Waldo Lake Research Articles

Waldo Lake, Oregon Chemical Composition: Major Ions, Buffering Capacity, and Nutrient Loading

Previous limnological investigations have identified Waldo Lake as one of the most pristine and chemically dilute lakes in the world. This study focusing on the major ion chemistry of Waldo Lake has confirmed this status. Situated at a topographical divide in the central Oregon Cascades, with a very small watershed (watershed area to lake area ratio = 2) and shallow, porous soils, Waldo Lake chemistry is dominated by precipitation input with relatively less influence from watershed processes. Based on median values, conductivity for Waldo Lake is 3.4 μS·cm−1, while the cation and anion sums are 39 and 29 μeq·L−1, respectively. Acid neutralizing capacity (ANC, also total alkalinity) is 17 μeq·L−1 (0.85 mg·L−1 as CaCO3), indicating that Waldo Lake is very weakly buffered and highly susceptible to acidification from acidic deposition, although there is no evidence that this has occurred. Chloride (14 μeq·L−1) and sulfate (2.1 μeq·L−1) are derived mainly from precipitation (wet and dry deposition), ANC is derived mainly from weathering of watershed base minerals, and base cations (Ca+Mg+Na+K) are derived from both precipitation (two-thirds) and weathering reactions (one-third). Waldo Lake has been classified as ultraoligotrophic based on the extraordinarily low values of primary productivity and nutrient concentrations. Reported nutrient concentrations vary widely due to the extremely low concentrations and insensitivity of methods employed. However, phosphorus has been identified as the limiting nutrient based on algal bioassay methods. Best estimates based on literature data are total P < 3 ug·L−1, about 50% as inorganic P, and total N < 100 to 200 ug·L−1, more than 90% as organic N. There is a net removal of most inorganic N and P from precipitation in the watershed and lake, but watershed and internal lake processes affecting N and P are not well understood. Estimated total phosphorus loading to the lake is 620 kg y−1 and estimated total phosphorus loss from the lake is 81 kg y−1, with about 85% of P retained in the sediments. Waste disposal facilities installed within the last 30 years could substantially increase phosphorus loading and thus alter the ecology of the lake, although remediation measures are now under consideration.

Waldo Lake History: Prehistoric Period to Present

ABSTRACT Waldo Lake and vicinity remained essentially an uncharted wilderness until the second half of the Nineteenth Century. The area was largely devoid of its aboriginal inhabitants when Judge John Breckenridge Waldo and his companions spent their summers recreating in the Cascades between 1880 and 1907. These Cascade Mountain respites ultimately led Waldo to call for the area's preservation. But Waldo Lake succumbed to another force in the history of the West, the reclamation movement. In 1905, promoters filed for water rights on Waldo for use as a natural reservoir. The first phase that began in 1905 was a failed attempt to develop the lake as a reservoir for power generation, ending in the mid-1930s as markets declined for hydroelectric power and irrigation water. Federal reclamation projects soon took up the slack, beginning in 1939 with a proposal to divert Waldo Lake out of the Willamette drainage entirely to the Upper Deschutes Project via canals and tunnels through the crest of the Oregon Cascades. Next, the Columbia River project of the U.S. Army Corps of Engineers proposed during the 1940s and 50s depicted Waldo Lake as a vital component of the Upper Willamette system of reclamation installations. By the mid-1950s the twin movements of recreation and wilderness preservation took root and renewed Judge Waldo's call for the protection of and recreation in such places as Waldo Lake. Initially, recreation development held sway, culminating in developed campground facilities in the 1960s. By 1984, the area surrounding Waldo Lake was officially designated as wilderness.

Phytoplankton Composition and Distributions in Waldo Lake, Oregon

ABSTRACT The phytoplankton community in Waldo Lake, Oregon is unusual for several reasons, including: (1) phytoplankton diversity is extremely low, with the dinoflagellate Glenodinium neglectum comprising more than 75% of the total phytoplankton; (2) phytoplankton densities are extremely small, with total density and total biovolume averaging 57 algal units ml−1 and 18.5 X 103 μm3 ml−1, respectively; (3) phytoplankton abundance and species composition are nearly uniform throughout the water column, surface to 120 m; (4) several phytoplankton taxa are rare, and some may be new species that have not yet been identified; and (5) picoplankton, which are abundantly present, may be important contributors to the lake's primary production.

Epiphytic Algae on Deep-Dwelling Bryophytes in Waldo Lake, Oregon

ABSTRACT Benthic bryophyte samples that were retrieved in 1990 from depths of 45 m to 110 m in Waldo Lake were analyzed in 1999 for epiphytes. Rewetting of dried material, most of which was liverworts, indicated extensive colonization by filamentous green and blue-green algae, diatoms and aquatic fungi. Bulbocheate, Oedogonium and Stigonema were the three most common filamentous genera present at nearly each of the six sampling sites. Analysis of diatom associations following the oxidation of dried bryophyte-algae subsamples resulted in identification of 37 taxa within 15 genera of typically attached species. Most species were of the genera Eunotia, Pinnularia and Cymbella. These taxa appeared to be widely distributed on the bottom of the lake, at some stations as much as 30 m to 40 m below the lower depth of the photic zone.

Phytoplankton Primary Production and Light in Waldo Lake, Oregon

ABSTRACT Waldo Lake is located in the Willamette National Forest along the west side of Oregon's Cascade Mountain Range. The lake is regarded as one of the most oligotrophic lakes in the world, chemically similar to distilled water, with very low rates of phytoplankton primary production and concentrations of chlorophyll a. Historically, vertical light transmission was considerable, with 1% of the lake's incident solar radiation penetrating to depths greater than 60 m. The lake remains exceedingly clear, as demonstrated by transmissometer profiles and Secchi-disk readings that range between 35 and 40 m. Deep chlorophyll maxima are usually found between 60 and 100 m where measurable light is less than 1% of surface illumination. Conversely, primary production rates and assimilation numbers are maximum in the lake's upper 20 m. Unusually large assimilation numbers in the upper 20 m suggests that the phytoplankton that occupy this stratum are photosynthetically efficient, capable of high rates of production with minimal chlorophyll. There are indications, however, that downward irradiance of blue, green and red light has shifted toward a condition in which the attenuation of blue light has increased more than green and red light. This may be attributed to an increase in phytoplankton density, expressed as a roughly 20-fold increase in phytoplankton primary production over the past 25–30 years. On this basis, Waldo Lake may have shifted from an ultraoligotrophic condition to a more eutrophic state.

Use of a Remote Operated Vehicle and Sonar to Characterize and Estimate the Distribution of Benthic Vegetation in Waldo Lake, Oregon

ABSTRACT Bryophytes that occur in Waldo Lake, Oregon were video-documented and their distribution estimated with sonar. In August 1990, the in situ growth form of the plants was directly observed for the first time using a remote operated vehicle (ROV). Specific growth form of the plants ranged from relatively uniform stand heights (0.25 to 1.0 m) within patches to moderately isolated forms best described as twisted “windrows” or “whorls.” The diameter of the whorls ranged from approximately 0.25 to 0.75 m in diameter and from 5 to 15 m in length. The whorl form was typically in association with patch edges. Plants were found at depths of 128 m (the maximum depth of the lake) and to an upper depth limit of approximately 40 m. The maximum distribution of plants was estimated at 48.9% of the lake area. The use of direct ROV video observation, combined with the sonar, proved to be an acceptable first step in qualitatively describing plant growth and estimating benthic vegetation distribution within the lake.

Deep-water Bryophytes From Waldo Lake, Oregon

ABSTRACT At least thirteen taxa of bryophytes occur between 40 and 128 m depth in Waldo Lake, Oregon. Many taxa exhibit morphological modification precluding positive identification below the level of genus. Liverworts comprise about 98% of the bryomass, the balance being pleurocarpous mosses with trace representation of acrocarps. Predominance of liverworts at extreme depth suggests that they are more viable than mosses under attenuated blue light. All liverworts except one are apparently aquatic forms of upland species. Two mosses are normally upland species, the rest aquatic. Red pigments in some liverwort taxa were maintained as deep as 70 m, but most lost pigment below 40 to 50 m. Sphagnum maintained red pigment as deep as 100 m. Although production of benthic plants would be expected to be exceedingly slow under conditions of low light, low temperatures, limited nutrient availability, and considerable hydrostatic pressure, new growth of 1.5 to 3 cm on liverwort stems approximates annual growth increments observed on upland plants.

Geology and Origin of Waldo Lake, Oregon

ABSTRACT Volcanism has been active in the central Oregon Cascade Range for at least the last 35 Ma. During that period interactions between the Pacific, North American, and Juan de Fuca plates have produced variations in the composition and rate of volcanism, the landward migration and narrowing of the axis of volcanism, and discreet deformational events. The result of these effects is widespread unconformities that have enabled Cascade Range workers to identify five mappable time-stratigraphic units. Waldo Lake occupies a position in the High Cascades physiographic province. The surrounding rocks are primarily very young (less than 1–2 Ma) basaltic andesite lava flows covered with a thin veneer of glacial drift. Waldo Lake was carved by a northward-moving glacier and is dammed on its southeast side by a lateral moraine. The location of the lake is probably controlled by a large north-south trending down-to-the-east normal fault.

Waldo Lake Macroinvertebrates

ABSTRACT A total of 41 taxa was collected from nearshore and offshore habitats in Waldo Lake. The highest taxonomic diversity occurred in nearshore habitats which were structurally more complex and heterogenous than offshore habitats. The presence of 39 taxa (Hydridae excluded) in nearshore habitats varied by habitat-type and taxonomic group. Habitat-type was based on substrate-type, and the presence of taxa in nearshore habitats was partially related to the substrate preferences of taxa. A limited number of taxa (i.e., 11) were collected from offshore habitats, which was, in part, a reflection of the relatively homogenous organization and structure of the deeper, offshore habitats of the lake. The percentage of functional feeding groups did not vary much by habitat, and the majority of taxa (i.e., 53%) was classified as predators. Chironomids had the highest relative abundance of all taxa, accounting for 27% of taxa collected in nearshore benthic core samples and 40% of taxa collected in offshore Ekman dredge samples.

Thermal and Chemical Properties of Waldo Lake, Oregon

ABSTRACT Thermal and chemical profiles were obtained periodically in ultraoligotrophic Waldo Lake, Oregon during years 1986 through 1999. Profiling was done on a seasonal basis between May and October. During this period the lake becomes thermally well-stratified. Epilimnetic temperatures peak in August, then rapidly diminish in response to decreasing solar radiation. By October, the lake nears autumnal turnover. During winter, the lake freezes over. The lake features an orthograde oxygen profile, and is well-oxygenated to all depths. The lake is highly dilute, as indicated by extremely low values for specific conductance (2.9–5.2 μmhos cm−1) and alkalinity (0.39–0.71 mg·L−1 as HCO3). pH readings were nearly all less than 7.0. Inorganic phosphorus and nitrogen concentrations were mostly less than the minimum detection limit of 1.0 μg·L−1. Dissolved silica concentrations ranged between 0.12 and 0.34 mg·L−1. TDS concentrations averaged 4.04 mg·L−1, with roughly 10% of all test results reported as 0.000 mg·L−1. The cause of the lake's extreme dilution is uncertain, but a major contributing factor may be the fact that the lake is fed entirely by direct precipitation and runoff, with no rivers or permanent streams entering the lake.

Waldo Lake, Oregon: Eutrophication of a Rare, Ultraoligotrophic, High-Mountain Lake

ABSTRACT Waldo Lake, Oregon, was described in 1970 as one of the most oligotrophic lakes in the world. But limnological data collected since then indicate that the lake has shifted toward a higher trophic status. This finding is based on three sets of evidence: (1) the spectral distribution of downward irradiance has changed, with blue light now being attenuated more rapidly, while the penetration of both green light and red light has increased; (2) phytoplankton primary production rates have increased 20-fold; and (3) zooplankton have become many times more abundant, and species composition has changed entirely. Although the cause of limnological change is uncertain, investigators believe that it has resulted largely from management and use of the lake. Accordingly, lake visitors have increased dramatically over the past 30 years, from a few hundred visits in 1967 to around 170,000 visits in 1994. Moreover, stocking the lake with 20 million fish between 1938 and 1990 may have disrupted the lake's seemingly fragile ecosystem. Remedial action to save the lake is now being proposed, including (1) repair or removal of sewage-disposal facilities that are possibly defective; (2) tighter restrictions on various lake and watershed uses, and (3) a permanent ban on fish stocking.

A History of Fish Management in Waldo Lake, Oregon

ABSTRACT Trout Oncorhynchus sp. and Salvelinus sp. were released into Waldo Lake beginning in 1889, although releases prior to 1938 are poorly documented. Trout releases were documented for most years between 1938 and 1990. Trout releases were discontinued after 1990. Brook trout are reproducing in the lake and are larger than the average size of brook trout in most lakes in the Oregon Cascade Range. Angling pressure appears to be light and angler catch-rate is poor except during autumn. Future management options include releasing additional fish into the lake, removing fish or leaving things the way they are.

Recent Changes in the Zooplankton Assemblage of Waldo Lake, Oregon

ABSTRACT Since 1969, two years after introductions of Mysis relicta, the species composition and total density of zooplankton in ultraoligotrophic Waldo Lake have undergone significant changes. During our study, spanning 1969–1998, taxa richness and zooplankter body size decreased. Zooplankton density increased by three orders of magnitude, from <1 m−3 to greater than 600 m−3. Hesperodiaptomus persisted from 1969 through 1998, and appears to be a major determinant in zooplankton dynamics. Rotifers, except Collotheca, were held to extremely low numbers, and cyclopoid copepods were eliminated. Bosminal longirostris, the only cladoceran which is presently common in the limnetic zone of this high altitude lake, exhibits daytime avoidance of the surface waters possibly due to high light intensities.

Preliminary Observations of the Benthic Cyanobacteria of Waldo Lake and Their Potential Contribution to Lake Productivity

ABSTRACT Cyanobacteria (blue-green algae) dominate the benthic habitats of Waldo Lake. These photosynthetic microorganisms may be the principal contributors to overall primary production in the lake, although hard data are not yet available. The main biomass of cyanobacteria consists of filamentous, nitrogen-fixing forms, which also produce a yellow-brown, UV-screening pigment (scytonemin) in their extracellular sheaths. This pigment is probably a necessity under these conditions of extreme water clarity in which UV radiation penetrates well. In addition, a conspicuous feature at 1 m to 5 m depths, along much of the shoreline, are living “stromatolites” which resemble shelf-like rock formations, and appear to be formed primarily by the growth of cyanobacteria. Further studies are underway.

Growth and Diet of Fish in Waldo Lake, Oregon

ABSTRACT Waldo Lake, located in the Oregon Cascades, is considered to be one of the most dilute lakes in the world. Even with low nutrient concentrations and sparse populations of zooplankton, introduced fish in the lake are large in size and in good condition when compared to fish from other lakes. This apparent anomaly is due to the availability of benthic macroinvertebrates. Taxa found in the stomach contents offish captured in Waldo Lake consist primarily of Chironomidae larvae and pupae, Trichoptera larvae and pupae, amphipods, Ephemeroptera larvae, and Odonata larvae.