LIDAR applications to fisheries monitoring problems

Recent advances in lasers, spectrometers, and multichannel detectors have significantly improved the capabilities of LIDAR (LIght Detection And Ranging) systems in the blue-green region of the electromagnetic spectrum. Because ocean water has minimum absorbance in the blue-green region of the spectrum, the LIDAR has great potential to become a versatile tool capable of providing the kind and the quantity of biomass and water quality (including temperature) data that have been thus far inaccessible to fisheries scientists. The basic physics of the LIDAR is described including the physics relevant to the problems of light scattering, reflection, and penetration of water. Two extremes of potential LIDAR application (broad, shallow light path and narrow, deep light path) are discussed in terms of estimation of floating egg abundance and fish aggregation at thermal fronts, respectively. It is anticipated that the application of LIDAR will allow better estimates of instantaneous rates of change in fish stock parameters, as well as increasing the amount of data collected to assess heterogeneity of stock abundance in both space and time.