Effects of the Exxon Valdez oil spill on the abundance and distribution of humpback whales (Megaptera novaeangliae) in Prince William Sound Exxon Valdez oil spill state/federal natural resource damage assessment final report

"Photo-identification studies of Prince William Sound humpback whales were conducted from May to September in 1989 and 1990 to assess the impact of the spill on humpback whale life history and ecology. In 1989, concurrent studies were conducted in Southeast Alaska on humpback whales to determine if whales avoided contaminated waters of PrInce William Sound and moved to other northern feeding areas. In 1989, photographic analysis of Prince William humpbacks resulted in the identification of 59 whales. In 1990, 66 whales were documented. More whales were seen in these two seasons than any year previous to the spill. The increase in whale sightings may have been due to the increase in effort during the 1989 and 1990. Because of the difference in survey effort before and after the spill, it is impossible to determine if in the number of humpback whales using the Sound. Distribution varied among years and may be related to prey distribution. Only one Prince William Sound humpback whale was documented to move from Prince William Sound to southeastern Alaska during the 1989 season. Calving rates during 1989 and 1990 were not significantly different than in previous years. No reports of dead stranded humpback whales occurred during the study period. No observations were made of humpback whales swimming through oil"--Abstract. Marilyn E. Dahlheim and Olag von Ziegesar. Title from cover. "December 1993." Also available online in PDF. Includes bibliographical references (pages 16-19). 1993 NMFS (National Marine Fisheries Service) Library Public Domain 1862