Small pelagic fish include anchovy, sardine, herring, and sprat. They comprise approximately one-quarter of the world's fish catch. The abundance and catch of the small pelagic fish fluctuate greatly on the scale of decades, notably anchovy and sardine off Peru, Japan, Southern Africa, and California. Climate varies on the same scale. How does climate affect small pelagic fish? Can our understanding of this relationship be used to inform management and policy?

Small pelagic fish occupy a key position in marine ecosystems. They respond to change from below (climate, bottom-up) and above (fishing, top-down). In turn, variation of stocks of small pelagic fish affect their prey (plankton) and predators (e.g. fish, marine birds and mammals, and human). Capture fisheries are now maximal and, as the human population increases, aquaculture will thus continue to grow, exacerbating the demand for small pelagic fish as food for cultured fish. The complex ecosystem and economic roles of small pelagic fish necessitate a holistic view of their dynamics.

The Small Pelagic Fish and Climate Change (SPACC) program is a part of Global Ocean Ecosystem Dynamics (GLOBEC). SPACC was formed to understand and predict climate-induced changes in the production of small pelagic fish. It is unusual in being composed of scientists from both academia and management. This book, a product of SPACC, presents the status of our understanding in 2008. It has 82 authors from 22 countries in Africa, Asia, Australia, Europe, and North and South America.