of rodents and probably rabbits as herbivores, with predators being mostly snakes, hawks, and owls.

Herbivorous grazers of region 3, the brackish to fresh water marsh,

are mostly nutria, muskrat, and the swamp rabbit (Sylvilagus aquaticus), and numerous species of waterfowl. Predators are again snakes,

predaceous diving birds, hawks, owls, and rarely mink.

Alligators,

largely omnivorous, occur in some parts of the marsh and in east Another omnivore here is the Gulf spotted

Texas lakes and streams.

skunk (Spilogale indianola).

The closed brackish marsh, region 4, is believed to have nearly the same fauna as region 3, based upon the limited amount of information available at the time of this writing.

More important than the food chain originating with the grazing of fresh marsh grass is that known as the "detrital food chain". Odum (1961) cited studies which showed that less than 5% of net production of marsh grass (Spartina) is consumed "on the stalk" by insects and other grazers. Most of the marsh primary production is channeled through the detritus food chain. As grass dies and falls into the water, the abundant microorganisms convert it into particles rich in bacterial and algal growth and containing abundant proteins, carbohydrates, and vitamins.

This material is consumed by all types of invertebrate animals including protozoans, nematodes, annelid worms, bivalve molluscs, micro

crustaceans, grass shrimp, insects and the vertebrate filter-feeding

fish. These, in turn, are grazed or preyed upon by filter-feeding and predatory fish, decapod crustaceans, insects, waterfowl, shorebirds and predatory diving birds, muskrats, nutria, alligators, frogs, snakes, turtles and others.

Thus, whether marsh production is finally channeled into predatory fish, hawks and owls, alligators, or human food stuff, much of it passes from marsh grass into the detrital food chain and up through other trophic levels.

Region 6, the prairie grassland, has major herbivore populations of rodents, rabbits, quail and prairie chicken that are preyed upon by snakes, coyotes, hawks and owls.

No information could be found about fauna of the Intracoastal Waterway and its dredge spoil banks.

All of the regions mentioned above must certainly have a wider variety of animals and plants than is presented here, but information for the segment of Texas coastline from High Island to Sabine Pass is very scant. No information whatsoever could be found for open water areas in the brackish marsh, such as Star Lake in the transect, but certainly, they must contain a complete aquatic system with import and export from and to the surrounding marsh and upland. It can be assumed however, that these ponds and bayous are of minor importance as habitat for species of animals spending part of their lives at sea and part in

estuarine areas, such as the white and brown shrimp, because communica

tion with the sea is indirect and tortuous, through Salt Bayou,

several ponds, and Sabine Pass.

3. Trinity River Bay-Head Deltaic Marsh and Swamp

This section of coastline is somewhat remote from the proposed sale area, but is an integral part of the bay system and will be given brief attention here. Most of the information given here, along with the simplified transect (Fig. 16; transect b. of Fig. 13b) from Fisher et. al., (1972).

The entire transect is underlain by the Kaufman-Tuscumbia-Nahatche soil association, which is composed of non-calcareous and calcareous, cracking clayey soils and calcareous loamy soils; and strongly acid clayey and loamy solids. Characteristics are very low permeability, high water table, high water-holding capacity, very poor drainage, low shear strength, very poor load-bearing capacity, and high organic content. The lower portion is subject to frequent tidal inundations and the high portion to occasional salt-water flooding (Fisher, et. al., 1972; and U.S. Dept. of the Army, 1973).

Region 1 is Trinity Bay and will be discussed elsewhere except to mention here that its edge marks the beginning of a salt-water marsh,

and that it receives considerable nutrient import from marsh, swamp

and stream above.

Tide Range

Region 2 is the salt-water marsh which corresponds roughly to an area from 6 inches below mean bay water level to just above high tide level. Vegetation here is cordgrass, glasswort,

seepweed (Suaeda spp.), maritime saltwort (Batis maritima) sea oxeye (Borrichia frutescens).

According to Renfro (1959), the salt cordgrass is the only species growing partly submerged in bay waters, probably because of the general turbidity of the water and the unsuitable bottom sediments.

Region 3 is a brackish water marsh. Near its upper limit, it grades into a fresh-water marsh, but near its lower limits, it approaches a closed brackish water marsh. Thus, vegetation gradually changes from the more salt-tolerant spartinas of the salt marsh through the euryhaline spartinas and saltgarass and rushes to the more oligohaline coastal sacahuista, spartinas, cattails, bullrush and rushes.

Region 4 is an inland fresh-water marsh and receives bay salt water only rarely during high hurricane tides. Most of the water is supplied by precipitation and river run-off. Dominant plants here are rushes, bullrush, cattails, and sloughgrass (Spartina pectinata). Toward the upper end, where the wetland is more poorly drained, a swamp has developed (Region 5). The swamp association includes cypress (Taxodium distichum), elm (Ulmus spp.), water oak (Quercus nigra),