The Observer, September 2004
Tracking the Sound’s environment
By Lisa Ka’aihue
Project Manager
After the Exxon Valdez oil spill of 1989, one of the problems with figuring out the extent of environmental damage was that there was no “before” to compare against the “after.” There had been no long-term monitoring of Prince William Sound’s health.
That changed with the passage of the Oil Pollution Act of 1990, which required environmental monitoring of the Sound.
Scientist Bill Driskell (left) collects blue mussels (right) from Sleepy Bay in Prince William Sound on a recent sampling trip. The council’s environmental monitoring program collects the mussels twice a year from 10 intertidal sites inside and outside the Sound. Photos by Lisa Ka’aihue, citizens’ council.
Thus was born the council’s Long-Term Environmental Monitoring Program. It started in 1993 at nine sites inside and outside the Sound. Its purpose is to detect oil pollution resulting from the operations of oil tankers and Alyeska’s Valdez terminal. The council program is based on a national program called “Mussel Watch,” which monitors levels of many toxic chemicals by analyzing the tissue of mussels collected from the seabed.
The council program now has ten sites. There are two in Port Valdez, five elsewhere in the Sound, two on the outer coast of the Kenai Peninsula, and one on Shuyak Island near Kodiak.
The two sites in Port Valdez receive the most intensive monitoring because they are so near the Alyeska tanker terminal. Mussels are collected there three times a year, and bottom sediments are collected as well.
Scientists visit the other eight sites twice a year to take mussel samples, but do not collect sediments.
The samples are shipped to a laboratory to analyze the tissue and sediment for hydrocarbons. Besides measuring the levels of hydrocarbons, the laboratory also “fingerprints” them, a process that tells where any crude oil in the mussels came from.
This technique can identify a long list of oils found in the Sound and nearby waters: North Slope crude; residual oil from the Exxon Valdez spill; oil products and discharges from the Alyeska terminal; oil from shale, coal or peat deposits; oil seeps from the Gulf of Alaska; and oil spilled during the Good Friday earthquake of 1964.
The council program, now in its 11th year, is the longest continuous record of regular mussel sampling in the region. The results are summarized in an annual report for the council. So far, the results show that the sites monitored are typically free from levels of oil pollution that would cause concern under current standards. The levels in the Port Valdez samples tend to be higher, but they are still fairly clean sites.
The most significant oil pollution sources picked up the program were related to an oil spill in Port Valdez in 1994, a sheen that escaped from Alyeska’s Ballast Water Treatment Facility in 1997, and oil from the Exxon Valdez that is occasionally evident at two sites heavily affected by the spill.
This year, the program will be expanded by adding sampling sites at Knight Island in a joint effort with NOAA’s Auke Bay Laboratory. The expansion is being funded by the Exxon Valdez Oil Spill Trustee Council.
Long-term monitoring is time-consuming, expensive, and difficult to fit into short-term budget cycles of institutions. But its value cannot be overstated. Such long-term sets of biological data are important in documenting ecosystem changes and determining if the changes are due to natural causes, such as variations in weather patterns, or to human causes, such as oil transportation activities.