Petition to List Lynn Canal Pacific Herring under the Endangered ...

Berners Bay. The summary below is based on Carlson (1980) and a more recent review
conducted by Williams et al. (2004).
Carlson (1980), Williams et al. (2004), and other authors use the following descriptors to
refer to Lynn Canal Herring: Auke Bay, Lynn Canal, Berners Bay, Juneau area. All of these
terms refer to the same population of Pacific Herring. This petition uses the name “Lynn Canal
Herring.” The Lynn Canal Herring historically inhabited all of Lynn Canal and adjacent bays,
inlets and coves, including Auke Bay, Berners Bay and Icy Strait.
a) Summer Feeding Areas
Accounts of Lynn Canal Herring distribution as described by Rounsefell and Dahlgren
(1935), Carlson (1980) indicate that the waters between Douglas Island and Admiralty Island in
southern Lynn Canal and northern Stephens Passage were the most important summer feeding
areas.
Tagging studies have shown that Auke Bay stocks do not intermingle with other stocks in
summer feeding areas (Dahlgren 1936 in Carlson 1980; Carlson 1977). From late may
through September, scattered schools of adult herring were found over much of the
nearshore waters of southern Lynn Canal and northern Stephens Passage, with consistent
concentrations along the western shore of Douglas Island (Carlson 1980). Depth
distribution ranged from the surface to near bottom, but mostly averaged between 5 m to
37 m. After mid-July, schools concentrated at 10- to 37- m depths.
(Williams et al. 2004).
b) Fall Migration
In the fall, Lynn Canal Herring move from summer feeding areas in more open waters to
deeper, sheltered areas in coves and bays, primarily Auke Bay and Fritz Cove (Carlson 1980).
Adult herring generally moved deeper in the fall (October) as water and air temperatures
cooled. Carlson (1980) suggests that the breakup of the thermocline serves as a cue that
stimulates movement of Pacific herring from feeding grounds to wintering areas. Herring
movements, from open passages into more sheltered wintering areas in Auke Bay and
Fritz Cove, were frequently tracked by larger predators such as humpback whales, Steller
sea lions, and seabirds.
(Williams et al. 2004).
c) Wintering Areas
Wintering grounds for Lynn Canal Herring are located primarily in deeper, low-current
areas from mid-Douglas Island to Benjamin Island near the eastern shoreline of Lynn Canal
(Carlson 1980, Williams et al. 2004). Recent acoustic surveys indicate that Slate Creek Cove is
also an important wintering area for Lynn Canal Herring (Harris et al. 2005).
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