Clam Bay Committee Agenda 10/03/2013 PELICAN BAY SERVICES DIVISION
Municipal Service Taxing and Benefit Unit
NOTICE OF PUBLIC MEETING THURSDAY, OCTOBER 3, 2013
THE CLAM BAY COMMITTEE OF THE PELICAN BAY SERVICES
DIVISION BOARD WILL MEET THURSDAY, OCTOBER 3 AT 3:00 PM
AT THE COMMUNITY CENTER AT PELICAN BAY, 8960 HAMMOCK
OAK DRIVE, NAPLES, FL 34108.
AGENDA
The agenda includes, but is not limited:
1 . Roll Call
2. Approval of September 5 Minutes
3. Discuss Draft of Chapter 4 of Clam Bay Management Plan
4. Establish priorities for continuing work on draft of Clam Bay
Management
5. Plan and next meeting date to discuss Management Plan
6. Discuss October 17 meeting with engineer(s)
7. Discuss City of Naples proposed project to replace culverts
connecting Clam Bay to Moorings Bay system with bridge on
Seagate Drive
8. Audience comments
9. Adjourn
ANY PERSON WISHING TO SPEAK ON AN AGENDA ITEM WILL RECEIVE UP TO THREE
(3) MINUTES PER ITEM TO ADDRESS THE BOARD. THE BOARD WILL SOLICIT PUBLIC
COMMENTS ON SUBJECTS NOT ON THIS AGENDA AND ANY PERSON WISHING TO
SPEAK WILL RECEIVE UP TO THREE (3) MINUTES. THE BOARD ENCOURAGES YOU TO
SUBMIT YOUR COMMENTS IN WRITING IN ADVANCE OF THE MEETING. ANY PERSON
WHO DECIDES TO APPEAL A DECISION OF THIS BOARD WILL NEED A RECORD OF
THE PROCEEDING PERTAINING THERETO, AND THEREFORE MAY NEED TO ENSURE
THAT A VERBATIM RECORD IS MADE, WHICH INCLUDES THE TESTIMONY AND
EVIDENCE UPON WHICH THE APPEAL IS TO BE BASED. IF YOU ARE A PERSON WITH A
DISABILITY WHO NEEDS AN ACCOMMODATION IN ORDER TO PARTICIPATE IN THIS
MEETING YOU ARE ENTITLED TO THE PROVISION OF CERTAIN ASSISTANCE. PLEASE
CONTACT THE PELICAN BAY SERVICES DIVISION AT (239) 597-1749. VISIT US AT
HTTP://PELICANBAYSERVICESDIVISION.NET.
9/30/2013 2:59:34 PM
M1
CLAM BAY COMMITTEE MEETING MINUTES
THURSDAY, SEPTEMBER 5,2013
LET IT BE REMEMBERED that the Clam Bay Committee of the Pelican Bay Services
Division Board met Thursday, September 5,2013 at 1:00 PM at the Community Center at
Pelican Bay, 8960 Hammock Oak Drive,Naples, Florida. The following members were present:
Clam Bay Committee
Susan O'Brien, Chairman John Domenie absent
Joe Chicurel Mike Levy
Tom Cravens
Also Present
Scott Streckenbein, Pelican Bay Services Division Board
Pelican Bay Services Division Staff
W.Neil Dorrill,Administrator Mary McCaughtry, Operations Analyst
Kyle Lukasz, Operations Manager Lisa Resnick, Recording Secretary
Also Present
Kevin Carter, Field Manager, Dorrill Management Group
Mohamed Dabees, P.E., Ph.D., Humiston& Moore Engineers
Tim Hall, Senior Ecologist&Principal, Turrell, Hall &Associates, Inc.
Lauren Gibson, Biologist& Project Manager, Turrell, Hall &Associates, Inc.
REVISED AGENDA
1. Roll Call
2. Approval of June 26 and July 16 Clam Bay Committee Meetings Minutes
3. Discuss Draft Clam Bay Management Plan
4. Discuss scientific services for PBSD
5. Watercraft violating County ordinance
6. Update on Beach Renourishment(add-on)
7. Audience comments
8. Adjourn
ROLL CALL
Four Committee members were present. Mr. Domenie was absent.
AGENDA APPROVAL
Mr. Cravens motioned,Mr. Levy seconded to approve th as - nded, adding
"Update on beach renourishment" The Committee v s favor and
the motion passed.
29
Clam Bay Committee Meeting Minutes
Thursday, September 5,2013
APPROVAL OF JUNE 26 CLAM BAY COMMITTEE MEETING MINUTES
Mr. Cravens motioned,Dr. Chicurel seconded to approve the June 26 Clam Bay
Committee meeting minutes as presented. The Committee voted unanimously in favor
and the motion passed.
APPROVAL OF JULY 16 CLAM BAY COMMITTEE MEETING MINUTES
Mr. Cravens motioned,Dr. Chicurel seconded to approve the July 16 Clam Bay
Committee meeting minutes as amended, deleting the sentence on page 27[regarding
title of Clam Bay Management Plan]. The Committee voted unanimously in favor and
the motion passed.
DISCUSSION UPDATED CLAM BAY MANAGEMENT PLAN
Mr. Hall explained that the updated draft included an outline and framework for the Plan
and incorporated relevant information from the 2008 plan regarding mangroves. The goals and
objectives were determined based on the Stakeholder input. With regard to species lists,the fish
and bird surveys done previously were still applicable; however, future surveys, although
interesting, were dependent upon the goals and objectives of the Plan, and only useful to identify
trends and did not add to the Plan's management capability. An application for a dredging permit
was not dependent upon the status or existence of the Plan.
The Committee was concerned about Chapter 6, Goal 4, and requested that Mr. Hall
include specific information under Goal 4 about the Seagate community's riparian rights and
passive recreation, including Ordinance 96-16 regarding boating speed and safety in Clam Bay.
Hall would revise the draft and include the requested changes, priorities, and
recommendations for review at the next Committee meeting.
Chairman O'Brien directed staff to schedule two Committee meetings. On O 01'fp r the
Committee would review the revised draft Management Plan and on October 17, th-V4114esuld
be a question and answer session regarding the potential design for future dry+' nee'
Humiston& Moore Engineers. 1
DISCUSSION OF SCIENTIFIC SERVICES FOR PELICAN B otp, R ` DIVISION
The Committee discussed briefly and consensus was no , i in• . Taff scientist.IL
'„
30 vo
Clam Bay Committee Meeting Minutes
Thursday, September 5,2013
WATERCRAFT VIOLATING COUNTY ORDINANCE
The Committee discussed their concerns regarding County Ordinance 96-16 regarding
controlling vessel speed and safety in Clam Bay. The Committee acknowledged that the Services
Division did not have any authority to enforce it; however, Chairman O'Brien planned to record
a log of activity to determine if a problem exists.
UPDATE ON BEACH RENOURISHMENT (ADD-ON)
Mr. Dorrill reported that according to the County Manager, a request was made that
Pelican Bay participate in the County's beach renourishment project; however, at this time not to
use Services Division revenue. A second request made was to amend the Services Division's
Ordinance to include beach renourishment and to consider funding the public portions of the
project seaward of the erosion control line. The concern was regarding easements and the use of
public funds to improve upland private property.
The Committee discussed at length their concerns regarding beach renourishment
including the Services Division's legal authority or lack thereof, use of public funds, benefits to
private property in Bay Colony, public beach vs. private beach construction easements, and
public access issues.
Mr. Levy explained that the Foundation is asking the Services Division to honor its
commitment that it made at the May Joint meeting to be responsible for beach renourishment.
Other Committee members did not agree the Services Division had the authority to do
beach renourishment.
AUDIENCE COMMENTS
None A.4, =`
ADJOURN
k
Mr. Cravens motioned and Chairman O'Brien seconded to adjourn. The Cidtrittee c I
voted unanimously in favor, the motion passed, and meeting adjourned a -
'rip"
Via_ '
Susan O'Brien, Chairman Minute 105$7 a o nick `., 2013 9:28:15 AM
31
Chapter 4 update for Oct. 3 Committee mtg.
4.0 Resource Description and Assessment
SOILS
Based on the National Resource Conservation Service (NRCS) "Soil Survey of Collier
County Area, Florida" (NRCS, 1998) there are 8 different soil types (soil map units)
present on the project lands. Two of the units are associated with the NRPA while the
remaining units are associated with the upland developments. The following sub-sections
provide a brief description of each soil map unit identified within the Clam Bay and
Pelican Bay areas. Information is provided about the soil's landscape position (i.e. its
typical location in the landscape on a county-wide basis), the soil's profile (i.e. textural
composition and thickness or depth range of the layers or horizons commonly present in
the soil), and the soil's drainage and hydrologic characteristics.
In addition, the hydrologic soil group is also identified for each soil. There are 4 groups
that are used to estimate runoff from precipitation. Soils are grouped according to the rate
of infiltration of water when the soils are thoroughly wet and are subject to precipitation
from long-duration storms. The four groups range from A (soils with a high infiltration
rate, low runoff potential, and a high rate of water transmission) to D (soils having a slow
infiltration rate and very slow rate of water transmission).
It is important to understand that where the soil survey shows mapping units named for
soil series, they represent the dominant undisturbed soils in that landscape that existed
predevelopment. They do not recognize or appropriately interpret the drastically
disturbed nature of urban landscapes created after the Soil Survey was completed.
The soils occurring within the development areas are as follows:
Immokalee fine sand(Map Unit#7)
Landscape position—Pine Flatwoods.
This is a nearly level, poorly drained soil. Individual areas are elongated and irregular in
shape, and range from 10 to 500 acres. The slope is 0 to 2 percent. Typically,the surface
layer is black fine sand about 6 inches. The subsurface layer is light gray fine sand to a
depth of about 35 inches. The subsoil is fine sand to a depth of about 58 inches; the
upper part is black, the middle part is dark reddish brown, and the lower part is dark
brown. The substratum is pale brown fine sand to depth of about 80 inches. The
permeability of this soil is moderate. The available water capacity is low. In most years,
under natural conditions, the seasonal high water table is between 6 to 18 inches of the
surface for 1 to 6 months. In other months, the water table is below 18 inches and
recedes to depth of more than 40 inches during extended dry periods. Rarely is it above
the surface. Hydrologic group is B/D.
Natural vegetation consists of South Florida slash pine, saw palmetto, wax myrtle, chalky
bluestem, creeping bluestem and pineland threeawn.
Chapter 4 update for Oct. 3 Committee mtg.
Urban land(Map Unit#32)
Landscape position—Urban Areas
Urban land consists of areas that are 75 percent or more covered with streets, buildings,
parking lots, shopping-centers, highways, industrial areas, airports and other urban
structures. Small areas of undisturbed soils are mostly lawns, vacant lots, playgrounds
and green areas. The original soils in some areas have been altered by filling, grading
and shaping. Urban land is nearly level except for some parking areas that are sloped to
drain off water. Individual areas are usually rectangular in shape and range from 10 to
1200 acres. The slope is 0 to 2 percent. The depth of the water table varies with the
amount of fill material and the extent of artificial drainage within any mapped area.
Hydrologic group is not applicable.
Urban Land-Immokalee-Oldsmar limestone substratum Complex(Map Unit#34)
Landscape position—Urban Areas
These nearly level poorly drained soils are on urban areas of the county. Individual areas
are blocky to irregular in shape and range from 20 to 500 acres. The slope is 0 to 2
percent. Typically, urban land consists of commercial buildings, houses, parking lots,
streets, sidewalks, recreational areas, shopping centers and other urban structures where
the soil cannot be observed. In 90 percent of the area mapped in this unit; urban land
makes up about 45 percent, Immokalee soils makes up about 35 percent and Oldsmar soil
makes up about 20 percent of the map unit. The soils occur as areas so intricately mixed
or so small that mapping them separately is not practical. The Immokalee and Oldsmar
soils may or may not have been filled or reworked to accommodate Urban land uses. The
permeability of the Immokalee is moderate and the available water capacity is low. The
permeability of the Oldsmar soil is moderately slow and the available water capacity is
low. In most years, under natural conditions, the seasonal high water table is between 6
to 18 inches of the surface for 1 to 6 months. In other months,the water table is below 18
inches and recedes to a depth of more than 40 inches during extended dry periods. Most
areas have had drainage systems installed to help control the seasonally high water table
and runoff. Hydrologic group is B/D.
Urban Land-Aquents Complex, organic substratum (Map Unit#35)
Landscape position—Urban Areas.
This unit consists of soil materials that have been dug from different areas in the county
and have been spread over the muck soils for coastal urban development. Individual
areas are blocky to irregular in shape and range from 20 to 300 acres in size. The slope is
0 to 2 percent. Typically, Urban land consists of commercial buildings, houses, parking
lots, streets, sidewalks, recreational areas, shopping centers and other urban structures
where the soil cannot be observed. The depth of this fill material varies from 30 to more
than 80 inches. Muck of various thickness underlies the fill material, with mineral
material under the muck. The depth to the water table varies with the amount of fill
material and the extent of artificial drainage within any mapped area. Hydrologic group
is not applicable.
Chapter 4 update for Oct. 3 Committee mtg.
Udorthents shaped(Map Unit#36)
Landscape position—Golf courses and athletic fields.
These nearly level to undulating, somewhat poorly to moderately well drained soils are
on golf courses and adjacent areas where soil material has been mechanically altered and
shaped. Individual areas are elongated and irregular in shape and range from 40 to 640
acres in size. The slope is 1 to 6 percent. A common profile has mixed grayish brown
and pale brown fine sandy loam to a depth of 18 inches. The next layer is gray gravelly
fine sand to a depth of about 37 inches. The subsoil is light brownish gray fine sandy
loam to a depth of about 47 inches. Limestone bedrock is at a depth of about 47 inches.
This map unit is comprised of many altered soils with widely differing chemical and
physical characteristics. Some areas maybe comprised entirely of fine sands to a depth of
80 inches. The depth to the water table varies with the amount of fill material and the
extent of irrigation and artificial drainage within any mapped area. Hydrologic group is
D.
Satellite fine sand(Map Unit#39)
Landscape position—Coastal ridges.
This nearly level, somewhat poorly drained soil is on low-lying coastal ridges. Individual
areas are elongated and irregular in shape and range from 10 to 400 acres. The slope is 0
to 2 percent.
Typically, the surface layer is gray sand about 3 inches thick. The substratum is light
gray to white fine sand to a depth of about 80 inches. Permeability is very rapid. The
available water capacity is very low. In most years, under natural conditions, the
seasonal high water table is at a depth of between 18 to 10 inches for 1 to 4 months. In
other months, the water table is below 40 inches. Rarely is it above the surface.
Hydrologic group is C.
Natural vegetation consists of Florida rosemary, sand live oak, south Florida slash pine,
sawpalmetto,prickly pear,pineland threeawn and creeping bluestem.
The soils occurring within the NRPA are as follows:
Durbin and Wulfert mucks, frequently flooded(Map Unit#40)
Landscape position—Mangrove swamps.
These level, very poorly drained soils are in tidal mangrove swamps. Individual areas are
elongated and irregular in shape and range from 50 to 1000 acres. The slope is 0 to I
percent. Typically, the Durbin soil has a surface soil of dark reddish brown to black
muck about 63 inches thick. The substratum is dark gray fine sand to a depth of about 80
inches. Typically, the Wulfert soil has a surface soil of dark reddish brown to black
muck about 40 inches thick. The substratum is dark gray fine sand to a depth of 80
inches. The permeability of the Durbin soil is rapid and the available water capacity is
high. The permeability of the Wulfert soil is rapid and the available water capacity is
moderate. The water table fluctuates with the tide and is within 12 inches of the surface
most of the year. The soil is subject to tidal flooding. Hydrologic group is D.
Natural vegetation consists of red, white and black mangroves.
Chapter 4 update for Oct. 3 Committee mtg.
Canaveral-Beaches Complex(Map Unit#42)
Landscape position—Beaches and low coastal ridges
This map unit consists of the nearly level, moderately well drained Canaveral soil on low
ridges and of beaches. Individual areas are elongated and irregular in shape and range
from 20 to 300 acres. The slope is 0 to 2 percent. Typically, the Canaveral soil has a
surface layer of dark brown fine sand about 4 inches thick. The substratum is brown to
light gray fine sand mixed with shell fragments to a depth of about 80 inches. Typically,
beaches consist of sand mixed with shell fragments and shells. Beaches are subject to
frequent wave action. The permeability of the Canaveral soil is rapid to very rapid. The
available water capacity is very low. In most years, the seasonal high water table is at a
depth of between 18 to 40 inches for 1 to 4 months. In other months, the water table is
below 40 inches. This soil is subject to tidal flooding under severe weather conditions.
Hydrologic group is C.
Natural vegetation consists of Australian pines, sea oats, sea grape, cabbage palm,
Brazilian pepper and salt grasses.
Insert Soils Map when Available
CLIMATE Chapter 4 update for Oct. 3 Committee mtg.
Clam Bay's climate falls within tropical classification, more precisely the tropical wet
and dry or savanna type, Aw under the Koppen system. As a consequence, there are
essentially two seasons are experienced. The wet season occurs in the summer and the
dry season occurs in the winter. Typical rainfall and temperature data is provided in
Tables 4.1 and 4.2.
In the summer the center of the trade winds shift north and moisture-laden breezes blow
from the east or south-east. In winter, the trade winds shift southward and the winds are
less constant. Weather, is then more influenced by fronts advancing from the northwest.
This brings cooler conditions, although temperatures never reach freezing, due to the fact
that they are being moderated by the surrounding waters. Cold fronts are typically
preceded by winds from the southwest, which clock to the west then northwest as the
front passes,with strong winds of 20-25 knots and cooler air. In general terms, winds are
predominantly southeast during the summer and northeast during the winter.
Historical meteorology for Clam Bay is based on data collected for 30 years (from 1981
to 2010) from the Naples Municipal Airport by the Florida Climate Center (NOAA &
FSU). The following charts present meteorological statistics for temperature and
precipitation.
1981-2010 TEMPERATURE AND PRECIPITATION NORMALS GRAPH
110.0
100.0
90.0 ® ,0.00.0.-0 amommk•-...me�-+
80.0 a.-�""°"""'' 0O .�.g 10 @ ,T.,, �`,.r"+..
70.0 = a
60.0 spa ..
50.01
40.0
30.0
20.0
10.0 .0 0 0
0.. .
...A»0
0.0 •-• • 0........•.m,..,s.M
Jan 11 a F,1.3 Jul S E Nov
0 Precip(in) 0 Min Imp(°F} 0 Avg Imp(CF) 0 Max Tmp(°F)
Chapter 4 update for Oct. 3 Committee mtg.
Temperature
The monthly average temperatures range from 64.5°F to 83.2°F. The lowest monthly
minimum temperature is 54.2°F while the highest monthly maximum temperature is
91.2°F. The data reflects a temperate climate with a narrow fluctuation in air
temperature.
Precipitation
Annual rainfall for the Naples Municipal Airport NOAA station is documented at 51.89
inches. The data in the table indicates the highest rainfall occurs during the summer, the
months of June, July,August, and September.
1981-2010 TEMPERATURE AND PRECIPITATION NORMALS CHART
0 Precip(in) 0 Min Tmp(°F) 0 Avg Tmp('F) j 0 Max Imp(CF)
January 1.85 54.2 64.5 74.7
February 2.10 56.8 66.9 76.9
March 2.38 600 70.0 79.9
April 2.36 63.4 73.3 83.2
May 1 3 16 68.5 782 87 8
June 8 8 73.9 81.9 89.9
i
July 7.27 74.9 83.1 91.2
August 8.58 75.3 83 2 91.0
September 7 6 74.8 j 82.4 89.9
October 4 1 70.0 78.5 86.9
November 2 04 62 9 72 1 81 2
December 1 4 57.0 66 8 76 6
I
Chapter 4 update for Oct. 3 Committee mtg.
Winds
Winds are predominantly easterly throughout the year, but with a tendency to become
northeasterly from October to April and southeasterly from May to September. Wind
speeds, not including storm events are, on average, below 10 knots. During the winter
months when fronts move through, for a day or two at a time, winds out of the northwest
to northeast may increase to about 25 knots.
Sea breeze
As the land surface around Naples and Clam Bay heats it in turn heats the air above it.
The warm air is less dense and tends to rise creating a lower air pressure over the land
than the water. The cooler air over the water then flows inland creating a sea breeze. In
the evening the reverse occurs and the cooler air over the land will flow back toward the
water creating a land breeze.
The incoming sea breeze acts as a lifting mechanism, resulting in the warmer air rising up
to higher altitudes. This creates cumulus clouds that begin to build which leads to the
development of afternoon showers and thunderstorms in the area.
Storms
Naples and Clam Bay specifically are within the Atlantic Tropical Cyclone basin. This
basin includes much of the North Atlantic, Caribbean Sea, and the Gulf of Mexico. On
average, six (6) to eight (8) tropical storms form within this basin each year. The
hurricane season lasts from June 1st to December 1st. The formation of these storms and
possible intensification into mature hurricanes takes
F SaHk-Sim Hurricans Scale
Ca tegory Wind speed storm surge place over warm tropical and subtropical waters.
mph e ! Eventual dissipation or modification, averaging seven
( ) (m) 1 (7) to eight (8) days later, typically occurs over the
colder waters of the North Atlantic or when the storms
. , ` ,. move over land and away from the sustaining marine
-,1.„,1,,, ,k�; , ..__ environment.
mr.. 111-130 9-12
(178-209) (2.7-3.7)
96-110 e-8 Due to the destructive nature of these storms, landfall
Two
(154-177) (1.8-2.4) can result in significant damage to upland development
74-95 4-5
One
(119-153) (1.2-1.5) and facilities from storm surge, waves, and wind. A
Additionalclesslicatbne good example of this would be Hurricane Wilma which
MM. formed in 2005.
nt
Chapter 4 update for Oct. 3 Committee mtg.
A tropical storm is defined by maximum sustained winds from 35-64 knots (40-74 mph).
A hurricane has maximum sustained winds that exceed 64 knots (74 mph). Hurricanes
are classified into different categories according to the Saffir-Simpson scale. Hurricanes
can also spawn severe weather such as tornadoes as they move inland.
The table below lists the number of tropical storms and hurricanes that passed through or
near Naples over the past 20 seasons including 1992 through 2012 as reported by the
National Oceanic and Atmospheric Administration (NOAA) Coastal Services Center and
Hurricane City (www.hurricanecity.com). Analysis of the available information indicates
that Naples, on average, is brushed or hit by a tropical storm or hurricane once every 2.71
years and is directly hit once every 7.05 years.
Table Number of Named Storms Passing through or near Naples
Year #of Storms Names
1992 1 Andrew
1993 0
1994 1 Gordon
1995 1 Jerry
1996 0
1997 0 ',�
1998 1 Mitch
1999 1 Harvey
2000 0
2001 0
2002 0
2003 0
2004 1 Charley .
2005 1 Wilma ',NA, spa ,`
2006 0
2007 0
2008 1 Fay
2009 0
2010 0
•
2011 0
2012 0
Chapter 4 update for Oct. 3 Committee mtg.
NATURAL COMMUNITIES
Mangroves
Mangroves are salt tolerant trees that grow in tidal areas of the tropics and are legally
protected for their ecological value,with such functions as;
• Providing habitat for marine and terrestrial wildlife.
• Protecting coastal areas from storm surges and coastal erosion.
• Acting as a natural filter for land based freshwater run-off.
• Forming the basis of an incredibly productive estuarine food chain which includes
many commercially valuable species.
Three species of mangrove are common in Florida as far north as Cedar Key and St.
Augustine, where cold winter temperatures limit their range. All have special biological
adaptations to cope with salt and unstable, mucky, low oxygen soils that result from the
tidal, hence continually waterlogged, environment. The dominance of mangroves in tidal
areas is a function of these adaptations and their ability to out-compete other wetland
plants.
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Red Mangroves and Propagules(inset)
Chapter 4 update for Oct. 3 Committee mtg.
Red mangroves (Rhizophora mangle) are recognized by their tangle of reddish looking
prop roots, long cigar shaped seedlings (the propagules which can be seen in the summer
months) and their large, pointed evergreen leaves. They are typically the most seaward
of the three species with the prop roots and vertical drop roots providing support, small
pores on the trunks called lenticels allow oxygen exchange via air as the waterlogged
soils become rapidly oxygen depleted. Salt is excluded from the plants cells through a
process called ultra-filtration in the roots. The characteristic propagules germinate on the
parent tree and drop and float for up to a year, finally becoming heavier at one end so that
when encountering a suitable substrate they are ready to root upright. Good tidal flushing
is essential for healthy development of red mangroves, to prevent the build up of toxic
metabolic waste products in the mangrove soils. The mass of prop and drop roots forms
extensive surface area under water for attachment of sessile, filter feeding marine species
(such as sponges, tunicates and mollusks) as well as hiding places for juvenile fish.
Birds, butterflies, insects and mammals find home and food within the canopy. Leaf drop
and eventual breakdown of red mangrove leaves is the start of productive estuarine food
webs.
Black mangroves (Avicennia germinans) are typically found a little further inland and
key identification features include the snorkel like pneumatophores which radiate
upwards out of the soil from the base of the trunk, a grey-black rough bark and slightly
pointed, oval leaves which are silvery with salt deposits on the undersides. The
pneumatophores play an important role in oxygen exchange and unlike the red
mangroves, which keeps salt out of body cells through filtration in the roots; the black
mangrove excretes salt out of the backside of the leaves. They are also reliant on
adequate tidal exchange but lack the supporting prop roots that typify the red mangrove.
Small white flowers and lima bean shaped propagules are apparent during the summer
months. When these propagules fall from the parent tree,they are able to float for a short
period before rooting in the mucky soil.
Chapter 4 update for Oct. 3 Committee mtg.
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Black Mangrove Pneumatophores
White mangroves (Laguncularia racemosa) are the third mangrove species and are often
found further inland than the other two species (although zonations described are typical
they can frequently vary). Since they often occur in drier areas, white mangroves do not
exhibit the adaptations to soft, anaerobic soil of the other species. The bark is
characteristically grooved and furrowed and leaves are oval, mid-green and leathery with
two small glands on the petiole at the base of each leaf which are responsible for salt
j excretion. White mangroves also flower in the spring and early summer and the small
I seedlings have the shortest floating dispersal stage of the three species.
iI
4
Chapter 4 update for Oct. 3 Committee mtg.
too
SALT
PORES .`
Buttonwood (Conocarpus erectus) is considered a mangrove associate, usually occurring
even further inland than the white mangrove. Small, round, brown seeds give rise to the
name. This is a hardy species, able to withstand the full sun, high temperatures and salty
conditions of coastal Florida. These characteristics also make it an excellent and
attractive landscaping plant.
•
Chapter 4 update for Oct. 3 Committee mtg.1P1
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Creeks
On the seaward edges of small islands and the tidal creeks, passes and estuarine
waterways that make up the Clam Bay system, a fringe of Red mangroves will be found
growing up to 25 feet in height. This zone can be just one or two trees in depth or extend
landward for some distance, depending on topography. The habitat provided by the prop
roots of red mangroves is of great importance to many fish and the tidal creeks are
popular fishing spots.
INSERT PHOTOS OF CREEK
Forests
Much of Clam Bay is comprised of low-lying basin forests and the dominant species
varies between red, white, and black mangrove throughout the system. Tides inundate
these areas via small surface waterways. Subterranean sources of water are also
important. Tidal flushing allows nutrients to be distributed within the forest and provides
for the transportation of dead leaves, twigs, etc. As this material decays, it becomes food
for marine life. It is this mangrove detritus which is consumed by the many organisms at
the base of the food chain and which in turn create the next level of the food chain
necessary to support the fish populations that characterize the mangrove community.
Associated plants include the succulent groundcovers Saltwort (Batis maritime),
Glasswort(Salicornia cervicornis), (especially where a fallen tree provides a break in the
canopy and light penetration to the forest floor) and, further inland and closer to
freshwater sources,the Leather fern(Acrostrichum danaefolia).
Chapter 4 update for Oct. 3 Committee mtg.
Recent History of Mangrove Management in Clam Bay
1999
A total estimate of 42.67 acres dead or stressed mangroves was provided by Turrell, Hall
& Associates, Inc. consisting of the main basin area adjacent to The Strand and several,
smaller, discrete areas possibly attributed to lightning strikes or where slight depressional
areas allow ponding and salinity/oxygen stress. Little change was noted later in the
summer at the time-zero survey although most mangrove plots showed significant
standing water which could be a function of the dredging work as well as tides and rains
around the survey time.
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The main die-off area (NW Clam Bay. adjacent to The Strand) 1999
2000
A full year after the dredging work, no dramatic changes were apparent, some mangrove
plots had declined; others appeared in slightly better health. Seedling recruitment was
good throughout. Heavy rains in late 1999 were thought to have contributed to a dieback
in groundcover noted by Lewis Environmental Services. No new mangrove die-offs or
expansion of stressed areas were noted. Work planned for 2001 included the
experimental Riley encasement method for mangrove propagules.
Chapter 4 update for Oct. 3 Committee mtg.
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Main die-off area 2000
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Chapter 4 update for Oct. 3 Committee mtg.
2001
Mapping of the die-off area was repeated and estimated to have increased in size,
spreading to the north, to encompass just under 50 acres. Additionally a few new
stressed areas were identified through aerial photographs. Individual plots showed some
additional tree losses but consistent seedling recruitment. Channel construction in the
main die-off area and close to Plot 7 is thought to have contributed to the recovery
process underway, illustrated by extensive Batis and dramatic seedling recruitment.
The observations generated sufficient concern amongst project managers in 2001 that a
suggestion for additional flushing channel construction in the die off area was made.
Main die-off area 2001
Chapter 4 update for Oct. 3 Committee mtg.
2002
Additional flushing channels were constructed in the die-off area during late 2001 and
results from the 2002 surveys show that these efforts appeared to have been successful
with a reduction of 12 acres made in the die-off area. Basis growth and seedling
recruitment was good. The problem of exotic vegetation growth in many areas was
highlighted and two new diffuse areas of stressed trees were identified. The presence of
standing water and bacterial mats suggested lack of flushing was responsible. The one-
way culverts installed at Seagate, thought to have reduced tidal exchange in Outer Clam
Bay, were removed in October to determine whether tidal exchange between Venetian
Lagoon and Outer Clam Bay could be achieved without affecting Clam Pass.
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Main die-off area 2002 with notable re-growth
Chapter 4 update for Oct. 3 Committee mtg.
2003
Stressed areas identified in 2002 were revisited and no changes were noted in 2003. One
of the aerially depicted mangrove stress locations was found, upon groundtruthing, to
actually be an infestation of exotic plant species. Of significance is a reduction in
calculated die-off area to just over 17 acres total with 14 acres in this main die-off region,
now classified as recovering.
Main die-off area 2003
I
Chapter 4 update for Oct. 3 Committee mtg.
2004
Die-off acreage was estimated at 18 acres total in 2004, with the addition of a new area
adjacent to the Contessa condominium building in Bay Colony and several new small
lightning strike areas throughout the system. Plot 7 continues to show the most dramatic
change of mangrove plots where most exhibit slow change in existing tree number, some
losses, some growth and size-class change, but consistent seedling recruitment. Storm
events in 2004 (Charlie, Frances, Ivan, and Jeanne) had minimal effects with some leaf
loss and limb breakage. Additional flushing channels were constructed during dry season
of this year. Water level monitors put in place last year were removed due to repeated
equipment failures.
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Chapter 4 update for Oct. 3 Committee mtg.
2005
Several stressed areas were noted as recovering this year including that adjacent to the
Contessa building where a drainage channel was in need of maintenance and clearing,
work which alleviated the problems. A new die-off area was identified near the County
boardwalk and it is suggested that clogging of channels due to Hurricane Charley may be
responsible. Total die-off acreage in 2005 is estimated at 24.7 acres. Plot 7 and Plot 8
continue to show significant re-growth.
Hurricane Wilma in October of 2005 caused considerable leaf loss, limb breakage and
leaf browning throughout Clam Bay although the constructed flushing channels alleviated
extensive ponding that could have occurred and the system weathered the storm well.
Work completed in 2005 included the last component in flushing channel construction.
1
Main die-off area 2005
Chapter 4 update for Oct. 3 Committee mtg.
2006
Stress damage from the 2005 hurricane season necessitated the need for a division of the
classification system currently used to define the status of the mangroves in the system.
Stressed mangrove zones are now classified as "die-off area" for mangroves stressed by
some factor other than storm events or"area of concern"for mangroves stressed by storm
events. It was estimated in 2006 there were 23 acres of recovery, 12.3 acres of stressed
areas of concern and 23.4 acres of die-off area present, bringing the total area of stressed
mangroves to 74.7 acres. Since the last mangrove channels were dug in 2004 and
dredging work continues when needed, most of the monitoring plots have shown
improvements and there has been a significant reduction of die-off in the original locale.
Main die-off area 2006
Chapter 4 update for Oct. 3 Committee mtg.
2007
The storm damage of 2005 added a level of difficulty to subsequent classification of areas
within the system. Extensive defoliation and falling of individual trees meant that areas
that could be termed stressed by the flow issues thought to have been responsible for the
original die-off in Clam Bay were in fact affected by the high winds and storm surge.
Approximately 4.9 acres of formerly classified `die off' area have been reclassified to
`recovered' this year. Stressed areas of concern that are likely not related to storm
damage total about 15 acres while areas of concern that we suspect are due to the storm
events have been estimated at about 25 acres. An additional 20 acres within the original
die off area has not yet fully recovered and so is also included in this category. A total of
10.6 acres of mangroves are still considered dead, a significant reduction from the
original die-off of over 50 acres in the late 1990's. This brings the total aerial estimate of
mangroves that are not at optimum health to about 70 acres.
Main die-off area 2007
Chapter 4 update for Oct. 3 Committee mtg.
2008
The 2008 monitoring report was the final report associated with the original 1998
restoration permits. Effects of the storms form 2005 still added a level of difficulty to the
classification of areas within the system. While the defoliation associated with the storms
had mostly recovered, falling debris affected several of the monitoring plots throughout
the system.
Approximately 35.4 acres of forest area have been removed from the die-off
classification since the implementation of the project. Stressed areas of concern that may
still be related to storm damage total or may be due to other factors (such as ponding or
drying) add up to about 7.1 acres. Areas throughout the system that have not yet fully
recovered but that have flushing channels and have shown marked increases in mangrove
recruitment and new growth have been removed from this category(approx. 20 acres).
A total of 7.3 acres of mangroves are still considered dead. This includes three main
areas, the initial die-off area east of the strand where there are about 5.5 acres still dead,
the damage from a tornado in the extreme north of the system accounts for about 0.8
acres, and the Hurricane Charley damage that resulted in a tidal restriction just south of
the Pass accounts for about 0.75 acres. Several lightening strikes and small discrete die-
offs spread throughout the estuary make up the remainder of the die-off acreage.
1E-
East of the Strand Die-off area,2008
Chapter 4 update for Oct. 3 Committee mtg.
2010
Even though the permit requirement for monitoring reports ended with the expiration of
the 1998 permits, the PBSD continued to monitor the mangrove health within Clam Bay
and document the positive results within the mangrove forest. Exotic eradication
activities were also continued to allow for natural regeneration of mangroves observed
elsewhere in the system.
Construction of the last component of the flushing channels was completed in the 2005-
06 season. Inspection of these flushing cuts this year showed that they are still operating
as designed and are contributing to the continued growth of new mangroves within the
system.
Stress in mangrove forest areas is still apparent, although in several areas this may still be
attributable to storm damage or to frost damage brought about by a couple of very cold
temperature nights. The spectacular recruitment of white mangrove seedlings, now 8 to
10 feet tall saplings, throughout the original die-off area is testament to the efforts
undertaken with the initial dredging and that work can be considered a success.
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Main die-off area 2010
Chapter 4 update for Oct. 3 Committee mtg.
2011 -2012
An infestation of boring beetles was discovered in the early months of 2011.
Observations within the system and research into the life habits of many boring
beetles led to the conclusion that white mangroves stressed by the sustained cold
temperatures in December 2010 and January 2011 were most susceptible to the beetle
attack. Cold stress reduced the abilities of these trees to fight off the boring activities
and many trees succumbed to them. Yellowing leaves, leaf drop, and eventual death
of the tree was the result. The dead trees were easily visible in the rooftop photos
taken periodically from the Grosvenor and Montenero condominiums. Efforts to
hatch beetle larva led to the identification of at least two species, a round-headed
(Longhorned beetles) and a flat-headed borer (Metallic beetles). No further loss of
trees was documented after 2012 as a result of the borers.
White Mangroves affected by cold and borers
Borer damage to stressed tree
Chapter 4 update for Oct. 3 Committee mtg.
INSERT 2013 SUMMARY AND PHOTO
Coastal Scrub
Coastal scrub is represented by a conglomeration of coastal species generally found in a
narrow band between the Mangrove forest and the beach areas. This is an important
habitat as it helps anchor the back dune sands and provides habitat for several listed plant
and animal species including the gopher tortoise (Gopherus polyphemus).
Y
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Cabbage Palm Hammock
This habitat is identified by the preponderance of cabbage palms (Sabal palmetto). It is
generally found in pockets located between the mangrove forest and the coastal scrub or
beach areas. Aside from the cabbage palms, sea grapes (Coccoloba uvifera),
buttonwood, and several other hammock species are common.
Seagrass Beds
Seagrasses are flowering marine plants of shallow, tropical regions. With a creeping
growth form connected by horizontal rhizomes they serve to trap and anchor sediment.
Both the grass blades themselves and the surface area they represent provide food and
Chapter 4 update for Oct. 3 Committee mtg.
attachment for marine species and seagrass beds are renowned for their value as nursery
habitats.
.k.
Shoal grass (Halodule wrightii) along interior channel south of Clam Pass
Several areas within the Clam Bay system host seagrass beds, specifically Outer Clam
Bay and waterways just inside Clam Pass. Three species are common in these southwest
Florida waters; the largest Turtle grass (Thalassia testudinum) with flat strap shaped
leaves, the smaller shoal grass (Halodule wrightii) with narrow, flat blades and Manatee
grass (Syringodium faliformis) with cylindrical blades. Of these three species only shoal
grass and turtle grass are found in Clam Bay. Shoal grass is by far the most common
though small areas of turtle grass are also present. Also common in Clam Bay is Paddle
grass (Halphila decepiens) which is usually more indicative of brackish water. Paddle
grass is much more ephemeral in nature and diligence is required to be able to locate it
during the time frames when it is present.
Seagrasses rely on good light penetration to enable photosynthesis and are sensitive to
reduced tidal water quality. Growing in shallow regions they are also vulnerable to
physical damage by boats. A variety of marine algae can be associated with grass
species, differing in the lack of a true rooting and vascular system. Several species of
both brown and green alga have been observed.
The 1992 Collier County Seagrass Protection Plan stated that seagrass coverage in Clam
Bay was equivalent to approximately 60 acres though a later Seagrass Inventory report
from 1994 clarified that seagrass coverage in Clam Bay was approximately 10 acres.
Based on anecdotal information and on comparisons with other seagrass areas in the
County during the same time frame, we do not believe that there was an 80% decline in
Chapter 4 update for Oct. 3 Committee mtg.
seagrass coverage during those two years but instead think that the 1992 report may have
over-estimated the coverage.
INSERT 1994 SEAGRASS COVERAGE MAP
Recent History of Seagrass presence in Clam Bay
1999
Prior to the initial dredging associated with the 1998 restoration and Management Plan,
seagrass acreage is estimated at 5.13 acres, restricted to Outer Clam Bay and the channel
leading to Clam Pass.
INSERT 1999 SEAGRASS COVERAGE MAP
2000-2004
Seagrasses show a slow decline during this time frame. Water quality testing within the
system does not indicate chronic degradation. The decline is attributed to the increased
tidal range caused by the dredging work, which results in longer exposure at low tides of
the shallow areas where seagrasses were present. The one-way culverts installed at
Seagate, thought to have reduced tidal exchange in Outer Clam Bay, were removed in
October 2002 to determine whether tidal exchange between Venetian Lagoon and Outer
Clam Bay could be achieved without affecting Clam Pass. Seagrass bed in southernmost
portion of Outer Clam Begins to expand in 2003 after removal of flap gates.
2005
An increase in the seagrass coverage within the channel transects was documented.
Increased density of the beds within the bay area east of Clam Pass is also noted.
2006
Shoal grass patches are still present in ecologically significant densities within the
channel north of the County boardwalk and just inside Clam Pass mouth. Sea grass beds
in Outer Clam Bay are still reduced compared to the 1999 pre-dredge conditions, but
their steady improvement since 2004 seems to have continued into 2006. Approximately
3.6 acres of seagrasses are noted along the transects.
INSERT 2006 SEAGRASS COVERAGE MAP
2007
Concerns related to the seagrass coverage within the bay were raised by adjacent property
owners this year and Collier County contracted an additional study by Post, Buckley,
Schuh, & Jernigan Inc. (PBS&J) to investigate seagrasses and nutrient inputs within not
only the Clam Bay System but also Venetian Bay, Moorings Bay and the entire Doctors
Pass area.
Some of the results of the PBS&J study relevant to the Clam Bay System were;
Chapter 4 update for Oct. 3 Committee mtg.
• That seagrasses were present within Outer Clam Bay. Paddle Grass (Halophila
engelmannii) was observed at 13 of the 30 randomly generated points within
Outer Clam Bay.
• That resident's concerns that seagrass coverage had declined from 60+ acres to
present were unfounded as early estimates of 60+acres were likely erroneous.
• That nutrient and chlorophyll-a levels within Outer Clam Bay, had increased over
the past 20 years but were still below median values for Florida estuaries.
Also as a result of these increased concerns regarding seagrasses, Turrell, Hall &
Associates expanded the annual seagrass survey to cover the entire bay and not just the
defined transects. Additional seagrass beds and macroalgae were observed in areas were
they had not previously been documented. Though all of THA observations were of
shoal grass, it was noted that all of the PBS&J observations were of paddle grass. It has
been observed in the past that paddle grass is very ephemeral in this system and it is
likely that the 2 months between the PBS&J and the THA surveys was enough time for
the paddle grass to disappear.
2008
This was the final monitoring event of the seagrasses associated with the 1998
Restoration and Management Plan permits.
Increases in seagrass coverage that were noted in 2007 continued through this year. A
small area of paddle grass was observed along Transect #2 which had been devoid of
grasses in the past. Other transect areas that have been devoid of grasses until this year
include the western shoreline of the channel between Clam Pass and Outer Clam Bay
(Transect 5). Seagrasses had been present along this area prior to the dredging but were
replaced by black mangrove propagules when the increased tidal range led to extended
drying times of the shoals where the grasses had been located. New grasses this year
have been observed along the edges of the channel in areas that do not dry out so much
during low tides.
In addition to the seagrasses, other observation made along transects indicate that the
biological diversity of the macro-invertebrate fauna within the system has increased.
Several mollusk species including Florida horse conchs, southern hard clams, stiff pen
shells, tulip snails, cockles, oysters, and several others were all observed.
2012
Seagrass coverage within Outer Clam Bay has continued to increase. The initial decline
noted immediately following the initial (1999) dredging activities appears to have been
reverse over the past 8 years. The decrease stabilized around 2004 and has reversed in the
past few years to where the grass beds are re-establishing previous areas and new areas
appropriate for the grasses (in terms of water depths and light penetration) are being
colonized. Approximately 4.43 acres of seagrasses were noted within the system this
year. Most of the seagrass observed was shoal grass though small patches of paddle grass
Chapter 4 update for Oct. 3 Committee mtg.
and turtle grass were also observed. Future monitoring of the seagrasses will be
conducted to see if this trend continues.
INSERT SEAGRASS 2012 MAP
2013
INSERT SUMMARY FROM 2013 REPORT
Oyster Bars
Oysters (Croassostrea americana) are filter-feeding bivalves, which were once common
within the tidal creeks of Clam Bay. They can form extensive bars and as such slow
water movement and commence the development of small islands. The surface area
provided by their convoluted shells provides habitat for many other marine species.
Deteriorating conditions related to closure of Clam Pass is thought to have resulted in the
disappearance of oyster bars in the system;though some re-occurrence has been observed
to the south of the pass in the last few years during seagrass transect monitoring. Oysters
have been documented around the perimeter of Outer Clam Bay in past years monitoring
efforts.
A 2011 benthic habitat assessment conducted by the Conservancy of Southwest Florida
found living oyster clusters in the upper reaches of Northern Clam Bay (a single cluster),
in the tributary between Outer and Inner Clam Bays (a single cluster), and throughout the
shoreline of Outer Clam Bay.
INSERT LOCATION MAP FOR OYSTERS
Tidal Flats
The sand and mudflats that are exposed at low tides are rich feeding grounds for many
species of wading birds. These organically rich sediments support a variety of mollusks,
worms and invertebrates that scavenge detritus or, in the case of many bivalve mollusks,
extend siphons at high tide and filter vast quantities of water. Birds such as a variety of
herons, ibis, egrets and spoonbills pick through the sediment for the invertebrate food
sources.
The dredging of the pass associated with the 1998 Restoration and Management Plan
resulted in an increase of tidal flats within the southern portion of the system. Increased
tidal range resulting from the dredging allowed more area to be periodically exposed
during the tidal cycle. Some of the area that had supported seagrasses prior to the
dredging work were converted into the tidal flats by the increased range and reduced
phase lag.
INSERT LOCATION MAP FOR FLATS
Chapter 4 update for Oct. 3 Committee mtg.
Sandy Beach
In addition to the 35-acre Clam Pass Beach Park, south of the pass, sandy beach also
extends north all the way to Wiggins Pass. Shorebirds feed on marine invertebrates such
as coquina clams and mole crabs at the water's edge and beaches are crucially important
habitat for nesting sea turtles. Coastal plants colonizing the dunes are key players in
trapping windblown sand and preventing coastal erosion as the first defense against
heavy winds and surge of tropical storms. Species common on the beaches of the Clam
Bay system include; Sea oats (Uniola paniculata), Seagrape (Coccoloba uvifera),
Cabbage palm (Sabal palmetto), Buttonwood (Conocarpus erectus) and Railroad vine
(Ipomoea pes-caprae).
INSERT LOCATION MAP FOR BEACH
Brackish Marsh
At the interface between forested mangrove areas and the water management berm are
depressional areas that have become colonized by aquatic freshwater plants such as
cattails (Typha latifolia), Carolina willow (Salix caroliniana), Bulrush (Scirpus
californicus), Needlerush (Juncus romerianus) and Leather fern (Acrostichum
danaeifolium). Wildlife such as otters (Lutra canadiensis), alligators (Alligator
mississippiensis), various turtles, and wading birds can be commonly observed. These
areas require regular maintenance to prevent the spread of nuisance and exotic plant
species and ensure optimal functioning of the water management system.
INSERT LOCATION MAP FOR MARSH
Tidal Passes
The Clam Bay system was originally part of a larger tidal system connected to the Gulf of
Mexico by three tidal inlets; Wiggins Pass, Clam Pass and Doctors Pass. During the
1950's and 60's this system was isolated from adjacent bays by the construction of
Seagate Drive to the south and the construction of Vanderbilt Beach Road to the north.
The practical effect was to leave Clam Pass as Clam Bay's only connection to the Gulf.
The exchange of seawater between Clam Bay and the Gulf is critical to the ability of the
mangrove forest to export organic matter, as well as excess salt and freshwater. It also
supplies oxygen rich water and nutrients from the Gulf. The greater the tidal amplitude
(or tidal prism) the greater the benefit to the mangroves — more needed resources are
delivered and more wastes are removed. Conversely, in the absence of surface water
circulation or tidal activity, mangroves slowly die due to deleterious changes in the
sediment: 1) in the absence of oxygenated water, the sediments become anaerobic or
anoxic, and 2) metabolic wastes and hydrogen sulfide accumulate in the anoxic sediment
(CBRMP, 1998).
Chapter 4 update for Oct. 3 Committee mtg.
Tides in the Gulf of Mexico are mixed, with the norm being two high tides and two low
tides experienced per day and normal amplitude (range) of approximately 2 feet. The
highest tides (springs) are experienced twice per lunar month at full and new moons when
the gravitational pull on the earth's surface waters is greatest. Neap tides also occur
twice per lunar month when the planetary (gravitational) influences of earth, moon and
sun are perpendicular.
Add Tidal Exhibit from Clam Bay Monitoring Report
It can be seen that the health of mangrove forests is directly related to the efficiency of
the tidal passes. These are dynamic creeks whose location vary annually and, as
illustrated by Clam Pass, can periodically close such as has happened at least five times
in the last 25 years (Turrell 1995; Tackney 1996).
INSERT PHOTO ARRAY OF PASS FROM VARIOUS YEARS
Tidal creeks are passageways for fish and marine invertebrates between the open waters
of the Gulf and the protected embayments of Clam Bay. Manatees and turtles may also
use the passes. Scouring action of the fast flowing tide generally prevents colonization
by seagrasses and other benthic plants and the substrate is typically sand and shell with
the finer sediments carried in suspension and deposited just outside the mouth of the pass
(the ebb shoal delta) or to the interior of the system on the incoming(flood)tide.
Chapter 4 update for Oct. 3 Committee mtg.
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Chapter 4 update for Oct. 3 Committee mtg.
Hardbottom Communities
Another important marine habitat marginally associated with the estuarine system is the
hard bottom reef community found just seaward of Clam Pass. In about 10-15 feet of
water a variety of sponges, stony corals, gorgonians, fish and associated invertebrates can
be found within a system of rocks and ledges. Outcroppings of similar habitat type occur
along the length of Collier County and are a little known resource of regional
significance.
Hardbottom outcrop off of Clam Pass
PLANT SPECIES -List to be added based on FLUCFCS Mapping
LISTED SPECIES
Smalltooth Sawfish (Pristis pectinata)
A juvenile smalltooth sawfish was observed in 2008 in the connector creek between Inner
and Outer Clam Bays. Smalltooth sawfish are found in the tropical and subtropical
Atlantic Ocean. In the western Atlantic they have historically ranged from New York to
Brazil, including the Gulf of Mexico and Caribbean Sea. Habitat destruction and
Chapter 4 update for Oct. 3 Committee mtg.
overfishing have succeeded in eradicating the smalltooth sawfish from the majority of its
former range. Consequently, it survives in small pockets throughout its current range.
The last remaining population in U.S. waters is off south Florida, a small remnant of a
population that once ranged from New York to Texas.
This sawfish primarily occurs in estuarine and coastal habitats such as bays, lagoons, and
rivers. It does at times occur in deeper waters, however, and may make crossings to
offshore islands. It can tolerate freshwater. This fish is easily recognized by its flattened
body and wing-like pectoral fins. The mouth is located ventrally, the eyes are positioned
dorsally. The "saw" is approximately 25% of the body's total length. It is widest at the
base, with teeth more broad than long, and spaced apart. The tips of the teeth are sharp,
becoming blunt over time. Dorsally, it is brownish or bluish gray body with a white
underside. The maximum length recorded is 24.7 feet (7.6 m); however, a length of 18
feet (5.5 m) is considered average. The average lifespan for the smalltooth sawfish is
unknown.
On April 1, 2003 the U.S. National Marine Fisheries Service placed the smalltooth
sawfish on the Endangered Species List, making it the first marine fish species to receive
protection under the Endangered Species Act. Florida has also designated critical habitat
areas to further protect its habitat.
Mangrove Rivulus (Rivulus marmoratus)
This small fish has not been identified within the Clam Bay system in previous surveys or
field work but the mangrove habitat is appropriate and they could be present in the upper
reaches of the mangrove forest. The mangrove rivulus is primarily a saltwater or
brackish water species, with limited occurrence in freshwater. Within the Everglades and
along Florida's west coast, this fish occurs in stagnant, seasonal ponds and sloughs as
well as in mosquito ditches within mangrove habitats. The mangrove rivulus is able to
survive in moist detritus without water for up to 60 days during periods of drought,
anaerobic, or high sulfide conditions.
This fish can reach a maximum size of 2 inches (5 cm) in length, however it is more
commonly observed at lengths between 0.4-1.5 inches (1.0-3.8 cm). The head and body
are maroon to dark brown or tan, with small dark spots and speckling on the body,
particularly the sides. The dorsal surface is always darker than the creamy ventral
surface. The color of the body is reflective of the habitat, with light coloration in areas of
light colored sediments and darker coloration in environments with dark leaf litter
substrates. A large dark spot surrounded by a band of yellow is located at the upper base
of the caudal fin in hermaphroditic individuals. Males lack this dark spot and have a red-
orange cast to their flanks and fins.
The mangrove rivulus was once listed as a threatened species in the Gulf of Mexico.
However, recently additional surveys have revealed the existence of numerous
populations. In Florida it has been downlisted to a species of special concern. In 1999, it
was submitted by the National Marine Fisheries Service as a candidate for protection
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under the Endangered Species Act. As of yet, it has not been officially listed as
endangered or threatened.
The main threat to the survival of the mangrove rivulus is habitat degradation and
destruction as well as exposure to pollutants. Disturbances that alter salinity and
temperature as well as vegetation cover may also reduce naturally occurring populations.
Loggerhead Sea Turtle (Caretta caretta)
Loggerhead sea turtles have been documented nesting on beaches within the Clam Bay
NRPA. Loggerheads are circumglobal, occurring throughout the temperate and tropical
regions of the Atlantic, Pacific, and Indian Oceans. They are the most abundant species
of sea turtle found in U.S. coastal waters. In the Atlantic, the loggerhead turtle's range
extends from Newfoundland to as far south as Argentina.
During the summer, nesting occurs primarily in the subtropics. Although the major
nesting concentrations in the U.S. are found from North Carolina through southwest
Florida, minimal nesting occurs outside of this range westward to Texas and northward to
Virginia. Adult loggerheads are known to make extensive migrations between foraging
areas and nesting beaches. During non-nesting years, adult females from U.S. beaches are
distributed in waters off the eastern U.S. and throughout the Gulf of Mexico, Bahamas,
Greater Antilles, and Yucatan.
Loggerheads were named for their relatively large heads, which support powerful jaws
and enable them to feed on hard-shelled prey, such as whelks and conch. The top shell
(carapace) is slightly heart-shaped and reddish-brown in adults and sub-adults, while the
bottom shell (plastron) is generally a pale yellowish color. The neck and flippers are
usually dull brown to reddish brown on top and medium to pale yellow on the sides and
bottom.
In the southeastern U.S., mating occurs in late March to early June and females lay eggs
between late April and early September. Females lay three to five nests, and sometimes
more, during a single nesting season. The eggs incubate approximately two months
before hatching sometime between late June and mid-November.
Loggerheads occupy three different ecosystems during their lives: beaches (terrestrial
zone), water (oceanic zone), and nearshore coastal areas ("neritic" zone). Because of
this, NOAA Fisheries and the U.S. Fish and Wildlife Service (USFWS) have joint
jurisdiction for marine turtles, with NOAA having the lead in the marine environment
and USFWS having the lead on the nesting beaches.
The loggerhead turtle was first listed under the Endangered Species Act as threatened
throughout its range on July 28, 1978. In September 2011, NMFS and U.S. Fish and
Wildlife Service listed 9 Distinct Population Segments of loggerhead sea turtles under the
ESA. The population in our Northeast Atlantic Ocean Segment is listed as endangered.
The agencies are currently proposing Critical Habitat designations on several areas which
contain a combination of nearshore reproductive habitat, winter area, breeding areas, and
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migratory corridors. The Clam Pass NRPA is contained within the LOGG-N-27 segment
of this proposed critical habitat area.
Gopher Tortoise (Gopherus polyphemus)
Gopher tortoises and their burrows are found along the coastal strand portions of the
Clam Pass NRPA. The range of the tortoise includes southern portions or Alabama,
South Carolina, Louisiana, Mississippi, and Georgia as well as most of Florida.
Gopher tortoises are one of the few species of tortoise that dig burrows. These burrows
can be up to ten feet deep and 40 feet long, and are as wide as the length of the tortoise
that made it. In addition to providing the tortoise a home, it has been documented that as
many as 350 other species also use the burrows including the indigo snake, Florida
mouse, gopher frog and burrowing owl.
Gopher tortoises can live 40 to 60 years in the wild and average 9 to 11 inches in length.
These tortoises are superb earth-movers, living in long burrows from 5 to 45 feet long
and up to 10 feet deep that offer refuge from cold, heat, drought, forest fires and
predators. The burrows maintain a fairly constant temperature and humidity throughout
the year and protect the gopher tortoise and other species from temperature extremes,
drying out, and predators. The mating season generally runs from April through June and
gestation for the eggs is between 80 and 100 days.
The shell or "carapace" of the gopher tortoise is mostly brownish gray and the underside
of the shell, or "plastron," is yellowish tan. Their front legs are shovel-like which helps
them when digging their burrows.
The gopher tortoise has been regulated in Florida since 1972 and has been fully protected
since 1988. Despite the afforded protection, gopher tortoise populations throughout the
state have declined. As a response to the continuing decline of the species, a new
management plan was drafted and approved in September 2007 as a precursor to
reclassifying the gopher tortoise from a "species of special concern" to a "threatened
species." The threatened status was approved and went into effect on November 8, 2007.
West Indian Manatee
Manatees have been sighted on numerous occasions within the Clam Pass NRPA
boundaries. Manatees can be found in shallow, slow-moving rivers, estuaries, saltwater
bays, canals, and coastal areas — particularly where seagrass beds or freshwater
vegetation flourish. Manatees are a migratory species. Within the United States, they are
concentrated in Florida in the winter. In summer months, they can be found as far west as
Texas and as far north as Massachusetts, but summer sightings in Alabama, Georgia and
South Carolina are more common.
Manatees are large, gray aquatic mammals with bodies that taper to a flat, paddle-shaped
tail. They have two forelimbs, called flippers, with three to four nails on each flipper. The
average adult manatee is about 10 feet long and weighs between 800 and 1,200 pounds.
They eat a large variety of submerged, emergent, and floating plants and can consume
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10-15% of their body weight in vegetation daily. Because they are mammals, they must
surface to breathe air. They rest just below the surface of the water, coming up to breathe
on an average of every three to five minutes. It is believed that one calf is born every two
to five years, and twins are rare. The gestation period is about a year. Mothers nurse their
young for one to two years, during which time a calf remains dependent on its mother.
Protections for Florida manatees were first enacted in 1893. Today, they are protected by
the Florida Manatee Sanctuary Act and are federally protected by both the Marine
Mammal Protection Act and the Endangered Species Act
ANIMAL SPECIES
The following lists of species have been observed within the Clam Pass NRPA and
adjacent Pelican Bay development areas.
Aquatic Invertebrates—Add from Conservancy Report
Fish
COMMON NAME SCIENTIFIC NAME
Atlantic needlefish Strongylura marina
Barracuda Sphyraena barracuda
Bay anchovy Anchoa mitchilli
Blacktip Shark Carcharhinus limbatus
Blue crab Callinectis sapidus
Cowfish Acanthostracion quadricomis
Flounder Paratichthys alb!gutta
Gray snapper Lutjanus griseus
Great barracuda Sphyraena barracuda
Gulf killifish Fundulus grandis
Inshore Iizardfish Synodus foetens
Killifish spp. Fundulus spp.
Leatherjacket Oligoplites saurus
Longnose killifish Fundulus simitis
Mangrove snapper Lutjanus griseus
Mullet Mugil cephalus
Mutton snapper Lutjanus anatis
Needlefish Strongylura marina
Permit Trachinotus falcatus
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Pigfish Orthopristus chrysoptera
Pinfish Lagodon rhomboides
Pipefish Syngnathus spp.
Puffer Sphoeroides parvus
Sailfin molly Poecilia latipinna
Sand perch Diplectrum bivittatum
Scaled sardine Harengula pensacolae
Sea robin Prionotus scitulus
Sheepshead Archosargus probatocephal
Sheepshead minnow Cyprinodon variegatus
Silver jenny Eucinostomus gula
Smalltooth Sawfish Pristis pectinata
Snook Centropomus undecimalis
Spot Leiostomus xanthurus
Spotfin mojara Eucinostomus argenteus
Spotted seatrout Cynoscion nebulosus
Tidewater silverside Menidia peninsulae
Triggerfish Batistes capriscus
White grunt Haemulon plumierii
Whiting Menticirrhus tittoratis
Reptiles and Amphibians
COMMON NAME SCIENTIFIC NAME
Banded water snake Nerodia faciata faciata
Black racer Coluber constrictor
Common garter snake Thamnophis sirtalis
Eastern coachwhip Masticophis flagellum
Mangrove salt marsh water snake Nerodia clarkii
Mud snake Farancia abacura
Red rat snake Elaphe guttata guttata
Ring-necked snake Diadophis punctatus
Yellow rat snake Elaphe obsoleta
American Alligator Alligator mississippiensis
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Brown anole Anolis sagrei
Eastern glass lizard Ophisaurus ventralis
Green anole Anolis carolinensis
Southeastern five-lined skink Eumeces inexpectatus
Cuban treefrog Osteopilus septentrionalis
Eastern narrow-mouthed toad Gastrophryne carolinensis
Eastern spadefoot toad Scaphiopus holbrookii
Giant marine toad Bufo marinus
Green treefrog Hyla cinerea
Oak toad Anaxyrus quercicus
Southern leopard frog Lithobates sphenocephalus
Southern toad Bufo terrestris
Squirrel treefrog Hyla squirella
Chicken turtle Deirochelys reticularia
Florida box turtle Terrapene carolina bauri
Florida softshell turtle Apalone ferox
Gopher tortoise Gopherus polyphemus
Green sea turtle Chelonia mydas
Loggerhead sea turtle Caretta caretta
Pond slider Trachemys scripta
Striped mud turtle Kinosternon baurii
Birds
COMMON NAME SCIENTIFIC NAME
American avocet Recurvirostra americana
American coot Fulica americana
American kestrel Falco sparverius
American oystercatcher Haematopus palliatus
Anhinga Anhinga anhinga
Bald eagle Haliaeetus leucocephalus
Barred owl Strix varia
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Belted kingfisher Megaceryle alcyon
Black skimmer Rynchops niger
Black vulture Rynchops niger
Black-and-white warbler Mniotilta varia
Black-bellied plover Pluvialis squatarola
Black-crowned night heron Nycticorax nycticorax
Black-necked stilt Himantopus mexicanus
Blue jay Cyanocitta cristata
Blue-gray gnatcatcher Polioptila caerulea
Boat-tailed grackle Quiscalus major
Brown pelican Pelecanus occidentalis
Brown thrasher Toxostoma rufum
Budgerigar Melopsittacus undulatus
Caspian tern Hydroprogne caspia
Cattle egret Bubulcus ibis
Chuck-will's-widow Caprimulgus carolinensis
Common grackle Quiscalus quiscula
Common ground-dove Columbina passerina
Common moorhen Gallinula chloropus
Common nighthawk Chordeiles minor
Common snipe Gallinago gallinago
Common tern Sterna hirundo
Common yellowthroat Geothlypis trichas
Double-crested cormorant Phalacrocorax auritus
Dowitcher long-billed Limnodromus scolopaceus
Dowitcher short-billed Limnodromus griseus
Downy woodpecker Pico ides pubescens
Dunlin Calidris alpina
Eastern screech owl Megascops asio
Eurasian collared dove Streptopelia decaocto
European starling Sturnus vulgaris
Fish crow Corvus ossfagus
Forster's tern Sterna forsteri
Glossy ibis Plegadis falcinellus
Gray catbird Dumetella carolinensis
Great blue heron Ardea herodias
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Great crested flycatcher Myiarchus crinitus
Great egret Ardea alba
Great horned owl Bubo virginianus
Greater yellowlegs Tringa melanoleuca
Green heron Butorides virescens
Green-winged teal Anas crecca
Herring gull Larus argentatus
Hooded merganser Lophodytes cucullatus
House sparrow Passer domesticus
Killdeer Charadrius vociferus
Laughing gull Leucophaeus atricilla
Least sandpiper Calidris minutilla
Limpkin Aramus guarauna
Little blue heron Egretta caerulea
Loggerhead shrike Lanius ludovicianus
Magnificent frigate bird Fregata magnificens
Mangrove cuckoo Coccyzus minor
Merlin Falco columbarius
Mocking bird Mimus polyglottos
Mottled duck Anas fulvigula
Mourning dove Zenaida macroura
Muscovy duck Cairina moschata
Northern cardinal Cardinalis cardinalis
Northern gannet Morus bassanus
Northern parula Parula americana
Northern waterthrush Seiurus noveboracensis
Osprey Pandion haliaetus
Painted bunting Passerina ciris
Palm warbler Dendroica palmarum
Peregrine falcon Falco peregrinus
Pied-billed grebe Podilymbus podiceps
Pilleated woodpecker Dryocopus pileatus
Piping plover Charadrius melodus
Prairie warbler Dendroica discolor
Purple gallinule Porphyrula martinica
Red knot Calidris canutus
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Red-bellied woodpecker Melanerpes carolinus
Red-breasted merganser Mergus serrator
Reddish egret Egretta rufescens
Red-shouldered hawk Buteo lineatus
Red-tailed hawk Buteo jamaicensis
Red-winged blackbird Agelaius phoeniceus
Ring-billed gull Larus delawarensis
Robin Turdus migratorius
Roseate spoonbill Platalea ajaja
Royal tern Sterna maxima
Ruby-throated hummingbird Archilochus colubris
Ruddy turnstone Arenaria interpres
Sanderling Calidris alba
Sandwich tern Sterna sandvicensis
Semipalmated plover Charadrius semipalmatus
Snowy egret Egretta thula
Spotted sandpiper Actitis macularia
Swallow-tailed kite Elanoides forficatus
Tri-colored heron Egretta tricolor
Turkey vulture Cathartes aura
Western sandpiper Calidris mauri
White ibis Eudocimus albus
White pelican Pelecanus erythrorhynchos
Willet Catoptrophorus semipalmatus
Wood stork Scolopax minor
Yellow-bellied sapsucker Sphyrapicus varius
Yellow-crowned night heron Nyctanassa violacea
Yellow-rumped warbler Dendroica coronata
Yellow-throated warbler Dendroica dominica
Mammals
COMMON NAME SCIENTIFIC NAME
Virginia opossum Didelphis virginia
Eastern mole Scalopus aquaticus
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Brazilian free-tailed bat Tadarida braziliensis
Big brown bat Eptesicus fuscus
Nine-banded armadillo Dasypus novemcinctus
Marsh rabbit Sylvilagus palustris
Eastern gray squirrel Sciurus carolinensis
House mouse Mus musculus
Roof rat Rattus rattus
Gray fox Urocyon cinereoargenteus
Black bear Ursus americanus
Raccoon Procyon lotor
River otter Lutra canadensis
Feral domestic cat Felis catus
Bobcat Lynx rufus
West Indian manatee Trichechus manatus
Bottle-nosed dolphin Turciops truncatus
HYDROLOGY
The most critical factor for mangrove maintenance is the hydrological regime, sometimes
referred to as the surface water or surficial hydrology. This is because the surficial
hydrology has both horizontal and vertical components and provides key ecological
functions to the mangrove forest.
With respect to the horizontal component, incoming water (both tidal and surface water
run-off) into a mangrove wetland brings with it nutrients, dissolved oxygen, and
marginally lower salt concentrations. Conversely, the outgoing water leaving a
mangrove wetland (through tidal exchange) removes metabolic waste products (e.g.,
carbon dioxide and toxic sulfides) and excess salt. The vertical component refers to
incoming water that percolates down into the sediment and root zone, and the sediment
drainage, on a falling tide,which removes metabolic wastes and excess salt.
It is the inflow and outflow of sea water that is critical to the ability of the mangrove
forest to manage these two ecological functions and as such dissipate salts, organic matter
and freshwater. It follows that anything that affects the system and alters the ability of
the system to perform these functions, will, in most instances, cause stress to the system
and, at some point in time, result in the death of the system, or portions of it.
The Clam Bay system was originally part of a larger tidal system connected to the Gulf of
Mexico by three tidal inlets; Wiggins Pass, Clam Pass and Doctors Pass. (Turrell 1996).
During the early 1950's this system was isolated form adjacent bays by the construction
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of Seagate Drive to the south and the construction of Vanderbilt Beach Road to the north.
The practical effect was to leave Clam Pass as Clam Bay's only connection to the Gulf.
In 1976 culverts were placed under Seagate Drive to provide some exchange from
Venetian Bay (a residential sea wall bay system) and improve water quality in the
Doctors Pass area. One-way valves were placed on the pipes in 1999 but there was not
enough head differential to operate the valves and they ended up acting as plugs instead.
In October, 2002 these valves were removed to promote more flushing and water
exchange in this southern portion of the system.
Hydrologic studies indicate that the tidal flushing capacity of Clam Bay prior to the
restoration dredging was limited and almost insignificant in Upper Clam Bay. The
preliminary hydrographic assessment of the Clam Bay system prepared by Tackney &
Associates, Inc. (August 1996) demonstrated rather dramatically that there was a
significant reduction in tidal range between the middle boardwalk and Inner Clam Bay.
Tackney described the flow in that area as "measurably reduced" and "very inefficient".
This connecting tidal creek is the key conduit for tidal input and outflow to the northern
reaches of the Clam Bay system. And its constriction and the ancillary constriction of
tributaries connection to it, impact the quantity and quality of the flushing that can occur
in Inner and Upper Clam Bay.
As noted earlier, it is the daily rise and fall of the tide and the exchange of seawater
between Clam Bay and the Gulf that are critical to the ability of the mangrove forest to
export both organic matter, and excess salt and freshwater as well as receive oxygen rich
water and nutrients. The greater the tidal amplitude (or tidal prism) the greater the
benefit to the mangroves — more needed resources are delivered and more wastes are
removed. Conversely, in the absence of surface water circulation or tidal activity,
mangroves can become stressed and, in certain instances, rapidly die due to deleterious
changes in the sediment or water levels. The consequence is that the root systems wither
and eventually the whole tree dies. Note that the tidal exchange mechanism that is
critical to the health of the mangrove forest was, within this ecosystem, seriously
constrained. (Turrell 1995). Another key aspect of the surficial hydrology is the vertical
location of the water level elevation relative to the mangrove sediment elevation.
Specifically, the mean low water (tide) elevation has to be sufficiently lower than the
mangrove sediment elevation in order for mangrove sediments to drain during low tide.
A persistent high surface water elevation stops sediment drainage and results in anoxic
sediment and the accumulation of toxic waste products.
It should be observed that the black mangrove forest does not require the kind of intense
flushing that is more typical of the red mangrove systems in order to maximize its
productivity. However, the total absence of meaningful exchange was certainly a
contributor to the significant degradation of the mangrove system within Clam Bay.
(Tackney 1996; Lewis pers. comm. 2008).
In this context Tackney observed that even in the absence of rainfall, the average water
surface elevations for the inner and upper bays were higher than the average surface
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elevation for the Gulf. Analysis of the tidal data indicated that average water surface
elevations in the Inner and Upper Clam Bays were both elevated above the average Gulf
water surface elevation by approximately 0.2 feet. This indicated that the tidal range in
Inner and Upper Clam Bays was muted and that the system was receiving significant
additional water through runoff and restricted capacity to drain additional inflow. In fact,
during portions of the Tackney study no tidal fluctuation was noted in the Upper Clam
Bay and only marginal tidal effects were observed in Inner Clam Bay.
The reduced tidal ranges were also accompanied by relatively large phase lags. The
phase lag is the average time delay measured in hours and minutes between the
occurrence of slack (high or low) water in the Gulf of Mexico and the measurement
stations. It is affected by both the distance between measurement stations and the amount
and quality of hydraulic resistance of the connecting channel. The longer the distance
and the higher the resistance, the more pronounced one would expect the phase lag to be.
In the upper bays, high and low waters generally occurred over three hours later than the
Gulf tides.
These conditions indicate that the tidal creeks connecting the interior bays are
hydraulically very inefficient. As a result, the upper bays are prone towards extended
periods of flooding as a result of freshwater runoff and the inability of the system to drain
efficiently. During Tackney's field studies of May 1996, rainfall of approximately 4
inches in three days was adequate to flood the Upper Clam Bay above high tide levels
and sustain this flooded condition for over two days. Accordingly, he concluded that the
creeks and bays that serve to connect the Inner and Upper Bays were significantly less
efficient in the ebb tide stage than they were in the flood stage. Studies undertaken by
both Lewis Environmental Services, Inc. and Turrell & Associates, Inc. would support
this conclusion. (Turrell 1995).
Finally, an additional attribute of the system that is directly related to tidal prism and the
quantity of inflow and outflow is the question of inlet stability. Inlet stability refers to a
tidal inlet's capacity to adequately scour out deposited sediments and prevent inlet
closure. For a given wave environment, inlet stability is governed primarily by the
volume of water (tidal prism) carried by the inlet. To remain stable, an inlet must have
the characteristic that a temporary constriction in cross sectional area produces an
increase in current velocities adequate to scour out the constriction. To function without
mechanical intervention, the system must generate sufficient volume off water on the ebb
tide to scour out the inlet naturally, otherwise the inlet will, over time, continue to close.
This is particularly true during periods of high wave activity and low tidal ranges.
(Turrell 1995; Tackney 1996). The five closures of Clam Pass that have occurred in the
past twenty-five years indicate that stability of Clam Pass is marginal. (Turrell 1995;
Tackney 1996).
Freshwater Component
Under predevelopment conditions, much of the area's rainfall was held on the surface of
the land in sloughs and other low areas. This water would either slowly filter through the
soil to recharge the shallow aquifer or move through the mangrove community to the bay.
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Less than ten inches of the approximately 53 inch average rainfall is estimated to have
been lost from the uplands east of Clam Bay as surface runoff. The storage capabilities
of the land thus moderated surface flows, preventing extremely high flow rates during the
rainy season and serving to maintain surface flow and groundwater flow during the dry
season. (FDER 1981).
In 1977 the Pelican Bay Planned Unit Development was established by Westinghouse
Communities, Inc. The development contains a mixture of residential, retail, commercial
and recreational facilities and lies east of Clam Bay. As a condition of development,
Clam Bay, the area that lies west of the Pelican Bay and consists of approximately 530
acres of mixed mangrove forest and wetlands was designated as the Pelican Bay
Conservation Area. As such, it was designated for conservation but with limited
recreational access. This area was eventually given to Collier County and is currently
classified as a Natural Resource Protection Area(NRPA).
The development of Pelican Bay had limited fill impact to the Clam Bay system, but it
did modify the pattern of freshwater entering the Clam Bay system. (Wilson, Miller et.al.
1996). The stormwater management system as designed, permitted and implemented at
Pelican Bay employs a series of detention ponds, swales and culverts to regulate the
discharge of run-off into Clam Bay. Discharge occurs almost continuously along the
eastern perimeter of the conservation area. Run-off from the northern end of Pelican Bay
is collected and discharged into Upper Clam Bay. Irrigation water for 27 holes of golf
and landscaping in Pelican Bay is approximately 3.0 MGD which approximates 26 inches
per year of additional rainfall equivalent, (Wilson, Miller et.al., 1996). When added to
the average rainfall for South Florida of approximately 53 inches per year, the local area
has an effective rainfall of approximately 80 inches plus annually. This is significant,
particularly when viewed in the context of predictable storm events that have the
potential for altering the amount of average rainfall entering the Clam Bay system.
The "Pelican Bay Water Management System — Stormwater Detention Volume and
Water Budget Analysis" (Wilson, Miller, Barton & Peek, Inc. April, 1996) describes the
water management system as being divided into six watersheds or drainage systems.
Rainfall, including irrigation, reaches the ground and either seeps into the ground or runs
off to a stormwater detention area within each system. The stormwater detention plan for
Pelican Bay has a standard, permitted design capacity to hold the first inch of stormwater
during a 25-year storm event. The stormwater is detained for flood protection and water
quality treatment. Stormwater discharge is controlled by a series of weirs designed such
that the post-development stormwater run-off rate does not exceed pre-development
rates. Stated differently, the system is designed to discharge stormwater in the
development portion of Pelican Bay in the same manner that it discharged stormwater
prior to development. The stormwater discharge exits the weir system for a final release
into Clam Bay.
Stormwater runoff from an additional 130 acres of watersheds, outside of Pelican Bay,
contributes an additional and significant volume of discharge to Clam Bay. This water
represents 7.9%of the total stormwater discharge to Clam Bay.
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As the area of Pelican Bay to the east has undergone development, it has increased the
impervious surface area, with a concomitant increase in surface runoff, which is
eventually discharged to Clam Bay. The daily irrigation water volume enhances the
saturation of the uplands which reduces their ability to accommodate rainfall volume,
thus effectively increasing surface and groundwater discharge. Groundwater discharge
can be commonly observed throughout-the eastern side of Clam Bay and is discernable as
a very slight sheet flow. Where this water encounters a discharge system, even one that
is not operating at peak efficiency, such as Outer Clam Bay, excess water is effectively
removed from the system. However, in the northern section, sheet flow was not
efficiently removed due to lack of flow through the forest. Thus, it accumulated,
increasing soil saturation and raising the mean water table elevation, and apparently
overwhelming the black mangrove's anaerobic soil/gas exchange mechanisms.
Mangroves in these areas became stressed and died.
WATER QUALITY—More detail to be added from annual report
During the initial environmental permitting of Pelican Bay, the agencies required water
quality testing within the Pelican Bay subdivision and the Clam Bay estuary to help
evaluate the impact of development on Clam Bay. The water quality-testing program
was first implemented by Pelican Bay Improvement District (PBID) starting in the early
1980's. In 1991, PBID became the Pelican Bay Services Division (PBSD), a dependent
Division of Collier County. PBSD continued the testing program after 1991. PBSD is
currently the responsible entity for the testing program.
The water quality testing is performed at several sample points within Pelican Bay and
Clam Bay. The sample point locations are shown on Figure 1. There are currently ten
sampling locations within Pelican Bay and Clam Bay. Sample points W-7, W-6, W-1,
North Seagate, and Upper Clam Bay (UCB) are within Clam Bay, which are categorized
as Class II waters by the Florida Department of Environmental Protection (FDEP). The
remaining five sampling points are PB-13, E PB-13, PB-11, Glenview, and St. Lucia, are
located in the stormwater treatment portion of the property (Class III waters) within
Pelican Bay.
Water quality sampling is conducted within the Clam Bay system on a monthly basis.
The samples are collected by PBSD staff and transported to the Collier County Pollution
Control laboratory for processing. Parameters sampled and collected, include;
• Field pH
• Field Temperature
• Field Salinity
• Field D.O.
• Ammonia
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• Carbon- Total Organic
• Chlorophyll a
• Copper* (added to the parameter suite in 2013)
• Nitrate-Nitrite (N)
• Nitrite (N)
• Nitrogen- Total Kjeldahl
• Orthophosphate (P)
• Pheophytin
• Phosphorus- Total
• Residues- Filterable (TDS)
• Silica(SiO2)
Add Sampling Station exhibit
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