California Sea Grant College Program

Assessment of the distribution and abundance of fish eggs in the sea is necessary to estimate fish spawning stock size and habitat. Knowledge of stock size is needed by fisheries managers to control catch. Knowledge of spawning habitat is needed to better manage fished stocks in an ecosystem context, and for policy formation. Our primary objective was to improve the methods used to assess the distribution and abundance of fish eggs. We did so by using machine vision, involving video and computers, to image, identify, and count eggs of target fish species collected with CUFES, the Continuous Underway Fish Egg Sampler, in real time. The result is REFLICS, the Real-time FLow Imaging and Classification System. Our secondary objective was to use this technology to investigate the spawning and mortality of eggs of pelagic fish, including the Pacific sardine (Sardinops sagax) and northern anchovy (Engraulis mordax) off Southern California.