Point aux Chenes:Past, Present, and Future Perspective of Erosion

by

Charles K. Eleuterius, Ph.D.

G. Alan Criss

Physical Oceanography SectionGulf Coast Research Laboratory

Ocean Springs, Mississippi

December 1991

Prepared for

Mississippi Department of Wildlife, Fisheries, and ParksCoastal Division / Bureau of Marine Resources

Biloxi, Mississippi

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Table of Contents

PageList of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

iii

List of Tables

Table Page I. Composition and characterization of sediment samples from Point aux Chenes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

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List of Figures

Figure Page 1. Study Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

2. Marsh associated with Point aux Chenes Bay . . . . . . . . . . . . . . . . . . . . . . . . . . 29

3. Centralized map of bottom sediments in the study area . . . . . . . . . . . . . . . . . . . 30

4. Wind speed (knots) and direction, January . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

5. Wind speed (knots) and direction, February . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

6. Wind speed (knots) and direction, March . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

7. Wind speed (knots) and direction, April . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

8. Wind speed (knots) and direction, May . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

9. Wind speed (knots) and direction, June . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

10. Wind speed (knots) and direction, July . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

11. Wind speed (knots) and direction, August . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

12. Wind speed (knots) and direction, September . . . . . . . . . . . . . . . . . . . . . . . . . . 32

13. Wind speed (knots) and direction, October . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

14. Wind speed (knots) and direction, November . . . . . . . . . . . . . . . . . . . . . . . . . . 32

15. Wind speed (knots) and direction, December . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

16. Predicted Tidal Ranges for 1991, Pascagoula, Mississippi. . . . . . . . . . . . . . . . . 33

17. Wave height distributions, January . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

18. Wave height distributions, February . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

19. Wave height distributions, March . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

20. Wave height distributions, April . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

21. Wave height distributions, May . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

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List of Figures (continued)

22. Wave height distributions, June . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

23. Wave height distributions, July . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

24. Wave height distributions, August . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

25. Wave height distributions, September . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

26. Wave height distributions, October . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

27. Wave height distributions, November . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

28. Wave height distributions, December . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

29. Sediment sampling locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

30. From chart circa 1848 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

31. From chart circa 1860 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

32. From U.S. C. & G. S. Coast Chart No. 189, 1896 . . . . . . . . . . . . . . . . . . . . . . . 38

33. From chart circa 1921 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

34. From aerial photograph of October 27, 1940 . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

35. From aerial photograph of April 30, 1952 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

36. From chart circa 1957 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

37. From aerial photograph of October 20, 1975 . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

38. From chart circa 1978 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

39. From aerial photograph of November 15, 1979 . . . . . . . . . . . . . . . . . . . . . . . . . 41

40. From aerial photograph of April 9, 1980 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

41. From aerial photograph of April 23, 1986 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

42. From aerial photograph of November 21, 1988 . . . . . . . . . . . . . . . . . . . . . . . . . 43

43. TMS pseudo-color image of Point aux Chenes, November 21, 1988 . . . . . . . . 44

44. TMS pseudo-color image of West Point aux Chenes-Bangs Lake, November 21, 1988 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

1

POINT AUX CHENES:PAST, PRESENT, AND FUTURE PERSPECTIVE OF EROSION

Introduction

Substantial losses of natural resources in the southeastern corner of Jackson County,

Mississippi, are occurring directly and indirectly because of coastal erosion. This area of

bays, bayous, and marshes (Figure 1) is comprised of Point aux Chenes Bay, Bangs Lake,

Middle Bay, Bayou Cumbest, Heron Bayou, west Grand Bay, and the contiguous marshes

and uplands with their intricate networks of small bayous, sloughs, and ponds. For

convenience, this coastal marine system will be referred to henceforth herein as simply

"Point aux Chenes". This is Mississippi's last remaining pristine estuary and it has both

economic and social value.

Background

The area supports limited recreational and commercial fisheries. Although access

to the area is somewhat difficult, there are recreational fishing enthusiasts present year-

round. Among the species available to the recreational fishery are sand sea trout (Cynoscion

arenarius), speckled sea trout (Cynoscion nebulosus), red fish (Sciaenops ocellata), Atlantic

croaker (Micropogon undulatus), and flounder (Paralichthys lethostigma). Subsistence

commercial fisheries also exist for these finfish plus shrimp (Penaeus setiferus, Penaeus

aztecus, Penaeus duorarum), crabs (Callinectes sapidus), and oysters (Ostrea virginica).

An extensive accounting of the area's myriad of marine life can be found in Perry and

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Christmas (1973), Christmas and Langley (1973), and Christmas and Waller (1973). Besides

the marine "fishes", the area is inhabited by other animals.

Among other wildlife are a large number of reptiles and mammals. Eleuterius (1974)

compiled an extensive list of animals that inhabited a slightly larger geographical region

which included Point aux Chenes. Reptiles and herptiles present include turtles,

salamanders, toads, skinks, tortoises, frogs, snakes, lizards, and the American alligator

(Alligator mississippiensis). Mammals that inhabit the area include the nine-banded

armadillo (Dasypus novemcinctus), Atlantic bottlenose dolphin (Tursiops truncatus),

opossum (Didelphis marsupialis), mink (Mustela vison), nutria (Myocastor coypus), raccoon

(Procyon lotor), muskrat (Ondatra zibethicus), and a number of bats. In addition to "fish",

mammals, herptiles, and reptiles, the area is also populated with many species of birds.

Eleuterius (1974) compiled a list of over 300 species of birds for which there had

been reported sightings at Point aux Chenes. While some of the birds are found there year-

round, others are migratory and visit the area only during certain seasons. This marsh-bay-

bayou complex is important to migratory waterfowl. Its value to migratory waterfowl having

been recognized by authorities, it is now a vital component of the North American

Waterfowl Management Plan (Coastal Mississippi Wetlands Initiative Team 1989). Based

on a ten-year survey, Rees (1991) reported that the area north of the former Grand Batture

Islands hosted an estimated 1,000 winter waterfowl annually. However, scientists at Gulf

Coast Research Laboratory, who have spent considerable time in the area during winter,

believe that this estimate for winter waterfowl is low (Lionel Eleuterius, David Burke, John

Caldwell, Personal Communications, October 1991). The authors, who have also made

frequent trips to the area during past winters, agree. Species comprising the greater

percentages of the estimate were redhead (Aythya americana), lesser scaup (Aythya affinis),

American widgeon (Mareca americana), and mallard (Anas platyrhynchos). The extensive

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marshes are a prime factor in attracting and retaining the large number of animals that

inhabit the area.

The flora of Point aux Chenes has been studied and mapped by Eleuterius (1973).

There are four general types of marshes in Mississippi: saline, brackish, intermediate, and

fresh water. Of the four types, almost all of the marshes in the study area are of the saline

or salt marsh type. According to Eleuterius' research, the saline region (Figure 2) supports

two major marsh plant species; black needle rush (Juncus roemerianus) and smooth

cordgrass (Spartina alterniflora). Both species almost always occur in pure stands, usually

with a common boundary between the two, therefore zonation by these two species is

typified by an abrupt change between them. The S. alterniflora normally forms a fringe

border between the J. roemerianus and the open water of the bays and bayous.

At Point aux Chenes, Spartina alterniflora and Juncus roemerianus grow in their

most robust forms which are characterized by their greater heights and greater densities.

Interspersed with J. roemerianus are some brackish water species; giant cordgrass (Spartina

cynosuroides), saltmeadow cordgrass (Spartina patens), and three-square sedge (Scirpus

olneyi). In addition, scattered throughout the area in special niches in the salt marsh and

uplands are less abundant species including an appreciable number of rare plants (Lionel

Eleuterius, Personal Communication, October 5, 1991).

Indigenous to the "salt flats", i.e. areas with unusually high salinity concentrations

at and near the surface of the substrate, which occur throughout the marsh, especially near

the marsh-forest margin, are a number of other marsh species. On these salt flats are found

glasswort (Salicornia bigelovii), seablite (Suaeda linearis), and saltwort (Batis maritimus).

North of what was once the Grand Batture Islands and around the west margin of Point aux

Chenes Bay, Eleuterius (1971) found extensive beds of the shoal grass, Halodule wrightii.

The rich and diverse flora of Point aux Chenes can be attributed, at least in part, to its

geology.

4

The geological evolution of Point aux Chenes involved a long, complex sequence of

events and processes. Among studies of its geology which served as sources for much of the

geological information synthesized here are those of Priddy and others (1955), Otvos (1973,

1990), Minshew and others (1975), Waller and Malbrough (1976), and Meyer-Arendt and

Kramer (1991). The oldest of the surface deposits found in the area today was deposited

during the mid-Pliocene epoch when an apron of fluvial-deltaic deposits covered the entire

region and coalesced to form the Citronelle Formation. Subsequently, during the

Pleistocene, regional uplift and erosion resulted in elevating and partially removing this

deposit. Early Pleistocene fluvial sediments were deposited in the study area and beneath

the present adjacent Mississippi Sound. Erosion, following this period of sedimentation,

removed much of the early Pleistocene sediments.

With the melting of glaciers and the frozen polar seas near the end of the Pleistocene

Epoch, the sea level rose, inundating the area. The nearshore Biloxi Formation, which

consists of marine deposits, developed during this period of encroachment by the sea as did

the Prairie Formation which was formed from fluvial sediments. As the Earth entered a new

ice age, withdrawal by the sea was accompanied by fluvial deposition along the seaward

margin (Prairie Formation) as it progressed southward. Coastal streams subsequently cut

valleys through the Prairie Formation and other underlying formations. At the peak of this

last glacial period (Wisconsin), the seashore was located approximately 70 miles south of

the present mainland shoreline which corresponds to the present seaward limit of the

continental shelf.

With the increase in sea level near the end of the Pleistocene and early Holocene

times, the sediments which filled the excavated fluvial valleys were of three different types.

Initially, freshwater sediments were deposited which were followed by deposition of

brackish sediments and which, in turn, were followed by marine deposition. Subsequently,

5

marshes and swamps developed behind the mainland shores adjacent to relatively quiescent

waters.

The Escatawpa River, rather than following its present course, i.e. connecting with

the Pascagoula River as a tributary, instead flowed south-southeast and emptied into

Mississippi Sound in the Point aux Chenes Bay-Grand Bay area. The Escatawpa River built

a sizable delta which encompassed all of the study area. Deterioration of this delta began

when the Escatawpa switched course and became a tributary of the Pascagoula River as it

is today. Bayou Cumbest and Bayou Heron, remnants of the former main Escatawpa River

channels, provide little fluvial sediment to Point aux Chenes.

With the change in the course of the Escatawpa River, the seaward transport and

deposit of fluvial sediments, which had formerly offset the sediments lost to erosion, ceased.

Then the abandoned delta of the Escatawpa began to erode away under the sustained attack

by waves under normal conditions, by larger waves that accompany ordinary storms, and by

the great waves and surges of tropical hurricanes. Currents have also played a major role

in the erosion of Point aux Chenes by carrying away the suspended sediments to be

deposited elsewhere and by transporting the sediments as bedload. The winnowing, sorting,

and transporting of sediments by waves and currents resulted in the formation of sandy

barrier islands along the seaward limit of the deteriorating and retreating delta.

Simultaneously, the marshy delta-remnant shores were eroded and retreated northwestward.

The sediment substrate of the marshes is rich in woody-peaty organic material and

mud, but due to the sandy sources of the material that formed this now abandoned delta, the

substrate contains a larger-than-average proportion of sand. Sediments comprising the

marsh substrate are unconsolidated, highly compactible, and contain a large proportion of

water. For foundations, the substrate represents the poorest engineering soil type.

In Mississippi Sound, remains of the Grand Batture Islands and the shoal area once

seaward of them is indicated by the sandy bottom sediments in Figure 3. The greatest clay-

6

mud concentrations are located in the deeper parts of the Sound which are least affected by

waves and currents. This muddy-bottom zone between Petit Bois Pass and Point aux Chenes

is approximately four miles wide at it greatest breadth.

Zones of mixed sandy-muddy bottom deposits up to two miles wide exist between

the predominantly sandy-bottom and the predominantly muddy-bottom areas. They are

found along the margin of the sandy belt skirting the mainland shore, along the sandy-bottom

zone north of the barrier islands, and along the intervening sandy shoals of Petit Bois Pass.

The sediment distribution pattern is the result of prevailing wave and current regimes that

mix, transport, and deposit sediments.

Weather patterns contribute indirectly to erosion at Point aux Chenes. The

subtropical anticyclonic Bermuda High exerts the greatest influence on the climate of the

area. When the Bermuda High intensifies during the spring, it extends its boundaries into

the Gulf of Mexico. This extension into the Gulf results in a shift in the source direction of

the winds to the southeast and south. Wind speeds of spring and summer are normally much

less than those of fall and winter. In early fall, the Bermuda High weakens and its boundary

of influence retreats toward the southeast from the Gulf. Simultaneously with the

withdrawal of the Bermuda High is a southward advance of the continental pressure systems

over the Gulf. As a result of the southward movement of the continental systems, northerly

winds become predominant.

During winter, westerly systems also influence the study area as cold fronts from the

northwest move southward over the Gulf of Mexico. Figures 4-15 from Eleuterius and

Beaugez (1979) show the monthly distribution of winds with regard to direction and speed

for the study area. Generally, the source of the winds during the period October-March lies

between northwest and northeast. The source of the winds during the period April-

September lies between southwest and southeast. The predominant source for all winds

7

during the year lies within the eastern quadrants. Forces associated with tropical storms and

hurricanes also have a profound impact on erosion in coastal areas.

While the principal season for hurricanes in the North Atlantic region is from June

through November, the preponderance of hurricanes occurs in August and September. One-

half of all hurricanes affecting the study area have occurred in September (Eleuterius and

Beaugez 1979). Large wind-driven waves associated with storms and hurricanes, i.e.

forerunners, are responsible for much of the erosion attributed to hurricanes. As they move

into shallower waters, storm surges put into suspension and carry away large amounts of

sediments.

Astronomical tides of the area are those of the adjacent Gulf of Mexico, but modified

by the bathymetry and geometry of Mississippi Sound (Eleuterius and Beaugez 1979). The

tides are primarily diurnal, i.e. usually one high and one low water per day. The principal

diurnal components of the tide are K1, O1, and P1 with periods of 23.93 hrs, 25.82 hrs, and

24.07 hrs, respectively. While the average diurnal range in tide, i.e. the difference in water

levels between consecutive high and low water stages, for Mississippi Sound at Pascagoula

(Figure 16) is 1.5 feet, the overall range in the astronomical tide during a year is

approximately 3.4 feet (National Ocean Service 1991). The tide wave approaches the study

area from the Gulf of Mexico via Petit Bois Pass, spreading outward after entering

Mississippi Sound (Eleuterius 1976, 1979). The maximum tidal current speed of 1 knot (0.5

m/s), calculated for the mouth of bays and passes (Eleuterius 1984), were later observed.

Wind has a profound affect on the tides. When the wind works in conjunction with

the tide, at the flood it drives the water level higher and at the ebb it drives the water level

lower than that prescribed by the tides. When the wind works in opposition to the tide, at

the flood it prevents the water levels from reaching the high and at the ebb it prevents the

water levels from attaining the lows prescribed by the tide. Because of the effect of wind

stress on water levels, the overall range in water elevations during a year exceeds that caused

8

by the astronomical tide-generating forces alone. Large excursions from the predicted

astronomical tide heights for Point aux Chenes occur during strong, sustained winds. The

wind blowing over the water surface is also the generative force for an important class of

progressive water waves, i.e. wind waves or "sea".

Information regarding the wave climate, i.e. the period, height, and direction of

waves, in Mississippi Sound is virtually nonexistent. The monthly distributions of wave

heights as a percentage of time are shown as frequency histograms in Figures 17-28

(Eleuterius and Beaugez 1979). These statistics were generated by the hind-cast method for

the area described by the following coordinates: 28°45'N, 87°30'W; 30°00'N, 87°30'W;

30°00'N, 89°30'W; and 28°45'N, 89°30'W. Although this site lies approximately 25 miles

south of Petit Bois Pass where the heights of waves are generally larger, the wave statistics

should still serve as a reliable relative indicator of the severity of the wave climate within

the study area. Waves during the period October-April, when northerly winds between

northwest and northeast prevail, are larger than in other months of the year. During the

period May-September, the waves, except those associated with stormy weather, are

generally smaller and less steep than those of fall and winter. The winds during this period

are predominantly southerly with their sources lying between southeast and southwest.

Therefore the direction of the wind-generated and waves is northerly. Swells, i.e. waves

generated by the wind but no longer under its influence, are also more prevalent during this

period and also normally approach from between southeast and southwest.

Point aux Chenes, an estuarine system with considerable economic and social value,

is in danger of simply disappearing because of coastal erosion. The goals of this study were

to: (1) determine from available historical and current information the events, forces, and

mechanisms responsible for the area's erosion; (2) determine the rate of erosion and the fate

of eroded sediments; (3) develop scenarios of the erosional processes that incorporate the

9

relevant forces and mechanisms; and (4) forecast the future of Point aux Chenes with regard

to coastal erosion.

Methodology

Assessing erosion at Point aux Chenes from a historical perspective required

synthesizing information and data from disparate sources and interpreting the resulting

aggregate of information. The literature was searched for relevant scientific papers,

scientific reports, and engineering reports. Archives at Gulf Coast Research Laboratory and

at other institutions and agencies were searched for pertinent maps, charts, aerial

photographs, and remotely-sensed imagery.

Because of fiscal constraints, only a select number of maps, charts, and aerial

photographs were chosen from those available for the period 1848-1988. Materials obtained

were those the authors believed would contribute the most toward making an overall

assessment of erosion. First, drawings outlining land masses were constructed by tracing

the shorelines from back-lit photographs, charts, and maps. The land masses on each

drawing were blackened, thereby producing images of the land areas in silhouette. These

silhouette charts were then digitized via an image scanner, imported into a computer, and by

use of computer software, transformed to a common scale for comparative analyses. The

silhouette charts and aerial photographs were studied for the effects of coastal erosion.

Using the set of charts and photographs, shoreline changes were determined at selected sites

by measuring along transects perpendicular to the shoreline. These measurements were used

to estimate the annual rate of land-loss.

Remotely-sensed data acquired by a Daedalus Thematic Mapper Simulator (TMS)

from a NASA ER-2 aircraft on November 21, 1988 were used, primarily, to delineate areas

of water and different vegetative assemblages. The Daedalus TMS, which has the same

spatial and spectral configuration as the Thematic Mapper aboard the Landsat-5 earth

10

resources satellite, is flown at an altitude of 65,000 feet and has a ground resolution of 25

meters. Under certain conditions, different species of vegetation can be distinguished by

their reflected spectral signatures.

The contrast-stretched digital brightness values of the TMS near-infrared band (.76-

.90 :m) were processed using an arctangent function on an Atlas/AGIS software system

(Delta Data Systems). A pseudo-color scale was assigned to the resulting processed

brightness values of the near-infrared band, i.e. 0 to 255. Psueudo-color images were

produced which show an unsupervised classification of the "surfaces" at Point aux Chenes.

To determine the type and composition of sediments at Point aux Chenes, samples

were taken by the authors in 1989 at seven sites (Figure 29). The results of grain-size

analysis of each sample, i.e. each type contribution to sediment composition, were expressed

as percentages of total sample weight.

Aerial photographs of Point aux Chenes were made from an airplane at altitudes of

900 and 700 feet. The aerial surveys enabled the authors to ascertain the present state of the

area with regard to erosion. The small-scale features that are not included on charts and that

do not appear on high altitude photographs were clearly visible from the aircraft. Slides

were made using 35 mm Kodak Ektachrome ISO 400 film and a Nikon camera with a 50mm,

1.4 lens.

11

Results

A single episodic event, a hurricane, brought about conditions conducive to the

acceleration of erosion at Point aux Chenes. However, since charts constructed before or

after the event were not available, the authors relied upon the work of others for establishing

the year of the hurricane event. The hurricane bisected Dauphin Island, thereby forming two

islands. The new island, formerly the west tip of Dauphin Island, was named Petit Bois.

The hurricane-generated cut that separated the new island from the old was, and still is,

referred to as Petit Bois Pass. Otvos (1990) concluded that this bisection of Dauphin Island

occurred between 1740-1766; based on the following references: Governor Cadillac's report

(Kennedy 1976); 1718 charts of DeLisle; 1718-1719 chart of Seur du Sault, 1719-1720 chart

of Serigny, and parts of other French surveys incorporated in the 1732 d'Anville map - all

of which showed Petit Bois Island as part of Dauphin Island. Otvos further cited the report

by Gayarrè who stated that the 1740 hurricane was responsible for washing away roughly

half of Dauphin Island. According to the 1773-1774 charts by Bernard Roman, a wide

passage existed at that time between Dauphin and Petit Bois. This breach, which has since

grown in width, allowed the larger waves generated in the Gulf of Mexico to enter

Mississippi Sound and attack the mainland shores including those at Point aux Chenes.

Grand Batture Island was developed by the reworking of the delta sediments by

waves and currents during the interim from the time of the change in the course of the

Escatawpa River to 1848 (Figure 30). The major axis of the island in 1848 was oriented

roughly northeast-southwest (40°-220°). The elongated barrier island sheltered Point aux

Chenes Bay, Grand Bay, and Middle Bay from attack by northerly-directed waves from

seaward. Personal observations indicate that the island was of low vertical relief and

vegetated by only brush and grass (Lionel A. Eleuterius 1956).

Comparison of the 1848 chart (Figure 30) with that for 1860 (Figure 31) revealed that

notable changes in the area occurred over the 12 year period. Storm surges and waves

12

associated with the hurricanes of 1852, 1856, and probably that of 1860, which made landfall

in the vicinity of Mobile, Alabama, reduced the elevations of Grand Batture Island while

simultaneously increasing its width via overwash. The storms and hurricanes also made

other changes. The islets north of the elongate, northwest-southeast oriented marsh islet and

north of and in close proximity to Grand Batture Island as well as islets within Middle Bay

and Grand Bay disappeared. The marsh area north of and connecting with the middle of

Grand Batture Island developed twin, eastward-oriented peninsulas.

Erosive processes during the 36-year period between 1860 (Figure 31) and 1896

(Figure 32) further altered Grand Batture Island by reducing its width and recurving its

southwest end. The tongue-like extensions of the marshes in Point aux Chenes Bay, Grand

Bay, the south shore of Middle Bay, and near the north shore-center of Grand Batture Island

became much narrower and, overall, smaller in size. The "birth" of some islets, widening

of others, and the formation of shoals as evidenced by the 1896 chart (Figure 32) were

probably the result of overwash. The sixteen hurricanes and tropical storms that occurred

during the 36-year period most likely contributed substantially to the erosion. Hurricanes

and storms, which crossed the coastline close enough to have caused erosion, occurred in:

1870, 1872, 1875, 1877, 1879, 1880, 1881, 1882, 1885 (2), 1887 (2), 1889, 1893, 1894, and

1895. The hurricanes of 1887, 1893, and the storm of 1895 made landfall at Pascagoula,

Mississippi.

During the 25 years between 1896 (Figure 32) and 1921 (Figure 33), erosion brought

about dramatic changes in the land masses. By 1921, Grand Batture Island was no longer

a single island, but had become fragmented into several islands. The remnants of the island

thus became known as the Grand Batture Islands. Figure 33 clearly shows that appreciable

erosion of the islands and peninsulas within Grand Bay had occurred. During this period,

the remnant of Grand Batture Island lying seaward of Grand Bay was reduced in size. The

long narrow, northeast-southeast oriented marsh island on the east side of Point aux Chenes

13

Bay became much narrower than before. Erosion of the marsh island, now known as South

Rigolets Island, had left it with a highly irregular shoreline. The seaward shoreline, where

once the approximate center of Grand Batture Island was located, retreated toward the

northwest approximately one-fourth mile. The breaching of that portion of Grand Batture

Island lying southeast of Point aux Chenes Bay permitted the entry of waves into the Bay

from a southerly direction. The erosion of the north shoreline of Point aux Chenes Bay by

wave action is apparent in Figure 33. During this period, 5 tropical storms and 7 hurricanes

made landfall near enough to have caused appreciable erosion. Two of the hurricanes,

occurring in 1904 and 1906, made landfall at Pascagoula, Mississippi.

Comparisons made between the 1921 chart (Figure 33) and the aerial photograph of

1940 (Figure 34) reveal the magnitude of the coastal erosion that took place over that period

of time. Almost all of the remnant islands that formed as the result of the multiple breaching

of Grand Batture Island were, by 1940, reduced to half their 1921 dimensions. The islands

and peninsulas within west Grand Bay were either reduced to half their former dimensions

or had disappeared entirely. Similarly, the elongate, northwest-northeast oriented marsh

island situated on the east side of Point aux Chenes Bay was reduced to half its 1921 width.

Reworked by wave action, the seaward shore of South Rigolets Island was transformed from

its highly irregular 1921 coastline to a nearly straight shoreline with a southwest-northeast

orientation. The irregular, east-west oriented north shore of Point aux Chenes Bay was

transformed into a nearly straight coastline. Crescent-shaped, flood-tidal deltas (dotted

lines), located between the adjacent islands south of Point aux Chenes Bay, indicate an up-

bay transport of sediment. During this period, four tropical storms struck the area in the

years 1922, 1923, 1934, and 1939, while hurricanes hit in 1926 and 1932. The 1932

hurricane made landfall between Pascagoula, Mississippi and Mobile, Alabama.

Between 1940 (Figure 34) and 1952 (Figure 35), erosive forces bisected the elongate

northwest-southeast oriented island on the east side of Point aux Chenes Bay. By 1952, the

14

seaward islands, remnants of Grand Batture Island, were reduced to approximately two-

thirds their 1940 lengths. The islets northeast of South Rigolets Island disappeared. The

seaward shore of South Rigolets Island along with all of the Grand Batture Islands migrated

northwest. The flood tidal deltas in the passages between the islands south of Point aux

Chenes Bay grew as the passages increased in width. On the northeast side of South

Rigolets Island, the length of the embayment, from seaward entrance to head, had increased.

In addition, the northwest-southeast oriented marsh island north of South Rigolets Island was

bisected. Two tropical storms made landfall in the vicinity during the 1940-1952 period.

The first storm occurred in 1944. The second storm made landfall at Biloxi, Mississippi in

1947.

Assessment of land mass changes over the relatively short period, 1952-1957, were

based on an aerial photograph of 1952 (Figure 35) and a navigation chart issued in 1957

(Figure 36). Among the noticeable changes that took place was the narrowing of the

peninsula that extends southeast of the seaward boundary of the south shore of Middle Bay.

Other changes were the narrowing of the northeast end of South Rigolets Island, the

recurving of the west end of South Rigolets Island, and the apparent disappearance of the

two flood tidal deltas between South Rigolets Island and the islets south of Point aux Chenes

Bay. Much of the marshy mainland shore in northwest Grand Bay eroded away, leaving a

highly irregular shoreline and many new marsh islands. Two tropical storms occurred in

1955 that may have contributed to these changes. The center of the first storm made landfall

at Bay St. Louis and the second passed through New Orleans.

The impact of erosion during the 18-year period from 1957-1975 is obvious from

comparisons made between the 1957 chart (Figure 36) and an aerial photograph of October,

1975 (Figure 37). Islets present in the northern part of Point aux Chenes Bay in 1957 were

greatly reduced in size and the linear north shore of 1957 became very irregular with many

small embayments. The two northwest-southeast oriented marsh islands north of the west

15

tip of South Rigolets Island were heavily eroded. The west end of South Rigolets Island was

cut off, forming a separate island. The island northeast of South Rigolets Island, a remnant

of Grand Batture Island, was reduced to roughly one-half of its 1957 dimensions. The

northeast tip of South Rigolets Island vanished during the interim. During this time period,

two tropical storms occurred, one striking Pensacola, Florida, and one hitting Pascagoula,

Mississippi. There were also several hurricanes that contributed to the area's erosion. The

hurricane that struck the Louisiana coast in 1965, while causing only minimal damage to

buildings and homes, was responsible for appreciable erosion of Mississippi's barrier islands

and mainland coast. Camille, the most powerful hurricane to strike the North American

continent in recorded history, struck the Mississippi Coast in 1969 with devastating results.

Although, the area is not shown in Figure 37, the islands that had lain southwest of South

Rigolets in 1957, i.e. the remnants of the western portion of the former Grand Batture Island,

were reduced to shoals by the force of this hurricane (author's personal observations). The

hurricane surge height in the study area was approximately 10 feet above mean sea level.

Because of the questionable accuracy of land areas depicted on the navigation chart

produced in 1978, it is difficult to ascertain exactly what changes occurred during the 1975-

1978 period. Silhouette charts produced from a 1975 aerial photograph (Figure 37) and the

navigation chart printed in 1978 (Figure 38) show few appreciable changes during this 3-

year period. The island that formed as the result of the bisection of the west tip of South

Rigolets Island sometime during 1957-1975 had since reconnected. Because of the length

of time required for revising navigation charts, errors that appear in this 1978 chart are

probably due to the cartographers' use of data that was no longer valid by the time the chart

was printed. After 1978 only aerial photographs or remote-sensing imagery were used to

produce the silhouette charts. The first of two notable errors that appear on the 1978 chart

is the existence of the northward oriented point on the northeast tip of South Rigolets Island

which, according to the 1975 aerial photograph, was shown to no longer exist. A second

16

significant error in the 1978 chart is the existence of some islands and the greater size of

others which, according to the 1975 aerial photograph, had either already disappeared or had

been reduced to a size much smaller than they appear on the 1978 chart. No tropical storms

or hurricanes made landfall near the area during the 1975-1978 period.

Conclusions drawn from comparisons made between the images produced from the

1978 navigation chart (Figure 38) and from an aerial photograph taken November 15, 1979

(Figure 39), support the previous determinations regarding the actual configuration of the

land in 1978. Figure 39 shows that no islands existed southwest of South Rigolets Island by

November 15, 1979. They most likely disappeared before October 1975, although we have

no evidence to substantiate this. There is strong coherence between the configuration of the

west end of South Rigolets Island as depicted in the charts for 1975 and 1979, neither of

which are in agreement with the shape depicted for that area in the 1978 navigation chart.

The evidence leads us to rely less on the shape and dimensions of land masses depicted on

the 1978 chart than we might have otherwise. Shoals, the submerged remnants of the former

Grand Batture Island, are visible in the 1979 aerial photograph.

The degree of erosion that occurred in less than five months, i.e. November 15, 1979

to April 9, 1980 (Figures 39 and 40), is clearly indicated by the diminished size of the

islands, islets, and peninsulas. In addition, the leeward and seaward shores of South Rigolets

Island and the north shore of Point aux Chenes Bay reflect the impact of erosion. Many of

the embayments and passages have increased in size. Hurricane Bob, which made landfall

near Grand Isle, Louisiana, caused a rise in sea level of about 3.5 feet at Point aux Chenes

and waves of appreciable size. However, most of the erosion can be attributed to the fury

of Hurricane Frederic that made land fall at Dauphin Island, Alabama, and Mobile, Alabama,

on September 14, 1979. Sustained winds of 115 knots and peak winds of 126 knots were

recorded as the hurricane made landfall. Frederic was the most intense hurricane of this

century to affect the Mobile, Alabama - Pascagoula, Mississippi area. The hurricane surge,

17

recorded at Dauphin Island at a height of 11 feet, washed over the island carrying with it

much sediment which it deposited as overwash fans on the island's north shore. Therefore,

even though the height of the surge at Point aux Chenes was less, it was still a significant

erosive force.

The changes due to erosion from 1980 to 1986 (Figures 40 and 41), a period of

approximately six years, were not great. Erosion of the shorelines around the north,

northeast, and east perimeter of Point aux Chenes Bay was manifested in the disappearance

of islets and the reworking of the seaward shore of South Rigolets Island. Although it lies

outside of the study area, it is worthwhile to note the degree of erosion that has taken place

east of Heron Bayou. On September 2, 1985, The center of Hurricane Elena moved onshore

at Biloxi, Mississippi. Maximum coastal winds of 91 knots with gusts to 117 knots were

recorded at Dauphin Island, Alabama.

During the period 1986 to 1988 (Figures 41 and 42), a period of approximately 30

months, erosion took a heavy toll on Point aux Chenes. Comparison of the size and

configuration of South Rigolets Island at the beginning and end of this period shows that the

island was reduced to two-thirds its 1986 size. The shoreline perimeter of Point aux Chenes

Bay from north around to the southeast was eroded extensively during this relatively short

time period. Similarly, the land masses contiguous to Middle Bay and west Grand Bay show

that substantial erosion had occurred. Florence, a minimal hurricane that made land fall over

southeast Louisiana on September 9, 1988, caused a rise in sea level of about 4 feet and

generated substantial waves at Point aux Chenes.

Changes in the location of the shoreline relative to a transect perpendicular to the

local shoreline were measured on the silhouette charts at several select points at Point aux

Chenes for the period 1940-1988. Based on this series of measurements, the average annual

land loss due to coastal erosion has been approximately 17 acres per year. This is higher

than what others have estimated the rate to be.

18

The percent grain-size composition and relevant statistics for the sediment samples

are included in Table I. Location of the sample sites are shown in Figure 29. At site 7, four

samples, 7a, 7b, 7c, and 7d, were taken inside the west end of South Rigolets Island and from

the submerged bar located southwest of the island. On the mainland side of the island,

sample 7a is from offshore, 7b is at the shoreline, and 7c is from the lower beach face.

Sample 7d is from the submerged bar offshore to the southwest. At site 8, a sample was

taken just offshore (8a) and another (8b) from the lower beach face.

The digital brightness values of the Thematic Mapper Simulator near-infrared band

(.76-.90 :m) were processed using an arctangent function via ATLAS/AGIS software (Delta

Data Systems, Picayune, Mississippi). To construct a pseudo-color image of the coastal

surfaces at Point aux Chenes from the processed, contrast-stretched brightness values, the

color palette and image manipulation algorithms of the FIGMENT software system (Dr.

Richard Miller) were used. The color scale key beside the images on Figures 43 and 44

represents the 256 processed brightness intervals of the near-infrared band, from the lowest

(bottom) to the highest (top).

While these unsupervised images provide some important information to those

familiar with the area, those unfamiliar with the area could be seriously misled by the

patterns. The lack of "groundtruthing" due to contract constraints forced the authors to rely

upon the systems unsupervised classification algorithms which has resulted in some areas

being classed the same even though the "surfaces" are quite different. The red color in the

lower parts of the figures represent the higher areas of the salt marsh while the dark green

represents the water-covered interior of the salt marsh. The yellow and light tan areas

represent the open savannas and flat, grassy areas of sparse pine forests. The "reds" and

"greens" in the lower parts of the false-color image show good correlation with the

distribution of the saline marsh vegetation described in previous studies (Criss 1990, Criss

and Eleuterius 1992, Eleuterius and Criss 1992).

19

Because of the 25 meter ground resolution of the TMS, there is a problem with

interpretation of these images that should be mentioned. The spectral signature obtained for

each 25 meter by 25 meter square of ground area is the aggregate of the spectral radiances

reflected from all of the "surfaces" within the square. Because of the possible spanning of

dissimilar "surfaces", e.g. a bayou and adjacent salt marsh, the resulting classification may

be neither bayou nor marsh, but something quite different.

Observed during one aerial survey were a series of offshore bars which paralleled the

south coast of South Rigolets Island, but which extended well beyond it in both directions.

20

Discussion

Comparative analyses of charts and aerial photographs indicate that coastal erosion

at Point aux Chenes has been and continues to be substantial. During the period when the

Escatawpa River discharged into Mississippi Sound at Point aux Chenes-Grand Bay, erosion

was limited to that caused by relatively weak tidal and wind-driven currents and waves

which were generated within the confines of Mississippi Sound. The Escatawpa River Delta

was situated in rather quiescent waters, sheltered from the Gulf of Mexico hydrodynamics

by the long barrier island, Dauphin. The amount of sediment eroded was more than offset

by the seaward transport and deposition of sediment by the Escatawpa River. With the

change in the course of the river, the supply of sediment it had provided to the coast ceased.

The former relationship between the amount of sediment deposited and that lost to erosion

was dramatically altered. Erosion became dominant, but was a relatively slow process when

compared to the rate of erosion observed today. When a hurricane cut through Dauphin

Island in 1740 creating a new island (Petit Bois) with a wide passage (Petit Bois Pass)

between them a new era of erosion began. The new passage allowed the larger waves

generated in the Gulf of Mexico to enter Mississippi Sound and attack the shores at Point

aux Chenes. Tidal currents also became stronger because the new passage allowed the

admittance of more tidal energy. The rate of erosion accelerated.

Tidal currents with speeds reaching 1 knot have been calculated for and observed in

the shallow coastal waters. Currents with speeds of this magnitude can efficiently transport

most sediments found in the area.

Wind waves and swells of dimensions sufficient to erode and transport sediments

occur year-round. However, it is normally during winter when strong northerly winds and

during late summer when strong southeasterly winds generate and drive larger than average

waves that the preponderance of erosion occurs. In general, the southerly-directed waves

21

of winter attack the shores exposed to the north and the northerly-directed waves of summer

attack the shores exposed to the south.

From 1848-1988, thirty-eight tropical storms and hurricanes have either made

landfall at Point aux Chenes or have passed in such close proximity as to cause erosion.

Large waves and surges accompanying hurricanes and tropical storms were responsible for

dramatic changes in the area.

Based on the changes in land masses as determined from charts and aerial

photographs for the period 1848-1988, the estimated rate of erosion is approximately 17

acres per year. There was, however, considerable variation in the annual rates of erosion

determined for each time period ascribed by the charts and photographs. This can be

explained largely by the non-uniform occurrence of tropical storms and hurricanes. The

variability in the rate of erosion between sites along the coast within a given time period is

most likely related to the differences in the degree of exposure to the direct attack of waves.

The orientation of the series of offshore bars that parallel the south shoreline of South

Rigolets Island indicates that the predominant wave direction is toward 310° during late

summer, one of the two most erosive periods of the year. Further study of these offshore

bars may provide information regarding the wave period and length of the most erosive

waves. Accurate information regarding wave dimensions and period are essential to the

construction of wave-refraction diagrams for the area. These diagrams will be needed for

judicious planning in the event a barrier to replace the former Grand Batture Island is to be

constructed.

Knowledge gained from monitoring coastal erosion at Point aux Chenes for several

years combined with that which has accrued from this study has enabled the authors to

develop two scenarios of coastal erosion for Point aux Chenes. The scenarios involve two

factors, water level and prevailing waves, which are of primary importance in the erosion

22

of the marshy shorelines. Other important factors contributing to the accelerated erosion are

the composition and engineering properties of the sediments.

The first scenario applies when the water elevation is low on the tidal plane, i.e. when

the still-water level is near the base of the scarp of the marsh substrate. Waves traveling

shoreward upon "feeling" bottom peak and break against the marsh substrate. Sustained for

a period of time, this process results in undermining the overlying marsh. When the

concavity reaches the depth where the weight of the overlying marsh and substrate can no

longer be supported, the substrate falls away in large clumps. Surging breakers have a

similar effect when the still-water level is near the base of the marsh substrate scarp.

The second scenario applies when the water elevation is high on the tidal plane, i.e.

near the top of the marsh substrate. These higher water elevations may be due to either

spring tides or strong winds directed toward the coast. In this case, waves directed

shoreward "feel" bottom abruptly as they approach the scarp and plunge forward, breaking

on top of the marsh substrate. If the scarp has been previously undermined by erosion, the

undermined portion may be broken away in large clumps under the impact of the breaking

waves. There is an effect of this scenario that should be discussed.

Sediment laden waters directed inland after impacting the marsh substrate may

literally cut away the marsh vegetation, leaving only stubble for 10-15 feet inland, beyond

which a fan of sediment is laid down. In some instances, the first few inches of the marsh

substrate may also be removed in the process. Narrow, irregular channels from 2-10 feet

long may be cut into the marsh by the attack of waves under the conditions described in this

scenario.

The accelerated erosion occurring along the marshy shores at Point aux Chenes is

due, in part, to the nature of the marsh substrate. Because the substrate consists of

unconsolidated sediments rich in decaying plant material and containing a large amount of

interstitial water, it is easily eroded. The numerous burrows of fiddler crabs and voids left

23

by decaying roots and other organic deposits weaken the substrate further, making it even

more prone to erosion.

The fate of sediments eroded from Point aux Chenes is only partly identified by the

sediment distribution chart (Figure 3). The large clumps of marsh substrate that break away

as described in the two erosion scenarios are rapidly broken down by wave action.

Winnowing and sorting by wave action separates the sediments into various components.

The fate of the sediments depends upon the length of time the sediments remain in

suspension relative to the period of the prevailing waves. If the length of time the sediment

remains in suspension is less than the period of the wave, the sediment remains near shore.

If, on the other hand, the length of time the sediment remains in suspension is greater than

the wave period then the sediment is removed from the area, perhaps to be deposited at some

great distance from the point of erosion.

The coarse sands generally remain in the area, likely moving offshore and onshore

with the seasonal changes in the wave climate. This material may accumulate to form

narrow strips of sand beach near the base of the marsh scarp. The finer sands may be carried

along shore by longshore and tidal currents or offshore by tidal and density driven currents.

Both coarse and fine sands are found within the embayments, carried there by flood-tide

currents or by waves entering the bays. The fine silts and clays which remain in suspension

longer may be carried farther into the bays before they are deposited, but more likely the

greater portion is carried seaward by ebb tidal currents.

Discerning the trend and rates of coastal erosion at Point aux Chenes permits rather

crude forecasting of the future of Point aux Chenes with regard to erosion. The northwest

retreat of the area's south and southeast margins due to erosion is one notable trend.

Occurring simultaneously with the retreating coastline has been the fragmentation and

overall reduction in the size of the marshy islands. With the breach of the protective barrier,

i.e. Grand Batture Island, and later its total destruction, the largely marsh areas behind it

24

have borne the brunt of the direct attack by waves and storm surges. The composition and

porosity of the marsh substrate makes the sediments particularly vulnerable to erosion.

Based on the information synthesized here, the future of Point aux Chenes is rather grim.

By 2042, over 850 acres will have vanished. The shoreline configuration will be drastically

changed from that at present. The seaward margin of the peninsula of marsh that now

terminates with the south shore of South Rigolets Island will likely be located at the present

north shore of North Rigolets. The marshy shorelines in all areas will have retreated from

their present positions. Accompanying this loss of wetlands will be losses in marine

"fishes", mammals, reptiles, herptiles, and birds, including migratory waterfowl. The

economic and social value of the area will suffer greatly.

25

Recommendations

Based on our study, we make the following recommendations:

1. Acquire the area referred to here as Point aux Chenes and designate it a wildlife

refuge.

2. Locate and identify all of the rare and endangered plants that now inhabit the

marshes and uplands at Point aux Chenes.

3. Continue efforts to construct a barrier where Grand Batture Island was located,

however, be certain that the seaward side of the barrier is oriented 40°-220°

to help stabilize the shoreline.

4. Establish a series of paired reference markers along the shores of Point aux

Chenes. These reference points, if monitored frequently, will provide a more

accurate determination of the rate of erosion than it is possible to ascertain

by other methods.

5. Initiate a program to educate the public, particularly residents of Jackson County,

regarding the value of Point aux Chenes.

Acknowledgements

We would like to express our appreciation to Mr. Joe Gill, Deputy Director, and Mr.

Larry Lewis, Chief, Coastal Management, Mississippi Department of Wildlife, Fisheries,

and Parks, Coastal Division/Bureau of Marine Resources for their support. We are indebted

to Dr. Thomas McIlwain, Director, Gulf Coast Research Laboratory, who, having recognized

the importance of the work, committed the Laboratory to providing the preponderance of

support needed. Mr. Malcolm Ware and Mr. Gene Brown, librarians at the Gunter Library,

made special efforts to secure certain essential materials. To them we owe a debt of

gratitude. We thank Dr. Ervin Otvos for his analyses of sediment samples. To Mr. Hank

Svelak and other members of the United States Geological Survey located at Stennis Space

26

Center, who were both generous with their time and equipment, we are also indebted. The

originals of three silhouette charts in this report were prepared by Mr. Joe Jewell when he

was a technician in the Physical Oceanography Section at Gulf Coast Research Laboratory.

27

Table I. Composition and characterization of sediment samples fromPoint aux Chenes (Sites identified in Figure 29).

________________________________________________________________________

Sample Components in Percentages CharacterizationSite samples Sand Silt Clay================================================================

1 -- 81.2 12.1 6.7 Muddy-fine sand

2 -- 79.6 10.4 10.0 Muddy very-fine sand

3 Small shell 72.0 21.2 6.8 Coarse silty very- fragments fine sand

4 Plant material 33.7 49.7 16.6 Very-fine sandy coarse silt

5 Plant material & 50.7 37.4 11.9 Coarse silty very- shell fragments fine sand

6 Plant material & 33.9 31.7 34.4 Very-fine sandy mudshell fragments

7a Molluscan 75.1 22.5 2.4 Coarse silty very- fragments fine sand

7b Molluscan & plant 83.2 14.3 2.5 Coarse silty very- fragments fine sand

7c Molluscan & plant 99.1 (0.9 mud) Fine sand fragments

7d Oyster shell 32.3 48.9 18.8 Very-fine sandy fragments medium silt

8a Plant material & 32.4 49.2 18.4 Very-fine sandyshell fragments coarse silt

8b - 99.2 (0.8 mud) Fine sand

9 Plant material 28.5 61.8 9.7 Very-fine sandycoarse silt

46

Literature Cited

Christmas, J. Y. and Richard Waller. 1973. Phase IV: Estuarine Vertebrates, Mississippi.Pages 320-406 in: J. Y. Christmas (editor). Cooperative Gulf of Mexico EstuarineInventory and Study, Mississippi. Gulf Coast Research Laboratory, Ocean Springs,Mississippi.

Christmas, J. Y. and Walter Langley. 1973. Phase IV: Estuarine Invertebrates, Mississippi.Pages 255-319 in: J. Y. Christmas (editor). Cooperative Gulf of Mexico EstuarineInventory and Study, Mississippi. Gulf Coast Research Laboratory, Ocean Springs,Mississippi.

Coastal Mississippi Wetlands Initiative Team. 1989. Coastal Mississippi WetlandsInitiative, Gulf Coast Joint Venture: North American Waterfowl Management Plan.Unpublished Report.

Criss, G. Alan. 1990. Evaluation of airborne Thematic Mapper Simulator (TMS) DigitalData and High Altitude Aircraft Infrared Photographs for Assessment of Conditionsin the Vicinity of Pt. aux Chenes Bay, Mississippi. Presented at the Fifty-fourthAnnual Meeting of the Mississippi Academy of Sciences, Biloxi, Mississippi, 22-23February 1990. Journal of the Mississippi Academy of Sciences 35(Supplement):73-74.

Criss, G. Alan and Charles K. Eleuterius. 1992. Delineation of Spectrally-Complex CoastalWetland Habitats Via a Combination of Data from the Daedalus Thematic MapperSimulator and Aerial Photographs. Presented at the Fifty-sixth Annual Meeting ofthe Mississippi Academy of Sciences, Biloxi, Mississippi, 13-14 February 1992.Journal of the Mississippi Academy of Sciences 37(1): 48.

Eleuterius, Charles K. 1974. Mississippi Superport Study: Environmental Assessment.Office of the Governor, State of Mississippi. 153 pages.

Eleuterius, Charles K. 1979. Hydrology of Mississippi Sound North of Petit Bois Pass.Mississippi Marine Resources Council. 57 pages.

Eleuterius, Charles K. and Sheree L. Beaugez. 1979. Mississippi Sound: A Hydrographicand Climatic Atlas. Mississippi-Alabama Sea Grant Consortium, Ocean Springs,Mississippi. MASGP-79-009. 145 pages.

Eleuterius, Charles K. 1984. Estimated Maximum Tidal Currents for Selected Passes inMississippi Coastal Waters. In: A Contingency Guide to the Protection ofMississippi Coastal Environments from Spilled Oil: Protection Priorities andRelated Environmental Information. Mississippi Department of WildlifeConservation, Bureau of Marine Resources, Long Beach, Mississippi. 48 pages.

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Eleuterius, Lionel. 1971. Submerged Plant Distribution in Mississippi Sound and AdjacentWaters. Journal of the Mississippi Academy of Sciences 17: 9-14.

Eleuterius, Lionel. 1973. Phase IV: The Marshes of Mississippi. Pages 147-190 in: J. Y.Christmas (editor). Cooperative Gulf of Mexico Estuarine Inventory and Study,Mississippi. Gulf Coast Research Laboratory, Ocean Springs, Mississippi.

Eleuterius, Lionel. 1973. Phase IV: The Distribution of Certain Submerged Plants InMississippi and Adjacent Waters. Pages 191-197 in: J. Y. Christmas (editor).Cooperative Gulf of Mexico Estuarine Inventory and Study, Mississippi. Gulf CoastResearch Laboratory, Ocean Springs, Mississippi.

Gazzier, C. A., R. L. Frederking, and V. H. Minshew. 1980. Mapping Coastal Wetlands ofMississippi with Remote Sensing. Pages 187-198 in: F. Shahrokhi (editor). RemoteSensing of Earth Resources Vol. III. The University of Tennessee Space Institute,Tullahoma, Tennessee.

Meyer-Arendt, Klaus J. and Karen A. Kramer. 1991. Deterioration and Restoration of theGrand Batture Islands, Mississippi. Mississippi Geology 11(4).

Minshew, V. H., Conrad A. Gazzier, Lynn P. Malbrough, and Thomas H. Waller. 1975.Environmental Geological Analysis: Jackson County, Mississippi. MississippiMineral Resources Institute, University of Mississippi.

National Ocean Service. 1991. Tide Tables 1991: High and Low Water Predictions. EastCoast of North and South America including Greenland. U.S. Department ofCommerce, National Oceanic and Atmospheric Administration.

Otvos, Ervin G. 1979. Barrier Island Evolution and History of Migration, North-CentralGulf Coast. In: Stephen Leatherman (editor). Barrier Islands. Academic Press.

Otvos, Ervin G. 1981. Barrier island formation. Marine Geology 43: 238-243.

Perry, Harriet and J. Y. Christmas. 1973. Phase IV: Estuarine Zooplankton, Mississippi.Pages 198-254 in: J. Y. Christmas (editor). Cooperative Gulf of Mexico EstuarineInventory and Study, Mississippi. Gulf Coast Research Laboratory, Ocean Springs,Mississippi.

Priddy, R. R., R. M. Crisler, C. P. Sebren, J. D. Powell, and Hugh Burford. 1955.Sediments of Mississippi Sound and Inshore Waters. Mississippi Geological SurveyBulletin, No. 82.

Rees, Susan Ivester. 1991. Environmental Studies. In: General Design Memorandum,Main Report: Improvement of the Federal Deep-Draft Navigation Channel;Pascagoula Harbor, Mississippi. U.S. Army Corps of Engineers, Mobile District.December 1990, Revised July 1991.

Waller, Thomas H. and Lynn P. Malbrough. 1976. Temporal Changes in the OffshoreIslands of Mississippi. Water Resource Research Institute, Mississippi StateUniversity.

CoverTitle PageTable of ContentsList of TablesTable I. Composition and characterization of sediment samples from Point aux Chenes

List of FiguresFigure 1. Study AreaFigure 2. Marsh associated with Point aux Chenes BayFigure 3. Centralized map of bottom sediments in the study areaFigure 4. Wind speed (knots) and direction, JanuaryFigure 5. Wind speed (knots) and direction, FebruaryFigure 6. Wind speed (knots) and direction, MarchFigure 7. Wind speed (knots) and direction, AprilFigure 8. Wind speed (knots) and direction, MayFigure 9. Wind speed (knots) and direction, JuneFigure 10. Wind speed (knots) and direction, JulyFigure 11. Wind speed (knots) and direction, AugustFigure 12. Wind speed (knots) and direction, SeptemberFigure 13. Wind speed (knots) and direction, OctoberFigure 14. Wind speed (knots) and direction, NovemberFigure 15. Wind speed (knots) and direction, DecemberFigure 16. Predicted Tidal Ranges for 1991, Pascagoula, MississippiFigure 17. Wave height distributions, JanuaryFigure 18. Wave height distributions, FebruaryFigure 19. Wave height distributions, MarchFigure 20. Wave height distributions, AprilFigure 21. Wave height distributions, MayFigure 22. Wave height distributions, JuneFigure 23. Wave height distributions, JulyFigure 24. Wave height distributions, AugustFigure 25. Wave height distributions, SeptemberFigure 26. Wave height distributions, OctoberFigure 27. Wave height distributions, NovemberFigure 28. Wave height distributions, DecemberFigure 29. Sediment sampling locationsFigure 30. From chart circa 1848Figure 31. From chart circa 1860Figure 32. From U.S. C. & G.S. Coast Chart No. 189, 1896Figure 33. From chart circa 1921Figure 34. From aerial photograph of October 27, 1940Figure 35. From aerial photograph of April 30, 1952Figure 36. From chart circa 1957Figure 37. From aerial photograph of October 20, 1975Figure 38. From chart circa 1978Figure 39. From aerial photograph of November 15, 1979Figure 40. From aerial photograph of April 9, 1980Figure 41. From aerial photograph of April 23, 1986Figure 42. From aerial photograph of November 21, 1988Figure 43. TMS pseudo-color image of Point aux Chenes, November 21, 1988Figure 44. TMS pseudo-color image of West Point aux Chenes-Bangs Lake, November 21, 1988

IntroductionBackgroundMethodologyResultsDiscussionRecommendationsAcknowledgementsLiterature Cited