Waterfront property owners have a unique opportunity to develop land in a manner that is protective of their investment and the natural system. Each property affects the health of our shoreline.
Our shoreline provides essential habitat for a diversity of fish, plants and animals. This map shows areas with specific functions that maintain the productivity of the nearshore ecosystem.
Click on the magnifying glass on the right to search for an address or parcel number.
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Arrows denote the extent of individual drift cells and the direction of net shore-drift within each. No arrows indicate shorelines with no appreciable drift.
Lines represent the deepwater edge of eelgrass. Though likely, it cannot be assumed that the entire area between the deep edge and the beach contains eelgrass.
Lines denote feeder bluffs that have been mapped by a coastal geologist as part of a regional effort.
Lines denote beaches where forage fish eggs have been found by trained field crews.
Icons represent approximate locations along a parcel of hard armoring, hybrid, and soft stabilization installations along the shorelines.
Wind generated waves move beach sediment along the shoreline. Although wind direction changes on a daily, weekly or seasonal basis, many shorelines exhibit a single overall direction of net shore drift. Also called littoral or longshore drift, net shore drift is determined through geomorphologic analysis of beach sediment patterns and of coastal landforms.
Many shorelines can be divided into discrete drift cells, which are independent of one another and for which distinct sediment sources and sinks can be identified. Feeder bluffs and feeder banks are sources of beach sediment.
Orca eat salmon, and salmon eat smaller "forage" fish. Two species of forage fish - sand lance and surf smelt - spawn on upper intertidal sand and gravel beaches. Net shore drift brings this sand and gravel from feeder bluffs and feeder banks. If any part of the reach is bulkheaded, the supply of sand and gravel diminishes.
Many species lay their eggs in eelgrass beds. Most important to salmon, and the three resident orca pods that eat salmon, are Pacific herring. During low tides, eelgrass shelters small animals and plants from extreme temperatures. On tide flats, eelgrass beds hold moisture like a sponge, offering additional protection for small creatures.
Eelgrass meadows cushion the impact of waves and currents, preventing erosion. Eelgrass roots weave sediments in place. This protection helps preserve the highly productive bacteria in the sediments which nourish large amounts of invertebrates.
Some bluffs, due to their height, erosion rate, or composition may be more significant sources of beach sediment than others. Smaller feeder banks are also important in the San Juan Islands where taller feeder bluffs are relatively rare.
Shoreline armoring in the Salish Sea poses a particularly serious threat to the function of feeder bluffs and banks, since the ongoing erosion of these bluffs and banks is so important to maintaining the supply of sediment to nearby beaches. This sediment, depending on the grain size, can be essential for the spawning of sand lance and surf smelt, the smaller fish that salmon feed on.
Preventing erosion through shoreline armoring diminishes the delivery of sediment and can have long-term impacts on beach condition and habitat functions for many species.
Orcas eat salmon, and salmon eat smaller "forage" fish. Two species of forage fish - sand lance and surf smelt - spawn on upper intertidal sand and gravel beaches. Net shore drift brings this sand and gravel from feeder bluffs and banks. If any part of the reach is bulkheaded, the supply of sand and gravel diminishes. Filling and bulkheading seaward far into the upper intertidal zone can bury and destroy surf smelt and sand lance spawning habitat.
Even on lightly armored beaches, wave action along the base of the structures may scour away fine-grained sediments. Beaches may gradually coarsen, eliminating essential sand lance and surf smelt spawning habitat.
Other beaches also have the right grain size (sand and small pea-sized gravel), but are not considered 'documented' and do not show up on this map. Because forage fish spawn year round in the San Juans, and because this type of mapping is labor intensive, there are very likely other beaches where forage fish lay their eggs.
The red dots indicate the presence of some sort of shore stabilization on some or all of the shoreline of a particular parcel. Most often, the red dot indicates the presence of a bulkhead, which is considered hard armor, and can be comprised of stacked logs or rocks, or a combination of both.
Older, failing bulkheads can cause more erosion to the shoreline since waves get behind the structure and/or around the edges. Newer installation techniques involve dovetailing the edges so less erosion to the neighboring properties occur. All hard armoring alters the shoreline, and in some cases degrades the productivity and habitat value, especially in the cases of spawning beaches. Bulkheads typically take the place of shoreline vegetation, reducing the insects and leaf litter upon which smaller fish feed, and reducing the shade from vegetation which prevents eggs from drying out.
Recently, alternative techniques have been developed which are known as 'soft stabilization.'' They mimic the nearby natural conditions, and can include re-sloping the bank, beach nourishment, specifically placed horizontal large logs, a few large rocks (no more than 20%), and installing native vegetation on the bank. Some projects may necessitate a 'hybrid' techniques which includes portions of hard armor to be effective. There are a few of these projects in the San Juans, and we are working to designate them separately.
Not all Puget Sound shorelines look the same. Some are rocky, some are sandy. Some are steep bluffs and rocky cliffs, others are broad salt marshes or tide flats. These differences reflect the geology of the coastline and the way in which it has been shaped by waves and tides.
Puget Sound shorelines can be generally divided into four different types: Rocky coasts, bluffs and beaches, smaller embayments, and large river deltas. Within each of these broad categories, there may be a variety of smaller landforms (sometimes called shoreforms). Embayments include a variety of lagoons and estuaries. Beaches include barrier beaches such as spits. These landforms are shaped by tidal processes and geomorphic proc-esses such as the erosion and deposition of sediment. The different land-forms may give rise to very different ecological processes and functions.