for the Galveston Bay System, are strongly influenced 

 by the significant amount of nursery area in East Bay 

 (appendix 6.2). Parker (1970) documented the signifi- 

 cance of East Bay as a nursery and migratory route for 

 juvenile brown shrimp, Atlantic croaker, and spot in 

 the Galveston Bay System. The oyster harvest of Gal- 

 veston Bay is greatly dependent on reefs in East Bay, 

 particularly Hanna's Reef, Elm Grove Reef, Moody's 

 Reef and Frenchy's Reef. These reefs have been in ap- 

 proved oystering areas since the mid 1950's (Hofstet- 

 ter 1977). Records of the Texas Parks and Wildlife 

 Department (see appendix 6.3) indicate that muskrat 

 and nutria densities are comparable to the Louisiana 

 portion of the Chenier Plain but the habitat for these 

 species is less extensive in Texas. 



Waterfowl are also valuable resources of the basin. 

 Some 20 species of ducks and geese winter in this area 

 around the Anahuac National WUdlife Refuge. Other 

 marslies on the north shore of East Bay centering 

 around Robinson Lake, Wallis Lake, Lake Surprise, 

 and East Bay Bayou support large populations of the 

 lesser snow goose, Canada goose, white-fronted goose, 

 mottled duck and the fulvous tree-duck. This area also 

 provides habitat for marsh and shorebirds and includes 

 such species as roseate spoonbill; common, snowy, and 

 cattle egrets; yellow-and-b lack-crowned night herons; 

 least and American bitterns; eared and pied-bill grebes; 

 long-billed curlew; whimbrel; common snipe and a 

 variety of smaller shore birds and gulls. Less common 

 species include: white-faced, and white ibises; oliva- 

 ceous, and double-crested cormorants; anhingas; and 

 white pelicans. All six species of North American rails 

 reside here. Mourning doves and bob-white quail are 

 found in the area. Five species of sea turtles are indig- 

 enous to the area and include the Atlantic ridley, 

 hawksbill, leatherback, green, and loggerhead. The 

 peregrine falcon, Southern bald eagle, brown pelican 

 and the red wolf have been sighted in the area (Lard 

 1978). 



Socioeconomics. Mineral extraction, manufactur- 

 ing, and agricuhure (fig. 3-12) provide the main 

 sources of employment in East Bay Basin. Oil and gas 

 are by far the most valuable product of the basin, 

 worth $91 million per year. Commercial fish and fur- 

 bearers produce an annual income of about $2.9 mil- 

 lion, agriculture $2.6 million, and sportfishing and 

 hunting an estimated $5.5 million. These figures sug- 

 gest tliat because of the basin's proximity to large 

 urban centers the game sportfish, and waterfowl are 

 the most important renewable resources of the basin. 



Effects of Human Activities on the Environment. 



Hydrologic effects : The hydrology of East Bay Basin 

 has been modified by several cultural activities and is 

 influenced seasonally by others. River discharge, tidal 

 currents, and circulation patterns have been modified 

 by human activity. The predominant factors appear 

 to be the opening of Rollover Pass and the GIWW. The 

 opening of Rollover Pass has improved circulation, 

 particularly in the upper end of East Bay. 



Oyster reefs in most of East Bay are healthy, 

 showing that water quality and circulation is ade- 

 quate. Upland agriculture, particularly rice farming. 



uses weirs on streams to control drainage and salinity. 

 This restricts water exchange between the marshes and 

 the bay. However, Uttle information is available about 

 the flushing frequencies for these wetlands. The banks 

 of East Bay Bayou are actively eroding because of 

 agricultural development, and creating sedimentation 

 problems downstream (U.S. Department of Agricul- 

 ture 1976). Water that is rich in nutrients, particularly 

 nitrogen and phosphoms, enters East Bay via the 

 GIWW from the Sabine Basin, suggesting the chemical 

 pollutants could be transported to East Bay from 

 the Beaumont-Port Arthur-Orange area (James et al. 

 1977). 



Canal density in East Bay basin is the lowest of 

 the entire Chenier Plain (1.5% of the land area). Oil 

 and gas development has resulted in the impoundment 

 of weflands through road construction (appendix 6.2). 



Beach and shoreUne erosion and the effects of 

 Rollover Pass and Bolivar Roads on sedimentation and 

 erosion have been well documented (U.S. Army Corps 

 of Engineers 1951, Jaworski 1971,Prather and Soren- 

 sen 1972, Seelig and Sorensen 1973, McGowen et al. 

 1977, and Morton 1977). Rollover Bay appears to be 

 filling with sediment derived from the Gulf beaches as 

 well as from upstream drainage areas. Approximately 

 200 ha (494a) of this bay are now less than 0.5 m 

 (1.6 ft) deep. Likewise, beach erosion and sediment 

 movement out of Rollover Pass appears to have con- 

 tributed to progradation of beaches on Bolivar 

 Peninsula north of the north jetty. 



H abitat effects : Habitat distribution in the East 

 Bay Basin is shown in plates 3A and 4A, and table 

 3.75. The rate of wetland loss to open water that 

 cannot be explained by cultural activities is 0.08%/yr, 

 a figure comparable to the low rate in the Vemiilion 

 Basin. This low rate is attributed to the natural firm- 

 ness of the substrate in East Bay Basin. The overall 

 wetland loss for East Bay Basin was 6.9% during the 

 period from 1954 to 1974 (table 3.75). The largest 

 loss resulted from fill placed on wetlands for im- 

 poundment levees. Since 1954, 87 ha (215a) have 

 been used for the construction of canals and for the 

 disposal of dredged material from the GIWW and 

 from canals for housing developments on Bolivar 

 Peninsula. 



Other habitat changes since 1954 are rather small. 

 Urban growth has altered natural ridge and agricul- 

 tural habitat and is expected to continue, particu- 

 lariy on Bolivar Peninsula. 



Effects on renewable resources : The opening of 

 Rollover Pass seems to have been beneficial to estu- 

 arinc organisms. Reid(1955, 1956) conducted an eco- 

 logical study of East Bay before and after the opening 

 of the pass. His data revealed a nearly two-fold in- 

 crease in salinity in the upper end of the bay and an 

 accompanying increase in salt-tolerant organisms. The 

 oyster fishery has continued to thrive in East Bay 

 although the salinity levels have increased. Shell dredg- 

 ing activities during the 1960's removed large quanti- 

 ties of oyster shell from East Bay and surrounding 

 areas. Sedimentarion from these dredging activities 

 smothered many adjacent hve oysters and covered 



150 



