Mississippi Sound Research Articles

Studies on the Gobies (Pisces: Gobiidae) of Mississippi Sound and Adjacent Waters. I. Gobiosoma

Data are provided on relative abundance, seasonal occur- rence, growth rate, ecological preferences, interspecific relationships, meristics and body proportions of Gobiosoma robustum, G. bosci and G. longipala, the known Gobiosoma species of Mississippi Sound. Compari- sons are made between G. longipala and its Atlantic seaboard cognate G. ginsburgi. The 15-month study, including 818 comparable collections at 17 stations productive of this genus, shows G. robustum to be scarce in mid- winter and most (83%) are taken in salinities from 22.3 - 32.3 o/oo. This species has restricted distribution within the Sound but, where present, may occur in considerable numbers. G. bosci exhibits a distinct preference for salinities below 22.3 o/oo and a size-salinity relationship is indicated wherein fish of the medium standard length classes (11.5- 22.0 mm) prefer low salinity (0.3 - 4.7 o/oo) and smaller fish are most common at higher salinities (14.8 - 24.7 o/oo). Though seldom abun- dant in individual collections, G. bosci is the most widely distributed Gobiosoma in Mississippi Sound. G. longipala is usually present in the area during late summer and fall and in moderate salinities (24.8 - 32.2 o/oo). Though widely distributed in- the Sound, it is less numerous than its local congeners and is seldom taken in quantity. G. longipala and G. ginsburgi are, on the basis of present data, considered to be allopatric species.

Dynamic characteristics of west Florida Gulf Coast beaches

During 1962 fifteen beach stations were established along the Florida coast and monitored at monthly intervals. Observations of beach profiles, sediments, wave conditions, water characteristics and wind speed and direction were recorded. Techniques closely followed those of a nearly contemporaneous study on California beaches ( Ingle, 1966). This made possible a comparison of beach conditions in a low- and medium-energy environment (Florida) with a high-energy environment (California). Average wave conditions in Florida range from low ripples in the low-energy eastern segment near Keaton Beach, to over 30 cm wave height along the broad arc from Cape San Blas to the Alabama-Mississippi peri-delta region. Maximum wave heights reach 100 cm and more along the Pensacola shore and approach the average condition for high-energy beaches. Longshore current velocities, however, are surprisingly constant and range from 30 to 150 cm/sec in the general area. The much larger waves of the California coast produce essentially the same range of current velocities. This is a function of the increase in dimensions of a surf zone as larger waves necessarily break farther offshore, thus the larger amount of water moved in translation is balanced by the increased area. Statistical studies of the sediment textural parameters confirm the observations of Schiffman (1965) regarding the greater variation in texture occurring in the swash zone than in other parts of the beach system. Some evidence suggests that sediment composition differences east and west of Cape San Blas reflect different sources. Magnitudes of profile changes are approximately a direct function of wave height up to average heights of 30 cm and more. Thereafter, increasing wave height apparently does not markedly increase the rate of sand level variation. Volumes of sand transported in longshore drift, however, are directly related to wave height, but show considerable variation from month to month and day to day. Net sand transport is to the west and apparently is actively prograding the large spits of the area from Mobile Bay to Pensacola. Wave energy decreases west of Mississippi Sound and transport diminishes.

Isotopic variations of dissolved inorganic carbon

The isotopic composition of the dissolved inorganic carbon in near shore waters varies systematically with chlorinity. Extrapolation to 0-chlorinity shows a δ 13 C range of −5 to −11‰ relative to the Chicago PDB 1 standard for the Hudson and Potomac Rivers and the bayous feeding into Mississippi Sound. The composition of a few samples of open ocean water shows a range of −1 to +2‰. The data suggest that the amount and isotopic composition of the total CO 2 and chlorinity of estuary and coastal waters may be used to characterize and to study the mixing of various water masses, and that it is necessary to re-evaluate paleoenvironmental methods of sediment classification based on the isotopic composition of sedimentary organic and inorganic carbon.

Studies of Annual Abundance of Postlarval Penaeid Shrimp in the Estuarine Waters of Mississippi, As Related to Subsequent Commercial Catches

Several workers and several lines of evidence have shown that the shrimp life cycle is very short, probably about 15 to 16 months, for the very small fraction reaching the largest adult size. Additionally, a great deal of commercial fishing is carried out upon sub-adult populations within the bays and shallow Gulf. In fact most shrimp that are caught have never spawned. These shrimp grow up within one warm season and they are derived from larvae which make their way to inside waters from the offshore spawning areas. Thus, it has been surmised for a long time that prediction of at least the relative abundance of the future shrimp could be deduced from studies of the numbers of young or juvenile shrimp in the bays right after they have completed their larval immigration. The first work on this problem was carried out by Baxter (1962) at the Galveston Laboratory of the Bureau of Commercial Fisheries. He sampled one area at the entrance of Bolivar Pass, leading into Galveston Bay, with a beam trawl. Work at the Gulf Coast Research Laboratory in Mississippi Sound was carried out under contract with the Bureau of Commercial Fisheries, and was initiated on 1 November 1962. The contract was terminated on 31 October 1964, although the work has been carried out on a reduced scale since that time. The present report covers the period of the contract.

Rainstorm Induced Mortality of Lancelets, Branchiostoma, in Mississippi Sound

Rainstorm Induced Mortality of Lancelets, Branchiostoma, in Mississippi Sound

Development of Clay Mineral Zones During Deltaic Migration

An understanding of the origin of clay mineral zones in coastal plain sediments is a prerequisite for the effective stratigraphic application of clay petrology. One common type of clay mineral zone is developed by the occasional migration of a major delta lying near the margin of two clay-petrologic provinces. As an active delta migrates from place to place along a coast, the magnitude of its detrital contribution to any location will vary between a maximum and a minimum. By this process the regressive deltaic phase sediments may alternate with transgressive marine zones in which locally derived or longshore drift material is relatively more prominent. If the major stream is supplying a clay mineral suite which differs from the longshore current-borne and locally derived clay (i.e., from local weathering, reworking of older beds, small river influx, etc.), a series of correlative regressive-transgressive clay mineral zones will be built up. This process is illustrated by comparing clay mineral variations in cores from the eastern Mississippi Delta area with the known deltaic history of the region. The abandoned St. Bernard Subdelta, which the Mississippi occupied from 1,700 to 2,800 years ago, has a clay mineral zone sequence similar to that in the sediments of interdeltaic Mississippi Sound which lies 40 miles east. This similarity allows the two sections to be correlated across facies boundaries so that the Recent chronology of the two areas can be related.

FACIES DELINEATION BY ACOUSTIC‐REFLECTION: NORTHERN GULF OF MEXICO1

This study in Breton, Chandeleur, and Mississippi Sounds combines the use of bottom‐penetrating acoustic‐reflection records with lithologic descriptions of piston and gravity cores for construction of sections showing boundaries of depositional facies units. Continuous acoustic records delineate morphology of buried horizons (lithologic breaks, changes in density, water content, or degree of lithification). Lithologic descriptions give internal structure and variations of particle size, color, components such as shells and wood fragments, and consistency. With these criteria, deposits were divided into the major broad facies units of sound deposits, delta deposits, basal and barrier island sands and Pleistocene clays. Delta deposits are recognized as being of two distinct periods of the St. Bernard subdelta, which has subsided beneath Breton and Chandeleur Sounds.Probable buried distributaries of these delta phases are recognized in the records. Sand bodies connecting islands in Mississippi Sound are suggested as remnants of an extensive barrier island which fronted the area previous to the subdelta growth and had its beginnings about 7,000 B. P.

Isotopic Organic Carbon Composition of Recent Continental Derived Clastic Sediments of Eastern Gulf Coast, Gulf of Mexico: GEOLOGICAL NOTES

The isotopic composition of organic C from 3 environments was compared: from continental-derived clastic sediments, from brackish-water sediments, and from open marine environments in southern Mississippi and Alabama, Biloxi Bay and Mississippi Sound, and the upper Gulf of Mexico. The per mil deviations from the C 13 C 12 ratio of a standard was an average of -26.2% for river sediments as contrasted with -19 to -21% for open marine. For sediments of Biloxi Bay and Mississippi Sound, lagoonal and channel environments, a systematic variation from river to open marine values was observed. A mixing of land- and marine-plant-derived organic materials which differ in isotopic composition is probably responsible for the systematic variation observed in sediments from river, through lagoonal to open marine environments. Other processes may complement the mixing process in producing the observed variation.

Development of Clay Mineral Zones During Deltaic Migration--Subsurface Recent Sediments of the Eastern Mississippi Delta Area: ABSTRACT

Three clay mineral zones have been recognized in cores from Recent sediments of the eastern Mississippi Delta area. The clay mineral suite in each of these zones is apparently related to the position of the active Mississippi Delta as follows: (1) during the regressive St. Bernard subdelta phase, when the active delta was near the cored locations, the clay suite deposited there was richly montmorillonitic, reflecting the type of clay being carried by the ancestral Mississippi River; (2) when the site of active deltaic deposition shifted to the west of the cored locations (in this case downcurrent), local transgressive conditions developed in the eastern Delta area, and the clay included in the sediments deposited there was influenced more by local weathering conditions an by longshore drifting of clay from the more kaolinitic eastern Gulf province. These two factors probably combined to form the slightly more kaolinitic clay mineral suite which characterizes the two transgressive phases above and below the sediments of the St. Bernard subdelta. Comparison of St. Bernard subdelta clays with modern Mississippi River clays indicates that the clay mineral suite carried by the river has become less montmorillonitic within the past few thousand years. The possibility exists, therefore, that the various ancient Mississippi River subdeltas may be characterized by distinctive clay mineral suites. The highly montmorillonitic clay carried by the St. Bernard phase of the Mississippi River affected, to a limited degree, an area to the east outside of the actual subdelta. This wider distribution, which was probably brought about by oceanic, wind, and tidal currents, extends across some environmental boundaries and has allowed the Recent section of the Mississippi Sound to be subdivided and correlated chronologically with the St. Bernard subdelta section approximately 40 miles away. End_of_Article - Last_Page 358------------

The Fauna and Flora of Horn Island, Mississippi

From 26 February 1944 until 4 February 1945, I was stationed with the U. S. Army on Horn Island, Mississippi, and decided to observe and record the animals and plants existing there. At the time, it seemed that little attention had been devoted to the wildlife of this island, but eventually it became apparent that some studies had been made. However, many of the observations have not been published and many of the records of the flora and fauna living on and around the island are scattered and unavailable. The most outstanding papers include those of Lloyd and Tracy (1901), Lowe (1921), and Pessin and Burleigh (1941). Cook (1942, 1943 a and b) described several of the animals observed. Smith and List (1955) recorded a number of amphibians and reptiles which were collected on Horn Island. Since 1945 more attention has been paid to this subject. Kopman (1946) enlightened the public regarding the seasonal activity of the animals and changing conditions in the Mississippi Sound region in his delightful “Wild Acres,” a book of the Gulf Coast country. From 1940 on many scientists and students of the Gulf Coast Research Laboratory visited Horn Island, but still comparatively little has been published. Rings and Richmond (1953) presented a brief survey on the mosquitoes collected by them during 1944 and 1945; the species listed by them, together with two additional ones, are included in this paper. The animals and plants actually collected or observed on Horn Island are listed in Part IV. Besides those collected by myself, species reported by other investigators are included. Longer study and more intensive collecting would doubtless result in many additions to the fauna and flora as known at present.

The Marine and Brackish Water Mollusca of the State of Mississippi

The study of marine life of the Gulf of Mexico has progressed slowly as compared to other regions of the United States. Much of this lack of progress is probably due to the absence of universities in the coastal area, and the absence of large populated centers where marine research would be encouraged. The early work was done by travelers and expeditions from places remote to the Gulf. Only in the present century has there been any attempt to establish marine laboratories on this seaside. Most of these laboratories have been located in rather remote, inaccessible places, and have usually suffered from inattention by the parent institution. In recent years, however, the search for oil, industrial growth of coastal cities, and the development of beach resorts have brought new roads and more people to the coast. During the same time the Gulf fishing industry expanded enormously, and, in value, became the largest fishery of the several important fishing regions of the United States. For instance, according to Fisheries Industries of the United States for 1956, the Gulf coast produced more in pounds and value than the Pacific coast, and more in value than the New England states. This new growth has stimulated a demand for more scientific knowledge of the Gulf and its waters. The scientific study of the Mollusca of the Gulf of Mexico has been carried on in the past in museums far from this region. The bulk of this work has dealt mainly with taxonomy, and even the geographical distribution of most species is poorly known. The writer’s purpose in the present work is to give a brief history of prior work on Mollusca along the Mississippi coast, to identify the species found in the area studied, and to discuss what is known of the distribution, abundance, and habits of many of the species. The work was done at the Gulf Coast Research Laboratory in Ocean Springs, Mississippi, and was carried on concurrently while the writer was engaged in other duties and activities. Most of the specimens were collected near the Laboratory or around Horn and Ship Islands, but both ends of Mississippi Sound received attention, and it is believed that the collections are representative of the entire area. The writer did not attempt to work in fresh water, and limited the marine collections to the area inside a line drawn one mile south of the barrier

Occurrence of Butterfly Fish in Mississippi Sound

Occurrence of Butterfly Fish in Mississippi Sound

Clay Mineralogy of Recent Sediments from the Mississippi Sound Area

AbstractRecent mud sediments of Mississippi Sound, Mobile Bay and contributory rivers contain a clay mineral assemblage composed essentially of kaolinite and montmorillonite. Illite is present as a minor component.The montmorillonite in these sediments appears to be at least partially complexed with organic material. This association is particularly evident in river and river mouth deposits and seems to be modified or partially destroyed in sea water. Organic material has been leached from river sediments with a sodium hydroxide solution and combined as a clay-organic complex with montmorillonite from Clay Spur, Wyoming.The clay mineralogy of sediments from Mobile Bay and areas outside of the barrier island chain is very similar to that of the river sediments. Within Mississippi Sound an apparent increase in the montmorillonite-illite content of the sediments relative to kaolinite from east to west is attributed to the invasion of mud from the Mississippi Delta into the western part of the Sound.Chemical analyses of these sediments along a section from fresh water to Mississippi Sound localities have shown a progressive increase in magnesium, potassium, and sodium, and a decrease in calcium.

Ecology of Foraminifera and Associated Microorganisms from Mississippi Sound and Environs

1. Foraminifera et cetera have been studied from approximately 400 surface-sediment samples in Mississippi Sound, the marsh and estuaries on the adjacent mainland, the barrier sand islands bounding Mississippi Sound on the south, and the open gulf outside the barrier islands. 2. The microfaunas in this area can be divided into four geographic and ecologic facies, as follows. a. The open-gulf facies occurs outside the barrier islands and is characterized by being composed mostly of calcareous Foraminifera, principally Nonionella atlantica, Cibicidina strattoni, Elphidium, various Miliolidae, Discorbis, and Rotalia beccarii var. Ostracoda are restricted to this facies. b. The sound facies contains arenaceous Foraminifera, principally Ammobaculites. c. The estuary facies is characterized by an abundance of Ammobaculites exilis and Ammosclaria fluvialis. Miliammina fusca is abundant. d. The marsh facies is characterized by Ammoastuta inepta, Arenoparrella mexicana, Leptodermella, Trochammina comprimata, T. macrescens, Urnulina, Haplophragmoides subinvolutum, and Recurvoides sp. Miliammina fusca is abundant. 3. A few subdivisions of these facies appear to be somewhat distinctive, as follows. a. Nearshore barrier-island faunas, generally characterized by low populations of Elphidium, Miliolidae, or Rotalia. b. Barrier-island lake faunas may contain a mixture of marsh and sound species, in some places with open-gulf species. c. Inner marsh samples are differentiated by abundance of Leptodermella and Urnulna. 4. There is mixing of faunas, as follows. a. The open-gulf faunas occur inside inlets between barrier islands and at some places behind the islands, where there is mixing with the sound fauna. b. The most abundant marsh and estuary species, Miliammina fusca, is mixed with the sound fauna near marsh areas, principally near the mainland. c. Marsh species occur in the estuary faunas, presumably due to mixing, and are most abundant where the estuaries are narrow. 5. The contrast between the open-gulf and the sound faunas is believed to be caused by the islands acting as a barrier to the invasion of the open-gulf water mass into the sound. This is aided by high runoff into Mississippi Sound. The presence of open-gulf faunas in the sound suggests that the routes of invasion of open-gulf water are along the bottom. Distributions of sound faunas in the open gulf probably reflect average hydrographic conditions. 6. In the San Antonio Bay area, near Corpus Christi, Texas, there are open-gulf and bay faunas similar to those in the Mississippi Sound area. Elphidium spp. and Rotalia beccarii vars. occur in the San Antonio Bay fauna. This is believed to be related to the low runoff so that most of the bay is undiluted open-gulf water. Few marsh and/or estuary species occur in the bay fauna. Atchafalaya Bay, a high runoff area with no barrier island, contains a mixture of bay, open-gulf, and marsh and/or estuary species.

Ecology of Foraminifera and Associated Micro-Organisms from Mississippi Sound and Environs: ADDENDUM

Ecology of Foraminifera and Associated Micro-Organisms from Mississippi Sound and Environs: ADDENDUM

DESIGN AND PERFORMANCE OF SEA WALLS IN MISSISSIPPI SOUND

The purpose of this paper is to describe briefly the various types of sea walls that have been constructed on Mississippi Sound, the performance of each type, and the conclusions with regard to sea wall design that can be drawn from this information.

Notes on the Forest Biology of Horn Island, Mississippi

Four islands, 8 to 13 miles f rom the mainland, separate the Mississippi coast from the Gulf of Mexico. These include Cat Island on the west, and Ship Island, Horn Island, and Petit Bois on the east. Horn Island is in Jackson County; the west end of the island, the longest one in the group, is 13 miles southeast of Biloxi, Mississippi, at approximately 300 13' N. and 88? 40' WV. The climate of Horn Island is mild; records available at Pascagoula, Mississippi, some 12 miles northeast, show a mean winter temperature of 52.9? F. and a mean summer temperature of 80.70 F. The highest temperature recorded at Pascagoula is 1010 F. and the lowest 160 F. The mean annual precipitation is about 58 inches, most of which falls during the warmer part of the year. Geologists believe that these coastal islands were at one time a part of the mainland, and that the entire Gulf coast is slowly sinking (McGee, 1891). The islands are separated from the mainland by a depression, which has become filled by the waters of the Gulf of Mexico, forming the Mississippi Sound. Soil samples taken at different places on Horn Island seem to substantiate this hypothesis, for in a number of places the soil is quite similar to that of the mainland. The nature of the bottom of the Sound, which is composed of hard clay, and the shallowness of the Sound, further substantiate this hypothesis of the origin of the islands and the sinking of the coast. Horn Island is 13 miles long and threefourths of a mile wide at its widest part. At the west end of the island is a sand bar approximately 2 miles long and at the east end another bar about one-half mile long (fig. 1). Between these sand bars the island is heavily wooded with slash pine.' Along the south (or Gulf) and north (or Sound) coasts, dune and beach sands form the major soils. In the interior of the island, are many depressions, some of which are inhabited by dune vegetation and others by marsh plants. In both conditions, Plummer fine sand predominates. This soil consists of fine, dark gray sand underlain by fine, white, water-soaked sand. This poorly drained soil supports scattered grass, which affords grazing for a hundred or more cattle. The sand bars at each end of the island are practically barren, the vegetation consisting mainly of widely scattered tufts of grass, with small patches of Croton and Hydrocotyle. Towards the interior of the island the ground rises to about 10 feet above sea level, and slash pine, together with an undergrowth of shrubs constitutes the major vegetation. On a few scattered patches on old dunes prickly pear occurs. At both the west and the east ends of the island sand dunes much higher than in the interior have buried tall pine trees to their crowns. Slash pine, the principal forest species, forms pure stands of various ages; the oldest trees measure 26 inches in diameter at breast height (d.b.h.) and are about 170 years old. Trees 12 inches or more d.b.h. are 90 to 100 years old, and those 8 to 10 inches d.b.h. probably are 40 to 50 years old. The reproduction ranges