Northwest Fisheries Science Center

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Document Type: Contract Report
Center: NWFSC
Document ID: 7759
Title: Columbia River oil spill study, June-July 1978
Author/Editor: Theodore H. Blahm, Joseph T. Durkin, George R. Snyder, Travis C. Coley, Robert L. Emmett
Publication Year: 1980
Publisher: National Marine Fisheries Service
Contracting Agency: U.S. Environmental Protection Agency. Seattle, Washington
Contract Number: EPA-78-D-X-0390

The purpose of this report is to outline the conduct and results of a short-term study done subsequent to an oil spill in the Columbia River near Portland, Oregon.  During the evening of 27 June 1978, the MS Toyota Maru No. 10 ruptured a fuel tank while hauling anchor near Columbia River Mile (rm) 102.5.  Between 30 and 58 thousand gallons of Bunker C (no. 6) fuel oil were released into the Columbia River.

Our major concern was the potential impact of the oil on juvenile chinook salmon (approximately 80 million) that were in the peak of their downstream migration; the oil could have affected them from rm 102.5 to the ocean.  Also of concern was the potential impact on other fish and aquatic organisms.

Bunker C oil components were found in the sediments from rm 105 to 4.5.  Globules of Bunker C residue were dragged off of the bottom with leadlines of nets at all beach-seine sites.  Residue was also found 13 inches deep in the beach sand near rm 72.  Oil in and on the bottom of the river and deep in the beach sand could not be removed, and subsequently it could cause alterations of the aquatic environment (from leaching, etc.) resulting in a degrading biological affect of some degree and consequences.  In addition:

  1. Bunker C oil components were identified on the water surface of the Columbia River at rm 18.
  2. Bunker C oil fractions were identified from 24 of 28 sediment samples taken from crm 4.5 to 105.
  3. Three of eighteen fish flesh samples contained significant Bunker C fuel oil components, while three additional samples were contaminated with petroleum hydrocarbons to a lesser degree.
  4. Finfish (demersal and pelagic) captured in the sampling gear employed showed a decrease in diversity and abundance from before to after the oil spill between rm 28 and 102.
  5. Previous stomach sampling (prior to spill) confirmed that finfish consumed those species of benthic invertebrates and insects which occur in Columbia rm 4.5 10 2.
  6. Fall chinook salmon juveniles were the only species that occurred in sufficient numbers after the spill to examine their stomach contents, which was mostly digested material, indicating that the food had been consumed prior to the spill or out of the affected area.
  7. Benthic infauna near the spill site sampled after the oil spill showed an increase from previous sampling; however, overall abundance during both samplings was relatively low.
  8. Benthic sampling between rm 4.5 and 29 revealed that 12 of 14 sites had fewer organisms per m2 right after the oil spill, but recovery to pre-spill levels was indicated in February 1979 samples.  The increase in numbers of organisms is partially attributed to seasonal variation.
  9. Dead amphipods (important food source) collected near Kalama, Washington were covered with Bunker C residue.

We did not find dead fish.  Our observations were based on catches of live fish, which could be survivors of pre-spill populations.  Indications from the data collected, and our observations in relation to finfish, benthic invertebrates, and sediments are that changes occurred which demonstrate an impact on the biota of the Columbia River and its estuary.  However, even with extensive riverine fishery baseline data in the area of an oil spill and the downstream reach, it is unlikely, using the present assessment approach, that conclusions could be made regarding the extent of damage to finfish resources from a Bunker C spill of the magnitude of Toyota Maru No. 10.

The National Marine Fisheries Service has recently prepared guidelines for collection and handling of environmental samples for trace analyses of organic chemical contaminants and for microscopic examination.  Chain of custody procedures are included in the guidelines; if followed precisely they will provide docume