Sunday, January 27, 2013

The Merwin Trap

     For kokanee spawn this year, we tried out a new piece of gear called a Merwin trap that has never been used in the state before. The idea to use one of these came from some of my southern counterparts, in particular Jim White in Durango. New Mexico uses a couple of these for both walleye and kokanee spawn operations. Jim found out about New Mexico's use of this piece of gear and thought that it would work great for some of our applications, particularly capturing the developing kokanee broodstock at the new Lake Nighthorse. Mike Martinez, a technician at the Durango hatchery, welded it up. The Lake Nighthorse fish aren't mature yet, so there wasn't any need for the trap yet in 2012 down there. So, I got to be the lucky guy to deploy this thing for the first time at Wolford Reservoir, where we knew we were going to have a good kokanee spawn season. 
     Here we are trying to figure out how to put the thing together:

     There is always a lot of kokanee activity right around the boat ramp, so we kept things simple with this first try and set it right there, using the dock to tie off to. In the photo below we are getting the lead figured out. It's ten feet tall, with a float line on top (you can see the white floats) and a weighted line on the bottom. The lead is 150' long, but we didn't use the whole length of it.

      Here it is, deployed and anchored. There are two pots with throats in them, so when fish that are swimming parallel to shore hit the lead, they turn out toward the lake to get around it. They are forced to swim into the pots and are not able to find their way back out. It's just like a huge minnow trap.

     This is what it looked like from above. Strong winds could be tough on this thing, so it was great to have a relatively sheltered spot.

     I had no idea what we were going to find after this thing fished for a night. I half-expected that there would be no fish at all in it. However, the picture below shows what was waiting for us the next day

     This was a very good sign. The best-case scenario in my mind is that we could potentially take as many as 2 million eggs out of this thing if everything went well. We took 1.9 million over the course of a few weeks. It was a spectacular success. This completely made up for the fact that the Williams Fork egg take was a bust this year, and it even covered a little bit for Granby's weak showing. Here we are picking up one of the pots on one of the spawn mornings (below).

     Check out this splake that showed up in the trap (below). We had a few show up, which surprised me. We haven't stocked them since 2000.

      Since this was the first time any of us had used one of these, we quickly figured out some things that we would design differently, and I'm already having a second one built. This might have great usefulness during Walleye spawn, and my friends in the Southeast region are going to try it at Pueblo in the spring. I can't wait to see how that works. 
     As far as using it next year for kokanee, I just have my fingers crossed that we still have kokanee living in either Wolford or Williams Fork next fall. Things are not looking good at all for those two lakes unless our weather pattern changes drastically.

On another note, I've got a new report on our website about the Colorado River, Pumphouse-Radium. Take a look if you're interested and let me know your thoughts, thanks!

Sunday, January 20, 2013

Tailwater time.

     My head has been spinning over the past week with Blue River tailwater data. So rather than write a post about some other topic, I'd like you to take a look at the report that I posted here a couple of days ago:

     This section of the Blue is always lumped in as one of our states three "mysis tailwaters," but during the time I've been around, it has become obvious to me that the Blue does not enjoy a constant benefit from the presence of mysis, but appears to enjoy an occasional benefit. One of the problems is that if the mysis are not present, that river has very little in the way of invertebrate life to serve as an alternate food source. Slow growth is the biggest glaring issue that would not be a problem if the river benefitted from mysis to the extent that the Taylor and/or the Pan do.
     So, I want to invite you to dig into this report if you're interested and see what you think. What I lack with respect to the Blue tailwater is the angler's perspective. I am an avid fisherman, but the Blue tailwater is not my cup of tea at all. So I would really like to hear from you guys who fish it on a regular basis. Let's use the comments section here to have a discussion regarding whether or not the conclusions that I'm coming up with on the Blue correspond with your perception of what goes on there. One funny thing about this section of river is that I get praised and criticised at the same time by different sectors of the public for the practice of stocking the brood culls there.  I'd like to hear where folks come down on that as well.
     As you read the report, let me know -- am I on the mark? Am I missing something? Thanks.

Sunday, January 13, 2013

Dead Giveaway.

      I often get comments from anglers that caught large rainbows in the Colorado or Blue and they wonder if it is one of the whirling-disease resistant fish that we have been slowly getting established.  I started stocking large numbers of very small WD-resistant rainbows (a strain that we call HXC's) into the Colorado and other rivers starting in 2010. Those fish have been growing 5-7" annually. The 2010 year class in the Colorado is now in the neighborhood of 14" and I'm hopeful that we may see wild recruitment in 2013 for the first time in decades. So, if the fish in question is is larger than 16", chances are very good that it was stocked privately. There are a handful of private landowners along some of the rivers that do stock fish into their reaches of river. We see these privately stocked fish show up in far-flung locations, both upstream and down. The other source of "non-wild" rainbows into the rivers is if one of the large reservoirs where we stock 10" catchable rainbow trout happens to dump some of those fish as it is spilling.
    We're trying to manage the genetics and usher in a new golden era, if you will, of wild, self-sustaining rainbow trout in our rivers. This takes time and patience but I am confident that we are on the verge of seeing this effort pay off, big time. When highly domesticated fish move into these areas and mix with the HXC's, it may hinder this process if they manage to inject their genetics into the mix. So if a large number of these fish turn up in our sampling reaches, it presents a bit of a concern.
     There are some other ways to tell if the fish you caught is not wild. Often the stocked fish are skinnier and have less color, such as the example below.

     Now, take a look at this dorsal fin:

     This is the dead giveaway that this fish was raised to a large size in a hatchery. Wild fish (or fish stocked at a very small size, therefore virtually wild) have a normal dorsal fin with straight fin rays and it's obvious when you lift the fin.

    Once you get in the habit of looking closely at the dorsal fin on the fish that you catch, it becomes very instructive.

   Here's an example of a one-year-old HXC. This fish was photographed in September of 2012, and was stocked at 1.5" in July of 2011. This year class averaged 9" in September and there are a good number of them out there. I caught a few of these on rod and reel myself this year and these fish make themselves known as soon as they are hooked. Even at 9" they'll take a little line off your reel. I can't wait to see how it will be to catch one twice that size. Look at the difference in color. I don't have a picture of me holding up the dorsal fin on one of these, but the fin rays are perfectly straight and not distorted.

Sunday, January 6, 2013

A Tale of Two Lakes.

     Here's a wonderfully simple story illustrating how straightforward field work in this profession leads to an immediate management change.
     I am blessed with a large number of alpine lakes in my area of responsibility. This includes the east side of the Gore range, the east side of the Never Summer range, the west side of the Indian Peaks, and the handful of lakes in the Williams Fork watershed. Plus a few others scattered around. Needless to say, I haven't made it to all of these lakes yet. I hope to make it to all of them before I retire.
     You're probably aware that we stock many high lakes throughout the state with cutthroats from an airplane. The vast majority of these lakes were historically fishless, usually being situated above thousands of vertical feet of various geological barriers which originally prevented the native fish in the mainstem rivers and tributaries from colonizing that far upstream. Human history has turned the tables and now the only places that are inhabitable by our native cutthroats are typically the waters upstream of these same barriers. So, stocking our high lakes serves both recreational and conservation purposes. We stock enough cutts in enough places that they are available for angling and harvest, while in some cases the conditions are right for the fish to establish self-sustaining populations, sometimes with nice spawning runs up lake inlet streams at high elevations. Actually, it seems to be more often the case that the successful spawning situations find the adult fish dropping into an outlet stream that has good spawning habitat and getting the job done there.
     We used to stock a lot more lakes than we do now, before the whirling disease crisis hit our hatchery system in the mid-'90's. At that time, much of our fish production went away for a few years while hatcheries were depopulated, disinfected, and new infrastructure providing clean water sources was built. All high lake stocking ceased for a few years. Once the hatcheries were back up and running, the high lake stocking schedule was slowly rebuilt, lake by lake. But many lakes never made it back on to the stocking schedule, for one reason or another, and remain that way today.
     While this sounds like an unfortunate development, there was a silver lining. Many of the lakes that had been stocked for years did not experience a drop in the quality of their fishing or the density of their populations. It turned out that conditions were good for natural reproduction in these lakes. Without a break in the regular stocking of these lakes, the self-sustaining potential there would never have become apparent. Conversely, many lakes became fishless again, hosting no successful reproduction at all.
     So, in my job I'm lucky to survey a handful of high lakes each year. Usually the purpose of these surveys is to verify that we are justified in either stocking a lake or not stocking it. It's a process of still getting the stocking schedule sorted out and maximized after all these years. And I've got to say, in a job that has more fun things to do than I can ever list here, these high lake surveys are at the very top, always. I consider myself unbelievably lucky to have the task of doing this. So much so, that in some part of my mind I'm always waiting for the other shoe to drop, for the bad news to come, and to find out that I'll be spending the next thirty years sitting in a cubicle in a windowless hole staring at a screen.
     I should explain that when you take a job as a fisheries biologist, you inherit a stocking schedule for all your waters. This schedule has been perused, tweaked, massaged, and altered by each biologist who had the job before you. When you are new in the job, you have no knowledge whatsoever indicating you should change anything in that schedule, so you don't. But you start collecting field data that picks up right where the previous guy left off, and you design your surveys and collect your data in a way that hopefully answers the question of whether or not there is a better way to be doing things. If you don't have data that directs you to make a change, you don't make a change.
    This past August, I recruited a handful of willing coworkers and we headed up to survey two lakes of interest, Crater and Pawnee. Crater Lake had been put back on the stocking schedule and had been receiving 2,000 1.5" cutthroats most years since 2001, while Pawnee was one of those lakes that had fallen off the stocking schedule, stocked for the last time in 1993, and had never found its way back on. I had received angler reports that Crater was full of brookies and macs. I had not ever received any reports from anyone regarding Pawnee. I was hopeful that we would find a happy, reproducing population of cutts doing fine in Pawnee.
     I was also intrigued by the report of lake trout in Crater. The combination of lake trout and brookies is not unusual in other areas of the Rockies. Lake trout were sometimes stocked in high lakes that were overrun with stunted brook trout populations to thin the brookies out, increasing the quality of the brookies that were left while at the same time providing an opportunity for a larger mac in the recreational catch. It seems that I've heard of this more in the Wind River range and other areas of Wyoming, but if this was true, it would be the only such lake in my area, to my knowledge. Also, if this report proved to be true, it didn't sound to me like there was much opportunity for those 2,000 1.5" cutthroat dropping in from the plane every year to survive. So I wanted to know if we were wasting those fish. I've seen a couple other scenarios in which we stock cutthroats into a lake with a prolific brook trout population and never get any recruitment out of them at all. That is a futile effort.
     Logistics for a high lake sampling trip are a little more complicated than a standard backpacking trip. We have to get gillnets, float tubes, and waders to the lake. That pretty much makes it a requirement to use animals of some kind. I've been on a couple Llama trips and been very impressed with the utility of those animals, but for this trip it would be Scott and Becky's horses doing the work for us.
     We made our way up the trail to a suitable base camp, at a point beyond which it seemed unwise to take the horses any farther. The following morning, after repacking gear onto our own backs, Chris and Scott headed for Crater Lake while Sean, Michelle, and I made for Pawnee.
     These lakes sit in spectacular glacial cirques with massive headwalls rivaling anything in the national park. As soon as we arrived at Pawnee, I set about getting the float tube inflated and set two 75' gillnets on opposite sides of the lake. While the gillnets soaked I cruised around the lake a bit on the float tube, then did some hiking around to check out the basin. The weather was completely still and from the time we arrived I never saw a rise on the water.
     Pawnee doesn't have much of a defined inlet. It seems that the inflows to the lake probably come from many directions, and most of it beneath large boulder and talus fields. The outlet, however, had a similar appearance to many I've seen that support spawning success. There is a beautiful small meadow immediately below the lake that the stream snakes its way through, with deep pools. I've often seen these types of places immediately below high lakes teeming with fish. The substrate was definitely on the large side and there wasn't an overabundance of good gravel, but I thought surely there was enough to get the job done. However, in all our traipsing around, we never saw a single fish. No fish in the outlet stream, no fish cruising the lake, no rise forms, nothing. We walked all the way around the lake, with good conditions for seeing into the water. And, ultimately, zero fish in the gillnets when I pulled them at the end of the day several hours later. So, I felt pretty confident in the assessment that Pawnee Lake holds zero fish.
     At camp that night, I got the report from Chris and Scott regarding what they found at Crater. It was exactly what I had expected: decent brookies up to 12 inches, a couple lakers in the 16-inch range, and no cutthroat to be found anywhere.
     Simple as that, we have a management change to make. It appears that all we've been doing stocking those cutthroats since 2001 is subsidizing the brook trout and lake trout diet in Crater Lake, while one basin over Pawnee Lake sits fishless and begging for cutthroats since 1993. Crater will no longer receive cutthroats, while Pawnee goes back on the schedule.
     That's how it works with our alpine lakes stocking program. It slowly evolves over time based on a slowly building base of firsthand information. I love the simplicity of the information combined with the significant physical effort required to get it, and the phenomenal work environment. It may not seem like much information, but it took a three-day effort to get it. I would love to do nothing but high lake surveys all summer long, but there are obviously other responsibilities, and summer flies by. This is why we can only make it to a few of them each year.
     The main unanswered question from this trip is, why weren't the cutthroats historically stocked in Pawnee Lake successful in reproducing? I've seen recruitment in lakes that appear far less hospitable. It's impossible to say. It may be a matter of one bad year in which conditions under the ice were just right for dissolved oxygen to drop to levels impossible for trout to survive. I'm optimistic that the outlet stream there will see spawners again, and cutthroats born there as well.

Tuesday, January 1, 2013

Hi there.

   Hi everyone. I am the Colorado Parks and Wildlife fisheries biologist responsible for managing the fish populations in Grand and Summit counties, Colorado - plus a little more on the downstream end. Everything that flows into the Colorado River down to State Bridge, minus the Piney River watershed, but including the Toponas country.
   Anyway, I have decided to start this blog as a method of interacting with my constituency. In the aquatic section of this agency, the traditional forum for public involvement has typically consisted of a meeting which we have called an "Anglers' Roundtable." My opinion is that the age of these meetings has come and gone. Don't get me wrong, there is still very much a place for face-to-face interaction, however our current technology allows for much more efficient means of communication. "Anglers' Roundtable" meetings are often attended by very few people. Sometimes not much that is constructive comes out of them.
   For the past couple of years, I have been participating in an ongoing bulletin board discussion on the website If you haven't checked that out, you should read up on that a little bit. It has been a huge success and definitely beneficial for everyone who has participated. However, I'm leaving that site and starting this instead. I've got a few reasons for that. My thread on that bulletin board has become the most-viewed item on that website, and yet I have no idea who owns or operates that site. I've never been contacted by anyone associated with that site. My assumption is that someone is attempting to make money from that website, and I don't have any particular reason to contribute to that.  The information that I am presenting has been paid for by the license-buying sportsmen of this state, and it doesn't seem quite right to put it out there using an outlet that is a for-profit enterprise. Another reason that I'm switching to this format is that it seems as if there are only a small handful of guys willing to interact with me on that thread, and they happen to be most interested in our kokanee and lake trout fisheries. That's not a problem, but my job is far more diverse than that. I certainly hope those guys come over to this blog and continue those conversations. However, I am hoping to pick up more folks interested in other aspects of our fisheries, and more representative of the full spectrum of our license holders. There will be a lot of kokanee and lake trout talk here, but after a while I get tired of talking in circles forever about just kokanee and lake trout, and I think folks get a little tired of reading about only that topic as well.
   I'm going to be learning this blogging thing as I go, so it's going to be a work in progress for a while. But my intention is to have good, detailed discussions through the comment sections. We can get as detailed as anyone wants to regarding the data that I collect and how I'm interpreting that data. I don't know the exact  requirements for a person to post on this blog, but I very much hope that folks will participate in that aspect of it. The public forum this will provide is the whole reason I'm doing this. I hope that folks post as who they actually are, because the practice of posting under a pseudonym is the biggest downfall of those other sites.
   I'll lay out a few ground rules to start off with. I'd like to keep the conversation somewhat limited to waters that I cover. Sometimes I can answer relatively simple questions about other waters around the state, but I don't typically examine the fine details of the management of those waters. Nothing that ever appears on this blog should ever be construed as me second-guessing or questioning the management of one of my counterparts in another part of the state. They know what they're doing there - I don't.
   So anyway, welcome aboard and I hope you stick with me on this new little adventure. 2013 is going to be a good year.