| Lake turnover is an interesting phenomenon | | | | In both cases "the turnover", combined with wind, |
| typical of most lakes that experience winter | | | | is natures way of re-oxygenating the water. Both |
| ice-over conditions. The best fly fishing lakes in | | | | winter and summer seasons induce layering of |
| the Kamloops area are no exception. | | | | water creating temperature bands (called |
| There are two times during the year that small | | | | thermocline). This lack of oxygen can be |
| lakes experience "turnover", in the spring and in | | | | determinant to fish and in many cases causes |
| the fall. In most cases, it's the spring turnover | | | | winter kill or summer kill of the fish. The mixing of |
| that is of most interest to the fly fishermen who | | | | the water created by the turnover and those |
| are dying to get going with their season. | | | | welcomed spring and fall winds, re-oxygenate the |
| So what is Lake Turnover? | | | | water to healthy levels critical to fish survival. |
| Lake turnover usually occurs 1-2 weeks after the | | | | Turnover is quite an event for the body of water |
| ice comes off the lake in the spring. The sun | | | | in which it occurs. It stirs up the lake bottom |
| melts the ice and warms the surface water until it | | | | creating floating decayed vegetative debris and |
| eventually reaches it's most dense state st 4C | | | | drastically increases the turbidity of the water. |
| (39F). This most dense or heavier water now | | | | Oxygen levels decrease for a short period and |
| follows the laws of physics and wants to sink to | | | | the fish usually turn off from feeding. This event |
| the bottom. As it begins to sink it displaces the | | | | usually last from 1-2 weeks, depending on the |
| less dense water below causing a complete | | | | wind. When the turn is done, the oxygen levels |
| flip-flop of the water column in the lake. | | | | rise quickly and the fish, god bless them, get |
| In the fall, lake turnover occurs before a lake | | | | hungry and start to feed again. |
| freezes over. The air cools the upper layer until it | | | | So, if you come across a lake in the spring that |
| reaches it's most dense state and then drops to | | | | looks dirty and full of debris, take note and get |
| the bottom. The lake then continues to lose heat | | | | the heck out of there because you will most likely |
| and as the temperature dictates, the lake finally | | | | be wasting your time. Go back there in a couple |
| freezes over. | | | | of weeks and you may enjoy some of the best |
| Why is this of concern? | | | | fishing of the season. |