Monterey Bay Salmon & Trout Project

As many of you know, the Salmon Ecology team at the Santa Cruz NOAA Fisheries Laboratory began conducting research on Scott's Creek salmonids in January 2002. The initial focus of the research was to (1) determine the range of life history strategies of salmonids in the watershed, and (2) evaluate the effects of the Monterey Bay Salmon and Trout Project hatchery-produced fish on the wild populations. This work was conducted primarily by myself and two research technicians- Chad Hanson and Morgan Bond, under the direction of our supervisor Bruce MacFarlane and in collaboration with the lab geneticist Carlos Garza. It didn't take long to realize the value of the Scott Creek watershed as a phenomenal outdoor research laboratory for the study of central California salmon and steelhead. Since that time many members of the Salmon Ecology team at Santa Cruz have started focusing on Scott Creek for the study of important questions in salmon biology. We have funded Chad and Morgan to enter graduate school at UCSC, where they are pursuing research questions related to the stream and estuarine ecology of Scott Creek fish. Ellen Freund joined our
program in January 2003 and is conducting comparative physiological ecology studies of salmonids in Scott Creek estuary and other coastal California estuaries. Another of our fishery biologists, Arnold Amman, has taken on a project monitoring the constantly changing environmental characteristics of the Scott Creek estuary as it fills and drains throughout the year. And Sue Sogard, our branch chief, is working with us on a project comparing development of juvenile steelhead and rainbow trout hybrids.

As you can imagine a complete report of all these projects would be very long, so I will provide just some highlights of our findings to date. The results from our hatchery study indicate there was no competition between hatchery and wild fish at the juvenile stages and that adult hatchery fish behave like and regularly spawn with wild fish. In short the hatchery is doing a great job and we have submitted detailed findings of this study as a paper to the Journal of Fish Biology. In addition we have been studying growth of juvenile fish in various habitats and have found that fish grow much faster in the estuary than in the upper reaches of the watershed. Work by Morgan has led us to speculate that the estuarine growth period for juvenile steelhead may be critical to their ocean survival. Genetic analysis of steelhead from throughout the watershed including resident steelhead (non-migrating rainbow trout) from above Big Creek falls had revealed genetic differences between steelhead that go to sea and those that choose to spend their entire life in the stream. An anecdote to this- we have resighted a couple fish that were tagged ABOVE Big Creek falls in June 2003 in the lower watershed, just upstream of the estuary during April 2004. Apparently these fish came over the falls and may be heading out to sea. We are now trying to quantify how often this happens. As many of you know, we installed an adult weir fish trap along the Scott Creek mainstem between the Queseria and Little Creek tributaries last fall to count, tag and sample the returning adults. While a bunch of fish got by the weir during winter storms, we were still able to catch over 100 coho and 340 steelhead this year. We estimate that there may have been as many as 450 adult steelhead spawning this year. Next year we hope to see that many steelhead and potentially similar numbers of coho as well. Finally much of this research was presented to a panel of top ranked fisheries biologists last fall as part of an independent review of NOAA Fisheries research activities. Our work in Scott Creek received a great deal of attention and the panel was so impressed, they asked for a tour of the watershed and hatchery. After this, they urged us to keep up our Scott Creek research efforts and our great relationship with MBSTP. Needless to say, with your support, we hope to continue conducting studies there for many years to come.

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