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In the history of OCS leasing substantial amounts of oil spilled from platforms have never reached the shore, and consequently, shore bird mortality has been negligible

However, two instances

of bird mortality due to tanker accidents have occurred in the eastern Gulf. In 1964, the tanker S.S. Brothers George, of foreign registry, became grounded in shoal waters just off Dry Tortugas. In spite of a specific order from the Coast Guard not to do so, her captain attempted to free her by offloading the cargo of fuel oil into the sea, thus decreasing her draft. The oil washed ashore, affecting nesting sooty terns and other shore and wading birds.

On February 14, 1970, the Greek tanker Delian Appollon ran aground, spilling a cargo of Bunker C in Tampa Bay. It was impossible to assess with accuracy the total number of birds harmed or killed because of northward migration of waterfowl taking place at the time. It is known that a total of 3,500 oiled birds were captured and treated. No estimate was made of the number that died untreated, or of those that did not survive following treatment (Florida Game and Freshwater Fish Comm., unpublished report). Although the brunt of this impact was borne by the estuarine waterfowl, some shorebirds were also killed during this incident.

Because no barging or tankering are anticipated as a result of this proposed sale, we do not predict this type of incident to be

repeated.

Indirect impacts on shorebirds include loss of habitat and nesting temporarily due to pipeline construction, and permanently, due

to the construction of onshore facilities.

Summarizing the impacts on the shoreline:

1) The source of impacts to the shoreline communities are oil

spills and pipeline construction operations.

The

possibility of large amounts of platform-spilled oil

reaching shore is thought to be extremely low.

2) In the event an oil spill reaches shore, a severe impact

is predicted for the benthic communities of jetties,

pilings, the sandy intertidal beach, and for shorebird
populations.

3) The natural removal of beached oil in the sale area is
predicted to be slow due to the relatively moderate energy
beaches present.

4) Impacts due to pipeline construction and burial operations through sandy beaches will result in the destruction of benthic intertidal organisms in the path of the operation. Recovery is thought to be fairly rapid. On the permanently exposed portion of the beach, devegetation could result in wind erosion, and shorebirds will be temporarily displaced from that portion of their habitat.

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It is difficult to conceive of any significant impacts

resulting from this proposal that would be sustained by any of the Texas bays. There is the remote possibility that oil could be found under the two tracts located about a dozen miles off Bolivar Roads, but they are considered to be gas prone, and liquid hydrocarbon production is expected to be minimal. These are the only tracts close enough to a bay entrance that, were spills to occur on them, oil could possibly penetrate a major estuary--the Galveston Bay system. However, if oil somehow penetrated the bay system the following impacts could be expected.

a.

Impact on Planktonic and Nektonic Estuarine Life

The effect of spilled oil on these estuarine forms

will be similar qualitatively to those described for pelagic marine life in the open Gulf in subsection B.1.above. In terms of quantity or severity, the estuarine spill will be worse for at least two

reasons:

1)

The estuary is, of course, a smaller, semi-enclosed body of water, and given the small Gulf tides, oil will likely remain more concentrated for a. longer period of time than in the open Gulf.

2) The larval and juvenile stages of many commercially and

ecologically important fish species are spent in the

estuaries and are therefore susceptible to a more

severe impact. It has already been pointed out that

larval stages are 10 to 100 times more sensitive to
oil contamination than their adult counterparts.

b. Impact on the Estuarine Benthos

Impacts will result from spilled oil and from pipeline burial. As with the planktonic and nektonic forms, we believe the effects on estuarine benthos will be qualitatively similar to those described for benthic communities of the open Gulf in subsection B.2. above. Because of the limited quantities of water involved, and the semi-enclosed configuration, the impacts will express themselves more severely.

One unique feature of the estuarine benthos is the commercially and ecologically important oyster reef. Both commercial and noncommercial beds occur in the estuaries adjacent to the sale area.

Oyster reef communities will sustain a significant impact in the event a massive oil spill penetrates the bay.

Galtsoff (1959) noted that the major effect of industrial wastes and soluble components of crude oil is a reduction of the rate of various physiological functions, principally, ventilation of the gills. Specifically, these pollutants cause a reduction in the amount of time during which the oyster opens its valves for feeding and respiration, and also interferes with the coordination of the ciliary motion with the result that the pumping capacity of the gills is

reduced. The reduction in feeding time (simultaneous with respiration) results in a lowered growth rate and poor quality oyster meats. It is well known that oysters can become contaminated with oil (Erhardt, 1972; Galtsoff, op. cit.; Mackin, 1962) both from a massive spill and chronic low-level spillage.

However, there is still a lively debate by several scientists as to whether the oysters can cleanse themselves when the water is again free of oil. Oil contamination imparts an oily taste to oysters, rendering them unmarketable.

The only other possible impacts could result if a pipeline were to be laid across a bay. As stated earlier, even determination of the need, let alone the routing of any new pipelines, is rendered difficult because of an OCS sale just held in this area. The routing of a pipeline onshore will depend also on the granting of permits by the appropriate State or local agencies.

In addition it is more prudent for the pipeline owners to route the line across firm land where emplacement and burial is more convenient and economical. However, because a pipeline route across a bay cannot be completely ruled out at this time, its impacts should be considered.

Because pipe burial produces roughly similar effects to routine navigation channel dredging, literature on the latter will be consulted in an attempt to predict the potential impacts.

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