Quasi‐decadal periodicities in growth and production of the copepod Eodiaptomus japonicus in Lake Biwa, Japan, related to the Arctic Oscillation

Copepods are important secondary producers that support higher trophic levels in aquatic food webs. Large‐scale climate events such as climate oscillations and global warming force on physical and chemical conditions in aquatic ecosystems might regulate copepod production through physiological and biochemical processes. We evaluated how large climatic and anthropogenic events impacted secondary production of copepods in Lake Biwa, the largest lake in Japan. We determined demographic traits such as body size, growth rate, biomass and production of the dominant copepod Eodiaptomus japonicus in this lake over four decades (1971–2010). To evaluate in situ food conditions and estimate growth and production for this omnivorous species, we firstly defined a size‐based food index (f), that is the ratio of in situ body size to ideal body size in adult females. Values of f were mostly