Dynamic model of krill Euphausia superba swarm

During the Italian Antarctic Expeditions to the Ross Sea, in the years 1989 - 1994, using the 38 and 120 kHz BioSonics dual-beam hydroacoustic system, numerous swarms of krill Euphausia superba Dana were registered . Analysis of their physical parameters was carried out. It is known that insects appear to disperse according to a reaction diffusion model with a constant diffusion coefficient (Okubo, 1980, 1986). It was assumed that the above mentioned model can also be applicable to krill swarms. Using physical parameters of the krills' swarm (density, length), the above assumption was verified.
It was found that the vertical density pattern of krills' swarm, with a mean density of up to 1000 individuals/m3, is consistent with the insect model predictions. That is why cohesive forms of krill aggregations are usually termed "swarms" rather than "schools", which is normally used for fish groupings.