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Habitats
c. Beaches: Beaches include coastal bluff-backed beaches and barrier beaches
(Shipman, 2008). About equal numbers of bluff-backed and barrier beaches total
1,788 beach segments (Simenstad et al., 2011).
d. Rocky coasts: Rocky coasts of the northern Puget Sound include pocket
beaches and plunging and platform shorelines (Shipman, 2008). There are 2,783
segments of these complex shorelines (364 plunging, 1,409 platform, and 1,010
pocket beaches) (Simenstad et al., 2011).
3. What has historically changed since the development of the Puget Sound shorelines:
a. Since historic surveys from the mid- to late-1800s, three deltas have virtually
disappeared as natural ecosystems, and the total length of river deltas in Puget
Sound has declined by 47%. In total, more than 232 km 2 of natural deltas have
vanished, almost 56% of their historic presence (Simenstad et al., 2011)—
equivalent to 2.5X the area of Lake Washington. The various tidal wetland
ecosystems that once composed these massive deltas have been lost to different
degrees; see below.
b. Even the area of small embayment estuaries have diminished by 69 km 2 , or 67%
of the historical 102 km 2 of small estuaries that once occurred along the shores of
Puget Sound—a loss still 1.2 greater than the area of Lake Washington. The
length of embayments has also declined: barrier estuaries have declined by 44%,
barrier lagoons by 46%, closed lagoons and marshes by 48%, and open coastal
inlets by 45% (Simenstad et al., 2011).
c. The length of bluff-backed beaches in Puget Sound has decreased by 8% and the
length of barrier beaches has declined by 12% since the mid- to late-1800s
(Simenstad et al., 2011).
d. The shoreline lengths of the complex rocky shorelines have also diminished to
some degree, by 9.5% in the case of pocket beaches, 9.3% in the case of plunging
rocky and 10.4% of rocky platforms (Simenstad et al., 2011).
Tidal wetlands of deltas and embayments
4. There are four main types of tidal wetlands in the estuaries of Puget Sound: mud flats,
emergent marshes, scrub-shrub (willow and other woody vegetation) tidal wetlands, and
tidal freshwater swamps (the once great tidal swamps, dominated by Sitka spruce, that
once occurred across the region) (Simenstad et al., 2011). These tidal wetlands are
important to the health of estuaries. They provide shelter and food for salmon and other
fish, help protect the shoreline from storms and large waves, and filter runoff from the
land (Martínez et al., 2007).
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