Post-release survival of surf scoters following an oil spill: An experimental approach to evaluating rehabilitation success

• Published in: Marine pollution bulletin 2013-02, Vol.67 (1-2), p.100-106
• Main Authors: De La Cruz, Susan E.W., Takekawa, John Y., Spragens, Kyle A., Yee, Julie, Golightly, Richard T., Massey, Greg, Henkel, Laird A., Scott Larsen, R., Ziccardi, Michael
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Anseriformes - physiology; Applied ecology; Biological and medical sciences; birds; Conservation, protection and management of environment and wildlife; Ecotoxicology, biological effects of pollution; Effectiveness; Environmental degradation: ecosystems survey and restoration; Environmental Monitoring - methods; Environmental Restoration and Remediation - methods; Fundamental and applied biological sciences. Psychology; Marine; Marine and brackish environment; Melanitta perspicillata; Oil exposure; Oil spills; oils; Petroleum Pollution; Physiological effects; Population Dynamics; Radio telemetry; Rehabilitation; San Francisco; San Francisco Bay; Sea duck; Sea water ecosystems; Spills; Surf; Survival; survival rate; Synecology; water pollution; Water Pollution, Chemical; Wildlife rehabilitation
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2012.11.027

► We compared post-release survival among three treatment groups of surf scoters. ► Oiled bird survival was lower than rehabilitated and non-rehabilitated controls. ► Rehabilitation improved survival of un-oiled birds but not oiled birds. ► Studies on oiling severity and species specific response may advance rehabilitation. Birds are often the most numerous vertebrates damaged and rehabilitated in marine oil spills; however, the efficacy of avian rehabilitation is frequently debated and rarely examined experimentally. We compared survival of three radio-marked treatment groups, oiled, rehabilitated (ORHB), un-oiled, rehabilitated (RHB), and un-oiled, non-rehabilitated (CON), in an experimental approach to examine post-release survival of surf scoters (Melanitta perspicillata) following the 2007 M/V Cosco Busan spill in San Francisco Bay. Live encounter-dead recovery modeling indicated that survival differed among treatment groups and over time since release. The survival estimate (±SE) for ORHB was 0.143±0.107 compared to CON (0.498±0.168) and RHB groups (0.772±0.229), suggesting scoters tolerated the rehabilitation process itself well, but oiling resulted in markedly lower survival. Future efforts to understand the physiological effects of oil type and severity on scoters are needed to improve post-release survival of this species.