Pond Boss Forums STOCKING A NEW POND Types of fish to choose Cage Culture Experiment with HSB

Bill and Others:

I would like to experiment with my first cage culture. The cage I will be building will measure approx 8'L x4'W x 4'H totalling some 128 cubic feet and be secured by my dock in a 19 acre gravel pit lake. The fish of choose will be Hybrid Stripped Bass (HSB)this time bought as fingerling in the 2-3" range this spring when available...hopefully in May, grown thru out the summer and released into the established lake in the fall with LMB/BG/YP/and pumpkinseed at some 6-8" in length. My goal is to purchase 500 of these HSB and put into the cage. The stocking density will be approx. 3.9 fish per cu/ft...or approx. half the "crowded high density" of 8/12 fish cu/ft. My first question is do HSB require high densities for stocking in a confined area or not? Is 3.9 fish per cu/ft to low.., promoting cannibalism, etc? Second, what brand and type of food and protein content will work best for this intensive seasonal growout with daily hand feedings of HSB? Thirdly, Bill can you explain how you overwintered your HSB in our cold climate and thick ice...did you feed at all...did you sink your cage below the ice or use an aeration system to move water around to help keep the water open thru out the winter and super chilling that same water? Thanks for now....and looking forward to the knowledge of others who have succeeded in their past cage cultures.

Rowly

Rowly - Your finished cage will probably have about 108 cuft of usable water space due to floatation and free board height of cage.

Literature recomendations are to stock before water temps of 70F.

Literature from North Central Aquaculture (NCA) says that research studies had problems with survival of HSB in alkalinities below 50 mg/L (ppm). Another study said that HSB were raised in Virginia in water with hardness less than 20 ppm BUT fish were NOT handled until harvest. NCA also recommended that stocking size should be minimum of 4" and best if they were 8". But this may be due to expected harvest size of 12"+ by summer end. Reason was not explained.

Paper in World Mariculture Soc (Estaurine Cage Culture of HSB contined:
1. Stocked densities ranged from 1.4, 2.8,4.2, to 5.6 fish per cuft. Fish at lowest density grew slightly better than others but not significantly better.
2. Fish tolerated temps in January down to 32.9F (0.5C) with no mortality.

3. Protein of feed seems to give best growth of HSB at 41%-45%. Trout and salmon diets are good to use. 8%-12% fat best; 16% fat okay.

4. Growth gets going at 64 and better growth is around 70F-74F and best growth is at 78-80F.

5. High densities not required for good survival.

6. Smaller fish (less than 7") seem to be more canibalistic. Not sure about this though. Try not to have a large size variation of stocked fish. Maybe Cull the smallest ones in the ones you buy if necessary. Maybe put culls/runts in a small cage, size of barrel for summer growout.

7. Overwintering. It may be best to sort fish and relese the largest ones before winter when water temps are about 52-58F. Slightly lower densities during winter may reduce stress on fish.

Cecil sinks his cages in I think about 6ft-8ft deep water; I do not. If your ice does not get thicker than 12" to 15" you should not have a problem by just letting the cage freeze into ice near dock. My fish have survived ice cover of 12"-14". This winter I measured my water temp in t bottom on the cage froze into the ice. Cage was 3.5 into the water. Ice almost covered cage with little height exposed; mostly just lid/top and a little of the float. Water temp just under ice was 32.4F and on cage bottom temp was 38.6F. I have found that caged fish can easily tolerate our winters in a cage if they are fat going into winter. Try feding a little bit as soon as ice goes off the cage and it is a nice sunny day. Keep feed amounts low until water gets 46 - 50F.

BE sure there is about a least 6"-12" of water below the cage bottom. When growing the fish in summer it is best to have at least 2 ft of water below cage bottom.

Did I get all your questions so far?

Bill:

Ditto, perfect answers as always. I think I have a good understanding and looking forward to my first cage culture experiment as I have been reading much over the last couple of years. Next week I will be getting 250 4-6" walleye that were overwintered in indoor tanks a little above freezing. The owner tells me that these walleye are added to lakes/ponds thru the ice and will eat and grow nicely before the LMB become active. He states this approach is as good or better than adding the 6-8" fall walleye into a lake when the LMB are still somewhat active in eating? What's your take on this method and survival rates???? This could be very expensive food for the LMB, if it doesn't work. Thanks

Rowly