grassflats. Although sea grasses may never have been a major component of Galveston Bay, they have 
been nearly eradicated from the estuary in less than 30 years. 
Information Needs 
There are many unanswered questions regarding this issue. Is land loss inevitable? If so, can man 
gainfully control the rate? If predicted atmospheric changes cause a greenhouse effect and contribute 
to a steady rise in sea level, what will be the extent of upland and wetland losses in Galveston Bay? 
Can new wetlands be created as fast as shorelines subside or erode? Does shoreline erosion contribute 
nutrients or toxicants to the bay? Can we model the processes of dredging and spoil disposal? Can 
dredged material be used to overcome subsidence and maintain or create wetlands? Will marshes 
created by man function in a similar manner as natural marshes? How long a period is required for 
full functioning to appear? How do natural versus created, man-made marshes compare regarding 
primary productivity, faunal community development, and the physical and chemical characteris¬ 
tics of the substrate? Are wetlands critical for fishery species, or can their functions be replaced by 
other habitats? Is displaced open-water habitat critical to fishery organisms? Is there an optimal 
open-water to vegetated-bottom ratio for estuaries, and if so, does it vary with the type of fishery 
organism or geographic location? Where is the nearest sand resource for beach nourishment? 
Energy Production in Galveston Bay 
The existence of petroleum and natural gas production facilities within Galveston Bay poses some 
unique environmental problems. Normal production activities create a number of bottom distur¬ 
bances. During the exploration phase, seismic activities involve the drilling of shot holes, energy 
pulse damage to benthic and pelagic species, and the physical disturbance of benthic species due to 
"spuddown" of work barges and propwash as seismic vessels operate in shallow water (see Appen¬ 
dix I). Site preparation activities often require dredging of access channels to the drill site. The bay 
bottom is soft, unconsolidated fine-grained mud that will not support drilling platforms. Site 
preparation usually requires dredging down to a firm clay base, and covering the site with a 2-foot 
deep pad of dead oyster shell to support the drilling barge. This impacts the bottom-dwelling 
organisms and increases turbidity nearby. The installation and removal of pipelines further disturbs 
the bay bottom. 
Drilling operations involve the disposal of fluids into the water column. Water used to rinse drill 
bit cuttings is routinely discharged into the bay. Production water, the brine produced from the wells, 
is also discharged into the bay, and may contain up to 25 ppm hydrocarbon material under existing 
Railroad Commission rules. Rig cleaning is usually performed by using bay water under high 
pressure to wash-down drilling barges when the drilling operation is completed. Oils and grease are 
washed overboard, along with quantities of drilling muds, solvents, soaps, degreasers, lubricants 
and other materials. The predominant drilling mud used in Galveston Bay is a barite-based 
compound outlawed in California for both offshore and onshore drilling due to heavy metal 
contamination of marine and ground waters. When a well is completed and a barge-mounted drilling 
rig prepares to leave the site, the bilge water is pumped into the bay to re-float the rig. Derelict 
structures and equipment left on-site by developers results in safety hazards and possible pollution 
problems. On the positive side, platforms and underwater structures provide attachment points for 
aquatic organisms in an environment typically poor in available solid substrates. The placement of 
oyster shell for drilling pads may enhance and diversify benthic communities. 
Information Needs 
The current and future impacts resulting from the discharge of fluids from energy production 
facilities need to be determined. Are the ecological impacts of energy-related bottom disturbances 
biologically significant? What is the cumulative impact of the concentration of production sites 
within this small area? 
Comprehensive Assessment of Cumulative Impacts 
It is readily apparent that the Galveston Bay System has been, is and will continue to be subjected 
to a number of external impacts that potentially may affect its productivity. Simultaneously, demand 
for its resources is increasing as the surrounding human population continues to grow. All 
ecosystems have limits on their ability to assimilate impacts. Historically, these limits have typically 
been unknown or unheeded until they have been surpassed. Other major estuaries—Chesapeake 
Bay, Delaware Bay, San Francisco Bay—have suffered major, perhaps irreversible, declines in their 
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