Other reports in this collection 5.3.2.2. Any effects of climate change on fisheries will occur in a sector that already is characterized on a global scale by full utilization, massive overcapacities of usage, and sharp conflicts between fleets and among competing uses of aquatic ecosystems. The question of whether overfishing, environmental change, or a combination of the two is responsible for major declines in fish stocks is still a matter for debate and is situation-specific. Fish habitats are downstream of many impacts, and fish integrate the effects.
Fish are symbolic of the health of ecosystems and our ability to manage our resources.
Persons engaged in this economic sector have limited occupational or geographic mobility. With climate change, global and regional problems of disparity between catching power and the abundance of fish stocks will worsen particularly with regard to the interaction between large mobile fleets and localized fishing communities. Aquaculture will develop in new areas sometimes assisting, sometimes disrupting existing traditional fishing techniques. Many studies have related historical changes in the abundance and distribution of aquatic organisms to climate changes. A general poleward extension of habitats and range of species is likely, but an extension toward the Equator may occur in eastern boundary currents.