Investigating What Happens at the Fish Weirs

The 2013 Kuskokwim Fisheries season is fast approaching, and we will be keeping you up to date on all of the information we get.  There are various types of information that come from different sources.  A lot of projects take place at weirs around the Kuskokwim Region, and so I thought I'd dive a little deeper into what actually goes on there. 

The Location – Salmon River

A tributary of the Aniak River, the Salmon River hosts one of many weir projects in the state of Alaska.  Like the George River Weir, the Salmon River Weir is a cooperative project between KNA and ADF&G/Commercial Fisheries.

 

Pictured here, just upstream of the project site, the Salmon River is home to various fish and wildlife species.  Calling this river home are all five species of salmon, rainbow trout, arctic char, dolly varden, grayling, and even pike and sheefish on the lower stretches.

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Last summer, I had the opportunity to help install the Salmon River weir, and talk with some of the people that worked with two of the cooperating agencies on these projects:  Kuskokwim Native Association (KNA) and Alaska Department of Fish & Game (ADF&G), this article is a summary of those experiences.

The project – Installing the Weir

Pictured here: aluminum picket panels lay waiting on the bank of the Salmon River, prior to installation.

 The panels are placed up against tripods to prevent fish passage in any place along the weir other than the gate, where fish are counted.

 

The tripods are moved into place from the bank to their proper position, essentially creating a fence across the river, where the tripods act as fence posts (pictured above,  ADF&G Biologist Kevin Schaberg).

Sandbags are used to weight down the tripods and prevent any movement of the weir.  Pictured on right, KNA Intern Dakota Phillips from Aniak, helps with the weir installation.

 

These posts are used to properly align the tripods, positioning them at the correct distance and angle from one another. 

Visitors to the weir include moose, bear, and sometimes even camp dogs!

The first portion of the river has metal tripods that were already in place upon arrival.  The second half consists of the wooden tripods, which have to be moved into position.  

 

The metal tripods have wooden planks connecting them, making it easier to traverse.  Here, Dakota carries a panel across to the middle of the river, where it will be placed carefully, to avoid any gaps in the weir.

After all of the panels are in place, and have a day to settle, and sand bags are placed at the bottom to prevent further movement.

As pictured, it takes several people to complete this sort of project.  Pictured below are KNA Intern Dakota Phillips of Aniak, ADF&G Technician Rob Stewart, and ADF&G Biologist Kevin Schaberg.  Not pictured here, but another contributor to the project was KNA Intern Charles Grammer from Venetie.

When all is said and done, the weir is put in place to allow free movement of water.  Occasionally, debris can get caught up on the fence, so daily maintenance and clean up is one of the many jobs of crew members located at the weir.

Summer 2012 at the Salmon River Weir

The fish weir was installed at the Salmon River tributary of the Aniak River to monitor spawning salmon.  To monitor multiple species that migrate at the same time, the fish are counted as they pass through this fence like barrier.

Photo Credit: Rob Stewart

Pictured here, College Interns Dakota Phillips and Charles Grammer, count fish at the gate.

There are many types of fish weir designs, most of which fit into two categories: fixed and floating.  Fixed weirs are simple and durable, but more vulnerable to flood damage.  Floating weirs are designed to sink during floods and allow debris to pass over them, but they are much more complex to install.

The Salmon River weir is a fixed design.  As we all know, there was a lot of high water last summer.  Rob Stewart, ADF&G Technician, speaks a little bit about what happened as a result of the flooding they experienced at the weir. He explains that the weir structure can only take so much flow before it will fail, so it is important to pull the weir before a flood gets too high.  The standard procedure is to remove the panels to relieve stress on the tripods and allow debris to pass.

According to Rob, “Things were going well this season at Salmon River until the morning of July 9th when, after several days of heavy rain the water began rising rapidly. As we were removing the panels several large trees landed on the weir preventing us from getting all the panels out. Some of the tripods were made of steel pipe while others were made of wooden beams. If a wooden tripod gets knocked out, it can wind up stuck in a logjam many miles below the weir. To prevent this from happening, we ran a rope through all the wooden tripods and tied it off to shore. Shortly afterward another tree collided and knocked all of the wooden tripods out. Luckily the rope pulled them to shore in an orderly line. The flood subsided slowly and we weren't able to reinstall until the 17th. The water stayed high for the remainder of July, and panels had to be pulled once again from the 22nd to the 26th. Such events create holes in our data that require us to estimate missed passage using counts from before and after these floods.”

A Day in the Life of a Summer Intern

For more information on the summer intern program or the fish weirs in general, contact Fisheries Biologist LaDonn Robbins at lrobbins@knafish.org or Fisheries Director Dan Gillikin at dgillikin@knafish.org.

For now, here's what summer interns Dakota Phillips and Brad Gusty had to say about their experience:

Dakota Phillips spent his summer as a college intern with KNA.  Having just graduated from high school in Aniak, Dakota spent the summer working for KNA before going to college at UAF.  He describes his summer as moving around a lot, going from the Salmon River Weir to Tatlawiksuk to George, wherever he was needed at the time.  One of the things he enjoyed the most was driving up the Aniak River, and would recommend the program to others because KNA is looking to bring more locals to the fisheries program, and because he loved the experiences he had.

Brad Gusty is originally from Stony River; he graduated from Aniak High School, and is also attending UAF this fall.  Brad spent his summer working at the fish wheels in Kalskag.  Brad enjoyed being outdoors and doing what he really loves to do – working with fish.  “Every day is a new day but there was always something different.  I really like working with the crew, we all got along really well.”    He learned about fish abundance, population, escapement goals and why the weirs and fish wheels are in place.  Part of his daily routine was to tag sockeye salmon, count fish species caught at the fish wheels, improve camp set up and appearance, in addition to learning about safety and boat/motor handling skills.    Brad would also recommend the program to others: “Anybody looking for a future in fisheries or marine biology would love this program!  It’s a great way to get exposed to living in a remote field camp, living a great Alaskan adventure, and understanding the importance of fish to our great state and its people.”

Last year, KNA had four summer interns working for them.   LaDonn says that KNA usually tries to get the announcements out at the end of March/beginning of April. We post it on the website (www.knafish.org) and our facebook page (www.facebook.com/KNAfisheries). For the college interns, we also try to make sure we get them posted on the college websites, and for the high school interns we send announcements out to the Kuspuk School District teachers.