Marine Science

"The chemical component of these studies had two major objectives: 1) to characterize the composition of various IXTOC I oil samples representative of different stages of weathering and 2) to characterize oil-seawater mixtures prepared from the specific mousse sample tested for acute toxicity. ... An attempt was made to assess acute toxicity of Mexican Oil to mixed phytoplankton populations and seagrasses by comparing photosynthetic rates in the presence and absence of a seawater-soluble fraction or oil-accommodated seawater preparation. ... Since oil from the IXTOC I may be in Texas waters while redfish are spawning and since the early stages in the life cycles of most organisms are usually considered to be those most susceptible to deleterious perturbations, it was decided to ascertain the effect of Mexican crude on redfish eggs and larvae. ... Two series of experiments were carried out on the acute toxicity of oil accommodated in seawater (OAS), made from the spilled Mexican oil. ... We investigated effects of oil on four species of invertebrates that included the commercial brown shrimp, Penaeus aztecus, a sandy beach bivalve, Donax variabilis, an intertidal burrowing detrital feeding polychaete, Scolelepis texana, and a common tidal crustacean, Emerita sp., important in tidal marine food webs (e.g. shore birds). ... Initial toxicity tests were conducted on adult C. nebulosus at various concentrations of oil accommodated in water (OAW) prepared from samples of 'mousse' collected by the U.S. Coast Guard Cutter Point Baker. A second set of toxicity tests were made utilizing fingerling or underyearling trout to ascertain size-related effects"--From each section's introduction.
Submitted to Environmental Protection Agency in fulfillment of Department of Transportation Contract DOT-CG08-8174
August 29, 1979