Upper Klamath Lake Research Articles

Record of Late Pleistocene Glaciation and Deglaciation in the Southern Cascade Range. I. Petrological Evidence from Lacustrine Sediment in Upper Klamath Lake, Southern Oregon

Petrological and textural properties of lacustrine sediments from Upper Klamath Lake, Oregon, reflect changing input volumes of glacial flour and thus reveal a detailed glacial history for the southern Cascade Range between about 37 and 15 ka. Magnetic properties vary as a result of mixing different amounts of the highly magnetic, glacially generated detritus with less magnetic, more weathered detritus derived from unglaciated parts of the large catchment. Evidence that the magnetic properties record glacial flour input is based mainly on the strong correlation between bulk sediment particle size and parameters that measure the magnetite content and magnetic mineral freshness. High magnetization corresponds to relatively fine particle size and lower magnetization to coarser particle size. This relation is not found in the Buck Lake core in a nearby, unglaciated catchment. Angular silt-sized volcanic rock fragments containing unaltered magnetite dominate the magnetic fraction in the late Pleistocene sediments but are absent in younger, low magnetization sediments. The finer grained, highly magnetic sediments contain high proportions of planktic diatoms indicative of cold, oligotrophic limnic conditions. Sediment with lower magnetite content contains populations of diatoms indicative of warmer, eutrophic limnic conditions. During the latter part of oxygen isotope stage 3 (about 37–25 ka), the magnetic properties record millennial-scale variations in glacial-flour content. The input of glacial flour was uniformly high during the Last Glacial Maximum, between about 21 and 16 ka. At about 16 ka, magnetite input, both absolute and relative to hematite, decreased abruptly, reflecting a rapid decline in glacially derived detritus. The decrease in magnetite transport into the lake preceded declines in pollen from both grass and sagebrush. A more gradual decrease in heavy mineral content over this interval records sediment starvation with the growth of marshes at the margins of the lake and dilution of detrital material by biogenic silica and other organic matter.

Associations between Water Quality and Daily Growth of Juvenile Shortnose and Lost River Suckers in Upper Klamath Lake, Oregon

Poor water quality from hypereutrophic Upper Klamath Lake in south-central Oregon has been suspected of contributing to the recruitment failure of two endangered endemic fish species, the Lost River sucker Deltistes luxatus and the shortnose sucker Chasmistes brevirostris. We used otolith daily increment widths as a proxy for juvenile somatic growth to construct two growth models: (1) a linear mixed-effects (LME) model examining the lifetime effects of lakewide averages of potentially stressful daytime water temperature, pH, and nighttime dissolved oxygen (DO), and (2) a simple linear regression model examining the effects of locally measured water temperature, pH, and daytime DO on growth of fish over 3 d before the fish's capture. Graphical relationships between daily growth and biweekly un-ionized ammonia failed to show a sublethal effect on the growth of suckers captured in areas where un-ionized ammonia surpassed levels lethal to both species. For both species, our LME models indicated that at temperatures greater than approximately 22°C, low nighttime DO (less than 4 mg/L for Lost River suckers and less than 1 mg/L for shortnose suckers) caused enough stress to reduce growth, whereas at temperatures less than approximately 22°C, any stress from low nighttime DO was not reflected in reduced growth. We attribute the pattern to the species' tolerance of low DO, the short duration of nighttime events, the fish's increased oxygen demand at higher temperatures, and growth compensation due to increased food resources associated with low DO. The combination of low DO and high temperature has also been implicated in adult fish kills in Upper Klamath Lake. Because 34% of the time lakewide August average temperatures exceeded 22°C, extended periods of warm temperatures and high primary production could affect the sizes of recruits surviving into fall. Both growth models suggested that shortnose suckers might be more tolerant of poor water quality than Lost River suckers.

68 A new paradigm for the aphanizomenon bloom problem in upper klamath lake

Upper Klamath Lake (UKL) is the largest lake in Oregon (area 287 km2, avg. depth 4.2 m). It is naturally eutrophic and regularly suffers nuisance summer blooms of cyanobacteria, principally Aphanizomenon flos‐aquae (AFA). Sediment coring studies show that AFA was absent or minimal until about 1880 when a steady increase began, culminating in the blooms of recent decades. These studies show concomitant increases in sediment N (∼20%) and P (∼50%) along with shifts in the algal flora indicating increased eutrophication. These changes correlate with increased human impacts, such as deforestation, construction, roadbuilding etc., and especially the ditching, diking and draining of adjacent wetlands for conversion to agriculture. Agricultural nutrient runoff, especially P, has been often cited as the cause of the AFA blooms, and most attention has been focused on the dynamics of UKL during the summer bloom. We propose that a more significant factor may be the loss of early‐season suppression of AFA because of the loss of the lake‐associated wetlands, which originally constituted 42% of the lake area, and which have declined in area by 66.3% since the late 1800's. The melting of snow and ice in the spring would flush into the lake a surge of wetland plant decomposition products, most significantly organic acids and humic substances. We propose that formerly these wetland effluents caused a complex of effects on lake pH, solar UV transparency, photochemical interactions, nutrient availability, and Daphnia grazing dynamics, which would have combined to prevent the development of any AFA bloom.

68 A new paradigm for the aphanizomenon bloom problem in upper klamath lake

Upper Klamath Lake (UKL) is the largest lake in Oregon (area 287 km2, avg. depth 4.2 m). It is naturally eutrophic and regularly suffers nuisance summer blooms of cyanobacteria, principally Aphanizomenon flos‐aquae (AFA). Sediment coring studies show that AFA was absent or minimal until about 1880 when a steady increase began, culminating in the blooms of recent decades. These studies show concomitant increases in sediment N (∼20%) and P (∼50%) along with shifts in the algal flora indicating increased eutrophication. These changes correlate with increased human impacts, such as deforestation, construction, roadbuilding etc., and especially the ditching, diking and draining of adjacent wetlands for conversion to agriculture. Agricultural nutrient runoff, especially P, has been often cited as the cause of the AFA blooms, and most attention has been focused on the dynamics of UKL during the summer bloom. We propose that a more significant factor may be the loss of early‐season suppression of AFA because of the loss of the lake‐associated wetlands, which originally constituted 42% of the lake area, and which have declined in area by 66.3% since the late 1800's. The melting of snow and ice in the spring would flush into the lake a surge of wetland plant decomposition products, most significantly organic acids and humic substances. We propose that formerly these wetland effluents caused a complex of effects on lake pH, solar UV transparency, photochemical interactions, nutrient availability, and Daphnia grazing dynamics, which would have combined to prevent the development of any AFA bloom.

Structural changes in gills of Lost River suckers exposed to elevated pH and ammonia concentrations

The Lost River sucker ( Deltistes luxatus) is a federally listed, endangered fish that occurs primarily in Upper Klamath Lake—a hypereutrophic lake in southern Oregon, USA. A decline of the sucker population in the lake over the past few decades has been partly attributed to adverse water quality conditions, including elevated pH and ammonia concentrations that occur during summer cyanobacterial blooms. We quantitatively analyzed structural changes in gills of larval Lost River suckers after they were exposed to elevated pH and ammonia concentrations for 30 d. Exposure to pH as high as 10 caused no observed structural changes. However, lamellar thickness and O 2 diffusion distance increased significantly ( P<0.05) at ammonia concentrations that did not significantly decrease survival, growth, whole-body ion concentrations, or swimming performance. Additionally, we qualitatively observed increases in the frequency of hyperplasic and hypertrophic mucous cells, tissue damage, epithelial lifting, and infiltration of white blood cells into paracellular lymphatic spaces at the highest sublethal ammonia concentration. These observed gill changes typically indicate compromised respiratory and ionoregulatory capacity, although such effects were not manifested in the assays we performed . Regardless, these structural gill changes appear to be a more sensitive indicator of exposure to elevated ammonia concentrations than are more traditional sublethal indices. Therefore, gill histopathology might be a relevant early-warning monitoring tool of the health of Lost River suckers in Upper Klamath Lake, and other species in similar eutrophic systems.

Assessing potential health risks from microcystin toxins in blue-green algae dietary supplements.

The presence of blue-green algae (BGA) toxins in surface waters used for drinking water sources and recreation is receiving increasing attention around the world as a public health concern. However, potential risks from exposure to these toxins in contaminated health food products that contain BGA have been largely ignored. BGA products are commonly consumed in the United States, Canada, and Europe for their putative beneficial effects, including increased energy and elevated mood. Many of these products contain Aphanizomenon flos-aquae, a BGA that is harvested from Upper Klamath Lake (UKL) in southern Oregon, where the growth of a toxic BGA, Microcystis aeruginosa, is a regular occurrence. M. aeruginosa produces compounds called microcystins, which are potent hepatotoxins and probable tumor promoters. Because M. aeruginosa coexists with A. flos-aquae, it can be collected inadvertently during the harvesting process, resulting in microcystin contamination of BGA products. In fall 1996, the Oregon Health Division learned that UKL was experiencing an extensive M. aeruginosa bloom, and an advisory was issued recommending against water contact. The advisory prompted calls from consumers of BGA products, who expressed concern about possible contamination of these products with microcystins. In response, the Oregon Health Division and the Oregon Department of Agriculture established a regulatory limit of 1 microg/g for microcystins in BGA-containing products and tested BGA products for the presence of microcystins. Microcystins were detected in 85 of 87 samples tested, with 63 samples (72%) containing concentrations > 1 microg/g. HPLC and ELISA tentatively identified microcystin-LR, the most toxic microcystin variant, as the predominant congener.

Assessing Potential Health Risks from Microcystin Toxins in Blue-Green Algae Dietary Supplements

The presence of blue-green algae (BGA) toxins in surface waters used for drinking water sources and recreation is receiving increasing attention around the world as a public health concern. However, potential risks from exposure to these toxins in contaminated health food products that contain BGA have been largely ignored. BGA products are commonly consumed in the United States, Canada, and Europe for their putative beneficial effects, including increased energy and elevated mood. Many of these products contain Aphanizomenon flos-aquae, a BGA that is harvested from Upper Klamath Lake (UKL) in southern Oregon, where the growth of a toxic BGA, Microcystis aeruginosa, is a regular occurrence. M. aeruginosa produces compounds called microcystins, which are potent hepatotoxins and probable tumor promoters. Because M. aeruginosa coexists with A. flos-aquae, it can be collected inadvertently during the harvesting process, resulting in microcystin contamination of BGA products. In fall 1996, the Oregon Health Division learned that UKL was experiencing an extensive M. aeruginosa bloom, and an advisory was issued recommending against water contact. The advisory prompted calls from consumers of BGA products, who expressed concern about possible contamination of these products with microcystins. In response, the Oregon Health Division and the Oregon Department of Agriculture established a regulatory limit of 1 microg/g for microcystins in BGA-containing products and tested BGA products for the presence of microcystins. Microcystins were detected in 85 of 87 samples tested, with 63 samples (72%) containing concentrations &gt; 1 microg/g. HPLC and ELISA tentatively identified microcystin-LR, the most toxic microcystin variant, as the predominant congener.

Harvesting of Aphanizomenon flos-aquae Ralfs ex Born. & Flah. var. flos-aquae (Cyanobacteria) from Klamath Lake for human dietary use

In western cultures, certain cyanobacteria have beenan accepted source of microalgal biomass for food forabout 30 years, in particular Spirulina(Arthrospira) platensis and S. maxima. Beginning in the early 1980s, another species, Aphanizomenon flos-aquae was adopted for similaruses. This is harvested from Upper Klamath Lake, thelargest freshwater lake system in Oregon. In 1998 theannual commercial production of Aphanizomenonflos-aquae was about 1 × 106 kg. Since thisspecies is not cultured like Spirulina inoutdoor ponds or raceways, it requires very differentprocedures for harvesting and processing. These arereviewed here and include extensive off-lake screensor on-lake barges, which dewater and concentrate thecells. Other procedures, such as those for removal ofdetritus and mineral materials, and those formonitoring and reducing the amounts of certaincontaminant cyanobacteria, which can producecyanotoxins, have also become important in qualitycontrol and marketing.

Effects of Ambient Water Quality on the Endangered Lost River Sucker in Upper Klamath Lake, Oregon

Abstract Populations of the Lost River sucker Deltistes luxatus have declined so precipitously in the Upper Klamath Basin of Oregon and California that this fish was recently listed for federal protection as an endangered species. Although Upper Klamath Lake is a major refuge for this species, fish in the lake occasionally experience mass mortalities during summer and early fall. This field study was implemented to determine if fish mortalities resulted from degraded water quality conditions associated with seasonal blooms of phytoplankton, especially Aphanizomenon flos-aquae. Our results indicated that fish mortality did not always increase as water temperature, pH, and un-ionized ammonia concentration increased in Upper Klamath Lake. Little or no mortality occurred when these water quality variables attained their maximum values. On the other hand, an inverse relation existed between fish mortality and dissolved oxygen concentration. High mortality (>90%) occurred whenever dissolved oxygen concentration...

Lethal levels of selected water quality variables to larval and juvenile Lost River and shortnose suckers

Resource managers hypothesize that occasional fish kills during summer–early fall in Upper Klamath Lake, Oregon, may be linked to unfavorable water quality conditions created by massive algal blooms. In a preliminary effort to address this concern, short-term (96-h-long) laboratory tests were conducted with larval and juvenile Lost River ( Deltistes luxatus) and shortnose ( Chasmistes brevirostris) suckers to determine the upper median lethal concentrations (LC 50s; also referred to as median tolerance limits) for pH, un-ionized ammonia, and water temperature, and the lower LC 50s for dissolved oxygen. The mean LC 50s varied among species and life stages as follows: for pH, 10.30–10.39; for un-ionized ammonia, 0.48–1.06 mg litre −1; for temperature, 30.35–31.82°C; and for dissolved oxygen, 1.34–2.10 mg litre −1. Comparisons of 95% confidence limits indicated that, on average, the 96-h LC 50s were not significantly different from those computed for shorter exposure times (i.e., 24 h, 48 h, and 72 h). According to two-way analysis of variance, LC 50s for the four water quality variables did not vary significantly ( p>0.05) between fish species. However, LC 50s for pH (exposure times of 24 h and 48 h) and dissolved oxygen (exposure times of 48 h, 72 h, and 96 h) differed significantly ( p≤0.05) between life stages, whereas LC 50s for un-ionized ammonia and water temperature did not exhibit significant differences. In general, larvae were more sensitive than juveniles to high pH and low dissolved oxygen concentrations. When compared to ambient water quality conditions in Upper Klamath Lake, our results strongly suggest that near-anoxic conditions associated with the senescence phase of algal blooms are most likely to cause high mortalities of larval and juvenile suckers.

A Test of Water Depth Niche Partitioning by Western Grebe Color Morphs

Darkand light-phase Western Grebes (Aechmophorus occidentalis) have been described by Storer (1965) and Ratti (1981). Ratti (1979) and Nuechterlein (1981) reported on reproductive separation and isolating mechanisms between color morphs. Data from Ratti (1979) indicate that light-phase birds represent reproductively independent populations and that morphs are separate species. Ratti (1979) stated that morphologically and ecologically, darkand light-phase Western Grebes are practically indistinguishable and may represent one of best avian examples of an exception to competitive exclusion principle (Grinnell 1904). However, Nuechterlein (1981) reported that light-phase birds tend to feed farther from shore than dark-phase birds. He also noted a preponderance of level dives by dark-phase birds and a preponderance of springing dives by light-phase birds. The light-phase diving posture is more perpendicular to water surface and may facilitate diving to greater These findings led to Nuechterlein's (1981) hypothesis that the two color phases may be segregating behaviorally into two subtly different ecological forms specialized for feeding at different depths. The objective of this research was to test Nuechterlein's (1981) hypotheses. Data were gathered at Goose Lake, Lower Klamath National Wildlife Refuge (NWR), and Tule Lake NWR, California; Upper Klamath Lake, Oregon; and Bear River NWR, Utah. Goose and Upper Klamath lakes are natural water basins; Lower Klamath, Tule Lake, and Bear River NWRs are artificial water impoundments. All surveys were initiated at sunrise, when most birds were actively feeding, and usually terminated by midmorning. Survey routes were determined from previous field work (Ratti 1979). One survey was conducted at each study area and, thus, all data are statistically independent. Birds were classified as dark-phase or light-phase (Ratti 1981); rare intermediates were not recorded. Each bird observed was recorded into 1 of 3 categories, based on an ocular estimation of distance from shore; A = 75 m. The location, number of birds, and color phase also were recorded on a map of survey route. After completion of bird surveys, I returned to bird observation sites and conducted a minimum of 3 water-depth transects. Transect lines were 100 m apart, parallel, and generally perpendicular to shoreline of observation site. I traversed transect lines from a canoe, and recorded water depth from ocular estimated distances of 15, 50, and 100 m from shore to correspond with distance categories of bird observations. Throughout study, distances were measured periodically from shore to verify my ocular estimations. Data from bird observations were tested using Chi-square analysis and mean depths were compared by t-test. Between 15 June and 20 July 1981, I observed 1,132 dark-phase and 596 light-phase Western Grebes and measured water depth from 106 transects. Variation in number of water-depth transects measured at each location was a function of distribution of birds along survey route. Distance from shore.-Observations of color morphs in categories of distance from shore were not random (Table 1). There was a clear tendency for

REQUIREMENTS FOR THE MAINTENANCE AND GROWTH OF APHANIZOMENON FLOS‐AQUAE IN CULTURE1,2

SUMMARY Aphanizomenon flos‐aquae has been introduced into unialgal culture in a completely defined medium and maintained for more than 3 years in the colonial flake form found in nature. The color and size of the flake and general appearance of the cells are substantially improved over those found in the original material at the time of collection from Upper Klamath Lake, Klamath County, Oregon. The alga readily forms both akinetes and heterocysts in culture Bacteria‐free cultures have not been obtained.A precipitate‐free medium designated ASM No. 8a has been developed from the ASM of McLachlan and Gorham. Their medium was altered by modifying the concentration of certain elements and by the addition of sodium bicarbonate, a 1/25 dilution of Arnon's trace element solutions B7 and C13, hydrogen ferric ethylenediamine di‐o‐hydroxyphenylacetate (EDDHA), and disodium ethylene dinitrilotetra‐acetate (Na2EDTA).

Mineral requirements for the growth of Anabaena spiroides in vitro

Anabaena spiroides Klebahn, isolated from Upper Klamath Lake, Klamath County, Oregon, was cultured in Gerloff's modification of Chu's number 10 medium. Preliminary to a study of the major nutrient mineral requirements, the initial culture medium was modified by elimination of sodium silicate, the addition of Tris(hydroxymethyl)aminomethane, and the substitution of hydrogen ferric ethylenediamine di-o-hydroxyphenylacetate (EDDHA) for ferric citrate – citric acid.Provision of mineral nitrogen in the medium was found unnecessary for growth, strongly suggesting that A. spiroides can fix nitrogen, but final proof awaits the development of bacteria-free cultures. Although phosphorus was required in relatively high concentrations to obtain maximum growth, it was apparently accumulated in the cells, allowing them to survive long exposure in phosphorus-deficient media. Several other major elements either were required in very minute amounts or were accumulated by the alga. Iron provided in the alkaline-stable chelate EDDHA was required in lower concentration than in Gerloff's medium. A definite, high requirement for calcium was found.A balanced medium was developed that supported an increase of 100% in dry weight, 23% in chlorophyll content, and 10% in organic nitrogen above that obtained in the initial medium.