Fisheries at Lagrangian fronts

This paper reviews the recent progress in the application of Lagrangian methods for detecting potential feeding and fishing grounds and the relationship between the dynamic features with strong gradients of the relevant indicators of water motion, Lagrangian fronts (LFs), and catches of different species of pelagic fish and squid. The locations of the LFs, approximating locations of the ocean features with increased values of the gradients of hydrological parameters, can be calculated by solving advection equations for a large number of virtual passive particles in the altimetric velocity field or in the velocity fields generated by numerical circulation models or obtained using high-frequency radars. The LFs can be easily identified in the near real time, under any weather conditions and in the areas with small contrasts of sea surface temperature. The proximity of catch sites to location of LFs has been shown with the help of statistical tests in different seas and oceans based on catch reports of fishing vessels. The active and passive physical mechanisms at fronts, that may provide favorable conditions for foraging and feeding, are discussed. The paper emphasizes the importance of fronts in marine ecology and sustainable fisheries.