Pulliam [75] discussed the relevance of the metapopulation
concept in evaluating the toxicology of wildlife. The most
direct implication is in the analysis of exposures, i.e., the share
of times spent in each habitat type by mobile biota, as estimated
through direct visualization of animals, radio tracking combined
with geographic information system analyses, etc. [76].
Other ecotoxicological implications of the metapopulation
structure of biota must also be taken into consideration. By
combining genotoxicity and population genetic analyses, it has
been shown that migration can mask pollutant exposures targeted
to selected components of the biota [77]. Considering
realistic population spatial distributions has practical relevance
in assessing the effects of pyrethroid pesticides used in cotton
crops. Maund et al. [78] showed that cost-efficient consideration
of landscape fragmentation patterns produced exposure
risk estimates considerably lower than those obtained with
nonspatially structured, standard regulatory methods [79,80].
Through the use of satellite imagery and geographic information
system techniques, the authors estimated the probabilistic
distribution of areas cultivated with cotton and their
vicinity to ponds where aquatic life should be protected in
Mississippi, USA. They compared their results with the corresponding
U.S. Environmental Protection Agency Tier II scenario
for the protection of aquatic life in relation with pesticides
applied to cotton crops. The latter assumes a standard
landscape configuration consisting of a 10-ha pond completely
surrounded by 10 ha of cotton crops, with high levels of erosion,
runoff, and drift entering the pond. Cypermetrin exposures
computed from the analysis of real landscape scenarios
were 50 to 100 times lower than those obtained using the U.S.
Environmental Protection Agency standard model pond and
parameters.