10-05-2023, 12:41 AM
(This post was last modified: 10-05-2023, 12:46 AM by wiperhunter2.)
I emailed Alan Ward, the biologist at Strawberry with some questions about the kokes there, below is his answers:
"It is definitely a poor year for kokanee at Strawberry this year. Not the worst we have seen, but still below average. However, it is not unusual to see dramatic fluctuations in kokanee populations from year-to-year, and this is true for most kokanee waters, not just Strawberry. One of the big reasons for these dramatic ups and downs is that you are basically relying on only one age class of fish. The majority of our spawning fish (and the fish that people catch during the previous summer) are age 3 fish, and then they all die that fall. Therefore, if you have one poor age class for whatever reason, you will often have a poor fishing season and subsequent spawning when they turn three years old. Then you start all over with a new group of fish the following year. Because of this, you will often see the dramatic fluctuations perpetuate through time, as one poor age class will often lead to another poor age class three years later, and a strong age class will hopefully produce recurring strong age classes every three years. However, just when you think you have these cycles with kokanee figured out, it all changes for some unknown reason(s), and you are left scratching your head. Every manager I have spoken with in the surrounding states mentions the same thing, that kokanee are a difficult species to predict.
As far as the spawning this year, it is unlikely that we will meet our statewide quotas with our current run at Strawberry. However, Flaming Gorge still has some fish coming in, and they will also be taking eggs from the late run kokanee into November. Therefore, we do not have the final tally as of yet. We are also looking into the possibility of acquiring some eggs from other states. However, it is interesting to note that many of our surrounding states are also seeing poor kokanee runs this year as well. Personally, I attribute a large portion of the blame for the poor run at Strawberry on the extreme drought conditions that we saw three years ago. Many of our streams here at Strawberry were too dry in 2020, and natural reproduction was severely limited due to the dry conditions.
Hope this information helps. Take care
Alan Ward"
I ask Alan some additional questions, here is his response:
"Fishing pressure does have an impact, but from the perspective of Strawberry, it is typically not a huge proportion of the population. Many of our kokanee are not ever caught by anglers. Kokanee strike out of aggression, and not all kokanee care to even strike a lure. Just watch some of the videos out there with cameras on lures being trolled. There are many of these kokanee that just do not care if a pink squid goes by. They simply do not attack it for food. From past data, we estimate that on the best years anglers may only harvest about 20-25% of the kokanee out there. So there is an impact, but not as much as we see with other species (80% of our rainbows are harvested in the first year after stocking). I cannot speak for the Gorge, but we typically see about 45 - 50% of our kokanee population come from natural reproduction. I know that Flaming Gorge had some USU studies from back in the 1990's where they documented considerable reproduction from in-reservoir spawning. We have not been able to do any similar research for Strawberry yet. We have attempted microchemistry work to determine natal origins, but the elemental indicators were not distinct enough among sources around the reservoir. Therefore, we are unable to determine exactly where our reproduction comes from, we just know how much we get since we do mark all of our hatchery stocks. We do see spawning congregations that stay in the reservoir, but have not been able to document their success. The type of kokanee (early or late run) does not necessarily mean that they will spawn in a lake or in streams. Both types of kokanee will spawn in streams and in the reservoir. Hope that helps"
"It is definitely a poor year for kokanee at Strawberry this year. Not the worst we have seen, but still below average. However, it is not unusual to see dramatic fluctuations in kokanee populations from year-to-year, and this is true for most kokanee waters, not just Strawberry. One of the big reasons for these dramatic ups and downs is that you are basically relying on only one age class of fish. The majority of our spawning fish (and the fish that people catch during the previous summer) are age 3 fish, and then they all die that fall. Therefore, if you have one poor age class for whatever reason, you will often have a poor fishing season and subsequent spawning when they turn three years old. Then you start all over with a new group of fish the following year. Because of this, you will often see the dramatic fluctuations perpetuate through time, as one poor age class will often lead to another poor age class three years later, and a strong age class will hopefully produce recurring strong age classes every three years. However, just when you think you have these cycles with kokanee figured out, it all changes for some unknown reason(s), and you are left scratching your head. Every manager I have spoken with in the surrounding states mentions the same thing, that kokanee are a difficult species to predict.
As far as the spawning this year, it is unlikely that we will meet our statewide quotas with our current run at Strawberry. However, Flaming Gorge still has some fish coming in, and they will also be taking eggs from the late run kokanee into November. Therefore, we do not have the final tally as of yet. We are also looking into the possibility of acquiring some eggs from other states. However, it is interesting to note that many of our surrounding states are also seeing poor kokanee runs this year as well. Personally, I attribute a large portion of the blame for the poor run at Strawberry on the extreme drought conditions that we saw three years ago. Many of our streams here at Strawberry were too dry in 2020, and natural reproduction was severely limited due to the dry conditions.
Hope this information helps. Take care
Alan Ward"
I ask Alan some additional questions, here is his response:
"Fishing pressure does have an impact, but from the perspective of Strawberry, it is typically not a huge proportion of the population. Many of our kokanee are not ever caught by anglers. Kokanee strike out of aggression, and not all kokanee care to even strike a lure. Just watch some of the videos out there with cameras on lures being trolled. There are many of these kokanee that just do not care if a pink squid goes by. They simply do not attack it for food. From past data, we estimate that on the best years anglers may only harvest about 20-25% of the kokanee out there. So there is an impact, but not as much as we see with other species (80% of our rainbows are harvested in the first year after stocking). I cannot speak for the Gorge, but we typically see about 45 - 50% of our kokanee population come from natural reproduction. I know that Flaming Gorge had some USU studies from back in the 1990's where they documented considerable reproduction from in-reservoir spawning. We have not been able to do any similar research for Strawberry yet. We have attempted microchemistry work to determine natal origins, but the elemental indicators were not distinct enough among sources around the reservoir. Therefore, we are unable to determine exactly where our reproduction comes from, we just know how much we get since we do mark all of our hatchery stocks. We do see spawning congregations that stay in the reservoir, but have not been able to document their success. The type of kokanee (early or late run) does not necessarily mean that they will spawn in a lake or in streams. Both types of kokanee will spawn in streams and in the reservoir. Hope that helps"
![[Image: 20231007-130217.jpg]](https://i.postimg.cc/18NfxwZ4/20231007-130217.jpg)
