Speaker: Dr. Marlon Lewis, Dalhousie University

Abstract: The world's oceans are undergoing alterations not seen in hundreds of thousands of years. The surface ocean is warmer, more acidic and deeper reaches are increasingly deoxygenated. New evidence now indicates that the oceans have lost a significant portion of their phytoplankton over the last 50 years - the base of the marine food chain - and as well appear to support only 10% of the large predators active prior to the industrial age. These are not isolated changes, and appear to have some - albeit complex - common causes. This talk will focus on the scientific evidence to date, with a view towards what the future might bring.