Background
In support of the Oregon Coastal Salmon Recovery Initiative surveys are conducted on Rogue River National Forest lands to monitor Coho salmon distribution. Three streams that originate in the AMA on Rogue River National Forest Lands remain accessible to Coho salmon: Palmer Creek, Beaver Creek and the Little Applegate River. For the past three years all three streams have been surveyed for spawning Coho. Two carcasses collected in 1998 represent the only observations of adult Coho in these streams for the past three years. All Forest Service spawning surveys are conducted in compliance with Oregon Department of Fish and Wildlife (ODFW) protocols. Streams were surveyed every 7-10 days between November 30 and January 15 for spawning Coho salmon. Surveys were conducted by South Zone Aquatic Team personnel and student volunteers from Southern Oregon University (including the REAL Corps program) and the Wilderness Charter School. Adult Coho and reds were recorded as well as data from adult carcass.
Findings
Five Coho reds and two adult Coho carcasses were observed in Palmer Creek in 1998. These represent a relatively low number compared to data from the 1980's but are an improvement over the past two years when no carcasses or reds were observed. At Beaver Creek and the Little Applegate River no adults, reds or carcasses have been observed for at least three years.
Snorkel surveys during the summer of 1998 revealed juvenile Coho on National Forest land in Beaver and Palmer Creeks. These juveniles could be the result of spawning activities in these streams or they may have migrated in from the Applegate River. Because of the low gradient in Palmer Creek, Coho could use even higher portions of the stream if the habitat were improved. In Beaver Creek there is a concrete dam across the stream on RRNF land approximately 3 miles above the mouth. This dam is a partial barrier to Coho migration (removal of the dam is planned for 1999).
Discussion
The advantage of spawning surveys is that they require very little training, allowing the work to be completed by relatively inexperienced volunteers at little cost. There is some argument that the data generated by inexperienced volunteers is unreliable because their results are often un-repeatable (different surveyors will count different numbers of reds within the same reach). Since the objectives of these surveys in the AMA are simply to monitor presence or absence and relative abundance, the data gathered by volunteers, though highly variable, is adequate.
The effectiveness of spawning surveys should be addressed considering that, in three years of surveys, no live spawning adults have been observed on National Forest lands. This year's surveys were the first in three years to provide any evidence of spawning activity (2 carcasses and 5 reds in Palmer Creek).
Snorkeling surveys in the summer might appear to be a more effective method of detecting Coho presence and could be suggested as a substitute for spawning surveys. The presence of juvenile Coho in Beaver and Palmer Creeks during the summer of 1998 gives the appearance that the weekly spawning surveys conducted in fall 1997, which failed to count any reds or adults, were ineffective. The decision to abandon spawning surveys must take into account several additional factors. Snorkel surveys are more labor intensive, the identification of juvenile fishes requires more training and experience, and expensive equipment is required to protect the diver from cold water temperatures.
The continued use of both survey techniques would be the most advantageous. The collection of data at two different times of year (the two methods are essentially separated by six months) provides additional insight into processes at work in the stream. The fact that no fall spawners were recorded but summer juveniles were indicates that a relatively low number of adult spawners made it into these streams and successfully spawned or that juveniles have migrated into these streams from the Applegate River. Both indicate that suitable Coho habitat exists in these streams. Conversely, if a relatively high number of adult spawners had been recorded but few or no summer juveniles, we could assume that the habitat was unsuitable or there was a large disturbance that destroyed the reds. This scenario would be valuable for designating areas in need of restoration or modification of management activities.
Follow-up
The continuation of spawning surveys is suggested as the most cost efficient method of monitoring the distribution of Coho salmon within the Applegate AMA. Summer snorkeling surveys should also be conducted, at least in years when spawning survey counts are very low, to verify the presence or absence of Coho in these streams.
The use of volunteers to conduct these surveys is not only a cost effective method of data collection, it also fosters an important partnership with the community we serve. The volunteers who participate in these surveys value the opportunity to conduct field work and establish contacts with possible future employers. Through their experiences in the field, the volunteers also develop ownership in the resource knowing that they have contributed to the preservation of an imperiled species. This ownership often results in a greater respect for the resource.
Submitted by: Gar Abbas, Assistant Fisheries Biologist, Siskiyou Zone, RRNF.