Pond Boss
Posted By: george Fish Mortality - 03/31/07 11:50 AM
Do I recall a discussion at the PB Conference, a couple of the top fishery biologists in the country discussing natural mortality of fish in streams and reservoirs?

Do I recall correctly, their conclusion that mortality from natural causes, as well as from catch and release, ~ 30% mortality numbers being tossed about?

If so, why do get overly concerned with finding a dead fish in our ponds?
Posted By: Theo Gallus Re: Fish Mortality - 03/31/07 12:13 PM
'Cause we're all such nice people? :rolleyes:

It is something you get inured to, over time. The first time I found a small (2"-3", probably) dead BG I was mortified, but now, who cares. But different sizes and species, at least for me, are each their own category that I will have to get used to. If I found a dead BG like that beautiful floater Cecil just had, I'd cry. (OTOH the dead cow I had last month, once the cause of death was known, was just lost money and 1700 lbs of nuisance - rather large to put in a shoebox and bury in the back yard.)

You didn't figure out that pure O2 resuscitation system for HSB because you're callous, did you, george? ;\)
Posted By: ewest Re: Fish Mortality - 03/31/07 12:31 PM
George you are right and it has been discussed here as well. Depending on the species it can be very high. For example FH life cycle 1-2 years (means they have to recruit or be replaced every year +- or they will be gone from natural morts even without predation). Often people fail to take in to account natural morts. in population analysis which is a serious mistake. It is important to distinguish between the static concept of standing crop ( a picture of fish #s at a fixed point in time) and the dynamic concept of life cycle (recruitment , growth , reproduction and death). I hope that is not to Long-Haired. \:D An easy way to think about it is that for every 70,000 BG born ( the appx. # of eggs of a BG pair in one year) only a few will reach adult stage and successfully reproduce and replace their parents. Yet that is way more than enough to over-populate and stunt unless there is extensive predation. Its all about understanding the nature of the fish and their balance and natural morts is a big part of the equation.

To answer your question - Most people do because they want to be sure something (sick fish)is not going to greatly increase the rate of natural morts.
Posted By: george Re: Fish Mortality - 03/31/07 06:45 PM
 Quote:
Originally posted by Theo Gallus:
'Cause we're all such nice people? :rolleyes:
You didn't figure out that pure O2 resuscitation system for HSB because you're callous, did you, george? ;\)
I'd give mouth to mouth resucitation to save my HSB... \:D
Seriously, I have not a lost a single HSB that I am aware of, other than stockers.
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