This project will synthesize the knowledge of North Pacific krill through modeling and comparative studies, across U.S. GLOBEC, Japan-GLOBEC, China-GLOBEC and related study regions, with the goal of understanding climate impacts on euphausiids in the North Pacific. The project will address the following research themes: 1) Identify the processes controlling the population dynamics and recruitment of krill as a function of ecosystem type and ascertain how these processes would be affected by climate change, to be accomplished through comparing and contrasting population responses from a number of different ecosystems, and; 2) Determine the response of krill populations at local and regional scales to basin- and global-scale change in climate forcing.
Intellectual Merit: Krill research funded by GLOBEC since 1998, and other research conducted by biological oceanographers in the U.S. and other nations bordering the North Pacific (China, Korea, Japan, Russia, Canada), have produced new information on the phenology, seasonal cycles of abundance, feeding, reproduction, and growth rates of North Pacific krill. This knowledge will be summarized into a series of multi-authored synthesis papers that focus on comparative life history of krill, how local populations interact with local ocean conditions, and how climate impacts these processes. This project will address questions such as: 1)What are the seasonal variations in distribution, abundance, growth rates and egg production in krill populations, and how do they vary regionally around the Pacific Rim? 2) Are growth rates and brood sizes related to seasonal cycles of primary production? 3) How do populations in the eastern and western Pacific respond to ENSO and PDO cycles? 4) How are individuals of the same species (Euphausia pacifica) adapted to survive year-around in the very warm water regions of the Yellow Sea, East China Sea and Japan/East Sea; what mechanisms enable individuals to survive the long winters in northern regions, e.g., the Gulf of Alaska, Sea of Okhotsk and northern California Current? 5) What interactions between physical transport and life-stage dependent dynamics control the local scale distributions of krill and are similar interactions important at regional and basin-scales?
All krill research carried out within the U.S. GLOBEC study regions (California Current and Gulf of Alaska) will be summarized, as will research carried out by our overseas collaborators. Metadata summaries will be produced. Krill experts from each nation will produce local "State of our Krill Knowledge" reports. Using these reports, joint multi-authored monographs and collaborative papers on krill ecology will be written. Furthermore, two international symposia on krill ecology will be convened.
Broader Impacts: This synthesis project will support one graduate student and involve three young scientists in China and Japan. Furthermore, krill are harvested in Japan and Canada, and pressure will soon mount to allow harvest elsewhere. Results of this synthesis will contribute to an assessment of krill resources and vulnerability in coastal ecosystems around the Pacific Rim. A tangible product of this research is a monograph of the population ecology, life history strategies, and interactions of krill with their environment in multiple regions of the North Pacific.
