74
Sediment availability has been crucial in this region for the environmental regeneration process of previously reclaimed estuarine areas and the adaptation to current
sea-level rise. Sediment reaches the estuaries from inland, related to deforestation
practices (mainly during the second half of the 20th century), but also from the marine
environment, where high-energy coastal processes continually erode nearby cliffs.
Therefore, the abundant sediment supply has allowed salt-marsh restoration in the
past and will probably continue to do so in the future because deforestation is only a
partial source of sediment, but coastal erosion represents a long-term process.
2.8 Conclusions
We demonstrated that temporal variations of benthic foraminifera and sand preserved in salt-marsh sedimentary records from northern Spain reflect former human
occupation and environmental regeneration processes. The analysis of the environmental regeneration of salt marshes, occurred mainly in the mid-20th century,
revealed that these ecosystems are able to accrete sediment very fast to reach equilibrium with the tidal frame; from 14–18 mm year
−1
up to 40 mm year
−1
at lower
elevation environments such as tidal flats. This information is of great interest in the
present scenario of sea-level rise because currently reclaimed salt marshes could be
regenerated, increasing the estuarine surface available for tidal inundation and, consequently, acting as natural defenses. This cost-effective adaptation strategy can be
utilized in worldwide temperate areas with enough sediment input to outpace ongoing sea-level rise.
Acknowledgements This research was funded by the ANTROPICOSTA-Anthropocene sedimentary record in the Cantabrian coastal environments (MINECO, CGL2013-41083-P), Formation
and Research Unit in Quaternary: Environmental Changes and Human Fingerprint (UPV/EHU,
UFI11/09) and HAREA-Coastal Geology Research Group (EJ/GV, IT976-16) projects. It is contribution 38 of the Geo-Q Zentroa Research Unit (Joaquín Gómez de Llarena Laboratory). This
chapter represents a synthesis of Ane García-Artola’s doctoral research funded by the Basque
Government (BFI08.180) and numerous papers published by the authors on this geographical area
over the last decade. Illustrations are original or modified from previously published versions.
References
Ackermann F (1980) A procedure for correcting the grain size effect in heavy metal analyses of
estuarine and coastal sediments. Environ Technol Lett 1(11):518–527
Allen JRL (2009) Tidal salt marshes: geomorphology and sedimentology. In: Perillo GME,
Wolanski E, Cahoon DR, Brinson MM (eds) Coastal wetlands: an integrated ecosystem
approach. Elsevier, Amsterdam, pp 403–424
Alve E, Murray JW (2001) Temporal variability in vertical distributions of live (stained) intertidal
foraminifera, Southern England. J Foraminifer Res 31(1):12–24
A. García-Artola et al.
Sediment availability has been crucial in this region for the environmental regeneration process of previously reclaimed estuarine areas and the adaptation to current
sea-level rise. Sediment reaches the estuaries from inland, related to deforestation
practices (mainly during the second half of the 20th century), but also from the marine
environment, where high-energy coastal processes continually erode nearby cliffs.
Therefore, the abundant sediment supply has allowed salt-marsh restoration in the
past and will probably continue to do so in the future because deforestation is only a
partial source of sediment, but coastal erosion represents a long-term process.
2.8 Conclusions
We demonstrated that temporal variations of benthic foraminifera and sand preserved in salt-marsh sedimentary records from northern Spain reflect former human
occupation and environmental regeneration processes. The analysis of the environmental regeneration of salt marshes, occurred mainly in the mid-20th century,
revealed that these ecosystems are able to accrete sediment very fast to reach equilibrium with the tidal frame; from 14–18 mm year
−1
up to 40 mm year
−1
at lower
elevation environments such as tidal flats. This information is of great interest in the
present scenario of sea-level rise because currently reclaimed salt marshes could be
regenerated, increasing the estuarine surface available for tidal inundation and, consequently, acting as natural defenses. This cost-effective adaptation strategy can be
utilized in worldwide temperate areas with enough sediment input to outpace ongoing sea-level rise.
Acknowledgements This research was funded by the ANTROPICOSTA-Anthropocene sedimentary record in the Cantabrian coastal environments (MINECO, CGL2013-41083-P), Formation
and Research Unit in Quaternary: Environmental Changes and Human Fingerprint (UPV/EHU,
UFI11/09) and HAREA-Coastal Geology Research Group (EJ/GV, IT976-16) projects. It is contribution 38 of the Geo-Q Zentroa Research Unit (Joaquín Gómez de Llarena Laboratory). This
chapter represents a synthesis of Ane García-Artola’s doctoral research funded by the Basque
Government (BFI08.180) and numerous papers published by the authors on this geographical area
over the last decade. Illustrations are original or modified from previously published versions.
References
Ackermann F (1980) A procedure for correcting the grain size effect in heavy metal analyses of
estuarine and coastal sediments. Environ Technol Lett 1(11):518–527
Allen JRL (2009) Tidal salt marshes: geomorphology and sedimentology. In: Perillo GME,
Wolanski E, Cahoon DR, Brinson MM (eds) Coastal wetlands: an integrated ecosystem
approach. Elsevier, Amsterdam, pp 403–424
Alve E, Murray JW (2001) Temporal variability in vertical distributions of live (stained) intertidal
foraminifera, Southern England. J Foraminifer Res 31(1):12–24
A. García-Artola et al.