay which Taylor 

Creek feeds into. 2 small 

mangrove islands on 

either side of mouth. 

8 Little Madeira Bay mouth July

Push Core - bar 

to west of east 

island X X N 25 10.517 W 80 37.934 120 12 13 2.5

Muddy; Thalassia and 

eel grass present but in 

bad shape; some 

algae. 

Mouth of Bay which Taylor 

Creek feeds into. 2 small 

mangrove islands on 

either side of mouth. 

8 Little Madeira Bay mouth July

Bag - bar to 

west of east 

island X N 25 10.517 W 80 37.934 120 12 13 2.5

Muddy; Thalassia and 

eel grass present but in 

bad shape; some 

algae. 

Mouth of Bay which Taylor 

Creek feeds into. 2 small 

mangrove islands on 

either side of mouth. 

9

Middle of basin s. of Little 

Madeira Bay Feb Push core X N 25 08.056 W 80 37.081 90 24 23 6

Hard rock substrate 

with only about 6" of 

sediment covering. 

Bottom vegetation very 

sparse with <1% 

Thalassia & Penicillus

Center of basin; fair 

distance from any islands.
37.050 356 15 15 6

Hard rock substrate 

with only about 4" of 

sediment covering. 

Bottom vegetation very 

sparse with <1% 

Thalassia; no 

Penicillus seen.

Center of basin so fair 

distance from any land.

Hard rock substrate 

with only about 4" of 

sediment covering. 

Bottom vegetation very 

sparse with <1% 

Thalassia; no 

Center of basin so fair 

distance from any land.

SALINITY

a (ppt)

GITUDE

 Error +/- FT

Top

Bottom

DEPTH 

(ft.)

BOTTOM 

CONDITIONS GENERAL AREA

mple descriptions
SALINITY

a (ppt)

GITUDE

 Error +/- FT

Top

Bottom

DEPTH 

(ft.)

BOTTOM 

CONDITIONS GENERAL AREA

mple descriptions

33.860 102 15 15 0.5

Very soft mud. Sparse 

grass, < 5% Halodule. 

Samples on mud bank 

100 yrds to SW of key 

to south of Park Key. 

Key is sparsely 

developed mangrove 

island.

37.722 93 26 26 0.1

Soft mud; scattered 

Thalassia - ~10-20%, 

not healthy where 

exposed on top of 

bank.

Taken about 200 yrds off 

Mangrove Island on top 

of mud bank and 

erosional side of bank.

Mud at surface with 

shell lag below; 

Taken about 200 yrds off 

Mangrove Island on top 
SALINITY

a (ppt)

GITUDE

 Error +/- FT

Top

Bottom

DEPTH 

(ft.)

BOTTOM 

CONDITIONS GENERAL AREA

mple descriptions

39.624 87 30 30 2.5

Very soft mud; devoid 

of anything living on 

surface; very distinct, 

well-defined areas.

~ 1/4 mile s. of mangrove 

Island. Shallow mud flats 

& grassy areas extend 

out for quite some 

distance.

39.624 87 30 30 2.5

Thallassia grass bed 

with 80% coverage in 

mud overlying shell 

lag; very distinct area.

~ 1/4 mile s. of mangrove 

Island. Shallow mud flats 

& grassy areas extend 

out for quite some 

distance.

Thallassia grass bed 

with 80% coverage in 

mud overlying shell 

~ 1/4 mile s. of mangrove 

Island. Shallow mud flats 

& grassy areas extend 
9

Dowsett and Bruce Wardlaw, U.S. Geological Survey, Reston, VA, provided helpful

comments and suggestions to improve this manuscript.

Thomas M. Scott, Florida Geological Survey, Tallahassee, FL. assisted in the

collection of all samples. Nancy Stamm, Lauren Hewitt, Alessandro Bagalia (volunteer),

Carey Costello, Steve Wandrei, Nancy Carlin, Jill D’Ambrosio, and Ian Graham, U.S.

Geological Survey, Reston, VA, prepared the samples for calcareous analysis. Tom

Sheehan, Nancy Durika, and Patrick Buchanan, U.S. Geological Survey, Reston, VA,

prepared the samples for palynological analysis. Rob Stamm and Patrick Buchanan, U.S.

Geological Survey, Reston, VA prepared the illustrations for this report.

METHODS OF INVESTIGATION

Collection of the Samples

The 13 sites discussed in this report were sampled in February and July of 1995.

Samples were collected by wading or snorkeling; this enabled us to make detailed

observations of the substrate, living fauna and flora, and micro-habitats that existed at

each site and to obtain representative samples from sub-environments. Table 1 indicates

the environmental conditions present for the samples taken at each site. Latitude and

longitude were recorded using the onboard GPS, and checked using a handheld GPS.

Data on the surface and bottom water salinity, water depth, substrate, water clarity, living

fauna, and a general area description were recorded for each site. Salinity measurements

were taken using a refractometer (Table 1; Figure 2).

Where possible, at least one push core (a 1.5” diameter clear plastic tube) and one

bag sample (1 gallon) were collected from each site. When a number of sub-environments

existed at a site, each subenvironment was sampled. Push cores were obtained by pushing

the plastic tubing into the substrate as deep as possible and maintaining a vacuum to

extract the tube; the tubes were cut at the sediment-water interface and sealed to prevent

disruption of the sediments. Bag samples were obtained by scooping the upper few inches

of sediment into a 1 gallon plastic bag. The samples discussed here represent a sub-set of

the total number of samples taken.

Benthic Foraminifera and Molluscs

The calcareous benthic fauna discussed in this report were extracted from the

upper 10 cm of the push-cores. The samples were washed through a 63μm sieve and

dried at <50°C. The >63μm size fraction was picked for benthic foraminifera and

ostracodes1

 using a random number table between 1 and 45. When possible, a total of 300

benthic foraminifera or ostracode specimens were picked from the sample and mounted on

gridded micropaleontologic slides. For samples containing fewer than 300 benthic

 

1 Osctracodes have been processed and picked from these samples. Analysis and discussion of the

ostracode distribution patterns will be included in a later report.
Feb-95 Salinity

Jul-95 Salinity
11

 foraminifera or ostracode individuals, all of the specimens present were picked. Molluscs

were picked from the >850μm size fraction; all molluscs, and fragments of molluscs

recognizable to the generic level, present in the push cores were picked. Species

abundances were standardized by calculating relative abundances (percent).

Pollen and Dinocysts

Material for palynological analysis was extracted from the bag samples. For each

palynological sample, 40 g of material (dry weight) was treated in hydrochloric and

hydrofluoric acid and processed for palynological studies. All samples were treated with

warm KOH for 2-5 minutes, given ultrasonic pulse treatment for 5 seconds, acetolysed,

and sieved between 8-150μm mesh. A tablet of Lycopodium marker grains was added for

each sample, and dinocyst and pollen concentration were calculated according to the

equation of Stockmarr (1971) using the value of 12,542 grains per tablet. One to four

slides were counted for each sample. For dinocyst analyses, when the first slide showed

fewer than 20 specimens, counting was not continued; four samples were examined (sites

1, 2, 3, and 6) but not counted although absolute cyst abundance was calculated.

Dinocyst recovery in all samples was low; only three samples contained sufficient material

to count 300 specimens. Most microscope slides are heavily dominated by phytoclasts.

For pollen analyses, 300 pollen grains were counted per sample whenever possible. The

two samples from the mouth of Little Madeira Bay (site 8) had much lower pollen

concentrations than the other samples, and approximately 150 grains were counted for

each of these samples.
12

ANALYSIS AND DISCUSSION OF THE BIOTIC COMPONENTS

Benthic Foraminifers

A total of sixteen surface sediment samples from 11 sites in Florida Bay were

analyzed for benthic foraminifers. Preliminary results from this analysis show a total of 29

species present in the >63μm size fraction (Table 2). The benthic foraminifer assemblages

are dominated by calcareous hyaline and miliolid forms. The dominant taxa include

Ammonia parkinsoniana typica, Elphidium galvestonense, E. delicatulum,

Quinqueloculina bicostata, Q. bociana, Q. poeyana, and Q. seminulum. Additional taxa

present are Miliolinella circularis, Rosalina floridensis, R. floridana and Archaias

angulatus.

Trends observed in the Florida Bay benthic foraminiferal distributions indicate a

strong association between the relative abundance of Ammonia parkinsoniana typica and

salinity. Results of linear regression analysis of the foraminiferal data and salinity show a

strong inverse relationship (R2

=.88) between Ammonia parkinsoniana typica and salinity

(Figure 3). Our results show that Ammonia parkinsoniana typica is most abundant (>20

percent) where average salinities are 18 parts-per-thousand (ppt) or less. Also associated

with low salinity is Elphidium galvestonense. At salinities greater than 18 ppt the relative

abundance of Ammonia parkinsoniana typica drops off significantly with Quinqueloculina

spp. becoming the dominant taxa and Miliolinella circularis, Elphidium delicatulum and

Archaias angulatus increasing in abundance. These trends are consistent with

observations of benthic foraminiferal distributions in the Gulf Coast where Ammonia

parkinsoniana typica and Elphidium galvestonense are associated with oligo- to euhaline

conditions (Poag, 1978, 1981). Lidz and Rose (1989) attribute the distribution of A.

beccarii ornata [=A. parkinsoniana typica] in Florida Bay to substrate and bay

physiography. However, a clear trend in their data exists where the abundance of A.

beccarii ornata decreases in regions where low salinities are less prevalent.

Our analysis has shown that the following species are good indicators of salinity.

By using combinations of the abundance's of several of the species the down-core salinity

patterns can be detected.

Species Minimum salinity

(ppt)

Maximum salinity

(ppt)

Ammonia parkinsoniana typica 0 18

Ammotium sp. 0 3

Articulina mucronata 11 23

Elphidium galvestonense 0 25

Miliolina circularis 15 26

Quinqueloculina poeyana 20 26
Table 2: Percent abundance of benthic foraminifera at monitoring sites

Site #

Month 

Collected

Agglutinated 1Ammodiscus ensisAmmonia parkinsoniana typicaAmmotium sp.Archais angulatusArtuculina mucronataBigenerina irregularisBolivina transluscensBuccella hannaiElphidium galvestonenseElphidium delicatulumGrassMiliammina fuscaMiliolinella circularisMiliolinella labiosaNodobaculariella cassisPeneroplis proteus

Basin South of Little Madeira Bay

Site 8 Feb 0.00 0.20 19.02 0.00 0.41 0.00 0.00 0.41 0.00 19.43 4.29 0.00 0.20 0.82 0.00 0.00 0.00

Site 8 July 0.00 0.00 31.77 0.00 3.69 0.00 0.00 0.25 0.00 29.56 0.74 0.00 0.74 0.25 0.25 0.00 0.00

Site 9 July 0.00 0.00 21.60 0.00 1.85 0.00 0.31 0.00 0.00 37.35 1.23 0.00 6.17 3.09 0.00 0.00 0.00

Site 11 July 0.00 0.00 8.88 0.00 1.72 0.00 0.00 0.00 0.00 23.21 5.16 0.00 0.29 10.60 0.57 0.00 0.00

Site 12 July 0.00 0.00 4.79 0.00 0.32 0.00 0.00 0.00 0.00 16.61 13.74 0.64 0.00 7.99 0.00 0.00 0.00

Bob Allen Keys

Site13 (mud) Feb 0.00 0.32 0.32 0.00 0.65 0.00 0.00 0.00 0.00 1.29 19.03 2.26 0.00 21.29 0.00 0.00 0.00

Site 13 (grass) Feb 0.32 0.00 0.65 0.00 2.90 0.00 0.00 0.00 0.00 4.84 5.81 0.65 0.65 21.61 0.97 0.00 0.00

Site 13 (mud) July 0.00 0.00 0.30 0.00 1.22 0.00 0.00 0.00 0.00 10.64 17.02 0.30 0.30 11.55 0.00 0.00 0.30

Northeastern Basin

Site 1 Feb 0.65 0.00 25.00 0.00 1.30 0.00 0.00 0.32 0.00 24.68 5.19 0.00 1.62 0.32 0.32 0.00 0.00

Site 1 July 0.33 0.00 36.93 0.00 2.29 0.00 0.33 0.33 0.00 32.68 2.94 0.00 2.61 0.65 0.00 0.00 0.00

Site 2 July 0.00 0.00 49.56 0.29 0.00 0.00 0.00 0.00 0.00 40.18 1.47 0.00 0.00 0.00 0.00 0.00 0.00

Site 3 July 0.00 0.00 20.50 0.00 0.21 0.83 0.00 0.00 0.62 9.11 23.40 0.00 1.24 4.97 0.21 0.00 0.00

Site 5 July 0.00 0.00 4.72 0.00 0.00 0.31 0.00 0.63 0.00 5.66 21.07 0.31 0.63 2.52 0.00 0.31 0.00

Site 6 Feb 1.00 0.33 9.00 0.00 10.00 0.00 0.00 0.00 0.33 34.00 1.67 0.33 7.67 1.33 0.00 0.00 0.00

Site 7 Feb 0.00 0.00 5.52 0.00 0.32 0.00 0.00 0.00 0.00 11.04 8.77 0.00 0.00 12.99 0.97 0.00 0.00

Site 7 July 1.24 0.00 2.17 0.00 24.46 0.00 0.00 0.00 0.00 8.67 4.33 1.55 1.86 9.60 1.24 0.00 0.00
Table 2: Percent abundance of benthic foraminifera at monitoring sites

Site #

Month 

Collected

Basin South of Little Madeira Bay

Site 8 Feb

Site 8 July

Site 9 July

Site 11 July

Site 12 July

Bob Allen Keys

Site13 (mud) Feb

Site 13 (grass) Feb

Site 13 (mud) July

Northeastern Basin

Site 1 Feb

Site 1 July

Site 2 July

Site 3 July

Site 5 July

Site 6 Feb

Site 7 Feb

Site 7 July

Quinqueloculina bicostataQ. bocianaQ. poeyanaQ. seminulumRosalina floridanaRosalina floridensisSpiroloculina antillarumTriloculina tricarinataTriloculina subrotundaTrochammina conicaTrochammina inflataTrochammina sp.

Number of speciemens counted / sample

0.00 7.36 3.68 9.61 0.82 31.90 0.20 0.00 1.43 0.00 0.00 0.20 489

0.99 1.48 2.22 7.88 1.48 17.98 0.00 0.25 0.49 0.00 0.00 0.00 406

8.02 3.70 11.73 2.16 0.00 0.31 0.00 0.00 2.47 0.00 0.00 0.00 324

3.44 18.05 14.33 12.32 0.00 0.29 0.00 0.86 0.29 0.00 0.00 0.00 349

10.54 12.14 21.41 7.35 0.96 0.00 0.00 1.92 1.60 0.00 0.00 0.00 313

12.90 16.13 12.58 10.32 1.94 0.00 0.00 0.97 0.00 0.00 0.00 0.00 309

22.26 6.13 24.52 6.77 0.65 0.00 0.00 0.00 0.97 0.00 0.00 0.00 310

12.77 8.81 21.88 11.85 2.13 0.00 0.00 0.61 0.30 0.00 0.00 0.00 329

1.95 1.30 11.69 22.40 1.30 1.95 0.00 0.00 0.00 0.00 0.00 0.00 308

0.33 0.98 6.21 11.44 0.98 0.00 0.00 0.98 0.00 0.00 0.00 0.00 306

0.00 0.00 2.64 5.57 0.00 0.00 0.00 0.00 0.29 0.00 0.00 0.00 341

7.87 6.42 7.04 12.22 0.62 2.07 0.83 1.45 0.41 0.00 0.00 0.00 483

3.77 11.64 21.07 26.73 0.00 0.63 0.00 0.00 0.00 0.00 0.00 0.00 318

1.33 0.33 9.67 3.33 0.00 0.00 0.00 17.33 0.67 0.67 1.00 0.00 300

6.82 15.58 18.83 16.23 0.00 2.60 0.00 0.32 0.00 0.00 0.00 0.00 308

14.86 7.12 15.79 2.79 0.00 0.93 0.00 1.86 1.55 0.00 0.00 0.00 323
R2 = .88 
16

Molluscs

Eleven samples from five sites in central and eastern Florida Bay were analyzed for

molluscan faunal content. Initial results of the analysis of the >850 μm size fraction are

shown in Table 3; 60 fauna were identified to species level, 8 to generic level, and 7 to a

broad family or environmental category (for simplicity some of the categories have been

combined in Table 3). The assemblages were dominated by four ubiquitous taxa that

comprised 54.7 percent of the total 15,923 specimens counted: Transenella spp.,

Cerithium spp., Brachiodontes sp., and Bittium varium. Anomalocardia sp., Parastarte

triquetra and the group of terrestrial and freshwater gastropods were also present in

significant numbers. Combined, these seven groups account for 72.6 percent of all the

specimens examined.

Table 4 lists the average, minimum, and maximum salinities for molluscs collected

at the monitoring sites in Florida Bay. An examination of this table, and of published

salinity ranges (Perry and Schwengel, 1955; Parker, 1959; Warmke and Abbott, 1961;

Andrews, 1971; Turney and Perkins, 1972; Emerson and Jacobson, 1976) indicates that

Cyrenoida floridana, Polymesoda sp., Melampidae, Mytilopsis leucophaeta and the group

of terrestrial and freshwater gastropods can be used as indicators of oligohaline to

mesohaline conditions in interpreting down-core salinity conditions. The majority of the

remaining molluscs are polyhaline to euhaline and can tolerate a wide range of salinities.

No obvious seasonal trends could be detected in the molluscan faunal data. A Qmode cluster analysis using the chord distance measure on the occurrence data set (Figure

4) demonstrates that the February and July samples from each site tend to cluster together.

This cluster pattern suggests that no significant changes occurred at these sites from the

dry to the wet season for 1995. An examination of the values for individual species at

each site reveals very few consistent patterns. Among the gastropods, only Cerithiopsis

greeni shows a trend, declining in abundance from February to July, but this species is

present in very low numbers at only three sites, so the results are inconclusive. Among the

pelecypods, Anomalocardia sp., Chione cancellata, and Lima sp., show consistent

seasonal changes at all five sites. These patterns may be related to seasonal spawning for

the individual species but without additional data this would be difficult to determine (see

Moore and Lopez, 1969, for a discussion of seasonal spawning in Chione cancellata). No

clear seasonal pattern of increasing or decreasing overall abundance could be determined

by examining the total number of specimens present at each site in February and July.

Figure 4 shows the molluscan assemblages from the 5 sites analyzed form 3 main

clusters. The first, cluster A, includes samples from the mud banks surrounding the basin

south of Little Madeira Bay (sites 11 and 12) and from the Bob Allen Keys mudbank (site

13). Cluster A is split into 2 smaller groups, one composed of the two samples from the

mudbanks southwest of Park Key (site 11) and a sample from Russell banks (site 12); the

other composed of the samples from Bob Allen Keys mudbank (site 13) and a sample from

Russell banks (site 12). Russell Key lies between Bob Allen and Park Key, so the

grouping of the Russell Key samples with samples from both basins, as indicated by the
17

cluster, is to be expected. Cluster B is composed of samples from the middle of the basin

south of Little Madeira Bay (site 9); the center of the basin represents a very different

substrate and deeper water than seen at any of the other sites (see Table 1 for a

description of the localities). The samples from the mouth of Little Madeira Bay (site 8)

form the most discrete cluster of the sites analyzed; the presence of a significant quantity

of mesohaline, and terrestrial and/or freshwater fauna in these samples, which are rare or

lacking in the other samples, probably accounts for the cluster pattern seen.

Turney and Perkins (1972) did a detailed analysis of the molluscan fauna in Florida

Bay during the 1950’s. They divided the Bay into four subenvironments on the basis of

salinity, variability of salinity, water circulation and wind, and they characterized the

molluscan fauna for each of these subenvironments. Site 8 at the mouth of Little Madeira

Bay is in Turney and Perkins’ (1972) northern subenvironment; the remainder of the sites

analyzed for molluscan faunal content (sites 9, 11, 12, and 13) are in Turney and Perkins

(1972) interior subenvironment. The cluster pattern seen in Figure 4 is consistent with

Turney and Perkins’ division.

The northern subenvironment, according to Turney and Perkins (1972, table 6),

averages 26 species/station; 29-32 species were reported from their sites (7399 and 7400)

located near the mouth of Little Madeira Bay. This report lists 26 molluscan faunal

groups for site 8. Turney and Perkins (1972) identify Anomalocarida cuniemeris as the

characteristic species of the northern subenvironment, and list Ostrea sp., Parastarte

triquetra, Lyonsia floridana, Rissoina browniana, Melongena corona, and Retusa

canaliculata [=Acteocina canaliculata] as species more common to this subenvironment

than elsewhere in Florida Bay. A comparison of this list with the data presented in Table 3

might lead to the conclusion that the environment has changed a great deal in forty years.

However, an examination of Turney and Perkins complete faunal list (1972, table 3)

shows the differences are not as great as their description implies. Of the ten most

abundant faunal groups found at site 8 in this study, Turney and Perkins list seven as

abundant or common as follows:

Species Site 8,

Feb. 95

(%)

Site 8,

July 95

(%)

Turney &

Perkins (1972)

Site 73991

Turney &

Perkins (1972)

Site 74001

Acteocina canaliculata 3.8 3.7 C C

Anomalocardia sp. 3.5 3.3 A A

Bittium varium 16.3 7.5 A A

Brachiodontes sp. 6.5 15.8 C A

Cerithidea spp.2 3.5 6.0 C C

Cerithium spp.2 10.6 16.2 C F

Crepidula spp.2 1.6 2.2 C F

Polymesoda sp. * 2.4 -- --

Rissoidae3 1.5 * F F

Terrestrial/Fresh water

 Gastropods3

45.5 25.9 R R

Transennella spp.2 0.9 2.1 C C
18

* Not among 10 most abundant groups in sample

1

 A=abundant, C=common, F=few, R=rare; after Turney and Perkins, 1972

2

 Turney and Perkins only report 1 species of this genus from these sites

3

 Turney and Perkins report 2 species from these sites

For the northern subenvironment of Turney and Perkins (1972), the primary

differences between their study and ours is the importance they accorded to

Anomalocardia as the characteristic molluscan fauna for this subenvironment, and the near

absence of terrestrial and freshwater gastropods from their data; the only exception is their

inclusion of two species of Truncatella. The combined group of terrestrial and freshwater

gastropods (including Truncatella) is the dominant component of the molluscan

assemblages found at site 8 in this study. Also notable are the increased numbers of

Cerithium found in our samples, and the occurrence of the mesohaline to oligohaline

fauna, Polymesoda sp. and Cyrenoida floridana, which Turney and Perkins do not list for

sites 7399 and 7400. Polymesoda [=Pseudocyrena Turney and Perkins] occurs at only

three of Turney and Perkins nine northern subenvironment sites (categorized as rare or

few), and they do not list Cyrenoida at all. There are many explanations for the

differences noted between the two studies, but an examination of a core (T-24) from the

mouth of Taylor Creek in Little Madeira Bay (Ishman, et al, 1996) indicates that

Polymesoda, Cyrenoida (listed as ? Semele in that report), and the terrestrial gastropods

have been present nearly continuously in Little Madeira Bay since at least the 1950’s. In

addition, the data from Core T24 shows that Anomalocardia has been a significant

component of the molluscan assemblage over time.

The interior subenvironment averages 34 species/station according to Turney and

Perkins (1972) for the 25 sites they examined within this subenvironment. The molluscan

assemblages examined at the four sites that lie within the interior subenvironment for this

study average 29 faunal groups/site. Turney and Perkins (1972) identify Brachiodontes

exustus, Pinctada radiata, Cerithium muscarum and Bittium varium as the characteristic

molluscan species for the interior subenvironment. In addition, they list Lucina

multilineata, Rissoina bryerea, Modulus modulus, and Olivella sp. as species that are

more common in this subenvironment than elsewhere in Florida Bay. A comparison of the

ten most abundant faunal groups from three sites examined in this study (9, 11, 13), with

data from three Turney and Perkins (1972) interior subenvironment sites (7173, 7402,

7403) in close proximity to our sites, illustrates the spatial and temporal variability of the

subenvironments. Of the 19 faunal groups that are abundant at least one of our modern

interior subenvironment samples, 14 are listed as common or abundant at least one site by

Turney and Perkins (1972) as follows:
19

Species Site 13,

mud,

Feb

(%)

Site 13,

mud,

 July

(%)

Site 13,

grass,

 Feb

(%)

T & P

(1972)

Site

71731

Site 11,

Feb

(%)

Site 11,

July

(%)

T & P

(1972)

Site

74031

Site 9,

Feb

(%)

Site 9,

July

(%)

T & P

(1972)

Site

74021

Acteocina canaliculata 7.3 * -- R 7.9 4.8 C * * F

Alabina spp. 14.5 * * -- * * -- * * --

Anomalocardia sp. 4.4 * * C 11.5 7.8 F 2.1 2.0 F

Bittium varium 2.9 10.6 2.2 A 10.1 14.2 A 8.4 2.1 C

Brachiodontes sp. * 45.0 64.2 C 6.4 5.7 C 3.1 9.6 A

Bulla sp. 2.9 * * F 1.1 2.7 C 2.0 2.0 C

Cerithium spp.3 14.5 9.6 4.9 A 10.6 16.2 C 12.8 11.8 C

Chione cancellata -- * 1.6 A * * F * * A

Crepidula spp.2 -- 6.5 2.0 F * 2.8 R 1.7 1.5 R

Laevicardium spp.2 14.5 2.3 * A 2.2 2.7 C 3.9 3.7 A

Marginellids * * 1.8 F * * F 1.7 1.5 C

Modulus modulus -- 2.8 * A * * F * * R

Olivella sp. 4.4 * * F * * -- * * F

Parastarte triquetra * * 1.6 R 31.0 11.8 F -- -- --

Pinctada radiata -- 3.6 2.2 C * * F * * A

Pyramidellidae 4.4 -- -- -- * -- -- * * --

Rissoidae4 -- 2.3 2.2 A * * F 4.1 4.4 F

Tellina spp.3 -- 2.6 * C 1.6 * R * * F

Transennella spp.2 21.8 4.1 9.2 F 9.4 15.8 C 45.2 39.9 A

* Not among 10 most abundant groups in sample

1

 A=abundant, C=common, F=few, R=rare; after Turney and Perkins, 1972

2

 Turney and Perkins only report 1 species of this genus from these sites

3

 Turney and Perkins report 2 species from these sites

4 Turney and Perkins report 3 species from these sites
Table 3: Percent abundance of molluscs (>850 microns) at monitoring sites

Site 

Number

Month 

Collected

GastropodsActeocina canaliculataAlabina spp.Batillaria minimaBittium variumBulla sp.Caecum puchellum / floridanumCerithidea spp.Cerithiopsis greeniCerithium spp.Crepidula spp.LimpetsMarginellidsMelampidaeModulus modulusMuricidaeOlivella sp.PyramidellidaeRissoidaeTriphora perversaVitrinellidTerrestrial / freshwater gastropodsRare Gastropods

Basin South of Little Madeira Bay

8 Feb 3.81 0.00 0.00 16.34 0.23 0.00 3.50 0.00 10.58 1.63 0.00 0.54 0.54 0.70 0.62 0.16 0.00 1.48 0.00 0.16 45.53 0.23

8 July 3.71 0.47 0.00 7.47 1.04 1.25 6.04 0.00 16.18 2.24 0.00 0.43 0.26 0.47 0.60 0.04 0.09 1.81 0.00 0.13 25.94 0.00

12 Feb 0.27 0.11 0.81 18.13 0.75 0.00 0.00 0.11 15.22 5.33 0.00 0.97 0.00 2.80 0.32 0.48 0.91 4.63 0.00 0.27 0.00 0.27

12 July 1.83 0.61 0.00 9.13 0.30 1.67 0.00 0.00 14.16 6.54 0.00 0.76 0.00 2.44 0.15 0.76 0.91 1.98 0.00 0.91 0.00 0.30

11 Feb 7.92 0.15 0.44 10.05 1.12 0.00 0.05 0.05 10.59 1.07 0.00 0.34 0.00 0.49 0.39 0.19 0.05 0.34 0.00 0.05 0.24 0.05

11 July 4.88 0.11 0.27 14.22 2.65 0.11 0.00 0.00 16.18 2.76 0.05 0.90 0.00 1.33 0.21 0.80 0.00 1.17 0.00 0.16 1.06 0.11

9 Feb 0.95 0.21 0.00 8.40 1.96 0.43 0.06 0.12 12.83 1.68 0.03 1.65 0.00 0.55 0.21 0.55 0.27 4.06 0.15 0.55 1.34 0.09

9 July 1.17 0.31 0.00 2.10 1.97 0.06 0.06 0.00 11.84 1.48 0.06 1.54 0.00 0.74 0.25 0.93 0.25 4.44 0.00 0.31 1.05 0.06

Bob Allen Keys

13 (grass) Feb 0.00 1.17 0.00 2.15 0.20 0.59 0.00 0.00 4.89 1.96 0.59 1.76 0.00 0.98 0.00 0.59 0.00 2.15 0.20 0.20 0.00 0.00

13 (mud) Feb 7.25 14.49 0.00 2.90 2.90 0.00 0.00 0.00 14.49 0.00 0.00 1.45 0.00 0.00 0.00 4.35 4.35 0.00 0.00 0.00 0.00 0.00

13 (mud) July 0.26 0.78 0.00 10.59 1.03 0.00 0.00 0.00 9.56 6.46 0.00 1.29 0.00 2.84 0.00 0.26 0.00 2.33 0.00 0.26 0.00 0.00

Total # specimens 

present in all samples 463 53 29 1618 219 60 189 7 2094 403 6 158 13 169 52 76 42 414 6 45 1272 17

Total percent of sps in 

all samples collected 2.91 0.33 0.18 10.16 1.38 0.38 1.19 0.04 13.15 2.53 0.04 0.99 0.08 1.06 0.33 0.48 0.26 2.60 0.04 0.28 7.99 0.11
Table 3: Percent abundance of molluscs (>850 microns) at monitoring sites

Site 

Number

Month 

Collected

Unidentified gastropod fragments, unknowns, and juveniles 

PelecypodsAnomalocardia sp.Arcopsis adamsiBrachiodontes sp.Chione cancellataCodakia sp.Cumingia tellinoideaCyrenoida floridanaLaevicardium spp.Lima sp.Mytilopsis leucophaetaNucula proximaParastarte triquetraPinctada radiataPitar sp.Polymesoda sp.Tellina spp.Transennella spp.Rare PelecypodsUnidentified pelecypod fragmentsTotal number of specimens / sample

Basin South of Little Madeira Bay

8 Feb 0.08 3.50 0.08 6.54 0.08 0.00 0.23 0.31 0.54 0.00 0.62 0.00 0.08 0.00 0.00 0.54 0.31 0.93 0.08 0.00 1285

8 July 0.73 3.28 0.30 15.80 0.22 0.00 0.17 0.17 1.25 0.09 0.00 0.00 0.09 0.43 0.26 2.37 0.52 2.11 0.00 4.01 2317

12 Feb 0.86 0.81 0.11 23.45 0.91 0.16 1.67 0.00 3.77 0.22 0.00 0.11 2.53 2.96 0.00 0.00 0.97 3.93 0.05 6.13 1859

12 July 1.37 0.46 0.15 30.29 2.13 0.15 0.30 0.00 2.74 0.30 0.00 0.00 3.81 1.67 0.00 0.00 0.46 12.33 0.15 1.22 657

11 Feb 1.80 11.51 0.00 6.36 0.29 0.00 0.39 0.00 2.19 0.05 0.00 0.00 31.03 0.44 0.00 0.58 1.55 9.42 0.05 0.78 2059

11 July 1.59 7.75 0.11 5.73 0.53 0.27 0.48 0.00 2.71 0.16 0.00 0.00 11.83 1.86 0.00 0.11 1.49 15.81 0.11 2.55 1885

9 Feb 2.05 2.14 0.31 3.12 0.43 0.12 0.31 0.00 3.94 0.00 0.00 0.06 0.00 0.40 0.98 0.03 0.55 45.16 0.03 4.28 3273

9 July 7.16 1.97 0.12 9.56 0.49 0.12 0.62 0.00 3.70 0.06 0.00 0.12 0.00 1.36 1.11 0.00 1.17 39.85 0.12 3.82 1621

Bob Allen Keys

13 (grass) Feb 1.37 0.39 0.00 64.19 1.57 0.00 0.00 0.00 0.59 0.39 0.00 0.00 1.57 2.15 0.00 0.00 0.78 9.20 0.00 0.39 511

13 (mud) Feb 0.00 4.35 0.00 1.45 0.00 0.00 0.00 0.00 14.49 0.00 0.00 0.00 2.90 0.00 0.00 0.00 0.00 21.74 0.00 2.90 69

13 (mud) July 1.03 1.81 0.26 44.96 1.29 0.00 0.78 0.00 2.33 0.78 0.00 0.00 0.26 3.62 0.00 0.00 2.58 4.13 0.00 0.52 387

Total # specimens 

present in all samples 304 636 26 2084 88 15 80 8 431 18 8 6 948 180 56 77 148 2909 9 487 15923

Total percent of sps in 

all samples collected 1.91 3.99 0.16 13.09 0.55 0.09 0.50 0.05 2.71 0.11 0.05 0.04 5.95 1.13 0.35 0.48 0.93 18.27 0.06 3.06
Table 4: Salinity values for molluscan fauna

Total Number Salinity (ppt) Specimens Sites Correlation Coefficient Minimum Maximum 

Average 

Gastropods:

Acteocina canaliculata 463 10 -0.4603 12 30 21.05

Alabina spp. 53 10 -0.0487 12 30 22.30

Batillaria minima 29 3 0.9635 15 26 24.00

Bittium varium 1618 11 -0.3127 12 30 21.86

Bulla sp. 219 11 -0.4309 12 30 21.86

Caecum puchellum / floridanum 60 6 -0.3193 12 30 19.83

Cerithidea spp. 189 5 -0.7318 12 24 18.10

Cerithiopsis greeni 7 3 0.3273 22 26 24.00

Cerithium spp. 2094 11 -0.5711 12 30 21.86

Crepidula spp. 403 10 -0.0253 12 30 21.05

Limpets 6 4 0.8165 15 30 21.00

Marginellids 158 11 -0.1292 12 30 21.86

Melampidae 13 2 1.0000 12 17.5 14.75

Modulus modulus 169 10 0.1331 12 30 21.05

Muricidae 52 8 -0.3876 12 26 19.31

Olivella sp. 76 11 -0.2305 12 30 21.86

Pyramidellidae 42 7 0.3860 12 30 21.71

Rissoidae 414 10 -0.0104 12 30 21.05

Triphora perversa 6 2 --- 24 30 27.00

Vitrinellid 45 10 0.0810 12 30 21.05

Terrestrial / freshwater Gastropods 1272 6 -0.4716 12 24 17.58

Pelecypods:

Anomalocardia sp. 636 11 -0.4042 12 30 21.86

Arcopsis adamsi 26 8 -0.0961 12 26 19.81

Brachiodontes sp. 2084 11 -0.0146 12 30 21.86

Chione cancellata 88 10 0.3703 12 30 21.05

Codakia sp. 15 5 0.2511 15 26 22.10

Cumingia tellinoidea 80 9 0.3396 12 26 20.06

Cyrenoida floridana 8 2 --- 12 17.5 14.75

Laevicardium spp. 431 11 -0.1469 12 30 21.86

Lima sp. 18 8 0.2954 12 30 21.13

Mytilopsis leucophaeta 8 1 --- 8 17.5 17.50

Nucula proxima 6 3 --- 15 26 21.67

Parastarte triquetra 948 9 -0.1521 12 30 22.39

Pinctada radiata 180 9 0.0027 12 30 21.44

Pitar sp. 56 3 0.9721 12 24 17.00

Polymesoda sp. 77 5 -0.6589 12 24 18.10

Tellina spp. 148 10 -0.2697 12 30 21.05

Transennella spp. 2909 11 -0.1042 12 30 20.83
Site 13 (mud) Feb.

Site 13 (mud) July

Site 13 (grass) Feb.

Site 12 July

Site 12 Feb.

Site 11 Feb.

Site 11 July

Site 9 Feb.
24

 Dinocysts

Dinocyst assemblages were examined from 18 samples at 13 sites in north-central

and northeast Florida Bay. The dinocyst assemblages in the samples consist of a small

number of taxa (Table 5). All samples are dominated by the various species of the genus

Spiniferites Mantell. Individual species were not differentiated in the present study due to

poor preservation and taxonomic difficulties within the genus Spiniferites. Members of

the Operculodinium israelianum (Rossignol) Wall plexus are listed as Operculodinium

and are present in relative abundances of 7-23 percent. Polysphaeridium zoharyi

(Rossignol) Bujak et al. is consistently present and comprises 5-34 percent of the

assemblages. All samples included low numbers of Nematosphaeropsis (probably N.

rigida Wrenn) and most included low numbers of Lingulodinium machaerophorum

(Deflandre & Cookson) Wall. A few specimens each of Tectatodinium pellitum Wall and

Tuberculodinium vancampoae (Rossignol) Wall are present in some of the samples. Only

two samples included single specimens representing members of the family

Congruentidiaceae.

Of the six samples from the basin south of Little Madeira Bay, three contained

higher percentages of Polysphaeridium zoharyi (Figure 5) and lower percentages of

Operculodinium than samples from other areas. P. zoharyi tolerates a wide range of

salinities from hyper to hyposaline conditions, but in modern Mississippi Sound it is

associated with low and fluctuating salinities. A sample from the basin south of Little

Madeira Bay (site 9, July sample) contains 33.7 percent Polysphaeridium zoharyi, the

highest abundance in any of the samples studied, and the lowest percentage of Spiniferites

(46.3 percent). A sample from the mouth of Little Madeira Bay (site 8, February sample)

contains 23 percent Polysphaeridium zoharyi and 58.6 percent Spiniferites. The

calculated cysts per gram for samples from the basin south of Little Madeira Bay range

from 45-125.

The northeast basin and the Bob Allen Keys show some similarities in dinocyst

distribution patterns. Eight samples from seven sites were examined from the northeastern

basin of Florida Bay (Figure 5), but four of these samples (sites 1, 2, 3, and 6; all February

samples) did not contain enough specimens to count. Three of the four samples in the

northeast basin contain the highest percentages of Spiniferites seen in all samples

examined for this report; these high values may be indicative of the influence from the

Atlantic water. Four samples from two sites were examined from the Bob Allen Keys.

Polysphaeridium zoharyi is present in relatively low abundances (5.6-14.4 percent) in the

northeast basin and at the Bob Allen Keys sites. Operculodinium shows the inverse

pattern; it is present in relatively high abundances (10.0-23.4 percent) for both areas.

Absolute abundance of cysts for the samples from Bob Allen Keys ranges from 13-73 per

gram. The calculated cysts per gram for samples from the northeast basin ranges from 10-

77.

Five sets of paired samples were examined to determine the influence of season,

substrate or other variables on the observed distribution patterns. February/July pairs were
25

examined from Bob Allen Keys mudbank (site 13) and Russell Bank (site 12) to see if

there were any distinctive seasonal differences. In both pairs, the February sample yielded

a greater number of cysts per gram, but the relative abundances of the taxa present in each

pair were quite similar. Substrate comparisons were made between two pairs of samples

from the Bob Allen Keys mudbank (site 13, February samples) and from Bottle Key (site

7, February samples). No significant differences in absolute abundance between the grass

and mud substrates could be detected. At Bottle Key (site 7), the mud sample had less

abundant P. zoharyi and more abundant Spiniferites than the grass sample. Bob Allen

Keys mudbank (site 13) grass and mud samples show remarkably similar assemblages.

Two mud samples taken at the same time from Russell Bank (site 12, February samples)

show some differences. The sample from the erosional side of the bank, in 2.5 feet of

water contains a slightly higher absolute abundance of cysts and a higher percentage of

Operculodinium relative to P. zoharyi than the sample taken from the top of the bank in 1

inch of water.

Absolute abundance of dinocysts in all the samples examined ranges from 10 to

125 cysts/g. These values are one to two orders of magnitude below those reported by

Wall and others (1977) for samples from the Middle Atlantic Bight and western South

Africa and are consistent with high sedimentation rates. The values are far below

concentrations that would be considered indicative of “bloom” conditions.
Table 5: Percent abundance of dinocysts at monitoring sites

N

O

T

C

O

U

N

T

E

D Site Number

Month 

Collected

Polysphaeridium zoharyiSpiniferites spp.Operculodinium spp.Nematosphaeropsis spp.Lingulodinium machaerophorumTectatodinium pellitumCongruentidiaceaeTuberculodinium vancampoaeCysts / gramTotal # specimens counted

Basin South of Little Madeira Bay

8 Feb 23.0 58.6 8.0 1.1 5.7 3.4 0.0 0.0 45 87

9 July 33.7 46.3 7.7 1.3 8.7 2.0 0.0 0.3 97 300

11 Feb 13.3 66.0 10.0 2.3 4.0 4.3 0.0 0.0 79 300

12 (top of bank)Feb 22.1 62.3 6.6 2.5 5.7 0.8 0.0 0.0 47 122

12 (side of bank)Feb 14.3 65.3 11.3 4.0 4.7 0.3 0.0 0.0 125 300

12 (side of bank)July 16.4 63.3 13.0 4.0 1.1 1.1 1.1 0.0 57 177

Bob Allen Keys

13 (grass) Feb 12.7 67.6 13.7 3.9 2.0 0.0 0.0 0.0 52 102

13 (mud) Feb 14.4 65.8 10.8 2.7 5.4 0.0 0.9 0.0 73 111

13 (mud) July 10.8 59.5 23.4 2.7 1.8 1.8 0.0 0.0 19 111

14 Feb 13.6 64.5 17.3 2.7 1.8 0.0 0.0 0.0 13 110

Northeastern Basin

X 1 Feb 23

X 2 Feb 29

X 3 Feb 23

4 Feb 11.1 70.4 15.7 1.9 0.0 0.9 0.0 0.0 53 108

5 Feb 15.0 70.0 10.0 2.5 0.0 1.3 0.0 1.3 31 80

X 6 Feb 10

7 (grass) Feb 12.3 57.0 19.3 5.3 4.4 1.8 0.0 0.0 77 114

7 (mud) Feb 5.6 69.8 20.6 2.3 1.6 0.0 0.0 0.0 73 126
50 60 70 80 90 100

ent abundance

Basin south 

of Little 

Madeira Bay

Bob Allen

Keys
28

 Pollen

Pollen assemblages were quantified from ten samples collected from five sites in

central and eastern Florida Bay during February and July, 1995 (Table 6; Figure 6).

Pollen composition and abundance show little variability among these samples. The

assemblages are dominated by pine (Pinus) pollen, which exceeds 70 percent abundance in

all but one sample. Oak (Quercus) pollen typically ranks second in abundance (3-10

percent), but pollen of the saltwort family (Chenopodiaceae) and aster family (Asteraceae)

each exceed 5 percent abundance in some samples (Table 6). Other taxa consistently

present in low abundances include Australian pine (Casuarina), red mangrove

(Rhizophora), black mangrove (Avicennia), hickory (Carya), wax myrtle (Myrica), sweet

gum (Liquidambar), and grass (Poaceae).

The high percentages of pine pollen seen in these samples are typical of marine

sediments, with the percent abundance of bisaccate pollen such as pine typically increasing

with distance from shore (Heusser, L.E. and Balsam, W.L., 1977; Mudie, P.J., 1982).

The lowest values for percent abundance of pine are recorded for the samples from the

mouth of Little Madeira Bay (site 8, see Table 6). The percent abundance of pine and oak

pollen seen in these Florida Bay samples is comparable to other assemblages from the Gulf

of Mexico and the eastern shelf of Florida (Litwin and Andrle, 1992; Edwards and

Willard, in press). The Florida Bay samples differ, however, in comparison of the minor

elements, particularly Rhizophora and Casuarina, which are not major components of the

flora in other regions.
Table 6: Percent abundance of pollen at monitoring sites

Site 

number

Month 

Collected

Pinus (Pine)Carya (Hickory)Taxodiaceae (Cypress)Quercus (Oak)Casuarina (Australian Pine)Schinus (Pepper Tree)Rhizophora (Red Mangrove)Avicennia (Black Mangrove)Conocarpus (Buttonwood)Celtis (Hackberry)Juglans (Walnut)Myrica (Wax Myrtle)Ulmus (Elm)Betula (Bircy)Alnus (Alder)

Basin South of Little Madeira Bay

8 Feb 57.04 1.41 0 9.86 2.11 0 0 2.11 1.41 0 0 2.82 0 0 0

8 July 72.73 3.25 0 4.55 0 0 0 1.3 0.65 0 0 0 0 0 0

9 July 87.5 0.3 0 4.88 1.52 0 0.3 0 0 0 0 0 0 0 0

11 Feb 74.63 0.6 0 8.66 2.09 0 0.3 0.3 0 0 0 2.39 0 0 0

11 July 88.95 0.29 0 4.07 1.16 0 0 0.29 0 0 0 0.58 0.29 0 0

12 Feb 84.54 0.63 0.32 5.68 0.63 0.32 0.63 0 0 0 0 1.89 0 0 0

12 July 83.73 1.36 0.34 3.73 0.68 0 0.34 0.34 0 0 0 0.34 0.34 0 0.34

Bob Allen Keys

13 (mud) Feb 75.63 0 0 10.04 1.43 0 0 0 0 0.36 0.36 2.87 0 0 0

13 (mud) July 88.36 1.03 0 3.08 0.68 0 0 0 0 0 0 0.68 0 0.34 0.34

13 (grass) July 92.59 1.23 0 2.78 0.93 0 0 0 0 0 0 0.31 0 0 0
Table 6: Percent abundance of pollen at monitoring sites

Site 

number

Month 

Collected

Nyssa (Gum Tree)Liquidambar (Sweet Gum)Magnolia (Magnolia)Ilex (Holly)Rhus (Sumac)Euphorbiaceae (Spurge family)Decodon (Swamp Loosestrife)ChenopodiaceaeAmaranthaceae (Saltwort/ Pigweed Poaceae (Grass family)Cyperaceae (Sawgrass family)Asteraceae (Aster family)Typha (Cattail)Fabaceae (Legume/Bean family)Pollen Concentration (pollen/gram)Total counted

Basin South of Little Madeira Bay

8 Feb 0.7 0.7 0.7 0.7 0 0 1.41 11.27 0 0 4.23 0 0 387 142

8 July 0 0 0 0 0 0 0.65 2.6 3.9 0 8.44 0 0 162 154

9 July 0 0.3 0 0 0 0 0 2.13 0 0.91 0.3 0.3 0.3 451 328

11 Feb 0 0.3 0 0.3 0 0 0 3.28 0.3 0 2.09 0.9 0.3 883 335

11 July 0 0.58 0 0 0.29 0 0 0.87 0 0.87 0 0 0.29 678 344

12 Feb 0 0.32 0 0 0 0 0 0.95 0.32 0.63 0.63 0 1.26 1069 317

12 July 0 1.02 0 0 0 0.34 0 2.03 0 0.68 2.03 0.34 1.02 462 295

Bob Allen Keys

13 (mud) Feb 0 0 0 0 0 0 0 1.79 0 0.72 0.36 0.36 1.44 648 279

13 (mud) July 0 0.34 0 0 0 0 0 0.68 0.34 0.34 1.03 0.34 0.34 916 292

13 (grass) July 0 0 0 0 0 0 0.31 0.62 0 0 0.31 0 0 781 324
JOHN PENNEKAMP

CORAL REEF

STATE PARK

L

1

Site 8

Site 9

Site 11

Amaranthaceae

Chenopodiaceae /

Pinus

Rhizophora

Quercus

POLLEN TYPES
32

SUMMARY

This analysis of selected sites in north-central and north-eastern Florida Bay is a

first step in building a database for analysis of down-core data. These data indicate the

changes in substrate and salinity conditions and the associated fauna and flora over a oneyear period. Indicator species for low salinity conditions, seagrass beds, and other

parameters of the environment have been identified for use in down-core analysis.

Additional information will be gathered as we continue to study and monitor selected sites

in Florida Bay. One concern in analysis of the down-core data is to understand the degree

to which seasonality contributes to fluctuations in the fauna and flora. Although

seasonality cannot be isolated as a single parameter, it would appear from this analysis that

seasonality is not a factor in down-core variability. No seasonality could be detected for

the 1995 sample sets, but this effect will continue to be monitored at these sites for a

period of at least two more years. Only by continued monitoring of the living fauna and

flora of Florida Bay can we begin to understand the geographic and temporal scale of the

variations seen in the south Florida ecosystem over time.
33

REFERENCES CITED

Andrews, Jean, 1971, Shells and shores of Texas: Austin, TX, University of Texas, 365 p.

Emerson, W.K., and Jacobson, M.K., 1976, The American Museum of Natural History

Guide to Shells: Land, freshwater, and marine, from Nova Scotia to Florida: New

York, Alfred A. Knopf, 482 p.

Heusser, L.E. and Balsam, W.L., 1977, Pollen distribution in the Northeast Pacific Ocean:

Quaternary Research, v. 7, p. 45-62

Ishman, S.E., Brewster-Wingard, G.L., Willard, D.A., Cronin, T.M., Edwards, L.E.,

Holmes, C.W., 1996, Preliminary paleontologic report on core T-24, Little

Madeira Bay, Florida: U.S. Geological Survey Open-File Report 96-543, p. 1-46

Lidz, B.H. and Rose, P.R., 1989, Diagnostic foraminiferal assemblages of Florida Bay,

and adjacent shallow water: a comparison: Bulletin of Marine Science, v. 44, n. 1,

p. 399-418.

Litwin, R.J. and Andrle, V.A.S., 1992, Modern palynomorph and weather census data

from the U.S. Atlantic coast (Continental Margin Program samples and selected

NOAA weather stations). U.S. Geological Survey Open-File Report 92-263, p. 1-

31.

Lodge, T.E., 1994, The Everglades Handbook: Delray Beach, FL, St. Lucie Press, 228 p.

Moore, H.B. and Lopez, N.N., 1969, The ecology of Chione cancellata: Bulletin of

Marine Science, v. 19, p. 131-148.

Mudie, P.J., 1982, Pollen distribution in recent marine sediments, eastern Canada:

Canadian Journal of Earth Science, v. 19, p. 729-747.

Parker, R.H., 1959, Macro-invertebrate assemblages of central Texas coastal bays and

Laguna Madre: Bulletin of American Petroleum Geologists, v. 43, p. 2100-2166.

Perry, L.M., and Schwengel, J.S., 1955, Marine shells of the western coast of Florida:

Ithaca, NY, Paleontological Research Institution, 318 p.

Poag, C.W., 1978, Paired foraminiferal ecophenotypes in Gulf Coast estuaries: ecological

and paleoecological implications: Gulf Coast Associations of Geological Societies,

Transactions, v. 28, p. 395-421.

Poag, C.W., 1981, Ecologic atlas of benthic foraminifera of the Gulf of Mexico: Woods

Hole, Massachusetts, Marine Science International, 174 p.
34

Stockmarr, J., 1971, Tablets with spores used in absolute pollen analysis: Pollen et Spores,

v. 13, p. 615-621.

Turney, W.J. and Perkins, B.F., 1972, Molluscan distribution in Florida Bay in Sedimenta,

University of Miami, Rosenstiel School of Marine and Atmospheric Science, v. III,

p. 1-37.

Wall, D., Dale, B., Lohmann, G.P., and Smith, W.K., 1977, The environmental and

climatic distribution of dinoflagellate cysts in modern marine sediments from

regions in the North and South Atlantic Oceans and adjacent seas: Marine

Micropaleontology, v. 2, p. 121-200.

Warmke, G.L., and Abbott, R.T., 1961, Caribbean Seashells: Narberth, PA, Livingston

Publishing Co., 348 p.

Wingard, G.L., Ishman, S.E., Cronin, T.M., Edwards, L.E., Willard, D.A., and Halley,

R.B., 1995, Preliminary analysis of down-core biotic assemblages: Bob Allen

Keys, Everglades National Park, Florida Bay: U.S. Geological Survey Open-File

Report 95-628, p. 1-35.