Monroe dissolved oxygen levels low??

Has anyone looked at the water quality report on Monroe??

Don't gamefish need minimum 5.0 dissolved oxygen levels?

Here is a link to the report http://www.lrl.usace.army.mil/wc/wq/mnrtext.html

[QUOTE=ThumpThump;307215]Has anyone looked at the water quality report on Monroe??

Don't gamefish need minimum 5.0 dissolved oxygen levels?

Here is a link to the report http://www.lrl.usace.army.mil/wc/wq/mnrtext.html[/QUOTE]

4-5 ppm is just a water quality guideline. Most fish can survive lower levels for various length durations. That said, I do believe some of the hybrid stripers got caught a bit and died. Don't think it was a big kill, but several were stressed from what I've heard. This reading is a result of thermocline dissolution and resultant mixing. It was taken about 2 weeks ago and I could almost guarantee would look completely different if taken today. The next one posted (if they update again) should have much higher oxygen levels and will also probably have a uniform temeprature profile from top to bottom, and be much cooler than the 70 degrees in this one.

Actually 5 ppm DO will be enough for fish to survive and even reproduce.
8 to 10 ppm DO would be much better. When you get below 3 or 4 ppm DO you are getting into low DO levels for most sport fish like Largemouth bass and or strippers. Look where there is a sharp drop of DO levels.

And one thing to remember is that the DO sampling equipment has to be maintained to make it's readings accurate and reproducible. Most agencies are using YSI type DO meters and Probes. These work with a semipermeable membrane and a anode and cathode made out of silver and gold. It's easy to contaminate the probe and make them malfunction. Unless you calibrate the probe frequently and maintain the probe you may be getting false readings.

The oxygen drop should correspond with the drop in temperatures at the Thermocline in the lake. They should be related.

Just think of humans. Those of us that live at sea level have about 23 percent oxygen in the air we breath. But those humans who live at altitude may only be breathing in air with 20% or even 19% oxygen.

Those humans that live at high altitude compensate for the low oxygen levels by having more red blood cells or red blood cells that are more efficient at holding oxygen.

Dissolved oxygen is not the only thing that the fish require. They need a good water quality and little or no pollution. The amount of Carbon Dioxide also effects the fish because the amount of CO2 in the water directly affects the pH of the water. High amounts of CO2 in pure water can increase the acidity of the water in seconds. However most water is buffered with other dissolved minerals, Carbonates, which react with the additional Carbonic Acid and neutralize this acid. The helps keep the water's pH at a stable level.

Now when you get down to a < 4.0 ppm DO the fish will have a harder time surviving. Remember that oxgyen dissolved though the gills by partical pressure and oxmosis. The oxygen in the water must be higher than the amount of oxygen in the fish's blood for this to work.

There are chemoclines in the water also. If you could divide any lake into small sections by longitude and latitude and then subdivide those columns of water into various depths and then take a sample of water at each small cub of water you could develop a map of the different levels of various chemical in the lake at that time.

The ecosystem of any lake is constantly changing with the varying amounts of sunlight on a diurnal (day/night) basis and though each month and year. The sun drives most all life processes on this earth.

One of the most limiting nutrients is phosphate. Most phospate in a body of water is tied up in the plant and animal life. There is very little free phosphate in most lakes. And any phosphate that's added to the water is quickly used up. Phospate is released back into the environment when the plant life dies and then decomposes. But bacteria in the lake ooze take up that phospate quickly.

Phosphate is necessary for a body to move. There is an energy cycle in animals that is used to move the mucles. ATP is converted to ADP in this cycle. I don't remember the exact chemical reaction now. I had to memorize that entire reation series for my Biology 101 class at Purdue many years ago but I have long forgotten that. But I do remember that phospate is the key element in the reaction.

My dad use to get phospate rock for his garden. For years he would add bags of Phospate rock to the soil. After thirty years that soil is some of the richest soil in the county. LOL

Phospate is what Ecologist and Limnologist call a "limiting nutrient". It's as important to the ecosystem as the foundations and roofs are to a building.

Indiana passes laws in the 1970s which took phosphate out of laundry detergents. Too much phosphate in a lake can cause too much algae to grow. This leads to speeding up the process of eutrophication.

You can still get phospate rock in bags at the Farm Stores. And TPS cleaner has a lot of phospate in it. It's used to clean hard to clean stuff.

Phospate in detergents makes a great cleaning agent.

Want to start up the food chain in a certain spot in your lake? Drop a bag of phospate rock on that spot. Ever wonder why rock piles attract fish? LOL. Chemicals are being given off by those rocks. Chemcials that the algae like to feed upon. And that in turn attracts the minnows and then the big fish.

Too much phosphate can lead to an overgrowth of algae. When that Algae dies in the fall of the year it's eaten by bacteria. If this occures below a thermocline in a eutrophic type lake where there is little DO in the lake bottom, hypolimnion you can really deplete the DO Levels near the lake bottom. Then anerobic type bacteria continue eating the dead algae and produce Hydrogen Sulfide Gas. H2S. H2S is very deadly to fish and humans. Not until later in the year when the surface water's cool enough for the lake to turn over will the bottom of this TYPE OF LAKE be available to the fish. Remember that Canadian Shield type lakes, Oligotrphic, don't have this problem because they are not very fertile and don't have a lot of algae growth or bottom material for bacteria to feed upon.

Also lakes that get a lot of wind can keep a lake unstable and prevent a thermocline from developing. High winds can create underwater instability and currents that run counter to the wind direction.

Each lake is different. That's why it pays to learn your lake.

[quote=ThumpThump;307215]Has anyone looked at the water quality report on Monroe??

Don't gamefish need minimum 5.0 dissolved oxygen levels?

Here is a link to the report http://www.lrl.usace.army.mil/wc/wq/mnrtext.html[/quote]