San Francisco Bay Fish Abundance and Global Scale Climate Shifts

• Activity Number: 428
• Type: Contributed
• Date/Time: Tuesday, August 3, 2010 : 2:00 PM to 3:50 PM
• Sponsor: Section on Statistics and the Environment
• Author(s): Teresa Anne Jacobson*+
• Companies: University of California, Santa Cruz
• Keywords: Poisson regression ; spatial modeling ; species abundance ; climate change ; San Francisco Bay ; generalized linear models

Abstract

The California Department of Fish and Game's San Francisco Bay Study, done in conjunction with the Interagency Ecological Program for the San Francisco Estuary, is an excellent data resource for estuary species abundance due to its nearly unequaled sampling longevity and density, extending back monthly for twenty-eight years and over seventy sites in the San Francisco Bay. We aim to correlate changes in observed abundance with local and larger scale climate variables; to do so we apply models built around a Poisson likelihood and incorporating overdispersion corrections, together with spatial and dynamic elements from dynamic generalized linear models. We show how this affects model fits compared to the commonly used simple nonlinear Gaussian or lognormal regression models, and demonstrate significant linkages between shifts in local abundance and Pacific basin scale climate variables.