Saturday, November 23, 2013

Brookies, etc.

A couple great questions from Keith:
   Jon-Thanks so much for doing this blog. I find it to be very infomative. I've got a couple of questions for you. First, I've found waters with large brookies to be rare and highly coveted by fisherman. Do you or does the department manage any bodies of water for trophy brookies, and if so what characteristics do you look for in a prospective body of water? The rare gems I've found with large brookies seem to be relatively small and eutrophic. Also, just out of curiousity, are hatchery fish all fed the same thing, regardless of species? I remember as a kid we had some bullheads in an aquarium that we fed Purina Trout Chow and they seemed to like it. Then again, they seemed to enjoy eating pretty much everything we threw in there. Thanks again!

Thanks Keith. We really don't have waters that are specifically managed with the goal of trophy brook trout production that I'm aware of. There could be in some other part of the state. It seems that more often, the conditions turn out to be right for brookies to get larger than average, and so we do what we can to encourage or perpetuate those conditions. I'm not aware of a regulation on any specific body of water that is aimed at trophy brook trout production. Again, there may be one somewhere that I'm not aware of. We do have the statewide regulation that allows for extra brookies to be harvested if they are under 8". For the most part, the deal with brookies is that the more harvest pressure you put on them, the better the quality is going to be. As I'm sure you know, they're very good at reproducing in Colorado.
     I've got a few bodies of water that have larger-than-average brook trout fisheries, and a couple others with some potential for that.
     There are a small number of high lakes in my area that happen to have quality brook trout, and sometimes that's just by chance. One of them, Crater Lake, I've written about previously. It has lake trout in it, that were stocked as a means to maintain constant predation pressure on the brook trout. It works there and it appears to be a self-sustaining fishery with natural reproduction of both species and brookies to over 12". 
     There's another obscure high lake that you'll have to find, or might know about already, that grows brookies to a solid 14" or so. It's not on any established trail and in fairly rugged country. It does not get a lot of visitation and so definitely doesn't have a lot of harvest pressure. It's not eutrophic, and sits in a pretty geologically sterile area. There are no lake trout. We don't stock it with anything. The only explanation I have for that one is that there doesn't appear to be a lot of good spawning habitat. So, I think that the number of brookies born every year is fairly low, and there's probably a lot of predation pressure on the ones that are born. It's relatively low in elevation as far as alpine lakes go, so probably has decent insect production, even if it doesn't get a lot of nutrient input. So the lake just seems to maintain itself at an equilibrium level of good quality. 
     Red Dirt Reservoir is an above-average brookie fishery. There are a combination of factors leading to that. First of all, it sits in a biologically-productive basin, in part because it's all cattle country. So there are a lot of nutrients going into the lake. Also, there is a lot of harvest pressure there because for whatever reason, the angling demographic of folks who use that reservoir leans toward the meat-fishing side of the spectrum. Lastly, and probably most importantly, there is a very robust population of fathead minnows in that lake. I was unaware of this until a couple of years ago when I went up there to see what the water level looked like. I went walking along the shore, and it happened to be when the fatheads were in spawning, and there were thousands of them everywhere. It seems strange that I hadn't realized they were there, but the gillnets that I use for sampling do not catch fish as small as fathead minnows, and I just hadn't noticed them before. So that combination of factors produces brookies up to 14".
     Monarch Lake is another one that has good brookies in it. I'm not aware of any fatheads there. But it gets a lot of traffic and a lot of harvest pressure. It also has browns in it, that probably keep quite a bit of predation pressure on them. It's a fairly productive lake. It doesn't drain any cattle country but it does have a ton of shoal area and submerged vegetation, etc., that provides good forage production.  I have received word-of-mouth accounts of brookies being caught there that came very close to breaking the state record but fell just short. I have not seen such a fish personally, but there are some nice ones.
     I've got two lakes that have the potential to be better brook trout fisheries than they are right now. One of those is Meadow Creek Reservoir. That lake is a classic stunted brookie fishery. There are a ton of fish up to 8" but hardly anything over that. It's one of those lakes that if you're there on the right still summer evening, at dusk the whole surface of the lake just boils with rise forms. But they're all made by tiny fish. So for 2014, I've put in a request for tiger trout for that lake. Hopefully they can perform the same function that the lakers in Crater Lake do, and thin things out a little. I haven't heard yet if my counterparts were even successful in making any tigers this fall, so we'll see about that one.
     Another one that could produce some better quality is Lower Cataract. It's got both browns and harvest pressure, but the spawning conditions must be good enough to overcome both of those pressures because the brookies are still somewhat stunted. I think that this lake is a great candidate to introduce fatheads into. The water level doesn't fluctuate because it's a natural lake, and there is a ton of shallow productive area with rooted vegetation that would be fantastic fathead habitat. So I'm looking into that. 
     So, I guess the take home message here is that for every place that has nice brook trout, the combination of factors to produce that effect is slightly different. There are common themes, but it's definitely true that no two waters are the same.

     Regarding your question about feed types in the hatchery. This is one area that I don't know much more than you do. I work closely with the hatcheries on a certain level, but on another level I am totally naive to what goes on there on a day-to-day basis. I've never had an aquaculture job, so I don't have that background. We have a spectacular group of hatchery managers that know their systems intimately and are always doing everything to stretch their production to the absolute limit. So if there is a particular feed type that works best for a certain strain or species, I'm sure they're using it. It's just a detail that I am not involved with. 
     When I got this job, one of the steepest learning curves for me was figuring out how to interact with the hatchery system. My tendency at first was to think of the hatchery as a static machine that cranks out the same number, type, and sizes of fish at the same times every year. It took me a few years to understand that this is not the case at all. In fact, no two years are ever the same in any given hatchery. The volume and temperature regime of a hatchery's water supply fluctuates every year, which can have a big impact on production. Add to that infrastructure problems or improvements, disease outbreaks, personnel limitations and various other complications, and it becomes nearly impossible to predict exactly what the output of a hatchery is going to be. So as a biologist you have to be able to have enough flexibility to adapt, take advantage of opportunities when they arise, and on the flip side, figure out how best to work around limitations or shortfalls.

Friday, November 15, 2013

Stocking schedule 2014

     'Tis the season of preparing my stocking requests for 2014. I try to invest as much time as I can into finely tuning my stocking schedule, and I learn more every year. It takes a few years to really start to understand what to tweak and what to leave alone.
     The way our stocking schedule works is like this: We have a centralized database (called "Trans 6") in which all the biologists submit their stocking requests. Around December 1, the database is opened to all the hatchery managers across the state, and they go through all the requests and select the ones that they can fill. Every hatchery is different in what it can produce and when. Each hatchery has a kind of "niche" that it tries to fill that it is best at. If the biologist who is making the stocking requests puts stuff in that no hatchery produces in that size, at that time, or both, then you end up with requests that don't get filled. So it's important to have a good understanding of what our hatcheries can and can't do.
     In 2013, I stocked a grand total of 3,617,620 fish into waters in my area. 2,089,096 of those fish were kokanee from Glenwood. Aside from those 2 million kokanee, 70% of the rest of my fish came from Rifle Falls hatchery. It is our biggest and most productive hatchery, and so I need to coordinate as closely as possible with them when making my stocking requests.
     In even years, we make our high lake plants with an airplane. I know that folks can get a little touchy about naming specific high lakes, so I won't do too much of that here. But I've made some changes, hopefully for the better. As I've said before on this blog, I really appreciate and want to encourage input from folks regarding alpine lakes. I have added lakes to the stocking schedule based on suggestions from anglers. I'm always looking for places we should be stocking to create a good alpine cutthroat fishery.
     One lake that I'll name is Pacific Lake. I put in a request to stock grayling there this year. Pacific hasn't been stocked for a number of years and doesn't appear to support natural reproduction. I've had several people ask me about it though, and it seems like a good place to try some grayling.
     I'd really like to track someone down who has been to Island Lake, in Grand County. I attempted to get there on a pack trip this year but didn't get past Gourd because of the weather. Island really takes some commitment to get to, as far as I can tell. We stocked it up through 1993, and haven't stocked it since. I can put it back on the schedule, but before I do that I want to know if there is a fishery there that is self-sustaining. We may not need to put it back on the schedule.
     Another thing I'm going to try is some tiger trout in Meadow Creek reservoir. I've netted that lake twice since 2007, and both times it's been loaded with stunted brookies. They top out at 10" at most, and they are in poor body condition. Tigers have been used in these types of situations to control stunted brookies. So we'll see if that works out.
     If you have any questions or input about high lake stocking and you don't want it to be seen by the general public, you can shoot me a private email at . As I was saying above, our high lake stocking program has benefitted from input I've received from high-lake enthusiasts. I can only make it to a few of them every year, and I've got a lot in my area.

Friday, November 8, 2013

Kokanee update

     Just a quick update on kokanee egg collection. Up here in my neck of the woods, things are getting off to a very slow start. At Granby, we haven't seen fish arrive in any numbers at all yet. They're still running 300 or so CFS out of Shadow dam which makes things really difficult down there. I really have no idea what to expect up there this year.
     We took spawn yesterday  - Thurday, the 7th - at Wolford for the fifth time. We had 173 ripe females in the trap, which yielded 146,000 eggs. We're now up to about 350K for the year there. Wolford has had an excruciatingly slow start. However, Thursday was our biggest day yet and felt like the run has finally started to pick up. On Monday the 4th, we took 105 spawns. Each time we spawn we clear the trap out. So from Thursday the 31st (or previous spawn day) to Monday the 4th, we had an average of 26.25 ripe females per day swim into the trap. From Monday the 4th to yesterday (the 7th), we had an average of 57.7 females per day. So the rate of activity essentially doubled this week.
     I'm very optimistic that this coming Monday will be our biggest day at Wolford yet this year. We've got Wolford covered for next year, but we would really like to see Wolford cover Williams Fork (need 360K eggs) and Granby (need 1.2 million). Last year Wolford did that. I don't know about this year, but I remain optimistic.
     We've seen nothing encouraging yet at Granby, but we're going to try to take spawn there next Thursday and see what happens. At this point there is pretty much no possibility that Granby will cover itself.

From Vanish, regarding the last post about the whitefish in Parshall:

Neat! I bet they used to be in the upper colorado. Many anglers find them to be trash fish but I really enjoy taking a trip to NW CO once a year to fish for them. They can give a pretty good tussle.

     Vanish, I agree with you that the whities get the short end of the stick from anglers sometimes. It hasn't always been that way.
     But I want to address your first statement about whitefish occurring in the upper Colorado at some point. I want to make it absolutely clear that there is NO historical account - not from John Wesley Powell, any of the original settlers, any old-time surveyor - of whitefish ever occurring in the upper Colorado. We are certain that they are not native to the Colorado River. They are native to the White and Yampa rivers. They were first introduced into the Colorado and Roaring Fork rivers in Glenwood by Colorado Fish & Game in the 1910's. Prior to that introduction, they had not lived anywhere in the Colorado.
     It may seem like a minor point, but I want to make sure that the biological significance of this is clear. Whitefish re-invading a place where they had previously lived would be a very different thing than whitefish pioneering a place they have never been. The latter scenario is the case here.
     We seem to have two distinct whitefish populations on the Colorado: one upstream of Glenwood Canyon and one downstream. I honestly can't say if the whitefish up in the Pumphouse neighboorhood really originated from the historic stocking downstream from Glenwood Canyon. Another theory that I have has to do with a trans-basin diversion that takes water from Yamcolo Reservoir, which is loaded with a native whitefish population (being a tributary to the Yampa River).  When they're running water through that ditch, it dumps into Egeria Creek, entering the Colorado River at McCoy. So, this is a trans-basin diversion. I don't know all the details but I do know that the owners of the water in that ditch use it to pay back water owed to the Colorado. So there can be a significant volume of water making that trip. It's entirely possible that larval or young whitefish from Yamcolo Reservoir have been entrained into that ditch, made their way down Egeria Creek and into the Colorado. It makes sense to me because that population of whitefish seems to have its "nucleus" in the vicinity of McCoy.
     The original stocked whitefish around Glenwood came from the White River. If the above theory is true, we have White River whitefish downstream, and Yampa River whitefish upstream. We are not able to distinguish between the two genetically at this point, but it would be an interesting question to answer in the future. It would be a great subject for someone to do a masters' thesis on.
    I can't figure out how to post PDF's on this blog. But here is a link to the Wild Trout Symposium that has an interesting article about whitefish. It's a huge document. But check out the article that starts on page 106, entitled "Becoming Trash Fish", about how people's perceptions of whitefish have changed over the past century. It's interesting stuff.