The limit to how much dynamism can be tolerated by shorefront stakeholders is
often related to the distance between the dune crest and the nearest human
infrastructure. Foredunes can be allowed to erode or be breached by storm waves if
the infrastructure is not close to the foredune and the foredune is not the only
protection (Arens et al. 2001; Nordstrom et al. 2007), but dunes in most developed
areas are narrow and close to human facilities and may not be allowed to evolve
solely by natural processes. Ongoing human efforts may be required to allow
portions of the dune to be mobile and evolve through time, while the overall
feature remains intact as a barrier against storm wave run-up. These efforts will
involve controls on beach raking, the use of sand fences and human-use structures
on the beach and in the dune, driving on the beach, managing endangered species,
and using exotic vegetation as ground cover. Establishing criteria for managing
dunes in developed areas as partially dynamic systems is a difficult task. Many of
the methods used to create dunes where they do not exist or to increase the
dynamism of stabilized dunes represent departures from past practices, so it is
likely that most projects will be experimental and small-scale and require a strong
public information component until the feasibility of large-scale future projects is
demonstrated.
2.4 Controlling Negative Human Actions
2.4.1 Restricting Beach Raking
Wrack (natural litter) lines contain seeds, culms, rhizomes of coastal vegetation,
wood debris, and nutrients that aid in the growth of new vegetation and sand
accumulations that evolve into new dunes (Godfrey 1977; Ranwell and Boar 1986)
The highest storm wrack line has the greatest amount of litter and is often far
enough landward of wave uprush during small storms to survive long enough to
provide the base for a new foredune. Raking to remove wrack eliminates the
likelihood of natural cycles of growth and destruction of incipient dunes on the
beach, and eliminates backshore habitats and the associated biodiversity. Raking is
one of the most common environmentally damaging actions on shores developed
for human use (McLachlan 1985; Nordstrom et al. 2000; Colombini and Chelazzi
2003; Dugan et al. 2003). Finding a way to retain wrack is critical to conserving or
restoring beach and dune habitats in developed areas. Alternatives for wrack
management include:
1. Selectively removing the cultural litter and leaving the natural litter using
nonmechanical methods
2. Leaving the highest storm wrack line on the backshore while raking the beach
below it
3. Restricting cleaning operations to the summer (tourist season) or after massive
fish kills
24
K. F. Nordstrom and N. L. Jackson
often related to the distance between the dune crest and the nearest human
infrastructure. Foredunes can be allowed to erode or be breached by storm waves if
the infrastructure is not close to the foredune and the foredune is not the only
protection (Arens et al. 2001; Nordstrom et al. 2007), but dunes in most developed
areas are narrow and close to human facilities and may not be allowed to evolve
solely by natural processes. Ongoing human efforts may be required to allow
portions of the dune to be mobile and evolve through time, while the overall
feature remains intact as a barrier against storm wave run-up. These efforts will
involve controls on beach raking, the use of sand fences and human-use structures
on the beach and in the dune, driving on the beach, managing endangered species,
and using exotic vegetation as ground cover. Establishing criteria for managing
dunes in developed areas as partially dynamic systems is a difficult task. Many of
the methods used to create dunes where they do not exist or to increase the
dynamism of stabilized dunes represent departures from past practices, so it is
likely that most projects will be experimental and small-scale and require a strong
public information component until the feasibility of large-scale future projects is
demonstrated.
2.4 Controlling Negative Human Actions
2.4.1 Restricting Beach Raking
Wrack (natural litter) lines contain seeds, culms, rhizomes of coastal vegetation,
wood debris, and nutrients that aid in the growth of new vegetation and sand
accumulations that evolve into new dunes (Godfrey 1977; Ranwell and Boar 1986)
The highest storm wrack line has the greatest amount of litter and is often far
enough landward of wave uprush during small storms to survive long enough to
provide the base for a new foredune. Raking to remove wrack eliminates the
likelihood of natural cycles of growth and destruction of incipient dunes on the
beach, and eliminates backshore habitats and the associated biodiversity. Raking is
one of the most common environmentally damaging actions on shores developed
for human use (McLachlan 1985; Nordstrom et al. 2000; Colombini and Chelazzi
2003; Dugan et al. 2003). Finding a way to retain wrack is critical to conserving or
restoring beach and dune habitats in developed areas. Alternatives for wrack
management include:
1. Selectively removing the cultural litter and leaving the natural litter using
nonmechanical methods
2. Leaving the highest storm wrack line on the backshore while raking the beach
below it
3. Restricting cleaning operations to the summer (tourist season) or after massive
fish kills
24
K. F. Nordstrom and N. L. Jackson