Pond Boss Forums Thread Like Summary - Reducing fish biomass

A customer needed to reduce some of the fish biomass in his 1/2 acre pond. We will do the same thing within 7-10 days. It was a marathon fish cleaning session as he hasn't cleaned any fish in a long time and was trying to re-learn how to do it. Dull knives, small fish cleaning space, etc. all made for a 4+ hour cleaning session. That and I was trying to teach him how to fillet all over again. He was getting the hang of it by the time we finished, and he's got a Bubba Fillet Knife on order. That will be here tomorrow.

We caught (in the span of 2 1/2 hours) the following:

12 Yellow Perch, all between 12.5" and 13.25" in length, from 1# to 1.35#
8 LMB One 1 1/4#, all the rest between 4# and 4.2#, all were 18"-19" long
35 HBG, all between 9.25"-10.25", and between 1# - 1.2#
2 HSB both right at 4# and IIRC 21" or so.

All fish were caught on a redworm or a 1/64th oz pink jig head and a wax worm. All 2.5'-3' below the surface.
Cooler 1


Cooler 2


Cooler 3


HBG


HBG Wt


HSB


HBG


YP1


YP2


YP Wt

Well you had to say definitively, LOL. I am more or less like the BOW owner, I prefer fish caught in cool water. The flesh seems firmer and there are not so many odd smells like the when the water is warm enough to take a bath in. LOL. There doesn't seem to be as much in guts as they are eating less or less frequently. I like to fish throughout the year but most of the fish I keep are from October through April.

I think it has a LOT to do with how the fish is handled after the catch.. Iced water in livewell? Fish on a stringer setting in shallow warmer water maybe.
I pour a bag of ice into cooler with fish on way home, meat stays firm.

There is very little production in the pond from the stocked fish - the bottom is clay and the sides are VERY steep - steep enough that the fish can't make beds.

He feeds the fish daily and he adds Fatheads & Golden Shiners in the Spring and Fall. Like I said earlier, he keeps close track of water quality and has the ability to add water from a well to flush out excess nutrients. He has a Vertex Bottom Diffusion aeration system plus a Volcano type surface agitator that he runs when the water temps are 70°F and above so the O2 stays high. He doesn't add Tilapia but he does use a peroxide based algaecide. When the algae floats he kills it then turns on the water and flushes it out of the pond before it sinks and decomposes.

Water clarity stays 18"-24" most of the year due to a number of 24"+ koi in the pond.

Since FA first grows on the bottom, if sunlight penetration is limited due to a phytoplankton bloom or dye, then in a pond with very steep sides, there won't be much substrate that it can grow on. Phytoplankton could be a much worse problem in such a pond, but in this pond, the owner uses a peroxide based algaecide, then turns on the water to flush out the dying algae from the pond - helping to mitigate nutrient loading on the pond.

In this pond, the owner knows that harvest is an integral part of pond management, but knowing and doing are two different things. So, me going there to harvest got him out there harvesting too, and me being there also helped him to remember how to fillet fish. He was having a problem with that (I believe) and that was part of his reluctance to harvest fish. Why harvest when you can't clean them? I showed him some different ways to do it, and he ordered some tools to help him fillet easier than what he was attempting prior. He says that the fish from cool water taste better than fish from warm water, so the main harvesting time is now and late Fall. Winter typically would be a great time to harvest the fish through the ice, but we only had a 1 week window this year where there was safe ice.

The pond owner used to grow Koi, and he has a large live rock saltwater aquarium in the house that he maintains himself, so he is aware of water quality issues and how that will impact the fish in the pond.

He has Walleye in the pond too, and since we saw a white grub on one of the HBG, AND he's never caught a RES out of the pond even though we've stocked 700 RES between 2.5" and 6" over the past 4 years, we are going to put in another 500 of the biggest ones I can source this year. Hopefully the WAE don't eat them all. He caught a WAE that was either 22" or 27" (I cant remember) last Fall and returned it to the pond.

Talk to Bill Cody. There are warmer water algae that will impart an "off" flavor to fish.

I believe whatever the fish are eating that time of year has the greatest effect on taste, certainly how the fish dies & is kept afterwards. Immediate icing best & certainly can't hurt nor:

https://en.wikipedia.org/wiki/Ikejime

Somewhere on the Web I watched a video of a women who enjoyed raw fish. She noticed the difference in taste & texture between Ikejima & a normal slow death of a fish. It is easy to learn to do & a modern ikejima device can be found on eBay.

One of my buddies in med school did a research project where he had to pith the fish and then take the samples immediately after the fish died. It was the same method.

He was a VERY precise guy, and is now an eye surgeon, so I suspect he got it exactly right every time.

I suspect I might miss every now and then, but I believe it is considered one on the most humane methods to euthanize research animals. Like our "taste" experiment, you typically don't want stress chemicals in your research animal tissues.