A Guide to Salmon Surveys for Citizen Scientists who volunteer with Friends of Auburn Ravine or
“How to be a salmon survey super star!”
This document will give you important info about the Salmon Surveys that we do on Auburn Ravine, and what you will be doing as a Salmon Survey Volunteer.
When we do the surveys, we try to get two types of information about the salmon of Auburn Ravine:
- The locations and quantities of any live salmon that we observe.
- The locations and quantities of the nests that the salmon dig into the gravel of the stream bed. (These nests are often called “redds”.)
We also try to get two bits of physical evidence from the salmon:
- A tissue sample for DNA analysis from any salmon carcasses that we find.
- The head from the carcass of any salmon is missing an adipose fin. (This will be explained below.)
Note: Our surveys are mainly about salmon but we also keep an eye out for steelhead. Our permit from CDFW only allows us to collect physical evidence from salmon, but if we see live steelhead, we will take note of the locations and quantities of them and their redds just as we do for salmon.
Why We Do These Surveys (The Small Stream Strategy.)
Auburn Ravine is one of many small streams that flow into the Sacramento River that once provided spawning grounds for thousands of salmon and steelhead every year. Luckily, some salmon can still spawn in some of these streams, like Auburn Ravine, but in many of the other streams, salmon cannot get upstream to spawn due to various impediments such as antiquated water diversion systems, and poorly designed culverts. And those same impediments to upstream migration are often dangerous to juvenile salmon as they move downstream toward the ocean. Many irrigation pumps and canals are not screened to keep out baby salmon so they die before they even get to the Sacramento River.
Over the last hundred years, the damage to salmon populations caused by the loss of these small stream spawning areas was dwarfed by the damage done by large dams on large rivers all up and down the valley. In total, those dams blocked salmon from accessing hundreds of miles of excellent spawning areas. To try to compensate for the loss of spawning grounds, a few fish hatcheries were built below some of those dams. Those hatcheries have saved California salmon from extinction, but they have also, over time, led to reduced vitality and reduced genetic diversity among the salmon. This has been described as “unintended domestication” which is reducing the ability of salmon to survive threats from climate change, and predators.
To counteract this “domestication” process, more natural spawning is needed. There are still some natural spawning areas below some of the big dams, but there is also a great potential to restore wild spawning in small creeks like Auburn Ravine.
Our “Small Streams Strategy” is to use Auburn Ravine as an example of how wild spawning can be re-established or increased in small streams at reasonable cost, and in reasonably short time frames, while protecting or even improving the reliability of water delivery for agriculture.
But to build a case for that, we need data.
What you do on these surveys will give us that data:
- Exactly how many salmon spawn each year in Auburn Ravine?
- Where are their preferred spawning areas?
- At what time of the year do they enter the creek, and when do they spawn?
And most importantly, what percentage of adult salmon each year in Auburn Ravine are the sons or daughters of salmon that spawned in Auburn Ravine in previous years?
This is important because some community members and agencies tend to dismiss the value of salmon in small creeks by saying “they are all strays”. By which they are suggesting that the salmon that come up Auburn Ravine, or other small creeks, just made a mistake and came up Auburn Ravine when they really should have gone back to the river or hatchery where they were born.
With the DNA samples that you collect, we will be able to prove whether or not Auburn Ravine is supporting a full natural life cycle for salmon – from egg to juvenile, and then to an adult returning to spawn years later.
If the data shows that we have a high rate of natural spawning success and returns of adults in subsequent years, we will be able to make a strong case to protect and enhance that process.
If the data shows that our adult salmon are not the sons and daughters of salmon that spawned here years before, that will prove that straying is a significant factor but it will also prove that something is killing the baby salmon before they get to the Sacramento River. That will give us a strong case to identify and mitigate whatever is killing the baby salmon.
Auburn Ravine Overview
Auburn Ravine flows from the foothills around the town of Auburn in a westerly direction down through Ophir, Newcastle, and Lincoln, and into the Sacramento River near Verona – a total of about 34 miles.
Here is a map that shows the course of Auburn Ravine highlighted in yellow.
Salmon Survey Sections
When we do the Salmon Surveys, we do not cover the entire creek. This is because most of the spawning takes place in an area about 5.3 miles long from Lincoln upstream to the area above Hemphill Dam. This map below shows the 5 creek sections that we survey. Section 5 is shown as going all the way to Fowler Road, but we only survey the first mile of that section above Hemphill Dam because above that the creek banks are too steep to conduct a survey safely.
This file gives driving directions to the beginning and end of every section. GPS coordinates are also provided for each start and end point.
A note about Hemphill Dam
This small dam is a major impediment to upstream migration of salmon and steelhead. Our surveys, and surveys conducted by CDFW, indicate that only 7 to 10 percent of the salmon that try to get over this dam actually succeed. During irrigation season this dam also poses a serious risk to young salmon and steelhead as they swim downstream. This is because there is no screen on the intake to the irrigation canal above the dam so small fish can get swept into the canal where they eventually die due to warm water, low oxygen, or capture by predators.
The safety of all volunteers is the most important aspect of every survey. No project is so important or urgent that we cannot take time to proceed safely. If you encounter any unsafe situation on the bank or in the creek, do not press on ahead. Make a U-turn and seek a better, safer, path forward. It is OK to bypass a part of the creek if trying to survey it will be unsafe. When wading, if the water gets higher than the middle of your thigh make a U-turn. If you go any deeper than that, you may not be able to keep your feet firmly planted on the streambed. Each volunteer will be given a walking stick. Having this third “leg” to steady you while wading or climbing the bank is a big help. Each pair of volunteers should have one actual walking stick, and one extension pole that doubles as a walking stick (more on extension poles below.)
The Salmon Survey Backpack
On survey days, we assign at least 2 volunteers to each section that we will be surveying that day. On some days we might not do all 5 sections. For example, we might not do Section 5 if the water has been so low that it is unlikely that any salmon got past Hemphill Dam and into Section 5. Or, if we only have 8 volunteers, we might skip Section 1 so we can still have 2 volunteers per section. Each pair of volunteers is given a small backpack with the equipment and supplies that they will need during the survey.
Here is a list of what is in each backpack. Don’t worry, it looks like a lot but it is not too heavy, and you might not be using all this gear on any particular day.
“A form, a form. My kingdom for a form!”
That is not exactly what King Richard said but he might have if he had been a scientist! So, yes, we have forms to fill out on this project. By recording some basic information about our observations and the samples we collect, we add credibility to the data and enhance its value when we use it to advocate for protection and improvement of wildlife habitat.
We have two forms:
- One form for recording our observations of live salmon and/or steelhead and their redds, and
- Another form for recording the collection of DNA samples and/or heads from salmon carcasses.
You should make sure that you have 2 blank copies in your backpack before you start a survey. The forms are printed on “Write-in-Rain” paper so you can use them on a rainy day. The forms are fairly self-explanatory with plenty of room to fill in your data.
Seen any Salmon Lately?
Yes, that is a common question among fishermen and citizen scientists, but what do salmon look like in Auburn Ravine? Here are some photos of salmon in Auburn Ravine to help you program that powerful computer between your ears so you will “know one when you see one”.
Seen any Salmon Redds Lately?
The nests that salmon and steelhead dig into the streambed gravel are called “redds”. The word “redd” comes from the same root as the word “ready”, so it implies that an area has been made ready for the eggs. Redds are dug by the female fish. Redds are usually oval in shape, 4 to 6 feet long (upstream to downstream), a few feet wide, and 6 or 8 inches deep. After the female deposits the eggs, and the eggs are fertilized, the female covers the eggs with gravel. The area where the redd has been dug usually appears to have a lighter color than the surrounding gravel because the algae has been washed off the gravel in the digging process.
This link will give you a good overview of what redds look like.
An internet search for “salmon redds” will give you many more examples.
In your salmon survey backpack you will find a laminated card like this that shows how to mark any redds that you see.
And what about those carcasses?
First of all, watch this 7-minute video about how to collect a DNA sample from a salmon’s heart.
The video also shows how to collect the head from any dead salmon that is missing an adipose fin (a small fin that is located between the back fin and the tail fin.) About 1/4th of all the salmon that are raised in hatcheries have that small fin removed, and a tiny coded-wire tag placed in their heads before they are released from the hatchery. If we collect any head from such salmon, we will give the head to the California Department of Fish and Wildlife (CDFW). They will locate, extract, and read the coded-wire tag to find out which hatchery that salmon came from and when it was released.
One thing that the video does not show is a new step that we added to the process in 2019 – that is adding enough ethanol to the small plastic container to cover the DNA sample. The ethanol will help to better preserve the sample until we can get it into a freezer. Each backpack has a vial with about 4 ounces of ethanol in it. You will only need to use about ½ oz. for each sample.
You can see many examples of what dead salmon look like by doing an internet search on “salmon carcasses”.
The main thing to know when looking for salmon carcasses is that they do not always wash up on a nice clean gravel bank. Some may be snagged underwater on tree roots or hung up by high water in tree branches. Some may be floating in muddy pools, and some may have been dragged up on the bank and partially eaten by otters, or raccoons, etc. If you see one underwater where you cannot reach it, you can try using the extension pole and “gig” that is included in each backpack. The gig consists of 3 or 4 sharp, barbed, fingers. The gig can be attached to the end of an extension pole and used to stab and pull a salmon carcass from underwater.
In each backpack, there is a laminated card that shows the process for getting a DNA sample from the salmon’s heart. If the heart is missing, look for the least decayed section of flesh that you can find and collect a sample of that.
There is also a card in the backpack showing how to fill out the head tag that needs to be attached to any heads that we collect. The tag is attached by running one end of the wire up behind the gill plate, out the mouth, and twisting it with the other end of the wire.
And…..where the heck am I?
(I need to have GPS coordinates to put on my data forms when I see a live salmon, a redd or a carcass.)
That is what the GPS units in the backpacks are for. Yes, you can get GPS info from your cell phone but we have found them to be somewhat unreliable along Auburn Ravine. Cell phones tend to have weak GPS antennas, so they also “reverse engineer” GPS coordinates by triangulating cell phone towers or sensing the location of WiFi hot spots. In our tests over the last 2 years, cell phones often misstated the GPS coordinates of locations along Auburn Ravine by up to a half mile. If you want to do a few comparisons of what your cell phone says vs the GPS unit, we’d like to see the results.
In each backpack there is a laminated card like this.
Each GPS unit has been pre-programmed so if you follow the four simple steps described on the card, you will get the GPS coordinates without having to be an expert on how to use that particular GPS unit. It may take a few minutes for the GPS unit to home-in on enough satellites to give a good reading, so you may see all dashes on the display until that process is done.
Copyright © 2020 by Friends of Auburn Ravine.