176
A. Cheminée et al.
for white seabream, that is bottoms with heterogeneous granulometry of small
rocks and gravel. This destruction and homogenisation of the habitats probably
severely reduced the nursery capacity of the Marseille roadstead area. 3152 m
of coastline were thus artificialised (Meinesz et al. 2006). On the basis of the
quantities of nurseries currently existing in a relatively pristine control area
(Montredon, Annexe 1, Fig. 11.5), it may be estimated that nurseries occupied
about 50 % of the coastline of Prado, or 1576 m Today, only 372 m remain
(Annexe 1), or a loss that may be estimated at more than 75 %. The case is
similar for the area of the Marseilles commercial harbour (‘Port Autonome’,
northern bay of Marseille): an examination of the old ordinance survey maps
(Fig. 11.7) dating from 1825 to 1866 (MEDDTL et al. 2012) shows that the
coast at the level of the location of the basins of the harbour had a morphology that was favourable for the occurrence of white seabream nurseries. The
harbour constructed from 1844 to 1975 resulted in the artificialisation of a
total of 11533 m of coastline (Meinesz et al. 2006), altering habitats that have
irreversibly lost their function as nurseries, given the radical transformation of
their morphology (sheer quay walls and greater depth). We estimate that this
coast also presented nurseries along 50 % of its length, and that they would
have supplied the adult habitats of today’s marine reserve ‘Parc Marin de la
Cˆ ote Bleue’, situated a dozen kilometres to the west of the harbour, and which
present few nurseries, like the core area of the Calanques National Park. The
impacts of these transformations are thus considerable.
11.5 Management Perspectives: What Means of Action
are Available?
11.5.1 Applying the ‘Seascape Approach’
The application of this ‘seascape approach’ to management involves deciding on
plans of action: in terms of practical recommendations for the managing authority,
it should be borne in mind that ill-conceived coastal developments that result in
the homogenisation of the environment at all scales (from micro-habitat to whole
seascape) are harmful in particular with regard to the nursery role of the coastal area.
In contrast, well-planned development schemes, purpose-designed on a case by case
basis with a view to maintaining the nursery value of the coastal areas, may be
envisaged. These theoretical notions should be integrated in practice in the statutory
and contractual management of the coast.
A. Cheminée et al.
for white seabream, that is bottoms with heterogeneous granulometry of small
rocks and gravel. This destruction and homogenisation of the habitats probably
severely reduced the nursery capacity of the Marseille roadstead area. 3152 m
of coastline were thus artificialised (Meinesz et al. 2006). On the basis of the
quantities of nurseries currently existing in a relatively pristine control area
(Montredon, Annexe 1, Fig. 11.5), it may be estimated that nurseries occupied
about 50 % of the coastline of Prado, or 1576 m Today, only 372 m remain
(Annexe 1), or a loss that may be estimated at more than 75 %. The case is
similar for the area of the Marseilles commercial harbour (‘Port Autonome’,
northern bay of Marseille): an examination of the old ordinance survey maps
(Fig. 11.7) dating from 1825 to 1866 (MEDDTL et al. 2012) shows that the
coast at the level of the location of the basins of the harbour had a morphology that was favourable for the occurrence of white seabream nurseries. The
harbour constructed from 1844 to 1975 resulted in the artificialisation of a
total of 11533 m of coastline (Meinesz et al. 2006), altering habitats that have
irreversibly lost their function as nurseries, given the radical transformation of
their morphology (sheer quay walls and greater depth). We estimate that this
coast also presented nurseries along 50 % of its length, and that they would
have supplied the adult habitats of today’s marine reserve ‘Parc Marin de la
Cˆ ote Bleue’, situated a dozen kilometres to the west of the harbour, and which
present few nurseries, like the core area of the Calanques National Park. The
impacts of these transformations are thus considerable.
11.5 Management Perspectives: What Means of Action
are Available?
11.5.1 Applying the ‘Seascape Approach’
The application of this ‘seascape approach’ to management involves deciding on
plans of action: in terms of practical recommendations for the managing authority,
it should be borne in mind that ill-conceived coastal developments that result in
the homogenisation of the environment at all scales (from micro-habitat to whole
seascape) are harmful in particular with regard to the nursery role of the coastal area.
In contrast, well-planned development schemes, purpose-designed on a case by case
basis with a view to maintaining the nursery value of the coastal areas, may be
envisaged. These theoretical notions should be integrated in practice in the statutory
and contractual management of the coast.