Species: Oncorhynchus clarkii pop. 2

NMFS (2002) reported the following: <br><br>Anadromous coastal cutthroat trout spawning typically starts in December and continues through June, with peak spawning in February. Coastal cutthroat trout are repeat spawners. Some individuals have been documented to spawn each year for at least five years (Giger 1972), others may not spawn every year, and some do not return to seawater after spawning, remaining in fresh water for at least a year. <br><br>Eggs begin to hatch within six to seven weeks of spawning, depending on temperature; fry emerge between March and June, with peak emergence in mid-April. <br><br>Sexual maturity rarely occurs before age four in anadromous coastal cutthroat trout (Johnson et al. 1999). Growth rates increase during the initial period of ocean residence, but decrease following the first spawning due to energy expenditures from migration and spawning (Giger 1972). Behnke (1992) reported the maximum age of sea-run cutthroat to be approximately 10 years. <br><br>Resident (non-migratory) fish appear to mature earlier (two to three years) and are shorter-lived than the migratory form (Trotter 2000). Smoltification has been reported to occur from one to six years of age, most commonly at ages two through four (Trotter 1997), and at sizes of from 175 to 225 millimeters (mm) (7 to 9 in) (Behnke 1992). <br><br>The diverse life history strategies shown by coastal cutthroat trout are not well understood but may represent unique adaptations to local environments and responses to environmental variability and unpredictability. The significance of the various life history strategies, the extent to which each strategy is controlled by genetic versus environmental factors, and the extent of isolation among individuals expressing these various strategies is largely unknown, though there is growing evidence that individuals may express multiple life history behaviors over time (Johnson et al. 1999). The few existing studies show that although both allele frequencies and morphology may differ between populations above and below barriers, the portions of the population displaying different life history strategies are generally more closely related within a drainage than are populations from different drainages (Behnke 1997, Johnson et al. 1999). These results indicate that migratory and non-migratory portions of the population of cutthroat trout represent a single evolutionary lineage in which the various life history characteristics have arisen repeatedly in different geographic regions (Johnson et al. 1999). Many coastal cutthroat populations are isolated above natural barriers. Recent studies have shown low levels of downstream migration over these natural barriers indicating that these isolated populations likely are contributing demographically and genetically to populations below them (Griswold 1996, Johnson et al. 1999). Furthermore, populations above natural barriers may represent genetic resources shared by populations below these barriers and therefore may constitute a significant component of diversity for the population (Johnson et al. 1999). There is increasing evidence that coastal cutthroat trout isolated for long periods of time above impassable dams retain the capacity to produce marine migrants. (NMFS 2002).