Dr. Rob Van Kirk's blog

Monitoring Juvenile Trout Numbers in Fish Creek (Harriman East)

Photo of five people electrofishing in Fish Creek.
Photo of three people electrofishing in Fish Creek.
Photo of juvenile rainbow trout being measured.

Personnel from the Henry’s Fork Foundation (HFF), U.S. Forest Service (USFS), and Brigham Young University-Idaho (BYUI) conducted an estimate of juvenile trout abundance in Fish Creek on April 15-16, as part of a long-term restoration and monitoring effort. How did our 2015 numbers compare with those in 2011, prior to major restoration of the creek?

Spring of 2015 shaping up to be driest in last 35 years

April 1 is an important date in water management in the western U.S. because it is the typical date of maximum water content in the snowpack at most mountain locations. Based on yesterday's data, I predict that April-June streamflow in the Henry's Fork at Island Park this spring will be the lowest in the last 35 years and possibly the lowest since the extended drought of the 1930s. And that's no April fooling.

HFF adds high-tech invertebrate sampling to water-quality network

Photo of invertebrate sampling in the Henry's Fork near Ashton Reservoir.
Photo of Brett Marshall using a net to collect invertebrates.
Photo of Brett and David in the river near St. Anthony.
Photo of Robert and Rob scraping invertebrates off of a rock.

Last week, aquatic invertebrate experts David Richards and Brett Marshall met us on the river to kick off an exciting new project that will allow HFF to monitor numbers and types of aquatic insects and other invertebrates using DNA “bar-coding”. Former HFF Board Chair Robert Dotson joined us for part of the day.

Implications of irrigation seepage for fisheries management

I’ve been traveling much of the past two weeks and haven’t had time to post a blog lately.  This week’s post is the presentation I gave at the Idaho Chapter American Fisheries Society meeting in Boise on March 4.

Here is a link to the slides, in pdf format. An explanation of each slide is given below.

Teasers from our 2014 Angler Attitude Survey

As most of you know, HFF conducted a survey of anglers in Harriman State Park (“the Ranch”) in 2014. The survey was identical to one conducted back in 2008, for direct comparison of angler attitudes and experiences between the two years. In 2008, the (new, improved) Buffalo River fish ladder and the Island Park Drought Management Planning process were each only two years old and so had not had time to fully affect the population of rainbow trout available to anglers. By 2014, two full fish generations had passed since implementation of these two major fishery improvement projects, and we went back to see whether anglers had noticed any difference in the fishing.

Water Supply Update

On Friday afternoon, just as I started writing my blog, I received a phone call from Idaho Department of Water Resources (IDWR) staff in Boise. The purpose of the call was to alert me that water-supply and administrative conditions were aligning to allow diversion of water upstream of American Falls Reservoir for aquifer recharge. That prompted me drop what I was starting to write and instead revisit the water-supply situation, which I last did on January 7. So, how are we doing five weeks later?

Effects of Island Park Reservoir on Sediment and Phosphorus Transport

This week I attended Idaho Department of Environmental Quality's annual Water Quality Monitoring workshop in Boise.  This was the workshop's 25th year, although it was my first time attending. HFF was invited to participate because of the large amount of water quality data we are now collecting and analyzing. This week's blog consists of my presentation at that workshop.

Here is a link to the powerpoint slides. The following text explains each slide.

What causes flow fluctuations at Ashton Dam? HFF solves long-standing mystery.

Graphs of river stage at five locations on Henry's Fork.
Graph of river stage above and below Ashton Reservoir.
Graphs of river stage above and below Ashton Reservoir; close-up.

For many years, outfitters and guides, anglers, and irrigation managers have inquired about the causes of daily fluctuations in streamflow in the Henry’s Fork downstream of Ashton Dam. These fluctuations are large enough to be noticed by anglers while they are out on the river and large enough to cause canal diversion rates to vary throughout the day. Although fluctuations occur year-round, they are highest in amplitude and have the greatest effect on fishing, river ecology, and irrigation operations during the late summer and early fall.

HFF’s “to-do” list hits high point

From the outside, it would appear that HFF’s busiest time of year is the month or two leading up to and surrounding Henry’s Fork Day in June. But, I’m going to make the case here that the next six or eight weeks are in fact the busiest of the year when averaged over the entire HFF team. If nothing else, this week’s blog will give you a good idea of the breadth of our work.


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