The response of marine ecosystems to climate variability associated with the North Atlantic oscillation

A strong association is documented between variability of the North Atlantic Oscillation (NAO) and changes in various trophic levels of the marine ecosystems of the North Atlantic. Examples are presented for phytoplankton, zooplankton, benthos, fish, marine diseases, whales and seabirds. NAO variability is shown to influence abundance, biomass, distribution, species assemblages, growth rates, and survival rates. Examples are drawn from across the North Atlantic. The impacts of the NAO are generally mediated through local changes in the physical environment, such as winds, ocean temperatures, and circulation patterns. The spatial variability in the physical oceanographic responses to NAO forcing leads to spatial differences in biological responses.