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TECHNICAL REPORT NO. 11
PHOTOGRAPHIC ANALYSIS OF NATURAL AND
IMPOUNDED SALT MARSH IN THE VICINITY
OF MERRITT ISLAND, FLORIDA
Clay L. Montague*
Alexander V. Zale
H. Franklin Percival
Florida Cooperative Fish and Wildlife Research Unit
117 Newins-Ziegler Hall
School of Forest Resources and Conservation
Institute of Food and Agricultural Sciences
University of Florida, Gainesville, FL 32611
and
Systems Ecology and Energy Analysis Program
Department of Environmental Engineering Sciences
A.P. Black Hall
University of Florida, Gainesville, FL 32611
Supported by:
The National Aeronautics and Space Administration
in cooperation with
U.S. Department of the Interior
Fish and Wildlife Service
Cooperative Agreement No. 14-16-0009-1544
RWO #15
15 December 1984
ACKNOWLEDGMENTS
This document was produced at the expense of the National
Aeronautics and Space Administration through the U.S. Fish and
Wildlife Service. We acknowledge the assistance of K. Key and M.
Busacca, NASA, and S. Vehrs and W. Leenhouts, USFWS, in pursuing
the issue and securing the funds for this investigaiton.
We greatly appreciate the cooperation of Mr. Jack Salmela,
Director of the Brevard County Mosquito Control District. Much
of this document stems from the hours he spent showing us photo-
graphs, describing Merritt Island prior to impoundment, and
sharing his thoughts about the history and future of mosquito
control on Merritt Island.
Likewise, we appreciate the cooperation of Mr. Willard P.
Leenhouts, Biologist at the Merritt Island National Wildlife
-Refuge, USFWS, who arranged and provided helpful Interpretation
during an overflight of Merritt Island marshes.
We thank R. Hinkle and his staff at the Bionetics Corpora-
tion, Kennedy Space Center, for technical assistance. J. and M.
Provancha, Bionetics Corp., graciously shared their knowledge of
interpretation of vegetation from aerial photographs.
Introduction
Qualitative analyses of available photographs and maps of
Merritt Island, Florida provide a large-scale, historical per-
spective of ecological changes of the marshes in the vicinity.
Sites that deserve closer scrutiny can be identified. Secondar-
ily, such an analysis provides a geographical orientation essen-
tial for communication not only between newcomers and those
familiar with the area, but also among those familiar with the
area but who refer to sites by differing methods.
Photographs and maps from various sources were examined.
Below are listed what we consider to be the most useful subset of
these for ecological and geographical assessment of salt marsh
impoundments on Merritt Island, Florida. The use of an image
processing system is beyond the scope of this study. Image
processing systems such as NASA's Image 100 system are very
useful for vegetative analysis if image data of an appropriate
scale are available. For Merritt Island salt marshes, LANDSAT
data are available, but the scale is much too large to distin-
guish the different types and amounts of marsh vegetation within
impoundments.
Sources of Photoqraphs.
1. Jack Salmela, Brevard County Mosquito Control District:
many ground-level and low-altitude aerial photographs, and two
16-mm films that show marshes in the vicinity of Merritt Island
just before, during, and after impounding or ditch-and-fill.
2. Agricutural Stabilization and Conservation Service
(ASCS), United States Department of Agriculture, Aerial Photo-
graphs of Brevard County, Florida: Index Sheets 1, 2 and 4 (1
inch = 1 mile) for 1943, 1951, 1958, 1969, and 1979, and corre-
sponding individual contact sheets (1:20000 to 1:50000 depending
on year). Except for 1979 contact sheets, all are available at
the University of Florida Map Library, Gainesville.
3. State of Florida, Department of Transportation (DOT):
annual-overflight color-infrared photos of Merritt Island, Flori-
da of varying quality for use in vegetative analyses (M.J. Pro-
vancha, personal communication). Available at Bionetics Corpora-
tion, Kennedy Space Center, Florida.
Sources of Maps.
1. Merritt Island National Wildlife Refuge, Marsh and Water
Management Plan (Leenhouts 1983): maps showing impoundments by
reference number (e.g. T-10-K, see Table 1) within each MINWR
Management Unit (1:60,000), and maps showing location of all
water control structures (1:9,600).
2. National Aeronautics and Space Administration (NASA),
Kennedy Space Center, Master Planning Maps: index (1:120,000),
and individual maps (1:9,600) show dikes and some water control
structures, but do not identify impoundments by reference number.
3. United States Geological Survey (USGS) Topographic Maps
(1:24.000): Oak Hill, Pardon Island, Mims, Wilson, Titusville,
Orsino, and False Cape quadrangles. Obsolete maps of 1949 to
1952 and subsequent photorevisions and orthophotomaps are avail-
able in the University of Florida Map Library, Gainesville.
These show the geographical names of various locations before
impoundment and record geographical, but not vegetational,
changes following impoundment.
4. Florida Regional Coastal Zone Management (FRCZM) Atlas,
Region 6, East Central Florida (East Central Florida Regional
Planning Council 1975a) and corresponding Environmental Quality
Assessment (East Central Florida Regional Planning Council
1975b). These show malor point sources of sewage in the vicinity
of Merritt Island, Florida. They are available in the University
of Florida Map Library, Gainesville.
Overflight, Site Visits, and Discussions
with Knowledgeable Persons
Interpretation of maps and photographs is greatly enhanced
by overflights of the area, site visits at ground-level, and
discussions with those familiar with the history of the marshes
as well as the photographs. On 7 September 1984, we visited with
Mr. Mark J. Provancha of Bionetics Corporation to discuss his
efforts to quantitatively analyze vegetation in marshes and up-
lands of Merritt Island using 1979 color-infrared aerial photo-
graphs made by the Florida Department of Transportation. On 3
December 1984, we flew over Merritt Island by helicopter with Mr.
Willard P. Leenhouts of the Merritt Island National Wildlife
Refuge, made photographs, and recorded notes of our in-flight
discussion on a portable tape recorder. On 4 December 1984, Mr.
Jack Salmela of the Brevard County Mosquito Control District
(BCMCD) reviewed and discussed with us some of the many low-
altitude and ground-level photographs and two 16-mm films he made
just before, during and after completion of the permanent mosqui-
to control measures of NASA and BCMCD (impoundment construction,
ditching and filling of salt marsh).
Results
Marshes in the vicinity of Merritt Island occur on the
western edges of current or former barrier beaches, on the wes-
tern side of Merritt Island, between old dune ridges, and ad3a-
cent to creeks such as Banana Creek, Moore Creek Seven Pines
Creek, Dummit Creek, and Max Hoeck Creek. Marshes that contained
Saltwort, Batis maritima, were the primary target of mosquito
control (J. Salmela, personal communication). Of secondary im-
portance were the tall rushes and grasses of higher marsh eleva-
tion: Black Needle Rush (Juncus roemerianus), and Spartina ba-
kerii, a cordgrass common to Merritt Island, but reported rarely
from other areas of the United States. The objective of mosquito
control was to keep such areas flooded sufficiently to prevent
the completion of the life cycle of the salt marsh mosquitoes,
Aedes taeniorhynchus and A. solicitans.
Pre-impoundment Salt Marshes of Merritt Island.
Prior to impoundment, Saltwort typically occurred in commu-
cities of mixed short vegetation consisting of Saltwort, Seashore
Saltgrass (Distichlis spicata), Salt Jointgrass (Paspalum vagina-
tum), and both annual and perennial species of glasswort (Sali-
cornia spp.). Marshes with this mix of vegetation are referred
to as "grassy" marsh by Mr. Jack Salmela of BCMCD. The marshes
of the west side of Merritt Island from Peacocks Pocket at the
south to Dummit Cove at the north, and the marshes west of Shiloh
from Duckroost Point to Turnbull Creek consisted of this mixed
"grassy" marsh at lower elevations and the taller S. bakerii and
J. roemerianus at higher elevations closer to hammocks, old dune
ridges, major uplands, or causeways. The marshes west of Shiloh
were well known for their extensive salt pannes (J. Salmela,
personal communication). These sandy areas of very high soil
salinity produced neither emergent vegetation nor mosquitoes.
Although large salt pannes occurred, they accounted for probably
less than 10% of the marsh area west of Shiloh.
The marshes of Moore Creek had few tall mangroves prior to
impoundment. Stunted White Mangroves (Laquncularia racemosa)
were present near the edge of the creek, but Paspalum and Dis-
tichlis dominated the interior of the marsh in BCMCD photographs.
Saltwort also occurred as an understory in sparsely popu-
lated forests of Black Mangrove (Avicennia germinans) or White
Mangrove.
Dense forests of tall mangroves were rare in the vicinity of
Merritt Island. Mangroves were typically more common in the more
easterly and southerly marshes. Near the water's edge along the
eastern side of Mosquito Lagoon and the Eastern half of Banana
Creek and north Banana River, small areas of dense mangrove
occurred (e.g. Pardon Island, Eddy Creek. Jack Davis Island).
Stunted White and Black Mangroves sparsely dotted the "grassy"
marshes of the west side of Merritt Island and the Shiloh mar-
shes. In these areas, mangroves also surrounded some of the many
circular ponds in the marshes, but were generally not a dominant
vegetation type. Freeze damage to mangroves, such as occurred in
late December 1983 is also evident in BCMCD photographs made in
the 1960's.
Nowhere in the Merritt Island National Wildlife Refuge did
extensive forests of dense, tall mangroves exist such as those
found in south Florida. Therefore, studies of south Florida
mangroves are only of peripheral interest in determining salt
marsh values in the vicinity of Merritt Island.
Even in marshes where mangroves were most dense, Mr. Jack
Salmela of BCMCD estimates that mangroves historically covered no
more than 30% of the marsh areas that were impounded. His photos
and 1:20,000 scale ASCS photos of the area confirm this estimate.
Saltwort was dominant in marsh with mangroves (e.g. Pardon
Island, Eddy Creek, Jack Davis Island). This type of marsh and
the mixed vegetation "grassy" marsh were the principal marsh
types prior to impoundment.
The mixed "grassy" marshes at Turnbull Creek (north tip of
Indian River) have never been impounded. These marshes and those
of the broken impoundment T-10-K (between Black Point Creek and
Marsh Bay Creek) are perhaps very similar to the marshes that
occurred prior to impoundment on the west side of Merritt Island
and west of Shiloh. The Turnbull Creek marshes are devoid of
mangrove; Saltmarsh Cordgrass (Spartina alterniflora) occurs at
water's edge. Unimpounded Saltwort-and-mangrove islands of the
east side of Mosquito Lagoon north of the Brevard County Line and
the marshes of the broken impoundment west of Playalinda Beach
are perhaps representative of the marshes of the east side of
Mosquito Lagoon and north Banana River prior to impoundment.
Post-impoundment Changes.
The most obvious changes created by impoundment are 1) the
loss of edge, 2) the loss of emergent saltmarsh vegetation in
areas of "overflooding," 3) the appearance of vegetation more
characteristic of fresher water, 4) the appearance of very low
turbidity, tea-colored water more characteristic of freshwater
swamps than of the Indian River or Mosquito Lagoon, 5) constant
change in vegetation caused both by impoundment and by the
changes in management of these impoundments, 6) an overall
increase in diversity of vegetation type among impoundments, Dut
not always within each impoundment.
It is not clear that impounded marsh has less net primary
production than had the natural salt marsh, and in fact, by
trapping nutrients in run-off, the production of both submerged
and emergent vegetation may be higher in impoundments that are
associated with an extensive watershed. Management activities in
general create changes of a frequency that induce early succes-
sional stages, which are believed to have higher net production,
but perhaps lower or similar gross production than later stages
(Odum 1969). In addition, given the same nutrients and sunlight,
slightly brackish marshes may be more productive than either
fresh or saltier marshes because salinity is more optimal more of
the time (less energy is needed to store or remove salts over the
long run, even in an environment of variable, but on average low
salinity). Loss of "tidal subsidy," (Odum et al. 1983)is more
than replaced by gains in pumping and freshwater retention in
these relatively nontidal salt marshes. This topic will be
covered in detail in the final report.
1. Loss of edge and limited access by estuarine fish. Large
expanses of estuarine edge formerly accessible to estuarine fish
may now be of limited availability, or completely unavailable.
Edge or ecotone is important to the survival of estuarine fish
both for food and protection from predators. Loss of edge is a
general consequence of impoundment that is perhaps most obvious
adjacent to Moore Creek, Banana Creek, Max Hoeck Creek, and
Pardon Island. Several creeks have been completely blocked by
dikes without water control structures (e.g. Drainout Creek,
Seven Pines Creek, south end of Jones Creek). Ditching activi-
ties may have partially mitigated some of the edge lost by im-
poundment. Perimeter ditches, if made accessible, and ditches
from ditch-and-fill can be used by estuarine organisms. Concen-
trated ditching, such as on Big Island (north of VAB) may not be
as effective as the same amount of edge dispersed throughout the
estuary.
Impoundments lacking water exchange capabilities with the
estuary are completely unavailable to estuarine organisms. How-
ever, it is unclear how detrimental limited access is to estua-
rine fish. The effect may vary with the degree of access and the
volume of estuarine water that enters an impoundment. When
impoundments are filled with estuarine water (via culverts or
pumps), planktonic eggs and larvae passively enter also. Pump-
passage mortality is unknown, however.
Use of impoundments by free-swimming organisms should vary
with the subsurface cross-sectional area of open water-control
structures. Design and operation of water-control structures may
result in selective avoidance by certain species or sizes.
Decreased accessibility may not mean less production of
estuarine fish because more resources may be available for each
growing fish, and limited access at the culvert may restrict
adult predators of juvenile fish.
Moore Creek is perhaps the single best example of estuarine
edge reduction. Considerable loss of the edges of Moore Creek
through diking to create impoundments C-15-C, D, E and C-20-A has
occurred. In addition, the mouth of Moore Creek has been diked
resulting in limited access to, and exchange with, the estuary.
Less estuarine water has entered since impoundment, as evidenced
by decreased salinity. The lower salinity of Moore Creek by
itself should have little effect on estuarine fish, however,
because they are euryhaline.
2. Overfloodinq. When water control is limited to capturing
rainfall, runoff, or estuarine water during limited times of high
water, adequate mosquito control requires holding water for much
of the time as insurance against its absence when needed. When
pumps are available, less water need be stored in impoundments to
achieve flooding when needed. The more powerful the pump, the
less anticipation is necessary, and hence less pumping and water
storage is needed to meet mosquito control objectives (J. Salmela,
personal communication). Therefore, in the more remote impound-
ments, where pumps are not available, water levels have in the
past been high enough to kill emergent vegetation, but this is
not essential for good mosquito control. Black Mangroves will be
killed when water covers their pneumatophores for two weeks, but
except for the need to store water, mosquito control can be
accomplished with water levels well below the tips of the man-
groves (Provost 1973). According to W.P. Leenhouts (personal
communication) Black Mangroves have been killed by overflooding
in, for example, impoundment T-40 (east of Cucumber Island), in
T-27-B, C, and D (Max Hoeck Creek and Max Hoeck Back Creek), and
in C-28-A (Jack Davis Island).
Generally all emergent saltmarsh vegetation is killed by
overflooding including the mixed "grassy" vegetation and the
taller grasses and rushes. Standing water with or without sub-
merged vascular plants results. On 1969 ASCS aerial photographs,
former marsh areas apparently without emergent vegetation and
with standing water included T-24-A, and B, T-10-A, B, C, D, E,
F, G, H, and I, and the estuarine edges of T-24-D and Shiloh 5.
Rotary ditching of marsh (e.g. T-24-C) can improve access by
mosquito-eating fish and thereby eliminate the need for water
storage for mosquito control.
Where management of waterfowl is an objective, however, the
growth of submerged aquatic vegetation such as Chara or Ruppia in
saltier water (to perhaps 15 o/oo) is desirable. However, some
of the areas that contain standing saline water are not often
utilized by waterfowl, for example T-21 at Duckroost Point (W.P.
Leenhouts, personal communication).
3. Production of Freshwater Marsh Vegetation. Because impound-
ments trap and hold rainwater and land drainage, the water and
soil salinity may drop to very near fresh during summer when
control structures are closed to capture rain. Except in those
impoundments managed for wintering waterfowl, dikes can be opened
in November when the mosquito breeding season is waning. Estua-
rine water can exchange, though exchange may be restricted both
by the stored head of freshwater and the small culverts in long
expanses of dike.
In areas that collect freshwater from large watersheds (e.g.
Shiloh 5 and T-24-D), or where estuarine exchange does not occur
due to lack of any water inlets or outlets in the dikes (e.g. T-
34, and some diked tributaries to Banana Creek), freshwater
emergent vegetation is common. Cattail (Typha latifolia) has
been a persistent invader in these marshes and impoundment T-34
is completely filled with willows (Salix sp.). Drought in summer
1984 caused lower water and presumably a corresponding increase
in soil salinity. Drought also necessitated pumping of estuarine
water into impoundments for mosquito control. Thus, Cattail died
in many of the impoundments where it had been prevalent (e.g.
Shiloh 3 and 5, T-24-D).
Cattail is not prevalent in the impounded Mosquito Lagoon
marshes except in the southern areas (Max Hoeck Creek and Max Hoeck
Back Creek) that have been impounded by the railroad causeway.
4. Low Turbidity, Tea-Colored Water. The water in impoundments
is more typical of the blackwaters of Southern swamps. Estuarine
water on 3 December 1984, however, was green and turbid, indica-
tive of abundant phytoplankton. Utilization of plant nutrients
in water by abundant emergent and submerged macrophytes and a
lack of water movement may explain the relative color and clarity
of impounded water.
5. Constant Changes in Impoundment Vegetation. Impounded salt
marshes are very dynamic and are perturbed frequently. The
response time of species is fast, however. Thus, these areas
should not be considered unstable, but rather resilient (Webster
et al. 1975). In Merritt Island salt marsh impoundments, water
stands on the marsh for extended and variable periods, and is
generally shallow, though levels fluctuate. Dissolved oxygen and
salinity fluctuations probably exceed those of the estuary, which
has sufficient volume to buffer such fluctuations.
The impoundment ecosystem constantly responds to this varia-
bility and manipulation. With the exception of mangroves, most
of the species of vegetation both in the natural marsh and the
impounded marsh respond quickly to changes. For example, rotary
ditching of impoundment T-24-C was followed by an expansion of
Distichlis within one year (W.P. Leenhouts, personal communica-
tion). Impoundment T-10-K was drained in 1969 and dikes were
removed in 1977 (Leenhouts 1983). Vegetation in that impoundment
is now very similar to that evident in Jack Salmela's pre-
impoundment photos of the west side of Merritt Island.
Standing water apparently has favored the production of
White Mangrove, which was found by J. Salmela to produce adventi-
tious roots and grow well under such conditions. Periodic
freezes in the vicinity of Merritt Island kill White Mangrove.
Sufficient freezes can also kill Black Mangroves, though they are
generally hardier than White Mangroves. Periodic freeze damage
opens the understory for invasion by faster growing marsh plants
such as the mixed "grassy" species or Spartina alterniflora. The
open understory may also favor the germination of mangrove seed-
lings. Mangrove growth in the vicinity of Merritt Island is
periodically reset by freezes, but other plants grow in their
temporary absence. As mangroves seedlings mature, they shade the
shorter plants and reoccupy the area, perhaps within 10 years if
freezes do not recur.
6. Impoundments are Heterogeneous. Varying water sources,
varying temperatures from west to east and north to south, and
varying management of impoundments create a variety of conditions
to which plants and presumably all species respond. Vegetation
of the natural salt marsh primarily consists of the eight species
listed in the first few paragraphs of Results. Impoundment
vegetation includes these plus a variety of fresh and brackish
water emergent, floating, and submerged vegetation. The diversi-
ty of vascular plants in some impoundments may be very low, or
vascular plants may not be present. However, in others, diversi-
ty is no doubt greater than in pre-impoundment marsh. The over-
all diversity of the Merritt Island salt marsh is higher because
of impoundment.
Conclusions
Areas of Greatest and Least Impact. Generally, impoundment
changes the composition of marsh vegetation, eliminates edge
habitat (ecotone), and results in a variable, inconsistently
changing environment. Because of the variety of conditions and
the frequent disturbance at appropriate frequencies ana scales,
species diversity, when the entire area of former salt marsh is
considered, is most certainly higher. To date we can provide
some rough indication of the areas we believe have been altered
most radically by impoundment, and those that appear to have been
altered least.
One of two areas of greatest alteration is between the
railroad causeway and the Shuttle Crawlerway impoundmentss T-27-
C, D, T-33-A, B, C, and T-29-A, B). These areas were dune slacks
that were once connected to either south Mosquito Lagoon or north
Banana River. Now they are ,completely or nearly completely
isolated from the estuary and are filled with freshwater vegetation.
The second area of greatest alteration is the west side of
Merritt Island in the vicinity of Titusville Road from Gator
Creek to Boggy Pond impoundmentss T-24-A, B, T-10-A, B, C, D, E,
F, G, and east end of Gator Creek). These impoundments have
little or no salt marsh vegetation, and many are managed for
waterfowl. In these, standing water without emergent vegetation
is actively sought.
The area of least impact appears to be the Shiloh 1 impound-
ment south of Griffis Bay. Vegetation here consists of salt
marsh species. No crude changes are visible on the ASCS aerial
photographs, as they are on all other impoundments. This is the
most saline of the Shiloh impoundments (Leenhouts and Salmela,
personal communications).
Perhaps next-to-least affected is impoundment T-27-A where
saltwater is pumped into the impoundment. Old dune ridges con-
tain the mixed vegetation "grassy" marsh, while the swales be-
tween the dunes contain open water. Saltwater also enters T-21
(Duckroost Point) via a drilled saltwater-well. Waterfowl use of
this area is low, perhaps because the standing water is too salty
to support Ruppia (Leenhouts, personal communication).
Undergoing more obvious changes, but still retaining signi-
ficant salt marsh vegetation, are the impoundments from Boggy
Pond around Black Point to Dummitt Cove (T-10-H, I, J, L, M, and
T-9). Although some overflooding is evident in lower areas,
these impoundments contain salt marsh species typical prior to
impoundment. These impoundments may have the highest diversity
of vegetation.
Moore Creek is of special interest; of all the impoundments
constructed, we believe the greatest amount of edge habitat was
removed or isolated here.
Also highly altered are the marshes of east Banana Creek
(C-21 & 36, T-34, T-35, T-37-A, B). T-34 west of Happy Creek has
no culverts and is entirely filled with willows. Overflooding is
apparent in Ross Creek (C-21 & 36).
Overflooding of mangroves is evident in the impoundments in
north Banana River near Jack Davis Island (C-28-A, B) and in
those on the east side of Mosquito Lagoon east of Cucumber Island
(T-40) and in Volusia County (V-1 and V-2).
On ASCS aerial photographs from 1969, a great deal of stan-
ding water is evident at the edges of Shiloh 3 and 5, and T-24-D
between Peacocks Pocket and Catfish Creek. Freshwater vegeta-
tion, especially Cattail, has grown fairly well in these impound-
ments. Some Cattail has survived last summer's drought, espe-
cially in Shiloh 3 and 5.
The marshes adjacent to Banana Creek west of the VAB have
also been considerably altered impoundmentss T-16, T-17, T-18-A,
B, C-15-D, C-20-A, B, C). Several creeks in this area have been
completely blocked (Drainout Creek, Seven Pines Creek, and the
south end of Jones Creek). Freshwater marsh vegetation, espe-
cially Cattail, is encroaching on this area. Higher ground,
however, contains S. bakerii in abundance, as perhaps existed
prior to impoundment.
Controllability of Marsh Vegetation. As is evident from the
restoration of natural marsh in T-10-K (dikes broken), in T-24-C
(rotary-ditched), and in the breached coastal strand impoundments
(west of Playalinda Beach), impoundment is reversible with re-
spect to marsh vegetation. Recovery occurs very quickly because
the plants of the natural salt marsh are effective colonizers and
grow rapidly. Vegetation and access by estuarine fish are con-
trollable with adequate water-control structures. Manipulative
experiments with whole impoundments have been done for many years
on Merritt Island, and the knowlegdeable people are still in the
area (e.g. Jack Salmela and W. P. Leenhouts). Unfortunately, the
results of most of these whole system experiments are not formal-
ly recorded. Managers use a great deal of trial-and-error to
refine their techniques, but details are not readily available.
Vegetation Mapping and Annual Overflights. With sufficient
training and ground-level or low-altitude overflights, analyses
of existing photos of Merritt Island can uncover and quantify
many details of the ecological history of its salt marshes.
Important details include the response of vegetation to specific
changes in management, and the loss of edge and partial mitiga-
tion by ditching. Mr. Mark J. Provancha of the Bionetics Corpo-
ration at Kennedy Space Center is mapping marsh vegetation in
impoundments from 1979 DOT color-infrared aerial photographs.
Freeze, drought, and changes in management have altered vegeta-
tion since 1979, but DOT color-infrared photographs from 1984 are
available.
Vegetation in impoundments and marshes can be adequately
monitored (perhaps with less effort and expense) with annual
overflights by helicopter. The purpose of these would be to
record major shifts in vegetation and compare these to weather
conditions and changes in management that occurred during the
previous year. Such records would be invaluable for the future
management of separate impoundments for ducks, wading birds,
estuarine fish, freshwater fish, wildlife observation, natural
marsh preservation, and sewage disposal, all within the con-
straint of adequate mosquito control. A suggested pattern for
annual overflights is shown in Figure 1.
Jack Salmela's Photographs. Mr. Jack Salmela's prints, slides,
and motion pictures are a resource of immeasurable value for
documenting the vegetation of pre-impoundment salt marsh and the
history of mosquito control on Merritt Island. Some of the slide
emulsions have deteriorated, and the motion pictures are brittle,
though can still be projected. Mr. Salmela recalls considerable
detail about these photos which has not been recorded. In our
opinion, the collection should be annotated and protected.
Sewage Input to Estuary. Nine major point sources of domestic
sewage enter estuaries in the immediate vicinity of Merritt
Island, Florida (East Central Florida Regional Planning Council
1975a, 1975b). In 1975, 8.67 million gallons per day (MGD) of
secondarily-treated effluent were discharged: 1.5 MGD into In-
dian River between Titusville Road and the railroad causeway, 0.9
MGD into Indian River between Titusville Road and the NASA cause-
way, and the remainder into Banana River, south of highway A1A
either directly or via Sykes Creek. During the Adaptive Environ-
mental Assessment, we were shown water quality data collected by
Brevard County that shows a general decline in nitrogen and
phosphorus in Banana River along a transect from AlA north to-
wards Banana Creek. Loss of nutrient or organic input by im-
pounding saltmarsh is not a problem for estuarine fish. Any loss
of nutrients has been more than mitigated by sewage and non-
point-source nutrients associated with development and agricul-
ture. The filtering capacity of these marshes may now be very
useful. Land or marsh application of sewage may help to abate
eutrophication of Indian River and Mosquito Lagoon. Increased
turbidity in Indian River may decrease seagrass production and
abundance.
References
East Central Florida Regional Planning Council. 1975a. Florida
Regional Coastal Zone Management Atlas, Region 6, East
Central Florida. Bureau of Coastal Zone Planning, Division
of Resource Management, Florida Department of Natural Resources.
East Central Florida Regional Planning Council. 1975b. Florida
Regional Coastal Zone Environmental Quality Assessment,
Region 6, East Central Florida. Bureau of Coastal Zone
Planning, Division of Resource Management, Florida
Department of Natural Resources.
Leenhouts, W.P. 1983. Marsh and water management plan, Merritt
Island National Wildlife Refuge, Titusville, Florida.
Odum, E.P. 1969. The strategy of ecosystem development.
Science 164: 262-270.
Odum, E.P., J.B. Birch, and J.L. Cooley. 1983. Comparison of
giant cutgrass productivity in tidal and impounded marshes
with special reference to tidal subsidy and waste
assimilation. Estuaries 6: 88-94.
Provost, M.W. 1973. Salt marsh management in Florida. Proc.
Tall Timbers Conf. on Ecology of Animal Control by Habitat
Management 5: 5-17.
Webster, J.R., J.B. Waide, and B.C. Patten. 1975. Nutrient
recycling and the stability of ecosystems. In Howell, F.G.,
J.B. Gentry, and M.H. Smith (eds.), Mineral Cycling in
Southeastern Ecosystems. Technical Information Center,
Office of Public Affairs, U.S. Energy Research and
Development Administration. pp. 1-27.
Table 1. Cross-referenced list of impoundments and their location by
several methods in common use at Kennedy Space Center and the Merritt
Island National Wildlife Refuge. Impoundments are listed in order of
their appearance on proposed overflight plan (Figure 1).
Impound-
ment
T-10-A
T-10-B
T-10-C
T-10-D
T-10-F
T-10-E
T-10-G
T-10-H
T-10-I
T-10-J
T-10-K
T-10-L
T-10-M
T-9
MINWR
Mgmt Unit
KSC
Master Plan*
F6,
F6
F6,
F6,
F6,
F6
F6
F6,
F6,
G5,
G5
G4,
G4
H3
H4
J3,
T-21
SHILOH 1
SHILOH 3
SHILOH 5
V-1
Topo Map**
F7
F7
F7
F7
G5, G6
G5
G6
G5
J4
J4, J5
J5, K4,
K2, Ll
K1, K2
J2, K1
V-2
T-44
T-43
T-42
T-41
T-40
T-39
T-39-SOUTH
T-38
T-27-A
T-27-B
T-27-C
T-27-D
T-33-A
T-33-B
T-33-C
T-29-A
J2,
J1
H2,
H1,
G2,
Gl,
Gl,
G2,
F2,
Fl,
Fl,
Fl
Fl
E2.
E2,
J1
J1
H2
H1
G2
G2
G3,
F3,
F2.
OH
K5 OH
H2, H3
Gl, G2
F3
F2 W
W & FC
FC
Fl FC
Fl FC
Geographic Name
Puckett Cr.
402 to RR track
402 to RR track
Roach Hole
402 to RR track
Boggy Pond
N of RR track and 406
Cow Pen Cr.
Cow Pen Cr.
Black Point
"Dusky Impoundment"
Dummit Cr.
Dummit Cr.
Dummit Cove
Duckroost Pt.
Georges Flats, Giffis
Bay
Onion Farm Is.
Boathouse Pt..
Turnbull Cr.
Georges Slough to
Glory Hole
Glory Hole to Cat
Hammock
Cat Hammock to Pardon
Is.
Pardon Is.
Pardon Is., Klondike
Bch.
Klondike Bch.
Cucumber Is.
Klondike Bch.
Klondike Bch., Eddy Cr
Eddy Cr., Max Hoeck Cr
Clark Slough
Max Hoeck Back Cr.
Max Hoeck Cr., Max
Hoeck Back Creek
Bald Pate Cr.
East of Pad 39B
SE of Pad 39B
Gator Hole
West of Pad 39A
Table 1. -- continued.
Impound-
ment
MINWR
Mgmt Unit
KSC
Master Plan* Topo Map**
Geographic Name
T-29-B
T-25-A
T-25-B
C-28-A
C-28-B
T-30
C-21-D
C-21-C
C-21-B
C-21 & 36
T-35
T-34
T-37-B
T-37-A
C-20-C
T-18-B
7 Pines Cr.
C-20-B
T-18-A
C-20-A
Moore Cr.
C-15-E
C-15-C
C-15-D
C-15-CB
T-17
T-16
T-24-D
T-24-C
T-24-A
T-24-B
E. Gator Cr.
E2
El,
El
E2
El,
D3,
C3,
C3,
E2,
E3. E4
E3,
E4,
E4
E4
E4
E4
E4
E4
E4, E5
D5, D6,
D6, D7,
D6
D6, D7
E5, E6
C6,, C7
E4, E5
E5
E5
E5, E6, F5
E6, E7, F5, F6
F6, F7
F6. F7
F6
F5, F6
0
0
0 & T
T
M
M
M
Broadaxe Cr.
Gulbrandson Cr. Pad 41
Pad 41
Jack Davis Is.
West Conrad Cr.
Is. East of Tea Hmck.
Buck Cr.
Tea Cr., Futch Pt.
Pepper Cr, Pepper Hmck
Billy Joe Pt, Ross Cr,
Picnic Is.
East of Happy Cr.
West of Happy Cr.
NE of VAB
NE of VAB
Drainout Cr.
SE of Shuttle Runway
Seven Pines Cr.
W of Seven Pines Cr.
Hubs Landing
E of Moore Cr.
Moore Cr.
E of Oyster Prong
Middle and W Prongs
W of Moore Cr.
Pine Is. Basin, Oyster
Prong S of NASA Pkwy.
E of Cedar Hammock Cr
Cedar Hammock Cr. to
Peacocks Pocket
Peacocks Pocket to
Catfish Cr.
Gator Cr to Catfish Cr
W Gator Cr near 402
E Gator Cr near 402
S of Beach Rd.
* Index to KSC
Master Planning Maps is shown in Figure 2.
** M = Mims, Fla.
W = Wilson, Fla.
OH = Oak Hill, Fla.
PI = Pardon Island, Fla.
FC = False Cape, Fla.
0 = Orsino, Fla.
T= Titusville, Fla.
MERRITT
UNITED STATES
MENT OF THE INTERIOR
0o50'o R35E
ISLAND NATIONAL WILDLIFE
BREVARD AND VOLUSIA COUNTIES, FLORIDA
R36E so'40' R37E
REFUGE
UNITED STATES
FISH AND WILDLIFE SERVICE
R38E so-so'
j. ."
-.
4 -,
T
20
S
28-4
It
28 40' --
T
22
T I L
S ---- -
T : '-
S I, .
I,'
28'30'
T
23
S
r
0- .4-t
'I-
T
24- -
s ;. -- -
R34E 8'50' R35E
COMPILED IN THE DIVISION OF REALTY
FROM SURVEYS BY US GS
REVISED 10/79
ATLANTA, GEORGIA JANUARY, 1973
Figure 1. Fly-over plan for
annual assessment of marsh
vegetation.
- J .
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jai
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o 5000 10000 20000 30000 40000 FEET
Scale I IMILES-
o 4 6 8 MILES
R38E so'80-
MEAN
DECLINATION
R 1973
4R FLA 632 413
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