The
micro approach solves some of the limitations of the macro approach, but it still ignores
the interaction between physical and biological components of the ecosystem. In other
words, population models do not take into account complete ecosystem structure (e.g.,
the biological and physical components) and function (e.g., ecological processes) and
therefore often ignore indirect use values of fish in marine ecosystems. Some population
models take environmental influences on biological components of ecosystems into account.
The review papers by Knowler (2002) and Armstrong (2006) are good examples of
such attempts. In general, population modelling tends to view abiotic (physical) components
as external factors of ecosystems, which is consistent with the population-community
approach in ecology.