Title: Population Levels and Reproductive Performance of Murres Based on Observations at Breeding Colonies Four Years After EVOS
Project Year and Number: 1992: R011
Other Fiscal Years and Numbers for this Project: None
Principal Investigator (PI): Don Dragoo, Alaska Maritime National Wildlife Refuge
Research Location: Kodiak Island
Restoration Category: Damage Assessment
Injured Resources Addressed: Common Murres
Abstract: The 1989 oil spill in Prince William Sound prompted surveys of seabird colonies in Prince William Sound and other areas westward along the spill trajectory. Most of these colonies have had censuses at least two and up to six different years out of the 18 years prior to the oil spill. Murres and kittiwakes on one nearby colony site, Middleton Island, have been censused 14 of the last 18 years. Cliff-nesting species such as the black-legged kittiwake and common murre were the primary emphasis of the 1989-90 censuses. Timing of egg laying and productivity (numbers of fledging chicks) were also noted for these species. In 1990, and continuing in 1991, the major effort was placed on replicate counts of murres in those areas that showed the most drastic changes relative to historical data. Semidi Islands and Middleton Island monitoring continued as the main control sites for murres (Nysewander, 1990; Nysewander and Dipped, 1990; Nysewander and Dipped 1991 - NRDA studies).
Approximately 320 seabird colonies, not including the Semidi Islands, occur within the area affected by the oil spill. These colonies contain about 1 million breeding seabirds of which about 300,000 are breeding murres (U.S. Fish and Wildlife, Catalog of Alaskan Seabird Colonies--Computer Archives 1986). Diving seabirds like murres are known to be easily impacted by oil spills (King and Sanger, 1979). In addition, these species are long-lived with low reproductive rates, thus making any mortality of adults a critical factor in these species' ability to recover. Direct mortality immediately following the spill was estimated at about 300,000 murres, including wintering and non-breeding birds.
This project will monitor the recovery of breeding common and thick-billed murres in the Barren Islands and Puale Bay colonies on the Alaska Peninsula. The reductions in numbers of breeding adults at these colonies, the delayed reproductive chronology, the lack of synchrony of egg laying, and the low or zero reproductive success seen the last three years at these colonies in the oil spill area are the major injuries that will be monitored by this study. The murre population in the oil spill area began to show some slight signs of recovery in 1991. However, the population may have essentially produced no young for three years, which could greatly extend the time needed for full recovery. The next several years of monitoring data for murres will give us important insight on how a murre colony recovers from such injury and how recovery might be facilitated if desirable. The extent and persistence of injury will determine the level of restoration necessary.
Prince William Sound
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Proposal: PDF Not Available
Funding Recommendations: View
Funding Detail For: 1992
Quarterly Project Tasks For: 1992
Annual Report: 1992: Not Applicable
Final Report: View
Publications from this Project: None Available