High Water and the Spawn

[Steve S.]

I fish the DuPage a lot, and water levels fluctuate abruptly with locally heavier rain. It doesn't take much to put her in flood stage. Don R. and I were discussing this on Saturday, so with rain in the forecast, I thought I'd put a few thoughts/questions out there.

 

1) Could extreme and continued flooding permanently postpone a spawning season?

 

2) Will bass try to spawn in flood waters if they have no choice?

 

3) Can newly laid eggs survive long enough to allow the river to return to normal pool? Do fluctuating temps kill the eggs, or are they washed away?

 

4) Will the males find their way back to the nests they were protecting?

 

5) Can newly hatched fry survive floods, and if so, how long? How likely are they to remain in the general vicinity of their nest? (Are they washing away down to somebody else's holes? )

 

6) At what point during their growth are they strong enough to survive the high water periods?

 

The Dupe is in need a gullywasher to cleanse some of that green moss out, though I guess it just breaks loose and never truly leaves. However, with the recent stable weather and spawn in process, I'd hate for the river to have a weak year class because of flooding.

 

Any thoughts???

[Guest rich mc]

i think the worst case would be having them spawn in high water and the level drops out leaving them high and dry. i believe they have a natural instinct to know where to nest. the second would be having dirty water making it harder for them to feed once they start feeding on their own.

i am just glad they dont all spawn at once, and do it in various areas to give some of them a better chance. rich

[Steve S.]

I saw nests last night that were vacated - possibly due to the lower water levels we're experiencing now on the Dupe. These beds were now in about 6" of water. Maybe they were rookie spawners?

[Bterrill]

I saw nests last night that were vacated - possibly due to the lower water levels we're experiencing now on the Dupe. These beds were now in about 6" of water. Maybe they were rookie spawners?

 

 

Sunfish

[jamie]

From what I've seen in the past week, they're already done in my area. Topwater baits are taking some rail-thin-spawned-out-ready-to-eat-again smallies. Seems to have been a good spawning season with a week or so of no rains to boost the water levels. Should be a good year class.

[Steve S.]

Jamie

 

Are the males around guarding nests still? They do guard the fry, don't they, or am I wrong?

 

The empty nests I saw were in the same areas I saw bass last week.

[Tim Smith]

Lots of good questions here.

 

These beds were now in about 6" of water. Maybe they were rookie spawners?

 

A good percentage of smallmouth males are rookie spawners because many of them don't survive the spawning process the first time through. In some places it has been shown that NONE of them survive.

 

Smallmouth do guard their fry for a short time. It is my understanding that largemouth (and probably spotted bass) differ from smallmouth in their fry guarding behaviors. This is from conversations with people who have studied smallmouth bass spawning, so pardon the lack of citations (yes, it's 2nd hand information).

 

Largemouth fry form a tight fry ball which the male followings. If the water rises, the largemouth fry head up the bank and into slack water and cover. Largemouth and spotted bass actually benefit from floods unless their nests are destroyed.

 

Smallmouth bass, in contrast, tend to guard a particular spot. When the floods come, the fry are on their own. Smallmouth bass reproductive success is negatively related to high spring floods.

 

As for the answers to your questions, Steve, I don't know most of those definitively but I'll tell you what I believe. There might be some studies out there I've missed. People should chime in if they have seen data on these things.

 

1) Yes. Males of most species will skip a spawn if they deem conditions unfavorable. No reason to believe smallmouth are different.

 

2) No. Bad conditions preclude spawning.

 

3) That depends. The size of a flood varies. The conditions around the nest vary. It is my impression that many smallmouth nests are positioned to avoid the worst of rising water conditions.

 

4) A nest abandonded for a prolonged period isn't likely to produce eggs. Depending on where the males are in the process, they may build a new nest and try again.

 

5&6) Fry can survive some floods if they have flow refuge. The sizes they can survive floods certainly varies. When they first hatch, they're still in a larval form, with a yolk and a very weakly swimming body. I assume nothing in that size class could survive any flood of substantial size. After yolk absorbtion at sizes considerably less than an inch, fish fry are pretty good swimmers. If they can get to refuge, fry shouldn't have any problems suriving a flood. This is one reason habitat is so important. Don't worry about fry getting washed down to someone else's section of river. Studies have shown that they come back to the spots where they were hatched.

[Steve S.]

Thanks Tim for chiming in. I've been keeping some mental notes of the smallies's behavioral patterns on a local stretch thoughout the seasons. It's interesting to note that I found one nest in what I believe to be precisely the same spot as last season. Next year we'll see if it happens again.

 

I presume that river bass have adjusted over the years to fluctuating conditions in order to ensure their survival. Last year, I imagined that it was a tough year for the spawn on the Dupe, since at times, the river seemed like it flooded every other week. When it is up and roaring, its hard to imagine anything surviving in the rage. I know all rivers flood, but the Dupe just seems more susceptible than others, and I wondered if because of this, its year classes are more negatively impacted than other rivers.