State of Our Watersheds: Shoreline Armoring Diminishes Nearshore Fish Habitat

The Lower Elwha Klallam Tribe has been keeping a close eye on shoreline armoring in the Port Angeles area, as increased armoring leads to decreasing habitat for nearshore fish.

Shoreline armoring is one of many indicators the tribe regards when it comes to the health of salmon habitat, as reported recently in the 2016 State of Our Watersheds report.

While the tribe has removed 2,700 feet of hardened shoreline within its Area of Interest, and is on track to remove another 1,750 feet in 2017, Clallam County has installed 1,933 feet of new armoring, 5,337 feet of replacement armoring, and has not removed any existing armoring.

Armoring involves use of physical structures to protect marine shorelines to stabilize coastal land, prevent erosion and protect residential and commercial infrastructures.

Shoreline armoring can alter the delivery, transport and accretion of sediments when bluffs become disconnected from their associated beaches and marine nearshore. This negatively affects the nearshore environment necessary for salmon survival, and severely limits forage fish habitat.

Sand lance and surf smelt, which make up a significant portion of juvenile chinook salmon diets, spawn almost exclusively on sand and gravel beaches, making them vulnerable to the degrading effects of shoreline modification and armoring.

The tribe has been paying attention to the differences in armoring both east and west of Morse Creek.

About 71 percent of the marine shoreline within the tribe’s Area of Concern, almost entirely west of Morse Creek, is armored. Conversely, 2 percent of the shoreline outside of the Area of Concern and eastward of the creek, is armored.

This significant difference in the degree of armoring of the shorelines west and east of Morse Creek may be the reason for the equally significant difference in the distribution of forage fish spawning habitat in both areas.

In addition, of the 305 forage fish surveys conducted in WRIA 18 by the state (with 82 positive for surf smelt and/or sand lance), only one survey found forage fish west of Morse Creek.

One thought on “State of Our Watersheds: Shoreline Armoring Diminishes Nearshore Fish Habitat

Comments are closed.