47
© Springer International Publishing AG 2017
C.W. Finkl, C. Makowski (eds.), Coastal Wetlands: Alteration and Remediation,
Coastal Research Library 21, DOI 10.1007/978-3-319-56179-0_2
Chapter 2
Recent Agricultural Occupation
and Environmental Regeneration of Salt
Marshes in Northern Spain
Ane García-Artola, Alejandro Cearreta, and María Jesús Irabien
Abstract Salt marshes reduce wave energy and offer natural protection from
storms and floods. In the last centuries these coastal areas have been intensely
impacted by human activities worldwide. In northern Spain, more than 50% of
the original salt marshes have been reclaimed with agricultural purposes since
the 17th century. However, many of these coastal wetlands have been recovered
since the agricultural decline during the 1950s. Benthic foraminifera and sand
content can be used as proxies to identify past episodes of salt-marsh reclamation
and to analyze the environmental regeneration process of previously occupied
lands. Foraminifera are absent in agricultural soils and increase in abundance
during the regeneration of the area, until total recovery is reached. Similarly,
sand content increases as tidal inundation takes place during the environmental
regeneration period. The physical disturbance originated by reclamation presents
a challenge for the
210
Pb dating method. Nevertheless, historical aerial photography provides a good record for age estimation. This can be supported by chronostratigraphic horizons of major pollution events and nuclear weapon testing
(i.e. heavy metals and
137
Cs). In the current context of sea-level rise, sediment
supply constrains the environmental regeneration of salt marshes. In northern
A. García-Artola (*)
Sea Level Research, Department of Marine and Coastal Science, Rutgers University,
71 Dudley Road, New Brunswick, NJ 08901, USA
Sociedad de Ciencias Aranzadi, Zorroagagaina, 11, 20014 Donostia-San Sebastián, Spain
Departamento de Estratigrafía y Paleontología, Facultad de Ciencia y Tecnología,
Universidad del País Vasco UPV/EHU, Apartado 644, 48080 Bilbao, Spain
e-mail: agarciaartola@marine.rutgers.edu
A. Cearreta
Departamento de Estratigrafía y Paleontología, Facultad de Ciencia y Tecnología,
Universidad del País Vasco UPV/EHU, Apartado 644, 48080 Bilbao, Spain
e-mail: alejandro.cearreta@ehu.eus
M.J. Irabien
Departamento de Mineralogía y Petrología, Facultad de Ciencia y Tecnología, Universidad
del País Vasco UPV/EHU, Apartado 644, 48080 Bilbao, Spain
e-mail: mariajesus.irabien@ehu.eus
© Springer International Publishing AG 2017
C.W. Finkl, C. Makowski (eds.), Coastal Wetlands: Alteration and Remediation,
Coastal Research Library 21, DOI 10.1007/978-3-319-56179-0_2
Chapter 2
Recent Agricultural Occupation
and Environmental Regeneration of Salt
Marshes in Northern Spain
Ane García-Artola, Alejandro Cearreta, and María Jesús Irabien
Abstract Salt marshes reduce wave energy and offer natural protection from
storms and floods. In the last centuries these coastal areas have been intensely
impacted by human activities worldwide. In northern Spain, more than 50% of
the original salt marshes have been reclaimed with agricultural purposes since
the 17th century. However, many of these coastal wetlands have been recovered
since the agricultural decline during the 1950s. Benthic foraminifera and sand
content can be used as proxies to identify past episodes of salt-marsh reclamation
and to analyze the environmental regeneration process of previously occupied
lands. Foraminifera are absent in agricultural soils and increase in abundance
during the regeneration of the area, until total recovery is reached. Similarly,
sand content increases as tidal inundation takes place during the environmental
regeneration period. The physical disturbance originated by reclamation presents
a challenge for the
210
Pb dating method. Nevertheless, historical aerial photography provides a good record for age estimation. This can be supported by chronostratigraphic horizons of major pollution events and nuclear weapon testing
(i.e. heavy metals and
137
Cs). In the current context of sea-level rise, sediment
supply constrains the environmental regeneration of salt marshes. In northern
A. García-Artola (*)
Sea Level Research, Department of Marine and Coastal Science, Rutgers University,
71 Dudley Road, New Brunswick, NJ 08901, USA
Sociedad de Ciencias Aranzadi, Zorroagagaina, 11, 20014 Donostia-San Sebastián, Spain
Departamento de Estratigrafía y Paleontología, Facultad de Ciencia y Tecnología,
Universidad del País Vasco UPV/EHU, Apartado 644, 48080 Bilbao, Spain
e-mail: agarciaartola@marine.rutgers.edu
A. Cearreta
Departamento de Estratigrafía y Paleontología, Facultad de Ciencia y Tecnología,
Universidad del País Vasco UPV/EHU, Apartado 644, 48080 Bilbao, Spain
e-mail: alejandro.cearreta@ehu.eus
M.J. Irabien
Departamento de Mineralogía y Petrología, Facultad de Ciencia y Tecnología, Universidad
del País Vasco UPV/EHU, Apartado 644, 48080 Bilbao, Spain
e-mail: mariajesus.irabien@ehu.eus