Proposed Abstract Title

Ecosystem services of beaches that are affected by armoring, and how this relates to priorities for bulkhead removal

Type of Presentation

Oral

Session Title

Bulkhead Removal - Putting goals into practice

Location

2016SSEC

Description

Shoreline armoring can impact a variety of “goods and services” provided by beaches and nearshore ecosystems of the Salish Sea. Shoreline managers struggle to balance genuine need for armoring to protect infrastructure versus unacceptable losses of ecosystem services – whether these be in marshes, sand dunes, or beaches. Changes caused by armoring may not be apparent to the public because they may be very gradual or ‘invisible’ below the ocean surface, whereas the benefits of armoring in terms of protection of homes are obvious. These tradeoffs and the uncertainties inherent in quantifying impacts mean that policy changes are readily resisted. We argue that we now know enough about negative consequences of shoreline armoring in a variety of physical environments that we can make science-based recommendations for prioritizing restoration actions. All armoring prevents shoreline translation and reduces marine-terrestrial connectivity to some extent, but our recommendations focus on two concrete issues: elevation of armoring, and locations critical for sediment supply. Armoring that is emplaced relatively low on the shore, and thus encroaches on the beach and actually covers some habitat types, has the potential to affect a wide variety of ecosystem services from forage fish spawning to beach recreation. Removing armoring from feeder bluffs is clearly another restoration target, because sources of sediment are essential to the maintenance of beaches and all their functions. In addition, our data suggest there is a cumulative effect of emplacing more armoring on already-altered shorelines; this effect is manifested in changes in grain size distributions, which indirectly affect many functions of beaches. We summarize what we have learned about armoring impacts in the Salish Sea and discuss the links to ecosystem goods and services that the public can relate to; emphasizing these linkages may make it more palatable to undertake large restoration projects or tighten armoring restrictions.

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Ecosystem services of beaches that are affected by armoring, and how this relates to priorities for bulkhead removal

2016SSEC

Shoreline armoring can impact a variety of “goods and services” provided by beaches and nearshore ecosystems of the Salish Sea. Shoreline managers struggle to balance genuine need for armoring to protect infrastructure versus unacceptable losses of ecosystem services – whether these be in marshes, sand dunes, or beaches. Changes caused by armoring may not be apparent to the public because they may be very gradual or ‘invisible’ below the ocean surface, whereas the benefits of armoring in terms of protection of homes are obvious. These tradeoffs and the uncertainties inherent in quantifying impacts mean that policy changes are readily resisted. We argue that we now know enough about negative consequences of shoreline armoring in a variety of physical environments that we can make science-based recommendations for prioritizing restoration actions. All armoring prevents shoreline translation and reduces marine-terrestrial connectivity to some extent, but our recommendations focus on two concrete issues: elevation of armoring, and locations critical for sediment supply. Armoring that is emplaced relatively low on the shore, and thus encroaches on the beach and actually covers some habitat types, has the potential to affect a wide variety of ecosystem services from forage fish spawning to beach recreation. Removing armoring from feeder bluffs is clearly another restoration target, because sources of sediment are essential to the maintenance of beaches and all their functions. In addition, our data suggest there is a cumulative effect of emplacing more armoring on already-altered shorelines; this effect is manifested in changes in grain size distributions, which indirectly affect many functions of beaches. We summarize what we have learned about armoring impacts in the Salish Sea and discuss the links to ecosystem goods and services that the public can relate to; emphasizing these linkages may make it more palatable to undertake large restoration projects or tighten armoring restrictions.