Dissolved Oxygen Requirements For Bass

[flipin4bass]

This is a good read...

http://www.fondriest.com/environmental-measurements/parameters/water-quality/dissolved-oxygen/#2

[J Francho]

Good read! Let's hear your take away from that. How did you apply it to bass fishing? I'll comment in a bit.

[Mr_Scrogg]

My head hurts.....

[Sam]

Flippin, did you ask a difficult question or what?

 

Seems to be an easy query to satisfy, but it is not.

 

I went to my bible of bass biology, Keith Jones book, Knowing Bass, The Scientific Approach to Catching More Fish, and I wish I could boil down what the research director at Pure Fishing wrote about oxygen and bass.  But I can't as I have not invested the time to read, outline and try to understand what Keith has written about his research.

 

I can give you one of his charts where he includes the Total and Preferred Range of Oxygen but I don't understand what how we figure "parts per million" using our current tools at our disposal.

 

Here is what Keith pens in his book on page 196:

Environmental Factor   Total Range    Preferred Range

Oxygen                            1.5 - 24 ppm    Greater than 5 ppm

 

Until I or another reader has the time to add their two cents via Keith's research this all I can add to the conversation.

 

I believe some sonar units can give you the oxygen ppm's under your boat.  However, my Lowarance units cannot do this so I will need to purchase a special oxygen ppm device to obtain the oxygen ppm's while fishing.

 

Just food for thought.

[scaleface]

For what its  worth. I had a light temperature probe. On Mark Twain lake the light and temp always plummeted where the depth finder showed a thermocline. I quit using it  . It seemed light , temp and O2 were always connected .Other lakes may be different .

[Sam]

Scale, Dr. Jones mentions water temperature and oxygen working together.

 

So you are correct with your information.

[RoLo]

Bass prefer DO levels of 5 ppm or more, that's always been the accepted benchmark (mg/L = parts per million).

The old timers will recall when we went through an era during the 1970s,

when every devout angler would tote an oxygen meter to the lake.

That in fact was overkill, and the oxygen meter craze eventually fizzled out.

 

Below 3 ppm dissolved oxygen, bass do become stressed and will relocate if possible.

Dissolved oxygen levels below 2 mg/L are deemed lethal, and generally result in a fishkill

 

Roger

[shanksmare]

What about the dissolved oxygen requirements for larger bass? I remember fishing in club tournaments in the 1970's when most of the time larger bass would die in the livewells. The smaller 2 or 3 lbers would be fine but the larger ones often died.

[Paul Roberts]

This is a good read...

http://www.fondriest.com/environmental-measurements/parameters/water-quality/dissolved-oxygen/#2

Yes, that is a good intro to oxygen in aquatic systems. Oxygen in many bass waters varies a lot more than most anglers seem to be aware of. It certainly surprised me and I didn't pay much heed to it, beyond the basics, for some time.

 

While the variability in DO in many waters may be news to many anglers, it's not news to the bass, they having evolved to handle variable and often quite low oxygen levels. On the whole most bass waters, the majority of the time, have ample DO. Critical seasonal times tend to be winter (in the north) and mid-summer. The broad range given by Keith Jones is correct but doesn't help much in our fishing. At 1.5ppm water is nearly anoxic and at 24ppm it is supersaturated with oxygen -both conditions can and do occur in our bass waters -sometimes in the same water body over the course of the season. 24hr changes can be quite drastic too. Although bass can survive across a broad range of DO, they may not be terribly happy in certain places and times and it undoubtedly affects their location, position, and/or their willingness to bite. The idea of a "preferred" concentration for bass appears to have little support, beyond saying they do best above 5ppm.

 

Some studies have shown bass will move out of nearly anoxic areas (~2ppm being the most frequently cited number) while other studies have shown bass not moving out but becoming inactive. Some populations are known to move/migrate to better DO conditions but many do not. It appears that populations that survive regular anoxia have developed the necessary survival behaviors over time and not as a short term decision –indicating that some bass populations may not have an inherent protocol in place to back up low DO alarm bells. This is a concern for managers because the potential for rapid DO depletion increases with human development (from fertility and siltation during runoff events) and DO depletion has been a cause of population extinctions before we got wise to curbing such pollution.

 

There's a fair amount known about oxygen in freshwater systems, the effects on bass in laboratory settings, and even some in natural/wild settings. But knowing when it's happening to your fish requires educated guessing. Knowing the possibilities is certainly helpful. The intro provided by flipn4bass is a good but very preliminary beginning