April 20, 2009
By Wayne Gustaveson
Lake Elevation: 3609                                           
Water Temp: 57-64 F

The long awaited bass spawn is here. The final spawning trigger is in place. Day length provides enough hours of light. The leak level is increasing. Finally, water temperature is spiking and will be in the 60s by the weekend. Early morning temperature on the day of the report was 57 degrees which is the minimum needed.

Jet Berry and BASS

Here is some bass spawning biology.  

A quick temperature rise from 57 to 64 is the trigger that makes it all happen. Males have longingly looked at potential nest sites all month but needed the temperature trigger before proceeding. This week bass are moving onto shallow flats. They prefer to start the nest at a water depth of 18-36 inches. The rising lake will make that nest progressively deeper but the nest starts out fairly shallow. Largemouth will nest at the base of a bush. Smallmouth will nest on plain rock. Crappie will nest in thick brush. All nests are made of small rocks that the male has cleaned by sweeping away sediment with its tail. Big males get first choice of the prime spots. Small males make due with what is left. When the nest is fanned and shaped, males leave the nest looking for a willing female. Females wait in deeper water just over the edge of the spawning flat or terrace. Spawning hormones are triggered by a quick temperature spike. Male advances that have previously been ignored are now accepted as the female returns to the nest site to spawn. The final courtship gesture is a quick jab in the side as the male strikes the female with its snout to start the eggs flowing so they can be fertilized. Spawning takes an hour or two. Sometimes more than one female is courted simultaneously. There is never more than one male.

Fertilized eggs are adhesive and stick to the rocks. With eggs on the nest, male bass set up camp and guard the nest ferociously. The day after spawning he chases everything, fish, bug, lure or shadow. It doesn't matter what it is. He chases it every time, no matter how close or how big.

On the second day he closes the circle a bit and chases only perceived threats that come within 10 feet. On the third day he chases only those things that actually threaten the nest. On the fourth day he watches and reacts only to real threats to the safety of the young.

Eggs hatch in 3-7 days depending on temperature. They swim about 3-5 days after hatching. Males guard swimming fry for a day or two. When tired of that he leaves them and returns to the nest site to start it all over again. That second nesting usually corresponds to warming after a slight cool down.

At Lake Powell the event is just starting. Most males will be spawning by Wednesday and be super aggressive on Thursday and Friday with moderate aggression continuing through the weekend.

This week will be particularly memorable because water in the main lake is crystal clear and the nests are shallow. All nests will be visible unit the lake starts to raise rapidly, the wind blows or water gets murky.  

Fishing this week will be superb. Good fishing will continue from now until the end of May. Striper and walleye fishing will be better in May. This week bass and crappie are in the forefront.