A recent article and several letters have appeared in the Santa Cruz Weekly regarding coho salmon, local and statewide forestry practices and pending policy changes, along with a quote from myself and comments about data collected by research that I and others conduct in the Scott Creek watershed. These articles have raised several issues that would benefit from clarification.
Relating to the context under which the interview with the Santa Cruz Weekly reporter was conducted, I should state this was not an interview I solicited. When contacted, I stated repeatedly that I was not an expert of forestry practices or policies nor was I the appropriate person in NOAA’s National Marine Fisheries Service to be commenting on such issues. I gave the reporter the name of a more appropriate spokesperson to contact within NOAA and the reporter implied that he would do so. I did agree to discuss local ecological challenges to coho salmon, including fluctuating ocean conditions, predation, and habitat issues. Regarding habitat issues, the reporter asked about local forestry practices and their potential impacts on stream temperatures. I replied that our research was not directly targeted at addressing the impacts of local forestry practices, and stated that stream temperatures were a complex issue with fish that involved more than simply being too high or too low, and related to other issues such as productivity in the stream and growth potential of fish under these conditions.
There are several reasons our research has not directly addressed forestry practices, none of which relate to our access agreements with Big Creek Lumber or any other landowner in the Scott Creek watershed. Our research is funded in part to monitor coho salmon and steelhead population dynamics in the Santa Cruz Mountains and try to understand ecological issues that may be impacting these fish. As quoted and implied in the article, we established our research site in Scott Creek in 2002, in part based on data available at the time that it had the largest population of coho salmon remaining in the area. This was attributed to the watershed having some of the least human-impacted habitat available in the Santa Cruz Mountains and also the presence of a small non-profit conservation fish hatchery on a tributary to Scott Creek. Since then, our program has been built on two primary objectives, which are to count the total number of adult fish returning from the ocean to spawn and to measure the number of juveniles successfully produced by those spawning adults and returning to the ocean as “smolts.” Such research would not be possible in any other watershed in the area, as there simply are not enough returning adult coho salmon in other streams to have the research be meaningful. The point of the above objectives is to separate terrestrial habitat impacts from ocean survival issues. Put more simply, if adults return to the river and juveniles are not produced, this implies a problem in the river, whereas if a large number of juveniles are produced in a given river and leave for the ocean, but fail to return- it implies challenges related to ocean conditions. There are subtleties within this that make the overall issues more complicated; however, there has been a general trend in our Scott Creek data (and data from other non-NOAA scientists) that when greater numbers of coho salmon return to Scott Creek, they do spawn successfully and a reasonable number of juvenile fish are subsequently produced and depart for the ocean.
In recent years, changes in coho population trends in Scott Creek and all other rivers in California have involved dramatic declines in adults returning from the ocean across the entire state and this has brought concerns about ocean conditions to the top of our priority list. In addition, no one would argue that the local selective harvest practices have less impact than other more severe practices, such as clear-cutting, as in other watersheds farther to the north. There are plenty of data on variables such as stream flow, turbidity, and temperature to indicate that other more human-impacted watersheds in the Santa Cruz Mountains have more degraded habitat than Scott Creek. This is not meant to imply that Scott Creek does not have habitat challenges or state one way or another that I feel Big Creek’s “self-regulation works” as printed in the original article. Rather, I believe that factors other than forestry practices are of greater concerns for setting local research priorities for coho salmon. This is the reason that I repeatedly asked the reporter to contact someone else in NOAA who is more familiar with forestry practices and policies, which is a statewide issue for salmon in California. With that said, given adequate time and funding resources, I would like to add studying the impacts of variable forestry management practices on local fisheries to our research task list.
The original article also quoted some numbers I provided for local salmon and steelhead populations that were questioned in subsequent letters to the editor. These numbers, although vague and lacking in detail are more or less accurate. And while I would like to see higher numbers for both species, the coho salmon in particular are dangerously low and we at NOAA-NMFS are very concerned. Since the devil is often in the details, it seems necessary to provide additional information here. The letters to the editor indicate much lower numbers, with specific reference to the past two years. In general we have only caught a few coho in our fish trap during the past few years, due in part to low numbers of returning spawners but also to variable efficiencies in trapping success associated with storm events. In other words we never catch them all. To compensate for this, our team conducts hundreds of hours of spawner surveys each winter with two people hiking over 30% of the watershed approximately every 10 days from late December to May, looking for coho carcasses and spawning redds (“nests” where eggs are laid in gravel). We also conduct extensive snorkel/dive surveys of the river to try and find fish that got past the trap for the purposes of counting and tagging. In addition, we make use of microchip technology, tagging juvenile coho smolts as they leave the watershed. If and when these fish return to the watershed one to two years later, it is likely they will swim through one of several in-stream antennae systems that can detect and read the unique ID code from each tag allowing us to determine if some fish returned from the ocean without even handling them. As we have an approximate idea of what percentage of juvenile fish were tagged, we can use this as an additional tool to estimate the relative number of untagged fish that returned to the river. With that said, through a variety of sampling methods, our team detected 12 unique coho salmon returning to Scott Creek this year. Sadly, most of these fish were male, and only one female carcass was directly observed in the river. As several fish were detected by our in-stream tag readers, and we know the ratio of tagged to untagged fish, we determined an upper estimate of possibly 40 fish returning to the river this year, including additional undetected females. At this point, it is simply too early to tell what the over all spawning success was for last winter and final results will not be available until further juvenile surveys are conducted this fall and smolt trapping next spring.
Finally, as a private resident of Santa Cruz county for 15 years, and a current home owner, it is my hope that a way can be found to maintain a locally owned and operated, environmentally responsible timber harvest practice here, rather than increasing the demand for timber harvest in someone elseís back yard, creating additional problems for their salmon, and increasing the overall costs and carbon footprint challenges associated with trucking lumber from far away.
Sean A. Hayes, PhD
Research Fisheries Biologist for NOAA Southwest Fisheries Science Center
Adjunct Faculty to University of California Santa Cruz
Santa Cruz community member
