fish stocks, catch records, river engineering projects, observations by fishermen and
anglers, etc.), each type of source having its own advantages and limitations. For the
Seine River basin, a database called CHIPS was developed to gather historical
written sources on freshwater fish in order to improve knowledge about past species
distribution and composition of communities [7]. While the oldest data stored in
this database date back to the sixteenth century, most of the observations relate to the
period from the nineteenth to the first half of the twentieth century and are therefore
complementary to the more recent electrofishing data set.
Archaeological remains of fish, generally obtained from food waste or latrines
in past habitats, provide another potentially useful source of data. They allow us to
address older periods and provide additional information for the periods already
covered by the written historical archives. In the Seine basin, numerous urban and
rural sites have provided archaeological fish remains for medieval and early modern
periods [8]. While archaeological remains provide insight into the past occurrence
of species, their main limitation concerns the uncertainty about the proximity of fish
supply sources. It can be suspected that some of the fish consumed locally were
actually caught in distant waters. The abundance of marine fish remains, particularly
on sites associated with the nobility and aristocracy, reinforces these doubts. Under
these conditions, it can be assumed that a significant proportion of the archaeological
remains, particularly when they concern rare species of high commercial value, were
not obtained from local catches.
We combined these different sources of data (i.e. contemporary, historical and
archaeological) to reconstruct the trajectories of fish communities in the Seine basin
at different temporal and spatial scales.
3 Non-native Species: An Accelerating Establishment
Combining different sources of information (e.g. palaeontological, archaeological,
written), Persat and Keith (1997) [9] estimated that, before human intervention,
the native fish fauna of the Seine River basin was likely to include up to 23 strictly
freshwater species, to which 11 diadromous species can be added. Through their
fishing activity, their ability to transport fish and, more broadly, their action on
their environment, humans are likely to have modified this native fauna very early.
However, the first known introduction of an exotic species into the Seine River
basin concerns the common carp (Cyprinus carpio). Its establishment, linked to the
development of pond fish farming, has been documented since the thirteenth century
[10, 11]. Since that time, the deliberate or accidental introductions of exotic species
have continued to such an extent that they now account for nearly 45% of the species
recorded in the basin (and even 55% of strictly freshwater species) (Fig. 1). The
second half of the nineteenth century marked the first phase of an acceleration in
the establishment of exotic species. It was partly the result of technical and scientific
progress in fish breeding – in particular the control of artificial reproduction of fish –
thereby facilitating the spread of species in the form of embryonated eggs, which
are easier to transfer than the fish themselves. More generally, it was in line with a
Changes in Fish Communities of the Seine Basin over a Long-Term Perspective
303
anglers, etc.), each type of source having its own advantages and limitations. For the
Seine River basin, a database called CHIPS was developed to gather historical
written sources on freshwater fish in order to improve knowledge about past species
distribution and composition of communities [7]. While the oldest data stored in
this database date back to the sixteenth century, most of the observations relate to the
period from the nineteenth to the first half of the twentieth century and are therefore
complementary to the more recent electrofishing data set.
Archaeological remains of fish, generally obtained from food waste or latrines
in past habitats, provide another potentially useful source of data. They allow us to
address older periods and provide additional information for the periods already
covered by the written historical archives. In the Seine basin, numerous urban and
rural sites have provided archaeological fish remains for medieval and early modern
periods [8]. While archaeological remains provide insight into the past occurrence
of species, their main limitation concerns the uncertainty about the proximity of fish
supply sources. It can be suspected that some of the fish consumed locally were
actually caught in distant waters. The abundance of marine fish remains, particularly
on sites associated with the nobility and aristocracy, reinforces these doubts. Under
these conditions, it can be assumed that a significant proportion of the archaeological
remains, particularly when they concern rare species of high commercial value, were
not obtained from local catches.
We combined these different sources of data (i.e. contemporary, historical and
archaeological) to reconstruct the trajectories of fish communities in the Seine basin
at different temporal and spatial scales.
3 Non-native Species: An Accelerating Establishment
Combining different sources of information (e.g. palaeontological, archaeological,
written), Persat and Keith (1997) [9] estimated that, before human intervention,
the native fish fauna of the Seine River basin was likely to include up to 23 strictly
freshwater species, to which 11 diadromous species can be added. Through their
fishing activity, their ability to transport fish and, more broadly, their action on
their environment, humans are likely to have modified this native fauna very early.
However, the first known introduction of an exotic species into the Seine River
basin concerns the common carp (Cyprinus carpio). Its establishment, linked to the
development of pond fish farming, has been documented since the thirteenth century
[10, 11]. Since that time, the deliberate or accidental introductions of exotic species
have continued to such an extent that they now account for nearly 45% of the species
recorded in the basin (and even 55% of strictly freshwater species) (Fig. 1). The
second half of the nineteenth century marked the first phase of an acceleration in
the establishment of exotic species. It was partly the result of technical and scientific
progress in fish breeding – in particular the control of artificial reproduction of fish –
thereby facilitating the spread of species in the form of embryonated eggs, which
are easier to transfer than the fish themselves. More generally, it was in line with a
Changes in Fish Communities of the Seine Basin over a Long-Term Perspective
303