5 Fish Assessment 5.1 Introduction The subbasin assessment is a technical analysis to determine the biological potential of the subbasin and the opportunities for restoration. It describes the existing and historic resources, conditions, and characteristics within the subbasin with the emphasis on designated focal fish and wildlife species and focal habitat types. The bulk of the assessment work was was done by the Yakama Indian Nation and WDFW with support and involvement of Klickitat County and Oregon Department of Fish and Wildlife. 5.1.1 Fish Focal Species and Species of Interest Four fish species were selected as primary focal species for this planning effort: white sturgeon (LMM) and steelhead, fall chinook, and coho. Lamprey were selected as species of interest. Table 18 Fish focal species and their distribution within the Lower Mid-Columbia Mainstem subbasin Focal Species Distribution White Sturgeon Lower Mid-Columbia River Mainstem Summer Steelhead Lower Mid-Columbia River Mainstem, Rock Creek, Spanish Hollow, Fulton Canyon Fall Chinook Lower Mid-Columbia River Mainstem, Rock Creek Coho Lower Mid-Columbia River Mainstem, Rock Creek 5.1.2 Rationale for Selection of Focal Fish Species Focal species and species of interest were chosen with the following considerations: 1) status under the Endangered Species Act; 2) ecological significance; 3) cultural significance; 4) US v. Oregon guidance. The determinations made by the aquatic technical committee to identify a species as a ‘Focal Species’ or ‘Species of Interest’ were made in consideration of the above factors as well as the amounts and types of information available. In addition, the committee limited the scope of focal species selection to a number of species that could be assessed within the limited time available. Table 19 Focal Species and Criteria Used For Selection in LMM subbasin Fall Focal Species Criteria Steelhead/Rainbow Coho White Sturgeon Chinook ESA Status Threatened None None None US v Oregon Significance Yes Yes Yes Yes Has Ecological Significance Yes Yes Yes Yes Has Cultural Significance Yes Yes Yes Yes Anadromous and/or Resident A and R A A A The following species were chosen as species of interest: 150 Table 20 Species of Interest and Criteria Used for Selection Focal Species Criteria Pacific Lamprey ESA Status None US v Oregon Significance No Has Ecological Significance Yes Has Cultural Significance Yes Anadromous and/or Resident A 151 Figure 19 General location map for Lower Mid-Columbia Mainstem Subbasin 152 5.2 White Sturgeon Rationale for Selection White sturgeon (Acipenser transmontnus) are the largest of the North American sturgeon and the largest freshwater fish found in North America. Historically, a majority of these fish in the Columbia were anadromous, inhabiting the Columbia River from the mouth upstream into Canada, the Snake River upstream to Shoshone Falls and the Kootenai River upstream to Kootenai Falls (Miller et al, 2004, Scott and Crossman 1973). White sturgeon are found in the lower Mid-Columbia mainstem of the Columbia River, they are a culturally and economically significant species, and there is limited information regarding this species in the lower mid- Columbia mainstem of the Columbia River. For these reasons, white sturgeon were selected as a focal species for subbasin planning in the Lower Mid-Columbia Mainstem Subbasin Plan. Key Life History Strategies, Relationship to Habitat Historically, it is believed that a majority of white sturgeon in the Columbia River were anadromous. However, the construction of hydropower dams throughout the Columbia River Basin has resulted in fragmented populations of white sturgeon throughout the Basin. Miller et. al, (USGS Website 2004) identify three distinct populations of white sturgeon in the Columbia River, those below the lowest dam (Bonneville) with access to the ocean, fish isolated between dams (as in the Lower Mid-Columbia Mainstem), and fish in several large tributaries. Although research is limited, existing studies indicate that the dams have not only blocked upstream access for spawning and feeding, but have also impacted the amount and location of spawning habitat and may have altered food availability, natural flow patterns, and water temperatures. Sturgeon spawn in the Columbia River from May to July in water temperatures of between 48 and 63 degrees F (Wydoski and Whitney, 1979). In an aquaculture setting, maturation seems to be determined more by size than by age (PSMFC 1992). However, maturation in an aquaculture setting may not relate directly to maturation in the wild. Quoted from PSMFC (1992): In the wild, the size or age of first maturity is extremely variable. Wild males begin to mature at about 49 in (125 cm) and 26 lb (12 kg) as 12-year-old fish. In the Snake River, some males may mature at 28 in (71 cm) and about 2.4 lb (1 kg; Cochnauer 1981). Females require a longer period to mature, generally 15-32 years. A few fish mature as younger, smaller fish, but an increasing proportion of the population matures as size and age increase (Beamesderfer et al. 1989, 1990a). In the lower Columbia River 95% of female white sturgeon mature between 124 and 196 cm, corresponding to an age of 16 to 35 years (Welsh and Beamsesderfer 1993; DeVore et al. 1995). Welch and Beamesderfer (1993) estimated median length-at-maturity of 165 cm for female sturgeon in the Bonneville and The Dalles reservoirs, and 193 cm for female sturgeon in the John Day Reservoir. Fecundity of white sturgeon varies with size, Wydoski and Whitney report that a 95.5 lb sturgeon contained 1.7 million eggs but that total fecundity could be as high as 3 million eggs. In 153 a summary of the Columbia River sturgeon, Worldstar.com states that “spawning sturgeon generally avoid slack water for spawning preferring to deposit their eggs in rocky areas with fast flowing water”. Parsley et al (1993) state that spawning and egg incubation occurred in water velocities that ranged from .8 – 2.8 m/s over substrates that were generally cobble, boulder or bedrock. Parlsey and Beckman (1994) report that there is suitable spawning habitat in the tailraces of four lower Columbia River Dams (McNary, John Day, The Dalles, and Bonneville) and that the amount of suitable spawning habitat tends to increase with increased river flow. The relationship between river flow and young of the year indexes of recruitment (and therefore spawning success), is depicted in Figure 20. The incubation period of sturgeon eggs is 7-14 days, depending on water temperature (Bajkov 1951; Conte et al. 1988). Cultured broods tend to hatch synchronously (Conte et al. 1988). Hatching is complete within 20-48 hours (ODFW 2004a). Most hatching occurs in darkness in the laboratory and may represent adaptive avoidance of visual predators (Brannon et al. 1986). The optimum incubation temperature for subsequent larval viability in a culture situation is 52- 63o F (11-17o C). Higher temperatures of 17-20o C result in higher mortality and hatching at earlier developmental stages (ODFW 2004a). A recent hypothesis proposed by Coutant and cited in ODFW (2004a) suggests that riparian areas may provide important habitat for newly spawned eggs and emerging larvae. If substantiated, this theory could identify a limiting factor in white sturgeon spawning success. Riparian flooding is directly related to hydrograph operation and reservoir level. Parsley et al (1993) report that young of the year white sturgeon were found at depths of 9-57 m., at water velocities of 0.6 m/s or less, and over substrates of hard clay, mud, silt, sand, gravel and cobble. Fish passage upstream is very limited for white sturgeon. McCabe and Tracy report that young-of-the-year white sturgeon have been captured less than two months after spawning was estimated to have begun. Young sturgeon grow rapidly during their first summer, reaching a minimum mean total length of 176 mm and weight of 30 g by the end of September (McCabe and Tracy 1993). Juvenile (those over 1 year old) sturgeon were found by Parsley et al (1993) in water depths of 2-58 m., at water velocities of 1.2 m/s or less, and over substrates that consisted of hard clay, mud, silt, sand, gravel, cobble, bounder and bedrock. 154 1.0 Recomended minimum flow Bonn to provide spawning habitat The D in all three reservoirs John Flow 0.8 0.6 0.4 0.2 No Data Ep (proportion of positive YOY tows/sets) of positive Ep (proportion 0.0 89 90 91 92 93 94 95 96 97 98 99 00 01 02 19 19 19 19 19 19 19 19 19 19 19 20 20 20 YEAR 1.0 1996 0.8 1991 199 1998 0.6 1999 1995 1993 Ep=0.0037*Flow-0.44 2 0.4 1990 R =0.5814 nneville Reservoir only Reservoir nneville ortion of positive YOY tows) of positive ortion o p Figure 20 Recruitment index for white sturgeon (proportion of sets capturing one or more young-of-year fish) in Bonneville, The Dalles, and John Day reservoirs, and average daily flow at McNary Dam (April-July) Note: The Bonneville index is based on standardized trawl efforts 1989-2003. The Dalles and John Day indexes are based on standardized gill-net effort initiated in 1997. All information is preliminary. Relationship with Other Species Adult sturgeon in the Columbia River have been reported to feed on clams, crayfish, smelt, suckers, northern pikeminnows, sockeye salmon, and Pacific lamprey, one stomach was reported to contain a house cat (Wydoski and Whitney, 1979). Sturgeon also ingest plant material but researchers believe that they ingest this plant material incidentally (Semakula and Larkin 1968; Cochnauer 1983). Juvenile white sturgeon feed primarily on algae and aquatic insects (PSMFC.Org, 2004).