Tidal_PAD_V1_Sec4.pdf - Snohomish County PUD

Snohomish County PUD –Pre-Application Document
4 – Existing Environment
British Columbia to take advantage of the basin’s protected bays and channels (Speich and Wahl
1995; USFWS 1997). During the breeding season, murrelets are concentrated where food and
nearby nesting habitat are abundant, including the Strait of Juan de Fuca, the south shore of Lopez
Island, the southwest shore of Lummi Island, Obstruction and Peavine passes between Orcas and
Blakely islands in the San Juans, Point Wilson, Point Roberts, Cattle Point, Green Point, Tongue
Point, and Dungeness Wildlife Refuge and Spit (Seattle Audubon Society 2007; Speich and Wahl
1995). Areas of winter concentration include Sequim, Discovery and Chuckanut bays; the waters
around the San Juan and Whatcom County islands; and, the inland waters east of and including
Admiralty Inlet (Seattle Audubon Society 2007; Speich and Wahl 1995).
Table 4-52. Site-specific description of the presence of the marbled murrelet by project area
Site
Admiralty Inlet
Species Present:
Yes
Spieden Channel
Species Present:
Yes
San Juan Channel
Species Present:
Yes
Guemes Channel
Species Present:
Yes
Deception Pass
Species Present:
Yes
Agate Passage
Species Present:
Yes
Rich Passage
Species Present:
Yes
Marbled Murrelet (Brachyramphus marmoratus) - Status: Threatened
Description
Admiralty Inlet is characterized by several features that make it favorable to the
presence of marbled murrelets. It possesses both under-story and canopy-forming
kelp, elevated current velocities as well as sill-type structures at both entrances which
promote enhanced mixing. It also possesses Pacific herring spawning grounds within
its confines.
Spieden Channel is also characterized by several features that make it favorable to the
presence of marbled murrelets. Like Admiralty Inlet, it possesses both under-story
and canopy-forming kelp, elevated current velocities as well as a narrow-shelf
shoreline of mixed rock substrate. It also possesses Pacific sand lance and smelt
spawning grounds within its confines.
San Juan Channel possesses both under-story and canopy-forming kelp, elevated
current velocities, and a narrow-shelf shoreline with a gravel based substrate. It also
possesses Pacific sand lance and smelt spawning grounds within its confines.
While Guemes Channel does not possess all of the same qualities as the above sites, it
does possess under-story kelp and elevated current velocities. It is also very near the
San Juan and Whatcom County islands, which are areas of year round marbled
murrelet concentration.
Deception Pass possesses several features that make it favorable to the presence of
marbled murrelets including both under-story and canopy-forming kelp, elevated
current velocities, and a narrow-shelf shoreline of mixed bedrock, gravel and sand
substrate.
Agate Passage is characterized by several features that also make it favorable to the
presence of marbled murrelets. Like Guemes Channel, it possesses only under-story
kelp, but elevated current velocities and the presence of Pacific herring spawning
grounds within its confines may attract marbled murrelets.
Rich Passage is perhaps the least favorable of all the sites for the presence of marbled
murrelets. Although it does not possess spawning grounds for any of the forage fish
species nor canopy-forming kelp, it does possess under-story kelp and elevated
current velocities as well as benthic substrates of mixed gravel and sand.
Sources: 1982 Survey - Speich and Wahl, 1989; DON, 2006; Evans- Hamilton, Inc., 1987; PSWQA, 1992;
4-144 January 31, 2008