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3.4 Phytoplankton and Periphyton
This section focuses on potential effects of the Proposed Project on the phytoplankton and periphyton communities in the Klamath River. For the purposes of this EIR the following terms have the following meanings:
- Phytoplankton: aquatic microscopic organisms, including algae, bacteria, protists, and other single-celled plants, that obtain energy through photosynthesis and float in the water column of still or slowly flowing waters such as lakes or reservoirs.
- Periphyton: aquatic organisms including aquatic plants, algae, and bacteria that live attached to underwater surfaces such as rocks on a riverbed.
- Algae: common name for photosynthesizing organisms that are a component of phytoplankton and/or periphyton (see above definitions) where algae typically include diatoms, green algae, and blue-green algae.
- Blue-green algae: common name for a type of phytoplankton that can produce toxic compounds that have harmful effects on fish, shellfish, mammals, bird, and people. Though blue-green algae are a type of cyanobacteria they are commonly referred to as algae. Cyanobacteria toxins are often referred to as “algal toxins”. For readability, and to reduce confusion, this EIR will primarily refer to cyanobacteria as blue-green algae, with the exception of referencing source material.
In a balanced ecosystem, phytoplankton and periphyton supply base energy for the food web, because they convert energy from the sun (through photosynthesis) into biomass. In addition to sunlight, water and air, phytoplankton and periphyton also rely on nutrients from the water (primarily nitrogen and phosphorus). An excessive nutrient load in the water can allow phytoplankton and periphyton to overwhelm the ecosystem, causing negative impacts to water quality and other environmental resources. In addition to water quality and environmental impacts, blue-green algae can produce toxic compounds that have harmful effects on fish, shellfish, mammals, birds, and people.
The State Water Board received several comments related to blue-green algae during the NOP public scoping process (Appendix A), including comments indicating that dam removal would reduce the incidence of blue-green algae blooms and associated toxins in the Klamath River system. Commenters related numerous instances in which they linked health impacts to water contact in the presence of blue-green algae toxins, and they described having to limit recreation and avoid water contact due to blue-green algae despite the cultural importance of the river. Several commenters also noted that they no longer eat fish from the Klamath River due to concerns about consuming blue- green algae toxins with the fish. Other comments indicated that blue-green algae growth would continue to occur in the Klamath River in the absence of the Lower Klamath Project reservoirs. There were also several comments regarding periphyton, suggesting that dam removal would reduce the prevalence of attached algae in the Klamath River, which could reduce parasite rates in anadromous fish. A detailed summary of comments received during the NOP public scoping process, as well as individual comments, are presented in Appendix A.
Discussion of blue-green algae toxins and their impact on water quality are addressed in Section 3.2 Water Quality. Discussion of the relationship between periphyton and fish disease is addressed further with respect to aquatic organisms in Section 3.3.2.3. Disease and Parasites. Discussion of blue-green algae and its impact on recreation are
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addressed in Section 3.20 Recreation. Discussion of tribal cultural resources impacts of blue-green algae are addressed in Section 3.12 Historical Resources and Tribal Cultural Resources and Appendix V to this EIR.
3.4.1 Area of Analysis
The Area of Analysis for phytoplankton and periphyton includes multiple reaches of the Klamath River, as listed below and shown in Figure 3.4-1.
Upper Klamath Basin
- Hydroelectric Reach (upstream end of J.C. Boyle Reservoir to Iron Gate Dam)
Mid-Klamath Basin
- Klamath River from Iron Gate Dam downstream to the confluence with the Salmon River
- Klamath River from the confluence with the Salmon River to the confluence with the Trinity River
Lower Klamath Basin
- Lower Klamath River from the confluence with the Trinity River to the Klamath River Estuary
- Klamath River Estuary
- Pacific Ocean nearshore environment
Note that the portion of the Hydroelectric Reach that extends into Oregon (i.e., from the Oregon-California state line [RM 214.1] to the upstream end of J.C. Boyle Reservoir) is only being considered in this chapter to the extent that conditions in this reach influence phytoplankton and periphyton communities downstream in California.
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3.4.2 Environmental Setting
Phytoplankton and periphyton (defined in bullets at the beginning of in Section 3.4) are the two primary groups of algae (i.e., algal communities) in the Area of Analysis. Phytoplankton, including blue-green algae, compose the majority of the algal community in the reservoirs since phytoplankton prefer relatively still water. In the Klamath Basin, blue-green algae frequently reach nuisance levels within Upper Klamath Lake, Copco No. 1 Reservoir, and Iron Gate Reservoir. In addition, blue-green algae can be found in portions of the Klamath River (e.g., backwater eddies and near shore shallows) where blue-green algae cells from upstream lakes and the Lower Klamath Project reservoirs have drifted downstream. These portions of the river can also support nuisance levels of blue-green algae under certain conditions. Typically, most of the riverine portions of the Klamath River are dominated by periphyton, which include diatoms, green algae, fungi, and bacteria that attach to the stream bed and/or other underwater surfaces. Larger aquatic plants may also be present in quiet backwater areas in the Klamath River; however, no known quantitative or species-specific information about these plants has been collected in the phytoplankton and periphyton Area of Analysis. Since no surveys have been conducted to determine the relative distribution or biomass^100 of large aquatic plants in the Klamath River, they are not discussed further in this section. Wetland and riparian habitat, along with associated plant species, are discussed in Section 3. Terrestrial Resources.
3.4.2.1 Phytoplankton
A number of different groups of organisms contribute to the phytoplankton communities in the Klamath River and mainstem reservoirs, including diatoms, green algae, and blue- green algae. The composition of the phytoplankton communities shifts seasonally in response to changing temperature, light, and nutrient levels. Phytoplankton form the base of the food web in lakes and reservoirs throughout the world; they are consumed by zooplankton, insects, and some small fish, which are fed upon by larger fish, birds, mammals, and humans. Diatoms and green algae are generally considered to be beneficial components of phytoplankton communities based on their important role supplying nutrients to the food web. When phytoplankton communities reach high concentrations in the water column (e.g., greater than 10 to 15 micrograms per liter [ug/L] of water), the species composition often shifts from the more beneficial green algae species to nuisance blue-green algae species. The shift in species composition can happen quickly (i.e., in days) due to blue-green algae’s relatively fast reproductive rates.
At high biomass levels, phytoplankton can create nuisance water quality conditions. A primary driver of nuisance conditions is extreme diel (daily) fluctuations in dissolved oxygen and pH due to the process of photosynthesis (the consumption of carbon dioxide and waste production of oxygen) and cellular respiration (the consumption of oxygen and waste production of carbon dioxide). During daylight hours, phytoplankton use sunlight to conduct photosynthesis, increasing the dissolved oxygen concentrations in water. Photosynthesis stops in the evening when sunlight is not available. During the night, cellular respiration consumes dissolved oxygen and results in decreases in dissolved oxygen concentrations in the water column. During both daylight and evening hours, dead and decaying phytoplankton are consumed by aerobic bacteria, using
(^100) The total mass of organisms in a given area or volume.
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dissolved oxygen from the water column and at times contributing to decreases in dissolved oxygen levels below those sufficient to support aquatic organisms (e.g., fish). The pH of water fluctuates with daily variations in photosynthesis and respiration. Photosynthesis consumes carbon dioxide in the water, such that when photosynthesis dominates during the day the pH increases. Cellular respiration releases carbon dioxide that, in contact with water, forms carbonic acid, decreasing the pH during the evening. Microbial decomposition of dead phytoplankton can also release free ammonia into the water column as cellular nitrogen is converted into ammonia, especially after a bloom when a high concentration of dead phytoplankton cells is being decomposed. Variations in dissolved oxygen, pH, and ammonia due to phytoplankton are primarily driven by the availability of sunlight and the resulting variations in the amount of photosynthesis and respiration. As more sunlight is available during summer months, there is generally more for photosynthesis at this time of year and a higher potential for larger variations in dissolved oxygen and pH in lakes, reservoirs, and rivers. In addition to dissolved oxygen, pH, and at times ammonia, high concentrations of blue-green algae species, such as Anabaena flos-aquae and Microcystis aeruginosa, can produce nuisance levels of algal toxins (e.g., anatoxin-a and microcystin) that are harmful to fish, mammals, and humans (see also Section 3.2.2.7 Chlorophyll-a and Algal Toxins ).
The stable lacustrine^101 environment created by Copco No. 1 and Iron Gate dams, coupled with high nutrient availability and high water temperatures in summer and fall months, provides ideal conditions for phytoplankton growth, especially the growth of blue-green algae species (Figure 3.4-2 and Figure 3.4-3). While cyanobacteria [blue- green algae] can be found in a variety of lake, reservoir, river, and estuarine environments, the cyanobacteria [blue-green algae] species Anabaena flos-aquae and Microcystis aeruginosa thrive in warm, high nutrient, and stable water column conditions (Konopka and Brock 1978; Kann 2006; Asarian and Kann 2011), where they can out- compete other beneficial algae species such as diatoms and green algae (Visser et al. 2016). While they do not thrive in fast-moving water, diatoms and green algae do not regulate their buoyancy, and thus they rely on mixing in the water column (e.g., from wind, convection, or slow currents) to remain suspended near the water surface where light is available for photosynthesis. In reservoirs with warm water and a stable water column, diatoms and green algae tend to settle out of the water column away from sunlight. Cyanobacteria [blue-green algae] cells contain gas sacs (vesicles^102 ), so they can control their buoyancy and remain near the water surface to obtain light for photosynthesis (Walsby et al. 1997). The ability to control their density and position in the water column gives blue-green algae better access to light and they can shade phytoplankton lower in the water column. Thus, blue-green algae are able to outcompete diatoms and/or green algae under lower mixing conditions in reservoirs. Microcystis aeruginosa can dominate the phytoplankton community in calm, stable lacustrine conditions, when their ability to float exceeds the rate of turbulent mixing in the water column (Huisman et al. 2004). However, blue-green algae abundance in the phytoplankton community decreases compared to diatoms and green algae when water column mixing in a water body increases (McDonald and Lehman 2013; Visser et al. 2016).
(^101) Pertaining to a lake, reservoir, or other calm water types. (^102) A small bubble-like hollow sac within a cell made of rigid proteins and filled with gas (Walsby
1994).
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As discussed above, blooms of floating algae (i.e., phytoplankton) can have negative impacts on water quality related to daily fluctuations in dissolved oxygen, pH, and nutrients such as ammonia. In the Klamath River, nuisance water quality conditions associated with phytoplankton are dominated by blooms of cyanobacteria [blue-green algae] species for both reservoir (Copco No. 1 and Iron Gate) and river portions of the Klamath River, particularly in the summer months (Asarian and Kann 2011; Gibson 2016). Within the phytoplankton and periphyton Area of Analysis, blue-green algae productivity is locally and seasonally associated with extreme daily fluctuations in dissolved oxygen levels (high during the day and low at night), elevated pH (above 8 s.u.), and free ammonia concentrations. Blue-green algae have a high cellular nitrogen content, so microbial decomposition of dead blue-green algae after a bloom can generate a relatively high amount of free ammonia and result in a further decrease in the water column’s pH. Multiple reaches of the Klamath River from the Oregon-California state line to the Klamath River Estuary are included on the Clean Water Act (CWA) Section 303(d) list of water bodies with water quality impairments for water temperature, organic enrichment/dissolved oxygen, nutrients, and microcystin concentration (USEPA
- (Table 3.2-3). Organic enrichment and dissolved oxygen depressions are particularly problematic during the summer and fall months when water temperatures are relatively high.
Nuisance and/or noxious algal blooms that occur in the phytoplankton and periphyton Area of Analysis are primarily composed of three species of blue-green algae: Aphanizomenon flos-aquae , Anabaena flos-aquae , and Microcystis aeruginosa. While these blue-green algae species are a natural part of aquatic systems in California, including the Klamath River, environmental conditions that favor the growth and bloom of these blue-green algae species have been created by human modifications to the Klamath River (e.g., dams on the Klamath River that form slow-moving or stagnant water and additional inputs of nutrients above natural conditions). Blooms of these blue-green algae species can cause water quality and human health concerns because these species have been associated with the release of algal toxins (State Water Board et al. 2010, updated 2016).
Aphanizomenon flos-aquae Aphanizomenon flos-aquae is a filamentous (thread-like), nitrogen-fixing cyanobacteria [blue-green algae] that is common in the Klamath Basin, especially in Upper Klamath Lake where it can comprise more than 90 percent of blue-green algae bloom biovolume (Figure 3.4-4 and Figure 3.4-5; Kann 1997; Eldridge et al. 2012). Nitrogen fixation is a cellular process where nitrogen gas in the air is converted into a biologically useful form of nitrogen for cellular growth. Aphanizomenon flos-aquae can thus provide its own source of nitrogen for algal growth, giving it a competitive advantage over non-nitrogen fixing algae species when phosphorus is abundant, but nitrogen is not. Aphanizomenon flos-aquae accounted for approximately 39 percent of the total phytoplankton biovolume measured between June and November 2007 at 21 sites in the Klamath Basin from the Upper Klamath Lake to Turwar, including Copco No. 1 and Iron Gate reservoirs (Raymond 2008). In a study of phytoplankton abundance at nine reservoir and river sites in the Hydroelectric Reach (i.e., Klamath River upstream of J.C. Boyle Reservoir to Iron Gate Dam), Aphanizomenon flos-aquae made up approximately 26 percent of the total phytoplankton biovolume measured in 106 samples collected during 14 sampling events in January and May through December 2009 (Raymond 2010). While members
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of the Aphanizomenon genus have been shown to produce cylindrospermopsin^103 and several neurotoxins in laboratory cultures, they have not been shown to produce microcystin. Thus, while Aphanizomenon flos-aquae is commonly found in the Klamath Basin, it is not likely to be the source of microcystin in the Klamath River (Eldridge et al. 2012). Nitrogen fixation by Aphanizomenon flos-aquae can provide a new nitrogen source within lakes and rivers when Aphanizomenon flos-aquae cells die and decay releasing fixed nitrogen and other nutrients contained in their cells. The additional nitrogen released can provide nutrients for Microcystis aeruginosa, potentially promoting Microcystis aeruginosa growth later in the season (discussed further below).
Figure 3.4-4. Microscopic View of Aphanizomenon flos-aquae Showing it in Bundles (upper left and right images) and Individual Filaments (lower left and right images). Photographs: Left, Barry H. Rosen; Right, Ann St. Amand. Source: Rosen and St. Amand 2015.
(^103) An algal toxin associated with adverse health effects such as gastrointestinal, liver
inflammation and hemorrhage, pneumonia, dermatitis, malaise, and long-term liver failure (Lopez et al. 2008). Cylindrospermopsin were only detected near or less than the method detection limit (<0.05 parts per billion) in the Upper Klamath Lake (Eldridge et al. 2012).
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muscle twitching, paralysis, and death. It was detected in September 2005 during one sampling event in Iron Gate Reservoir, at levels ranging from 22 to 34 μg/L (T. Mackie, pers. comm., 2005). Additional details about anatoxin-a concentrations measured in the Klamath River are found in Section 3.2.2.7 Chlorophyll-a and Algal Toxins and Appendix C – Section C.6 Chlorophyll-a and Algal Toxins. While anatoxin-a has been measured in the Klamath Basin, the extent of anatoxin-a production by Anabaena flos-aquae in the Area of Analysis for phytoplankton and periphyton is largely unknown due to the limited sampling to date. Toxin production by some strains of Anabaena flos-aquae appears to be sporadic, and the circumstances which prompt toxin production are unknown. While Anabaena flos-aquae have also been found to produce the algal toxin microcystin (Lopez et al. 2008), it is widely assumed that the severe blooms of Microcystis aeruginosa in the Area of Analysis are responsible for the detected concentrations of microcystin rather than Anabaena flos-aquae because the measured biovolume of Anabaena flos-aquae is typically much less than the Microcystis aeruginosa biovolume. The relative proportion of microcystin contributions from Anabaena flos-aquae versus Microcystis aeruginosa has not been documented for the Klamath Basin.
Figure 3.4-6. Microscopic view of Anabaena flos-aquae, recently renamed Dolichospermum flos-aquae. Source: Kudela Lab 2018.
Microcystis aeruginosa Microcystis aeruginosa is a round- or oval-shaped unicellular, colony-forming cyanobacteria [blue-green algae] (Figure 3.4-7 and Figure 3.4-8; Eldridge et al. 2012). Microcystis aeruginosa are not capable of nitrogen fixation , unlike Aphanizomenon flos- aquae or Anabaena flos-aquae , so this species is dependent on ammonia and other nitrogen sources for growth, and the availability of nitrogen in the water column may limit
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their occurrence in portions of the Klamath Basin (Eldridge et al. 2012). In phytoplankton sampling conducted in Iron Gate and Copco No. 1 reservoir ranging from 2005 through 2010, Microcystis aeruginosa accounted for up to approximately 78 percent of the total phytoplankton biovolume in some samples collected at open water reservoir monitoring stations (Raymond 2008, 2009, 2010; Asarian et al. 2011), suggesting favorable habitat conditions in the reservoirs for this species.
Analysis of blue-green algae species present in the Klamath River from the Upper Klamath Lake to Turwar identified Iron Gate Reservoir as the principal source of Microcystis aeruginosa to the Klamath River downstream of Iron Gate Dam. Phytoplankton samples were collected either once or twice a month from April to December 2012 at fifteen sites along the Klamath River, including Copco No. 1 and Iron Gate reservoirs. The types of phytoplankton present were identified and genetic analysis (deoxyribonucleic acid [DNA] sequencing) was performed to identify genetic differences between the blue-green algae populations at the sample sites. Blue-green algae bloom populations at sites upstream of J.C. Boyle Dam were predominantly Aphanizomenon flos-aquae with some Anabaena flos-aquae ( Dolichospermum flos- aquae ) and a small amount of Microcystis aeruginosa present, but blue-green algae bloom populations in Copco No. 1 and Iron Gate reservoirs were primarily Microcystis aeruginosa and Aphanizomenon flos-aquae. Microcystis aeruginosa cells were present in low concentrations upstream of Copco No. 1 Reservoir, suggesting the majority of Microcystis aeruginosa cells in Copco No. 1 and Iron Gate reservoirs grew in the reservoirs and they were not transported into the reservoirs from upstream. Genetic analysis of the Microcystis aeruginosa populations showed Copco No. 1 Reservoir populations were dominated by one genetic type the entire year, but the Microcystis aeruginosa populations in Iron Gate Reservoir and immediately downstream of Iron Gate Dam had a simultaneous change in the dominant genetic type in late August. The genetic change was also detected in the Microcystis aeruginosa populations in the Klamath River downstream of Iron Gate Dam. The simultaneous timing of the genetic change in Iron Gate Reservoir and downstream Microcystis aeruginosa populations, but no corresponding genetic change in Copco No. 1 Reservoir, provides direct evidence that downstream river populations are originating in Iron Gate Reservoir rather than Copco No. 1 Reservoir or locations farther upstream (Otten et al. 2015).
Blooms of Microcystis aeruginosa are of particular concern since this species is known to produce the algal toxin microcystin, a hepatotoxin that affects liver function in animals and humans (State Water Board et al. 2010, updated 2016; OEHHA 2012). In humans, exposure to microcystin has been documented to cause abdominal pain, headache, sore throat, vomiting, nausea, dry cough, diarrhea, blistering around the mouth, pneumonia, muscle weakness, and acute liver failure (OEHHA 2012) (see also Section 3.2.2. Chlorophyll-a and Algal Toxins ). Studies suggest that the presence of toxin producing Microcystis aeruginosa blooms could result in acute (short-term) and chronic (long-term) effects on fish including increased mortality, reduced fertility, reduced feeding, and habitat avoidance (Interagency Ecological Program 2007; Fetcho 2008, 2009; CH2M Hill 2009; Teh et al. 2010; Kann et al. 2013) (see also Section 3.3.2.3 Habitat Attributes Expected to be Affected by the Project ).
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Figure 3.4-8. Blue-green algae Microcystis aeruginosa bloom. Photograph: Susan Corum. Source: Stillwater Sciences et al. 2013.
Algal blooms of nitrogen-fixing Aphanizomenon flos-aquae and Anabaena flos-aquae early in the year (spring) can supply a new nitrogen source to lakes or reservoirs, potentially promoting Microcystis aeruginosa growth later in the year (summer and fall) (FERC 2007; Eldrige et al. 2012; Otten et al. 2015). As blooms of Aphanizomenon flos- aquae and Anabaena flos-aquae die and decay, fixed nitrogen in their cells is released and becomes a source of nitrogen for Microcystis aeruginosa , which cannot fix nitrogen from the atmosphere. Studies of cyanobacteria [blue-green algae] dynamics in 2009 in the Upper Klamath Lake report a low initial Microcystis aeruginosa population followed by an increase after a major decline in an Aphanizomenon flos-aquae bloom. The Microcystis aeruginosa population continued to increase rapidly during a second Aphanizomenon flos-aquae bloom, suggesting that these two species can coexist (Eldridge et al. 2012).
Cyanobacteria [Blue-green Algae] Thresholds and Guidelines Thresholds and guidelines for cyanobacteria [blue-green algae] densities (in cells/mL) and algal toxin concentrations (in μg/L) that are protective of human health have been established and are occasionally updated (see also Section 3.2.3.1 Thresholds of Significance ). The World Health Organization (WHO) specifies for safe recreational water contact (not drinking water) a cell density of less than 20,000 cells/mL for
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cyanobacteria [blue-green algae] species and a microcystin concentration of less than 4 μg/L for a relatively low probability of adverse human health effects during recreational water contact (Falconer et al. 1999). The California Cyanobacteria and Harmful Algal Bloom (CCHAB) Network, composed of various entities with expertise, including the State Water Board, the California Department of Public Health (CDPH), the California Environmental Protection Agency Office of Environmental Health and Hazard Assessment (OEHHA), Native American tribes, and reservoir managers has established thresholds and guidance for the cyanobacteria [blue-green algae] cell densities and cyanotoxin [algal toxin] concentrations for the protection of human health in recreational waters. The 2010 CCHAB thresholds (also referred to as the SWRCB/OEHHA Public Health Thresholds or the California Health Thresholds) recommended posting a health advisory warning sign^105 if the Microcystis aeruginosa cell density was greater than or equal to 40,000 cells/mL , the potentially toxigenic^106 cyanobacteria [blue-green algae] species cell density was greater than or equal to 100,000 cells/mL, or the microcystin concentration was greater than or equal to 8 ug/L. The 2016 CCHAB thresholds revised the 2010 CCHAB thresholds and specified primary and secondary threshold triggers for posting health advisories for recreational water contact (Table 3.4-1). The 2016 CCHAB thresholds are 4,000 cells/mL for total potentially toxigenic cyanobacteria [blue-green algae] species cell density and 0.8 ug/L for microcystin concentration, which are approximately one to two orders of magnitude less than the 2010 CCHAB thresholds (State Water Board et al. 2010, updated 2016).
Table 3.4-1. 2016 California Cyanobacteria Harmful Algal Bloom (CCHAB) Trigger Levels for Human Health.
Trigger Level
Primary Triggers^1 Secondary Triggers
Total Microcystins (ug/L)
Anatoxin-a (ug/L)
Cylindrospermopsin (ug/L)
Total Potentially Toxigenic Cyanobacteria [Blue-green Algae] Species (cells/mL)
Site Specific Indicators of Cyanobacteria [Blue-green Algae]
Caution Action 0.8^ Detection
(^2 1) 4,000 Blooms, scums, mats, etc. Warning TIER I 6 20 4 -^ - Danger TIER II 20 90 17 -^ - Source: (State Water Board et al. 2010, updated 2016) (^1) Primary triggers are met when ANY toxin exceeds criteria. (^2) Must use an analytical method that detects less than or equal to 1 ug/L anatoxin-a.
(^105) The advisory signs communicate to the public the potential risk of exposure to algal toxins in
the associated waterbody and contain information about how to avoid or minimize the risk. The advisory signs include: “Caution – Harmful algae may be present in this water”; “Warning – Toxins from algae in this water can harm people and kill animals”; “Danger – Toxins from algae in this water can harm people and kill animals” (California Water Quality Monitoring Council 2018). (^106) Potentially toxigenic cyanobacteria [blue-green algae] that have been detected in California include those of the genera Anabaena , Microcystis , Aphanizomenon , Planktothrix , and Gloeotrichia.
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demand from decaying organic matter (e.g., bacteria, algae, plant litter) exported from upstream Klamath River reservoirs (PacifiCorp 2006; FERC 2007).
Documented algae species in the Klamath River periphyton community include nuisance filamentous (thread-like) green algae species such as Cladophora sp. (FERC 2007), which can form dense mats in some places in the Lower Klamath River. These mats tend to be patchy and occur in lower velocity areas. They are not a dominant feature of the Klamath River, but in some locations they are an important habitat for the polychaete worm ( Manayunkia speciose ) that is the intermediate host of the fish parasites Ceratomyxa shasta and Parvicapsula minibicornis (Figure 3.4-9). The factors influencing periphyton abundance and community composition are complex and include physical factors such as nutrients, substrate, flow velocity, shading, light availability, and water temperature (Biggs 2000), as well as ecological factors (such as macroinvertebrate grazing) that interact with the physical factors (Power et al. 2008). The Lower Klamath Project dams influence the abundance of periphyton by altering the nutrient availability, riverbed substrate, flow, light availability, and water temperature in the Klamath River (NMFS 2010; NMFS and USFWS 2013; Alexander et al. 2016; Gillett et al. 2016). Analysis and modeling of pre- and post-Klamath Irrigation Project hydrology indicates that operation of the Klamath Irrigation Project upstream of the Lower Klamath Project dams has altered Klamath River flows by increasing flows in October and November, decreasing flows in the late-spring and summer, and decreasing the peak flows (NMFS and USFWS 2013). As a result of upstream Klamath Irrigation Project operations, the Klamath River peak flows downstream of Iron Gate Dam are less frequent, resulting in less frequent high-velocity flows that would scour streambed sediments downstream of the dam. In addition to lower peak flows, the Lower Klamath Project dams trap sediment behind the dams and reduce the availability of fine sediments downstream that can be transported at lower flows, leading to streambed armoring and less frequent scouring events that disturb the streambed. Reduced scouring frequency along with higher fall water temperatures, promote dense growth of periphyton. Additionally, operation of the upstream Klamath Irrigation Project results in flow modifications downstream of the Lower Klamath Project dams that alters the light availability for periphyton on the streambed, with lower flows generally decreasing water depth and increasing light penetration to the streambed for periphyton photosynthesis. These conditions favor proliferation of polychaete worm habitat and subsequent infection of fish by parasites (NMFS 2010; NMFS and USFWS 2013; Alexander et al. 2016) (see also Figure 3.4-8 [parasite life cycle]). Overall, data regarding the distribution, community composition, and biomass of periphyton in the Area of Analysis for phytoplankton and periphyton are limited.
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Figure 3.4-9. Lifecycle of Ceratomyxa shasta. Source: NMFS 2012.
3.4.2.3 Hydroelectric Reach
Phytoplankton Phytoplankton dynamics in the Hydroelectric Reach can be influenced by upstream conditions, so the following briefly discusses phytoplankton conditions from the Upper Klamath Lake to the Hydroelectric Reach before detailing the conditions within the Hydroelectric Reach. In the Upper Klamath Lake, the mean total phytoplankton biomass annually increases from relatively low concentrations ranging from less than 5 mg/L wet weight to approximately 15 mg/L wet weight per data collected between 1990 and 1996 in winter and spring (January to May) to peak concentrations ranging from approximately 30 mg/L wet weight to 60 mg/L wet weight per data collected between 1990 and 1996 in summer to fall (June to October), before decreasing to relatively low concentrations again in late fall/early winter (November to December) (Kann 1997). In addition to the seasonal change in total phytoplankton biomass, the phytoplankton community also has an annual seasonal shift from diatom-dominated communities in spring (Kann 1997; ODEQ 2002; Sullivan et al. 2009) to blue-green algae-dominated communities in summer and fall (Eilers et al. 2004; FERC 2007; Eldridge et al 2012). Phytoplankton biovolume in summer and fall is dominated by blue-green algae blooms comprised primarily of Aphanizomenon flos-aquae , but also includes Anabaena flos-aquae and Microcystis aeruginosa (Eilers et al. 2004; FERC 2007; Eldridge et al. 2012). Data from 2009 indicate concentrations of Microcystis aeruginosa in the Upper Klamath Lake are typically low during the early part of the calendar year, but concentrations increase later in the year following the decline of large blue-green algae blooms dominated by Aphanizomenon flos-aquae (Eldridge et al. 2012). Microcystis aeruginosa is believed to
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and Link River (Figure 3.4-11; Raymond 2005; Kann and Asarian 2006; Sullivan et al. 2009). In Lake Ewauna and the Keno Impoundment, phytoplankton concentrations are observed to decrease, which is attributed to dead and decaying phytoplankton, especially blue-green algae, settling out of the water column and forming lake and impoundment sediments (Deas and Vaughn 2006; Stillwater Sciences et al. 2013; ODEQ 2017).
Figure 3.4-11. Total phytoplankton biovolume in mm 3 /L from June 1 to September 30 for the years 2001 to 2004. River miles associated with Klamath River features are based on the river miles in 2006 and differ slightly from current river miles in this EIR. Station definitions: UKL Pel Mar = Upper Klamath River at Pelican Marina; Link Mouth = Link River at Mouth; Keno Res 66 = Klamath River at Hwy 66 Keno Bridge; Keno Dam = Keno Dam outflow; Abv JCB Res = Klamath River upstream of J.C. Boyle Reservoir; JCB Res = J.C. Boyle Reservoir at log boom; Bel JCB Dam = Klamath River downstream of J.C. Boyle Dam; Abv JCB PH = Klamath River upstream of the J.C. Boyle Powerhouse; Abv Copco = Klamath River upstream of Shovel Creek; Copco Res = Copco No. 1 Reservoir; Bel Copco = Klamath River downstream of Copco No. 2 Powerhouse; IG Res = Iron Gate Reservoir near dam; IG Dam = Klamath River downstream of Iron Gate Dam; I- Shasta = Klamath River at I-5 Rest Area and Klamath River upstream of Shasta River. Source: modified from Kann and Asarian 2006.
Phytoplankton abundance, including abundance of blue-green algae, generally decreases in the Klamath River with distance downstream of Keno Dam to upstream of Copco No. 1 Reservoir (Figure 3.4-11; Kann and Asarian 2006; Kann and Corum 2009; Asarian and Kann 2011; Watercourse Engineering, Inc. 2016). In this reach, turbulent mixing and higher water velocities that constitute unfavorable growing conditions and break apart phytoplankton cells, and cold groundwater-fed springs in the J.C. Boyle Bypass Reach that add flow and cool the river creating less favorable water temperatures for growth, result in decreasing phytoplankton concentrations and associated algal toxins (i.e., microcystin) between Keno Dam and the upstream end of Copco No. 1 Reservoir (see also Section 3.2.2.7 Chlorophyll-a and Algal Toxins and Appendix C – Section C.6.1 Upper Klamath Basin ). Additionally, the proportion of the
December 2018 Volume I
phytoplankton community composed of diatoms increases relative to blue-green algae between Keno Dam and the upstream end of Copco No. 1 Reservoir (Kann and Asarian 2006).
Measurements of Microcystis aeruginosa abundance (measured by biovolume) between 2001 and 2004 also show a decreasing trend from Upper Klamath Lake to upstream of Copco No. 1 Reservoir (Figure 3.4-12). Individual measurements for Microcystis aeruginosa taken during this period are represented by circles (o) in Figure 3.4-12, but the circles overlap and appear as a single circle when multiple measurements have the same value (e.g., multiple non-detect results for sites appear as a single circle at zero along the x-axis). Box and whisker features showing the statistical trends (e.g., 25 to 75 percent of measurements occur within the biovolume range encompassed by the box) are shown for most sites, but these box and whisker features cannot be seen for sites with primarily non-detect results for Microcystis aeruginosa (i.e., biovolume equal to zero) because they are compressed at the x-axis. While there were eight detections ( percent of measurements) of Microcystis aeruginosa in the Keno Impoundment/Lake Ewauna, no Microcystis aeruginosa was detected in 24 samples collected between the Keno Dam outflow and the Klamath River site upstream of J.C. Boyle Reservoir. At sites from J.C. Boyle Reservoir to the Klamath River site upstream of Copco No. 1 Reservoir, there were one to two detections (5 to 15 percent of measurements) per site in the July to October period (Kann 2006).
