ABSTRACT
This chapter reviews the major geochemical and ecological characteristics of the northeastern Pacific abyssal plains, a comparatively well-studied region by deep sea standards, and examines the system’s resilience in view of climatic change and in situ human activities. El Nino-Southern Oscillation events are characterized by reversals of the atmospheric pressure systems in the south and central Pacific and switching of the sources of the intensely upwelled water masses along the southeastern Pacific continental margin. The goal of iron fertilization of the oceans would be to stimulate primary production and export production in iron-limited, high-nutrient-low-chlorophyll regions of the ocean, such as the eutrophic Pacific. Organic matter synthesized at the ocean’s surface through photosynthesis constitutes the primary source of energy for seafloor communities. Hard substrata are limited to regions of recent volcanic activity, such as mid-ocean ridges, submarine canyons, seamounts and volcanic islands, and areas of very low sedimentation conditions, which allow the accretion of ferromanganese nodules.
