  Real food web data available in the literature presents us with the relations
between various species, sizes of these species, metabolic types of the species
and other useful information, which allows us to define parameters for the
mathematical dynamical models of these food webs, and perform theoretical
studies of these models. Unfortunately, the researches often face the problem
of the extinction of the species in such situations, which could be an
important limiting factor. In this paper, we propose a simple algorithm of
parameterisation that leads to the existence of positive steady state and
improves persistence of the species in multi-species models of real food webs.
