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C. Hily and M. Bernard
characterized by a heterogeneous mosaic of habitat types, particularly on rocky
shores in which the well-known patterns of vertical zonation are fragmented by
the microhabitats created by crevices, boulders, pools. . . Seascape ecology is
becoming more and more recognized as a valuable approach of the marine ecology
(Turner 2005), but most studies focused on subtidal coastal habitats, mainly on coral
reefs and seagrass meadows (Boström et al. 2011). At low tide period, intertidal
landscape can be observed in large scale, much larger than subtidal landscapes
including in clear waters. Moreover, the in situ experiments are easier, and field
procedures are close to those developed for sampling vegetation and animals in
terrestrial environments. The measurement of heterogeneity and complexity in
rocky shores and beaches is possible both at the habitat-landscape scale and at the
microhabitats scale. This heterogeneity explains also the great variations of the
intertidal landscape over very short vertical and horizontal distances.
The field accessibility of the intertidal zone explains the numerous papers published for decades on the ecology and the diversity of the fauna and flora, and on the
structuring effects induced by the physical stress of emersion. However landscape
ecology which considers interactions between spatial patterns, ecological processes
and scales (Risser et al. 1984) remained few developed in intertidal.
Today, anthropogenic disturbances are dramatically increasing on coastal areas.
The intertidal zones are particularly affected by human and agriculture effluents and
lots of fishing and recreational activities. The impacts at the landscape scale are
almost never considered. Coastal conservation and management need strong bases
to evaluate and characterize changing in the marine ecosystems at large scales, to
propose valuable management methods to minimize impacts and to restore biodiversity. Consequently, methodological approaches are need to quantify changing
and evolution of intertidal habitats both at the local and regional scales (Polis et al.
2004). Landscape approach adapted to intertidal zone would be a new methodological development to evaluate changes, with limited costs, at pertinent scale both
in term of ecosystem functioning and environmental management, and to complete
protocols based on local sampling which are usually applied in biodiversity measurements in marine environment. In this paper, we studied some rocky shores patterns
which can be used in a landscape ecology approach, from examples on the Brittany
shores (France). The aims are to look for the opportunities provided by the landscape
ecology to characterize rocky shores habitats and, in a feed-back loop, look for opportunities to use the visual changes as indicators of changes in ecosystem structure
and functioning under natural and/or anthropogenic disturbances. We present, as an
example, a visual landscape index based on the development of the green opportunistic macroalgae to characterize the intensity of the recreational hand-fishing activity
in the low eulittoral boulder field habitats (Bernard 2012).
C. Hily and M. Bernard
characterized by a heterogeneous mosaic of habitat types, particularly on rocky
shores in which the well-known patterns of vertical zonation are fragmented by
the microhabitats created by crevices, boulders, pools. . . Seascape ecology is
becoming more and more recognized as a valuable approach of the marine ecology
(Turner 2005), but most studies focused on subtidal coastal habitats, mainly on coral
reefs and seagrass meadows (Boström et al. 2011). At low tide period, intertidal
landscape can be observed in large scale, much larger than subtidal landscapes
including in clear waters. Moreover, the in situ experiments are easier, and field
procedures are close to those developed for sampling vegetation and animals in
terrestrial environments. The measurement of heterogeneity and complexity in
rocky shores and beaches is possible both at the habitat-landscape scale and at the
microhabitats scale. This heterogeneity explains also the great variations of the
intertidal landscape over very short vertical and horizontal distances.
The field accessibility of the intertidal zone explains the numerous papers published for decades on the ecology and the diversity of the fauna and flora, and on the
structuring effects induced by the physical stress of emersion. However landscape
ecology which considers interactions between spatial patterns, ecological processes
and scales (Risser et al. 1984) remained few developed in intertidal.
Today, anthropogenic disturbances are dramatically increasing on coastal areas.
The intertidal zones are particularly affected by human and agriculture effluents and
lots of fishing and recreational activities. The impacts at the landscape scale are
almost never considered. Coastal conservation and management need strong bases
to evaluate and characterize changing in the marine ecosystems at large scales, to
propose valuable management methods to minimize impacts and to restore biodiversity. Consequently, methodological approaches are need to quantify changing
and evolution of intertidal habitats both at the local and regional scales (Polis et al.
2004). Landscape approach adapted to intertidal zone would be a new methodological development to evaluate changes, with limited costs, at pertinent scale both
in term of ecosystem functioning and environmental management, and to complete
protocols based on local sampling which are usually applied in biodiversity measurements in marine environment. In this paper, we studied some rocky shores patterns
which can be used in a landscape ecology approach, from examples on the Brittany
shores (France). The aims are to look for the opportunities provided by the landscape
ecology to characterize rocky shores habitats and, in a feed-back loop, look for opportunities to use the visual changes as indicators of changes in ecosystem structure
and functioning under natural and/or anthropogenic disturbances. We present, as an
example, a visual landscape index based on the development of the green opportunistic macroalgae to characterize the intensity of the recreational hand-fishing activity
in the low eulittoral boulder field habitats (Bernard 2012).