The Smolt Trap


GENERAL INFORMATION
SMOLT TRAP DATA OVERVIEW
SIGN UP to VOLUNTEER (for April / May 2006)

 

2005 Smolt Trap Survey News

2005 was a very unusual year at the Big Spring Creek Smolt Trap. Not only did the number of Coho Smolt decrease by 75%, compared to 2003 and 2004 numbers - but as if to make up for this 'lack of excitement', our volunteers also experienced a couple of very unusual encounters. The encounter of species such as Pumpkinseed (Red-Eared Sunfish) and what seemed to be a juvenile Chinook salmon along with the very low number of Coho Smolt rendered us quite baffled, and Monitoring Coordinator Mark Stamey is currently trying to explain these phenomena.

Pumpkinseed Lepomis gibbosus (4.2 inches)
Picture taken from: Richard S. Wydoski and Richard R. Whitney: Inland Fishes of Washington. University of Washington Press, Seattle, 2003.

Red-Eared Sunfish prefer the quiet waters of lakes and ponds with dense aquatic vegetation, and although they don't mind cooler water temperatures too much, they grow best where summer water temperatures reach at least 70°F!
The encounter with a juvenile Chinook salmon almost forced us to shut down the Trap after only two weeks of operation. After consulting with the National Marine Fisheries Service and Paul Dorn from the Suquamish Tribe, however, we were able to obtain the necessary permits for handling endangered species and could continue our survey.

Nevertheless, the very low numbers of Coho Smolt in 2005 remain unexplained, and it is our hope that we simply missed the peak of migration due to the very early and warm  spring weather we experienced this year.

Many thanks go to our great volunteers at the trap: Bill Lee, Jim Miltimore, Ed Robinette, Mark Menard, Kathleen Ryan, Tom Waller, Michael and Annie Henry, Jill Thomas, Bill Bolitho, and Nancy Lane's students from the Green River Community College. You did a great job!! We appreciate your help!!

All these questions have led to the decision that we will conduct a fourth Smolt Trap survey at Big Spring Creek in 2006. 

General Information

What is a smolt?

"Smolt"  is one of the life-stages of a juvenile salmon.  This life stage occurs  when the juvenile salmon begins its migration from freshwater to the estuary and adjusts to living in saltwater. Different Pacific Salmon species spend different amounts of time rearing in freshwater. Coho salmon, the focus of our study, spend one to two years rearing in freshwater after they emerge from the gravel as fry. Coho reach about 50-100 millimeters in size before they smolt and begin migration to the estuary. The timing of this movement correlates with spring freshets (high water flow from snow melt).

 
    Juvenile Coho                                 Juvenile Rainbow Trout

What is a smolt trap?

A smolt trap is a standardized method of quantifying how many fish are moving through a water system.  There are several different types of smolt traps.  The objective of the study and the size of the system determine the type of smolt trap to use.  
On big rivers and streams, "screw traps" are often used to catch fish moving downstream. These traps only capture a portion of the fish in the river because the trap does not collect fish from the entire channel.   

Our trap is a full-spanning v-shaped weir that is modeled after traps developed in the 1970s by Washington Department of Fish and Wildlife. This method is commonly used to evaluate juvenile coho use of winter rearing habitat, which is the purpose of this project. The weir allows water to flow downstream but all fish over a certain size are forced to swim into a livebox where they wait until someone collects them. The captured fish are then identified and measured before they are released downstream to continue their migration.
 

How are volunteers involved?

Our smolt trap needs to be checked twice daily. 
Trained volunteers and Mid Sound staff share the responsibility of checking the trap. This entails identifying, measuring and documenting the fish in the trap and releasing them downstream.
When checking the trap, it is also important to clean off the screens to allow for water to flow through, and also to check for gaps where the fish might be able to escape. During high water, the most dedicated volunteers assist with keeping the screens clear and making sure that the panels are not washed out.

The smolt trap is an exciting volunteer opportunity for those interested in scientific field work and collecting data. If you like fish, you will love being a smolt trap volunteer.
 

Why do we need a smolt trap?

The purpose of the Big Spring Creek study is to evaluate overwinter use of Big Spring Creek by juvenile Coho salmon. Because Coho spend one to two years in freshwater after hatching, freshwater habitat is very important to their survival.
Big Spring Creek is used as winter habitat for juvenile Coho because of the must reduced flows from those of Newaukum Creek.  Our initial results will help us evaluate  future restoration efforts on Big Spring Creek.

Trap Installation 2005:

 Big Spring Creek: March 23, 2005 until May 31, 2005.
 

Volunteer Training: 

The 2005 Smolt Trap Survey is finished. If you are interested in volunteering, you may sign up for our 2006 survey at Big Spring Creek.

Trap duration:

    Late March through end of May
(volunteers sign up for morning or
    evening times of their choice.)

How long does monitoring take?

The trap is monitored twice daily (between 6 and 9 AM and again between 6 and 9 PM). During high flows, the trap needs to be checked more often. Each check takes between 1/2 hour and an hour.

Volunteer Commitment

To those of you who have volunteered with our smolt trap project in the past and want to do it again, WELCOME BACK! 

We ask that new smolt trap volunteers make a minimum commitment to check the trap at least 4 times during the trapping period (April and May), since it will take at least a few times for you to get comfortable with your identification skills.




Equipment

Most of the needed equipment is provided.  However, there is only a limited number of waders available, and volunteers are encouraged to bring their own.  

Trap Location

The Big Spring Creek Smolt Trap is located near Enumclaw, Washington. Directions will be given at the training.

Are You Interested in Volunteering at the Smolt Trap?

Sign up online

For more information, contact Andrew Pavone, Monitoring Coordinator andy@midsoundfisheries.org.