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Posts: 1000
| Are there any tools out there for measuring dissolved oxygen? I'm looking at the Sugar Lake Muskie Assessment (July) and they show depths, temperature, and dissolved oxygen. It appears that dissolved oxygen dropped to almost nothing right after the thermocline. |
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Posts: 192
| you could take a water sample at multiple with an integrated water sampler
http://www.hoskin.ca/catalog/index.php?main_page=product_info&produ...
then do a winkler titration to measure Dissolved oxygen Or.....
You could use a Hydrolab Quanta (much more expensive but convenient)
http://www.hachhydromet.com/web/ott_hach.nsf/id/pa_quanta.html#
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Posts: 16632
Location: The desert | Yes.
YSI. |
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Posts: 2894
Location: Yahara River Chain | Pointer has it right. When working in the wastewater field I would use (as most WWTP would) a Yellow Springs Instrument aka YSI. You calibrate them by using elevation and temperature. This may be more intensive than what most folks would get into. There is also a proper way to change the membrane as well.
Just read the above "then do a winkler titration to measure Dissolved oxygen". Yikes, this is a big lab procedure that doing it right would need a stirring plate, chemicals, and buret (or at least from what I remember).
Edited by muskie! nut 2/8/2014 9:02 PM
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Location: Eastern Ontario | Does your depthfinder not tell you everything you need to know mine does?
Edited by horsehunter 2/9/2014 6:55 AM
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Location: Eastern Ontario | A few years ago Bass Pro Shop used to sell a oxygen monitor the fact that they no longer carry it tells me it wasn't a big seller. I don't want to target deep water fish ( below around 30 feet) . |
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Posts: 2894
Location: Yahara River Chain | tolle141 - 2/8/2014 5:01 PM
It appears that dissolved oxygen dropped to almost nothing right after the thermocline.
Really depends on the lake as well.
If this is true, how does lake trout live below the thermocline? |
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Posts: 1000
| Thanks for the info. The report said that dissolved oxygen dropped to almost nothing at 23 feet. I'm just wondering if there's something convenient that's not hundreds of dollars. If a lake has insufficient oxygen below say 15 feet, then it'd be nice to know. |
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Posts: 2894
Location: Yahara River Chain | If the lake has some fertility then it more than likely would not have much DO below the thermocline. As the O2 gets taken up by the decomposition of bio matter on the bottom and no way of introducing O2 (current or springs) once the lake stratifies, then its a good guess that the fish will be above the thermocline and more so later in the season (Jul thru turnover). Now you should be able to see the thermocline on any good sonar unit, if not you'd better learn how to tune one before the season begins. |
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Location: Eastern Ontario | How deep is the lake?
Is your depthsounder showing fish of any kind below 15 feet?
If the lake is shallow the wind should be rolling it over |
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Posts: 20218
Location: oswego, il | Yep it all depends on the lake. Take eagle lake in Canada. Excellent oxygen to the bottom of the trout holes even in summer. I have seen lakes in Illinois unable to.support life below 8ft during a hot summer. I know another lake that is over 90ft deep and only supports life in the top 15ft during a hot summer. |
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Posts: 1000
| It's a pretty deep lake ~60 feet I believe. Clarity is 13-16 feet in summer. Weedbeds go down to 20+ feet. |
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Location: Eastern Ontario | Weeds at 20 feet would be producing oxygen in the daytime |
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Posts: 59
| muskie nut nailed this one. Aerobic bacteria use oxygen when the break down algae, vegetation or other detritus. The lake will not mix through the thermocline, and if there is enough respiration below the thermocline there will not be enough oxygen to support fish. Every lake I have fished in Iowa is hypoxic below the thermocline in summer. I would venture to guess that most midwest lakes in large, agricultural watersheds would be the same. Iowa has temperature and oxygen profiles for most fishing lakes from different stages of the year. It sounds like you have something similar to look at.
The YSI probes are the easiest way to measure dissolved oxygen (there are other brands that make DO probes and a variety of combination units too) |
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