April 1993Effects of the-on Valdez Oil Spill on Murres: A Perspective From Observations at Breeding Colonies

• Main Authors: David R. Nysewander, G. Vernon Byrd, Eric P. Knudtson, U. S. Fish, Wildlife Service, Bird Study Number
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Ke~w-&. &on VaZdez; oil spill; Common Murre; Thick-billed Murre; Una; Gulf of Alaska; Middleton I; Chiswell Is; The Triplets; Barren Is; Puale Bay; Ugaiushak I; Semidi Is; Triplets; thick-billed murre; Alaska; uria
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.376.148; http://www.arlis.org/docs/vol1/36773092.pdf

Sh&dbhq~istnrv: This damage assessment study was initiated in 1989 as part of a detailed study plan and modified and continued in 1990 and 1991. The study was designed to determine the nature and extent of the injury, loss or destruction of murres (Uria spp.) in the oil spill zone. These data will provide a base for developing a recovery monitoring and restoration plan. Bhstcact. We surveyed murres (Uria spp.) annually from 1989 through 1991 at breeding colonies within the trajectory of the oil to determine whether numbers had declined and to evaluate the effects of oil on nesting phenology and reproductive success, following the 1989 Evron Valdez oil spill. The colonies we surveyed contained the majority of the estimated 200,000 murres attending colonies in the affected area, and we found reduced numbers at all study colonies following the spill. In addition, nesting was delayed and productivity rates were far below normal following the spill. In contrast, numbers of murres did not decline and reproductive parameters were normal at 2 colonies we surveyed outside the trajectory. The only indication of recovery since the spill was a slight increase in reproductive success at monitored colonies in 1991. The most likely cause of reduced numbers of murres at cliffs