any soft crab mortality this week in flow through systems?

[e_schott]

With the widespread low oxygen levels in the upper bay, has anyone had big die offs of crabs in their flow through systems?
I took a reading of essentially ZERO oxygen in a creek near me on the weekend.
You can reply to me directly if you don't feel like telling the whole world about it.
I will retain information for research only and will not put it out without specific notification of respondents.
The information would carry just geographic location, not crabber or address info.
-Eric Schott
Univ of MD Center for Environmental Science
Institute of Marine and Environmental Technology
Baltimore
schott@umces.edu

[ChrisS]

Eric,
Wouldn't the system itself provide some oxygen, even in depleated water?

[jack1747]

Eric,
Wouldn't the system itself provide some oxygen, even in depleated water?

I was thinking about that yesterday while working the floats.  I have a Mag Drive pump running temporarily and the discharge hose is just laying in the tank instead of going thru the spray head.  Was quite a bit of surface action so I think that would be ok.

[ESchott]

Both correct that the system can provide some oxygen, but in some cases there just may not be enough air mixed with the water to get O2 levels up to where the crabs need it.
I took a reading in a nearby creek that gave me a reading of almost zero oxygen.
It only climbed to about 1/3 of the oxygen level needed to sustain life in the shedding tank, even though it was sprayed from a 2 inch line above the tank.
Obviously the proof is in the results: if your crabbies are not dying, then the water's OK.
Anyway, glad to hear that things may be OK elsewhere. 
Oh, one last thought. Oxygen levels may be worse at night or early morning, because the algae in the water are not producing oxygen at overnight.

[ChrisS]

Eric,
I didnt say things were alright here, infact is a darn shame when you have crabs climbing out of the water to breathe!

Hope you guys are doing something about it!

[e_schott]

It IS a shame. I am also hearing about crabbers pulling up pots with dead crabs in them as a result of dead zone water moving into the area after they were trapped. 
As you could guess, the solution is difficult, because the cause is so vast. Too many nutrients from a lot of sources. That's not saying it's impossible to fix, but it will take a lot of cooperation in a lot of places.
To get a look at the scale of the dead zones in near real time, see DNR's website on bay conditions.
http://mddnr.chesapeakebay.net/eyesonthebay/currentconditions.cfm

[ChrisS]

We all know what the cause is, politicians tell the news to say its from lawn fertilizers and farm run off, and the 2.6 billion gallons of raw sewage getting dumped in the river every other week is of no harm at all.

Every time there's a sewage spill, someone should be getting sued!!

[ChrisS]

I tell ya, what this place needs is Erin Brockovich, with all the industries pumping high toxins into our air and water, rivers and creeks so dirty and contaminated fish can't even live, if the water gets into an open sore, you'll likely lose that finger. Cancer rates among the highest in the nation.

[jack1747]

I was thinking about that yesterday while working the floats.  I have a Mag Drive pump running temporarily and the discharge hose is just laying in the tank instead of going thru the spray head.  Was quite a bit of surface action so I think that would be ok.

Guess I was wrong.... All my peelers were dead yesterday.   There also was a perch floating belly up gasping for air I guess.

[e_schott]

Sorry to hear that and I hope it does not happen again.
Did you have bad smelling water in the creek?  When the oxygen gets really low and the water gets mixed up from the bottom you can get sulfur compounds that would be toxic. You would smell that.
Send me a message offline if you'd be willing to discuss more about the water or system.

[genecrabman]

Guess I was wrong.... All my peelers were dead yesterday.   There also was a perch floating belly up gasping for air I guess.

Crank the water up...........More water flow on hot dayz is cooler water..............And only put 300 peelers in the tank...    Also the longer the "DROP" of the water the more oxygen it will create...My Water drops about 18"....

[Double-D Crabber]

my lil mating pair is residing nicely in a/c

[Dreampixels]

my lil mating pair is residing nicely in a/c

Now the Dickens ya say........................................... I see you fish also

[jack1747]

Crank the water up...........More water flow on hot dayz is cooler water..............And only put 300 peelers in the tank...    Also the longer the "DROP" of the water the more oxygen it will create...My Water drops about 18"....

I turned the sump pump on...   Thanks