Research about Gulf of Alaska, Prince William Sound

USGS2001

Persistence of oiling in mussel beds after the Exxon Valdez oil spill

Persistence and weathering of Exxon Valdez oil in intertidal mussel ( Mytilus trossulus ) beds in Prince William Sound (PWS) and along the Gulf of Alaska was monitored from 1992 to 1995. Beds with significant contamination included most previously oiled areas in PWS, particularly within the Knight Island group and the Kenai Peninsula. In sediments, yearly mean concentrations of total petroleum hydrocarbons ranged from <60 μg/g in reference beds to 62,258 μg/g wet wt., or approximately 0 to 523 μg/g dry wt. total polynuclear aromatic hydrocarbons (TPAHs). In mussels, mean TPAH concentrations ranged up to 8.1 μg/g dry wt. Hydrocarbon concentrations declined significantly with time in some, but not all mussels and sediments, and should reach background levels within three decades of the spill in most beds. In 1995, mean hydrocarbon concentration was greater than twice background concentration in sediments from 27 of 34 sites, and in mussels from 18 of 31 sites.

Alaska↗

USGS1978

Minisparker profiles and sedimentologic data from R/V Acona Cruise (April 1976) in the Gulf of Alaska and Prince William Sound

In April 1976, the U.S. Geological Survey, Office of Marine Geology conducted a geophysical and sediment sampling cruise in the northern Gulf of Alaska between Seward and Kayak Island (Fig. 1) to obtain data on seafloor hazards pertinent to the OCS oil and gas lease sales. Stormy weather interrupted the planned data collection, during which time supplemental profiles and samples were collected in Prince William Sound including Montague Strait, Valdez Arm, Port Valdez, and Columbia Bay (Fig. 1). High resolution seismic profile records were made using a 600 Joule Del Norte Minisparker along 1151 km of track lines as shown on maps 1 and 2. Sediment samples collected with grab samplers (58) and gravity core (3) and bottom camera stations (14) are also shown on the track line maps and on figures 2 and 3. This report indicates the seismic reflection records and shipboard logs that are publicly available and includes track line maps and a text that; (1) shows examples of characteristic seismic profiles, (2) describes geologic hazards observed on specific profiles, and (3) includes summary descriptions of sediment samples and bottom photographs.

Alaska↗