Pecan Island Research Articles

South Pecan Island freshwater introduction restoration project, Louisiana, USA

Wetlands in Louisiana’s Chenier Plain are undergoing persistent deterioration that will become increasingly problematic if not adequately addressed. Many projects are proposed with the goal of protecting or restoring the wetlands. One such type of projects is freshwater introduction, aims to decrease the salinity levels in a marsh. The project is located in the Mermentau Basin in southeastern Vermilion Parish, Louisiana. The study allows freshwater to drain into the Chenier subbasin, while reducing the effects of excess water in the Lakes subbasin. The area is studied using the aerial view geographic information systems (GIS) map alongside with the aerial photos and LiDAR images of canals located near Pecan Island. Moreover, the general mass-balance formulas for both water level and salinity are derived.

Species Diversity of Louisiana Chenier Woody Vegetation Remnants

NEYLAND, R. AND H. A. MEYER (Department of Biological and Environmental Sciences, McNeese State University, Lake Charles, LA 70609-2000). Species diversity of Louisiana chenier woody vegetation remnants. J. Torrey Bot Soc. 124:254-261. 1997-The cheniers of southwestern Louisiana are linear arrayed ridges up to 3 meters high and 450 meters wide. These prehistoric shorelines now stand as relict islands surrounded by coastal marsh. Although the chenier woodlands were once extensive, most have now been converted to rangeland, roads and homesites, and therefore presently exist as remnants. The woody species in six remnant sites were sampled in order to determine species diversity and importance. High numbers of the introduced species, Sapium sebiferum (L.) Roxb., resulted in species diversity in the two Little Chenier sites being significantly lower than those on Grand Chenier, Tiger Island and Pecan Island. This appears to be due to a higher level of habitat destruction in the Little Chenier than in the other cheniers. Importance values suggest a high degree of heterogeneity among the sites chosen for study. For example, Quercus virginiana L. Celtis laevigata Willd., Cephalanthus occidentalis L. and Sapium were each the most important species in at least one of the sampled sites. An ordination of the six sites suggests that only three sites form an ecologically meaningful cluster and the remaining three sites are clearly segregated from all others. The ordination pattern may be due primarily to varying levels of habitat destruction as a result of historic anthropogenic activity.

The geomorphology of the Mississippi River chenier plain

The chenier plain of the Mississippi River is a shore-parallel zone of alternating transgressive clastic ridges separated by progradational mudflats. The term chenier is derived from the cajun term chene for oak, the tree species that colonizes the crests of the higher ridges. The Mississippi River chenier plain stretches 200 km from Sabine Pass, Texas, to Southwest Point, Louisiana and ranges between 20 and 30 km wide, with elevations of 2–6 m. The timing and the process of formation could be re-evaluated in the light of new chronostratigraphic findings in the Mississippi River delta plain. The stratigraphic relationship between the Teche and Lafourche delta complexes and Ship Shoal offshore indicates that these delta complexes belong to different delta plains that developed at different sealevels. It appears that the Teche delta complex is associated with the late Holocene delta plain which developed 7000 to 3000 yrs B.P. when sealevel stood 5–6 m lower than present. A regional transgression occurred between approximately 3000 BP and 2500 yrs B.P., leading to the transgressive submergence of the late Holocene delta plain, producing the regional Teche shoreline. The timing of this transgression conforms to the age of the most landward ridge in the chenier plain, the Little Chenier-Little Pecan Island trend, which dates at about 2500 yrs B.P. This ridge trend was originally interpreted as representing the Teche delta complex switching event with the landward Holocene/Pleistocene contact representing the high stand shoreline. The implication of this new interpretation is that the Little Chenier-Little Pecan Island trend represents the high stand shoreline, a continuation of the Teche shoreline separating the late Holocene and Recent delta plains, and that the Holocene/Pleistocene contact represents the leading edge of the marshes transgressing onto the Prairie Terrace. Significant mudflat progradation seems to require a westerly position of the Mississippi River, but the numerous different forms and ages of cheniers do not correspond well to the timing of major delta complex switching. Progradation of the chenier plain appears to be associated with building of the Recent delta plain and not the Teche complex of the late Holocene delta plain. The occurrence of individual ridges appears to be primarily tied to delta lobe switching within the Lafourche complex and variations in sediment supply from local rivers. The recent development of the Atchafalaya delta complex to the west is the closest position of an active distributary to the chenier plain since sealevel stabilization; a new episode of rapid mudflat progradation is thus taking place.

North Pecan Island Field: a Mature Trend Discovery in Miocene of Southern Louisiana: ABSTRACT

The Exxon 1 M. J. Epley discovery well for North Pecan Island field was completed in early 1982 as a discovery of significant new gas and condensate reserves in the mature Miocene trend of south Louisiana. The field is located in Vermilion Parish within a large megablock between 2 major down-to-the basin growth-fault systems and is on the southern end of a south-plunging structural nose. Traps in 2 fault segments are formed in southeasterly dipping beds upthrown to 2 north-dipping, sealing faults. Six separate Robulus chambersi sandstones contain gas and condensate reserves. Major gas and condensate reserves from sandstone reservoirs in the R. chambersi section were discovered in the mid-1960s 3.3 mi. west in the Pecan Island field and in the North Freshwater Bayou field, 5 mi northeast of the North Pecan Island field discovery. Several earlier dry holes just north of the discovery were drilled seeking to extend production from the upstructure Fire Island field (3 mi north), which produced a limited amount of gas and condensate from R. chambersi sandstones. Extensive structural and isopach mapping, aided by new high-resolution seismic data, revealed the North Pecan Island prospect to be structurally high to production at Pecan Island and that the prospective section was deposited over a growing paleostructure. Four wells have been completed to date in the field, with flow rates as high as 30 MMCFGD. Current estimates place the new field recoverable at approximately 250 bcf of gas and 6 million bbl condensate. End_of_Article - Last_Page 236------------

Feeding Ecology of Gadwalls in Louisiana in Winter

Feeding ecology of gadwalls (Anas strepera) wintering in southwestern Louisiana was examined during November-March 1977-78. Gadwalls consumed 95.3% plant vegetation, 0.5% plant seeds, and 4.2% animal matter. Algae comprised one-third of the diet, and common widgeongrass (Ruppia maritima), dwarf spikerush (Eleocharis parvula), spiked watermilfoil (Myriophyllum spicatum), and baby pondweed (Potamogeton pusillus) were also important foods. Diet was similar for both sexes, and food preference was usually related to relative abundance of available foods. Wintering gadwalls consumed large amounts of vegetation to meet metabolic requirements, thus habitat management practices should ensure the production and availability of nutritious and preferred foods during October-May. J. WILDL. MANAGE. 46(1):71-79 Over 1 million waterfowl winter in southwestern Louisiana (H. A. Bateman, unpubl. reps., La. Wildl. and Fish. Comm., 1977-78). Many areas have been modified through construction of impoundments and weirs that regulate water levels and increase production of waterfowl foods (Chabreck 1976). However, thousands of hectares of habitat are lost annually due to oil and commercial development, channelization, diking, erosion, and saltwater intrusion (Duffy 1974). Concern over habitat loss and the welfare of wintering waterfowl has stimulated interest in the requirements of wintering waterfowl and how well present management meets these requirements (Fredrickson and Drobney 1979). Gadwalls comprise over one-third of the wintering duck population in southwestern Louisiana (Bateman, unpubl. reps., 197778). Gadwall numbers in managed areas have increased dramatically in the past few decades (Perry et al. 1971). Previous feeding-ecology studies of wintering gadwalls have been confined to the southeastern United States, and did not assess seasonal variation in diets (Kerwin and Webb 1972, Landers et al. 1976). I examined the feeding ecology of gadwalls to identify seasonal requirements and suggest modifications in present management practices that may better provide for dietary needs. I thank R. Crawford, T. Joanen, L. McNease, K. Paulus, D. Trauger, and W. Wrenn for help during the study. I am grateful to personnel of Sabine National Wildlife Refuge and Little Pecan Island Hunt Club, B. Richard, and hunters for providing gizzards. P. DuBowy helped with invertebrate identification, R. Carlson with proximate analysis of foods, and A. Afton, R. Blohm, R. Sayler, G. Swanson, and 2 anonymous referees with manuscript review. Financial support was provided by the U.S. Fish and Wildlife Service, University of North Dakota, and the Society of Sigma Xi.

The Morgan Site: An Important Coles Creek Mound Complex on the Chenier Plain of Southwest Louisiana

The chenier plain of southwest Louisiana supported a relatively dense population in the Coles Creek period. The Morgan site, located on the Pecan Island chenier, was a major center for the local inhabitants in Middle and Late Coles Creek times (c. AD 800–1000). Recent excavations at this site by the Lower Mississippi Survey resulted in the delimitation of the site, revealing areas of intensive occupation. A rich midden was tested to work out temporal changes in the local ceramics of the Coles Creek period. The excavation techniques employed enabled us to distinguish micro-evolutionary changes within the Baytown Plain rim mode assemblage recovered at Morgan. Determining such changes within the ceramics of the Coles Creek period has contributed to the relative dating of the Morgan mounds. The excavation methods presented here provide a means for ascertaining which Coles Creek components in the region were occupied contemporaneously. This information is fundamental to further studies on settlement and subsistence in the chenier plain.

Developments in Louisiana Gulf Coast in 1974

The Louisiana Gulf Coast region consists of the 38 southern parishes of Louisiana and 21 continental shelf areas extending out to the 6,500-ft water-depth limit. There were 1,724 exploratory and development wells drilled in 1974, a decrease of 12% from the previous year. Of the exploratory wells, 21% were successful. Success for development wells was 67% for 1974. A total of 23 significant new-field discoveries was drilled in 1974, 10 onshore and 12 offshore. The most important are South Timbalier Block 37, Eugene Island Block 367, Jennings Townsite, Raccoon Lake, North Vinton, West Johnson's Bayou, and Hopedale Lagoon. The most significant of the new pools and extensions are Eugene Island Block 313, South Pass Block 62, South Marsh Island Block 128, Vermilion Block 331, Pecan Island, Pine Prairie, Mystic Bayou, and Golden Meadow. Geophysical activity increased 4% onshore and 8% offshore. Evaluation of recently acquired leases and anticipation of future sales account for the increase offshore. Record amounts were bid for leases offshore in March 1974, and royalty bidding was introduced at the October Federal Lease Sale.

Developments in Louisiana Gulf Coast in 1973

The Louisiana Gulf Coast region consists of the 38 southern parishes of Louisiana and 21 continental-shelf areas extending out to the 6,500-ft water-depth limit. There were 1,966 exploratory and development wells drilled in 1973, a decrease of 0.9% from the previous year. Of the exploratory wells, 21% were successful. Success for development wells was 72% for 1973. A total of 20 significant new-field discoveries was drilled in 1973, 6 onshore, 14 offshore. The most important are Bayou Sherman, Bay Lizette, South Bayou Boeuf, South Marsh Island Block 131, Eugene Island Block 342, South Marsh Island Block 269, and West Cameron Block 643. The most significant of the new pools and extensions are Gibson, Pecan Island, Eugene Island Block 333, and Eugene Island Block 339. Geophysical activity declined 28% onshore and increased 43% offshore. This increase in offshore activity is attributed to the revitalized federal leasing program. Leasing activity onshore declined 15% from a year ago with the downdip Miocene trend being the most actively leased. Only 5 tracts were leased offshore compared to 178 last year.

Pecan Island

The Mississippi delta is a complex consisting of the recent bird-foot delta and several fossil deltas now modified by the isostatic downwarping of this region localized on the edge of the active Gulf-geosyncline. Chenier Islands are stranded sand beaches in a marshland environment. Initially formed along the sea shore they indicate former coast lines. On the chenier plains of south-western Louisiana hurricanes have significant geomorphic effect. In the paper the interplay between chenier formation and delta development is discussed based on the results of Rich. J. Russell's research work. The description utilizes the author's observations from field trips in 1959 and 1963.

Pecan Island. A Chenier Ridge in the Mississippi Marginal Delta Plain

Pecan Island. A Chenier Ridge in the Mississippi Marginal Delta Plain

Notes on Little Pecan Island, Louisiana

On May 25, 1946 Mrs. Wauchope and I were the guests of Mr. and Mrs. M. L. Vincent, Jr., of Lake Charles, Louisiana, on a picnic to Little Pecan Island in southwest Louisiana. During the day, we made a small excavation to sample a ridge which had previously yielded some human bones and fragments of pottery.About five miles of marsh separate Little Pecan Island from Grand Chenier Ridge, not far from the town of Grand Chenier (Fig. 54). The waters of Little Pecan Lake wash its north and east shores. The island is about three miles long and is nowhere over 500 yards in width.

VII Interpretations and Conjectures

A comparison of Tchefuncte traits suggests that there are three groupings or foci which at present comprise the Tchefuncte culture. The Copell site on Pecan Island, although a single site, represents the first group. The absence of pottery, presence of artifacts with burials, interment in a cemetery, and other traits tend to isolate this component from other Tchefuncte groupings.The three shell midden sites, Tchefuncte, Little Woods, and Big Oak Island form another grouping. The construction and use of shell middens, presence of certain types of bone and shell artifacts, and styles of chipped flint projectile points differentiate these midden sites from the others.The third grouping is represented by the two mound sites, Lafayette and Lake Louis. The traits of circular mounds, differences in the styles of projectile points, and absence of other Tchefuncte traits delimit this focus.A number of traits held in common, or traits which overlap from one component or site to another, link all of these groupings together to form the Tchefuncte culture. For instance, burial traits and styles of bone implements link the Copell site with the midden sites of the Tchefuncte period. The midden sites and the mound sites are bound together by common types of pottery and pipes. For the reader who disagrees with our interpretations, or who has a better method, we have listed all of our traits in the summaries of each component (Chapter II).