Monterey Bay Salmon & Trout Project

Monitoring Steelhead life history in Scott's Creek

The National Marine Fisheries Service (NMFS) is currently conducting a study funded by the Department of Fish & Game to evaluate how hatchery raised steelhead contribute to the population of natural run steelhead in the Scott's Creek watershed. This is a complex study (actually designed by MBSTP board member Jamie Alonzo), which looks at the interactions between fish released from the Kingfisher Flat Fish Rearing Facility and natural run fish at all life history stages from fry to smolt to adult.

The first phase of this project looks at the genetic make-up and age distribution of steelhead adults. To do this, we catch adult steelhead and collect tissue samples for genetic studies. Scale samples help us to determine their age. We also mark each fish with a color coded Floy tag.

There was a great steelhead run this year and, with the assistance of MBSTP volunteers, we were able to capture (and release) 54 adult steelhead (37 natural run fish, 17 hatchery fish). We were also able to attach data logging tags to 10 of these fish. These tags record the temperature and depth of the water where these fish travel. If anyone catches or sees a fish carrying one of these tags, please remove the tag, release the fish and give me a call (Sean Hayes - 831.420.3937). We'd love to get the tags back and learn what these fish are doing at sea!

We are currently concluding our surveys for spawning steelhead. While we haven't analyzed the data yet, we've already learned several things. Steelhead are very promiscuous, with both males and females spawning with several different mates over a period of several days to weeks. In addition, we saw lots of spawning between natural and hatchery fish, indicating that hatchery fish are doing well when they return to the stream and are making healthy contributions to the population. Genetic sampling of the juveniles will eventually give us an idea of exactly how well the hatchery fish are fairing on the spawning grounds.

DNA samples and gill samples were collected from 63 hatchery steelhead prior to their release into Scott's Creek. In addition, we have set up a trap in lower Scott's Creek in order to monitor the movements of hatchery and natural run smolts as they head to sea. To date we have caught and released 51 steelhead smolts (24 hatchery, 27 natural) and 1 coho smolt. We will be analyzing the gill samples soon to measure how prepared the smolts are to make the switch into saltwater.

We are also taking measurements of water quality and flow to get an idea of habitat suitability. We started taking these on 2/13/02 and continue to collect data biweekly at 4 locations in the Scott's Creek watershed. We plan to put temperature loggers at several locations along the watershed which will give us hourly temperature measurements throughout the year. We didn't receive much rain in March or April and stream flows are really starting to slow down. We will continue to monitor this throughout the year. On a more positive note, we are beginning to see the results of an amazing coho run this year. The creeks are just full of coho fry emerging from their redds. Please check out some of the photographs we've supplied to the MBSTP web page. We will continue to monitor the creeks throughout the summer for the distribution and growth of this year's coho and steelhead fry.

Miscellaneous Information * 3 UCSC students have been hired part-time to assist in these research activities.* * I (Sean Hayes) was hired as the lead scientist on this project in January, 2002. * * * We hope to hire another full-time staff member for this project by April 1, 2002. * To date we have participated in 3 Scott's Creek Watershed Council Meetings, the latest of which were on January 29th and February 19th, 2002, to update local landowners as to our research activities.

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