Waptus Bull Trout Population

Overview

The Waptus River is the larger of the two major tributaries of the upper Cle Elum River, entering the river about 5.5 miles above Cle Elum Lake. The Waptus originates as the outflow from several lakes high in the Alpine Lakes Wilderness about two miles upstream of Waptus Lake. From the outlet of Waptus Lake the river flows for approximately 8.5 miles to its confluence with the upper Cle Elum River. Most of the river is in the wilderness, with the last mile or so flowing through the Okanogan-Wenatchee National Forest (Figure 17). Numerous high-gradient creeks are tributaries to the river, all of them subject to seasonal flow depletion and all providing limited access for fish. A waterfall located on the lower Waptus River approximately 2.5 river miles above the mouth (near the Hour Creek confluence) is believed to be a complete barrier to upstream fish migration.

Population Information

Population Distribution and Life History

There have been very few bull trout redd surveys conducted in the Waptus River. These include incomplete surveys conducted by WDFW in 1997-98 and a single survey in the reach below the barrier waterfall conducted by the USFWS in 2003. Also in 2003, the USFWS conducted a redd survey in a reach extending from Waptus Lake upstream approximately 0.6 mile. No bull trout redds were observed in any of these surveys (USFWS 2004b). Bull trout were present historically in Waptus Lake. Catch records compiled by WDFW documented bull trout presence in the 1940s and early 1950s when they were evidently abundant according to anecdotal accounts. The species presence in the lake was further documented by WDFW in 1996 when a single juvenile was captured in a gill net and again the next year when an adult was caught by hook-and-line (Anderson 2001). In 2003, the USFWS sampled the lake via angling for 6-8 hours and captured numerous brook trout but no bull trout. Juvenile bull trout were reportedly observed in the Waptus River (specific location unknown) during snorkel surveys conducted by the Forest Service in 1990, but an extensive presence/absence survey conducted by the USFWS in 2003 throughout the length of the river produced only one potential bull trout observation, which was made above the lake (USFWS 2004b). A subsequent genetic analysis of a tissue sample taken from this juvenile fish revealed it to be an F₂ hybrid (see Population Status section below).

In 2017 Mid-Columbia Fisheries collected 14 eDNA samples in the Waptus River on 1km intervals (Parrish 2017). Three samples were taken upstream of the lake, 11 samples were taken downstream of the lake, and four samples were taken in Spinola Creek. Analysis showed three of the 18 samples were positive for bull trout DNA. Two of those were "weak" positives, meaning they could be the result of a far-away bull trout, or of contamination. The author suggested a re-sampling the Waptus area paired with snorkeling, fishing, or other surveys to determine presence or absence of bull trout. In 2024, a follow up eDNA survey was conducted on a finer scale, at 0.5km intervals. 50 eDNA samples were collected in the Waptus river and its tributaries (Chief Creek, Goat Creek, Hour Creek, Shovel Creek, Spade Creek, Spinola Creek, and Trail Creek) (Taylor 2024). Zero of the samples were positive for bull trout DNA. The team also spent a short amount of time fishing (~1.5 hours) near the mouth of the Upper Waptus river and caught what appeared to be a bull trout x brook trout hybrid. Subsequent genetic analysis of a tissue sample from this fish confirmed it as an an F₂ hybrid. The hybrid was noted as being triploid

It is believed that Waptus Lake once supported a healthy and likely distinct population of adfluvial bull trout. At this point, the evidence suggests that while some bull trout may persist in Waptus Lake, a viable population may not. It is also possible that a resident component exists in the Waptus subwatershed but this has not been confirmed. Further investigation is warranted.

Natural Barriers limiting distribution

A waterfall located on the lower Waptus River approximately 2.5 river miles above the mouth (near the Hour Creek confluence) is believed to be a complete barrier to upstream fish migration. Other migration barriers exist upstream of Waptus Lake. The Chief Creek barrier falls is about 0.5 miles upstream of the confluence with the Waptus River at 47.51834, -121.21976. The upper Waptus River, upstream of the PCT crossing, is primarily fed by Shovel Creek in the late summer, as the mainstem Waptus River goes dry during low flows (last observed dry on 8/27/24 at 47.52175, -121.21727). Shovel Creek is high gradient and a fish passage barrier is likely at 47.524868, -121.215872.

Threats

Connectivity

Fish Passage Barriers

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Entrainment

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Dewatering due to flow management

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Land-use Issues

Forestry

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Agriculture and Grazing

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Recreation

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Roads and Development

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Mining

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Ecological Interactions

Brook Trout

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Other Invasive Species

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Diminished Prey Base

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Disease

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Water Quantity and Quality

Flow issues/dewatering

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Current and modeled future temperature conditions

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Fisheries Impacts

Angling Regulations/Fisheries Use/Poaching (Recreational)

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Management/Monitoring (Research)

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Other Threats

Low Population Resiliency

Climate Change

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Update Notes

2012 BTAP text copied into Yakipedia and edited to match new format inXXXXXX by Aimee Taylor. ADD LINK TO 2012 BTAP pdf placemark

Additional edits proposed by Alex Conley, Aimee Taylor and XXXXXXX small group. Reviewed, and updated and approved by BTWG in XXXXXXXXXXXXX

Specific detail on out of cycle updates: