California is experiencing one of its coldest springs in recent memory and the effect on fishermen has been both despair and confusion.
This past week I received a number of phone calls from fishermen wondering if they should make the long drive to Clear Lake to fish. They”re all concerned about the windy conditions and cold temperatures and what that will do to the fishing.
If you think the fishermen are confused with the cold and windy weather we”re experiencing, how about the bass? One day they move onto the spawning beds and then a blast of cold weather hits and they move off. This could go down as one of the latest spawning periods for bass in years.
According to fishery biologists, water temperature and length of day are what determines the spawning cycle for largemouth bass. During the spring months when the water temperature reaches 60 degrees, the male bass selects a location and fans an area about the size of a dinner plate with his tail. When the water warms up to 62 degrees or more, the females start to stage near the spawning beds. The actual spawning occurs when the water temperature reaches about 65 degrees and the height of the spawn occurs when the temperature reaches between 68-70 degrees.
Water temperature determines how long the eggs take to hatch. When it is less than 65 degrees it can take as long as 12 days for the eggs to hatch. However, if the water temperature rises to 70 degrees, the eggs will hatch in two or three days. This is important because the longer the eggs take to hatch the more vulnerable they are to predation from other fish or crayfish. Bluegill and other fish constantly try to devour the eggs. The longer the eggs take to hatch the more will be devoured by other fish.
If the water temperature never warms up to 65 degrees, most of the females will still spawn although the success of the spawn is diminished. This often occurs in northern states.
So far this year there have been very few days when the water temperature has even reached 60 degrees at Clear Lake ? most of the time it has been hovering around 55-58 degrees.
During cold springs, such as we are experiencing this year, the survival rate for the young bass is much lower than in warm months. Even under optimum conditions less than 1 percent of the spawned bass will survive. A typical nest will see approximately 2,000 eggs actually hatch but fewer than 20 fingerlings will survive to 10 inches.
Young bass feed on their yolk sack and plankton for the first week of their lives. Within two weeks they start to feed on insect larva and other small aquatic creatures. By October the young bass are normally between 2-3 inches in length and feeding heavily on small minnows or even other young bass. Like most predator fish they are cannibalistic and think nothing of gulping down a brother or a sister. In fact, stomach analyses of bass have shown that up to 10 percent of the contents are comprised of young-of-the-year bass.
The later in the year the bass spawn also impacts the overall population. If they spawn too late the young bass go into the winter with little body fat and have a lower survival rate.
It”s not only the bass that delay spawning when the water is cold. Channel catfish require a water temperature between 70 and 85 degrees to spawn. The optimum for spawning success is 75 degrees. Catfish are well into their spawning cycle by the first of May most springs at Clear Lake. However, this year that could be delayed until well into June.
Other fish such as bluegill and crappie also require warm water to spawn. So far this year that just hasn”t happened. In fact, the water at Clear Lake is considerably colder than at nearby lakes. For example, the water temperature at Lake Berryessa has been averaging from 60-65 degrees, at least 5 degrees warmer than Clear Lake. One reason the water is colder at Clear Lake is because of the lake”s higher altitude. The lake is at 1,328 feet, which means the nights are much colder than at the lower-elevation lakes.
The one thing we can count on is that when the water temperature does finally rise to 70 degrees there should be bass by the hundreds moving into the shallow water to spawn.
