regulation and eutrophication) were considered as well. Harmful algal blooms observed
in the outer estuary have also been addressed through dedicated models.
A new concern is the transfer of contaminants to aquatic species and from one
trophic level to the next, as determined using nitrogen isotopic signatures. Primary
producers (biofilm, leaf litter, macrophytes) have the lowest trophic levels,
macroinvertebrates (Gammarus sp., Lymnaea sp., Corbicula sp., leech) have an
intermediate trophic level, and fishes (roach, European perch, gudgeon, tench,
bullhead, pumpkinseed and black bullhead) are at the top of the Seine River food
web. For example, the transfer of polycyclic aromatic hydrocarbons (PAHs) and of
phthalate metabolites between these trophic levels is presented in Box 2.
Box 2
Targeted monitoring of river biotic communities for PAHs, phthalates and
their metabolites.
Polycyclic aromatic hydrocarbons (PAHs) and phthalates are the main
organic micropollutants in the Seine hydrosystem and in three fish species
[15] and prevent waterbodies from achieving good chemical status as defined
by the Water Framework Directive (WFD). Biomonitoring of PAH and
phthalates is complex, since they are rapidly metabolized in aquatic organisms,
especially fish. Therefore, we monitored the levels of key PAH and phthalate
metabolites in aquatic organisms caught in the river, from primary producers to
macroinvertebrates and fish in order to assess the bioaccumulation and transfer
of these pollutants and their metabolites across the trophic web [16].
The levels of PAH metabolites did not vary with trophic levels, likely due
to the rapid elimination of these degradation products. We observed a trophic
amplification of phthalate metabolites, probably since the excretion rate is
slower (Fig. 3). This raises ecotoxicological concern, since phthalate metabolites also have deleterious effects.
3 From Understanding Processes to Gaining Knowledge
That Supports Decision-Making
PIREN-Seine has developed a wide array of models, from numerical to conceptual.
1
Numerical models aim to synthesize knowledge on the functioning of the hydrosocio-system, on the whole basin, such as Riverstrahler, or on a river sector, such
as ProSe. It enables to explore the possible futures of the basin over the next
1 Details on PIREN-Seine models are given in the first chapter of the book [5] and in the
corresponding chapters.
River Basin Visions: Tools and Approaches from Yesterday to Tomorrow
389
in the outer estuary have also been addressed through dedicated models.
A new concern is the transfer of contaminants to aquatic species and from one
trophic level to the next, as determined using nitrogen isotopic signatures. Primary
producers (biofilm, leaf litter, macrophytes) have the lowest trophic levels,
macroinvertebrates (Gammarus sp., Lymnaea sp., Corbicula sp., leech) have an
intermediate trophic level, and fishes (roach, European perch, gudgeon, tench,
bullhead, pumpkinseed and black bullhead) are at the top of the Seine River food
web. For example, the transfer of polycyclic aromatic hydrocarbons (PAHs) and of
phthalate metabolites between these trophic levels is presented in Box 2.
Box 2
Targeted monitoring of river biotic communities for PAHs, phthalates and
their metabolites.
Polycyclic aromatic hydrocarbons (PAHs) and phthalates are the main
organic micropollutants in the Seine hydrosystem and in three fish species
[15] and prevent waterbodies from achieving good chemical status as defined
by the Water Framework Directive (WFD). Biomonitoring of PAH and
phthalates is complex, since they are rapidly metabolized in aquatic organisms,
especially fish. Therefore, we monitored the levels of key PAH and phthalate
metabolites in aquatic organisms caught in the river, from primary producers to
macroinvertebrates and fish in order to assess the bioaccumulation and transfer
of these pollutants and their metabolites across the trophic web [16].
The levels of PAH metabolites did not vary with trophic levels, likely due
to the rapid elimination of these degradation products. We observed a trophic
amplification of phthalate metabolites, probably since the excretion rate is
slower (Fig. 3). This raises ecotoxicological concern, since phthalate metabolites also have deleterious effects.
3 From Understanding Processes to Gaining Knowledge
That Supports Decision-Making
PIREN-Seine has developed a wide array of models, from numerical to conceptual.
1
Numerical models aim to synthesize knowledge on the functioning of the hydrosocio-system, on the whole basin, such as Riverstrahler, or on a river sector, such
as ProSe. It enables to explore the possible futures of the basin over the next
1 Details on PIREN-Seine models are given in the first chapter of the book [5] and in the
corresponding chapters.
River Basin Visions: Tools and Approaches from Yesterday to Tomorrow
389