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by Cecil Baird1 |
Cecil Baird1 |
This is from Jim Held a respected researcher in aquaculture. I received this via a yellow perch list serve I am on. I don't completely agree with his comments on yellow perch but he does knows more about aquaculture than I will ever know.
Folks,
It's been a while since we've considered the potential of walleye and hybrid walleye (sauger x walleye) for commercial culture. Many of you receiving this e-mail were involved in the NCRAC and SeaGrant studies back in the 90's, so I thought I would update you on some recent work. In a small study over the past year, the Northern Aquaculture Demonstration Facility has come up with what we think are some fairly spectacular results. We combined early out-of-season spawning with intensive fry rearing (Bob Summerfelt's method) and both pond culture and RAS of the trained fingerlings to produce extended growth walleyes (for stocking) and food-size hybrids (for consumption).
More and more resource agencies and lake associations are requesting extended growth (8"+) fingerling walleyes for stocking. The high cost of small (grade 10) forage makes this a very expensive proposition. Training the fry and maintaining them in culture until they can take larger, less expensive forage is a big step in reducing production costs. We also had some success at keeping the fish on formulated feed during grow-out in the ponds. Alternatively growing the pure bred walleyes up to the 8"+ size in RAS could provide the high value product that makes recycle economically feasible. An added benefit of the intensive culture protocol is protecting the fingerlings from diseases like VHS and eye fluke that has impacted production of extended growth walleye fingerlings here at the Lake Mills State Fish Hatchery.
RAS culturists have always wanted a food fish that they could "finish" in 1 year completely indoors. It seem clear to me that yellow perch just don't fit the bill. The current intensive fry culture techniques (green water, artemia) are expensive and inefficient. Additionally, because of the slow growth of the very small fingerlings the perch just don't make it to market size within the year. Early spawning of the walleye and hybrids gave us an extra six weeks of culture time, and most importantly the fry culture didn't involve the use of any live feed. Even in our first attempts, with the advice of Alan Johnson, we were quite successful in getting the newly hatched walleye to take feed and survive. RAS culture of the hybrids resulted in fish that averaged 160g and 10.5" by Nov. 1st with fillet yields in the 50% range and fillets that weighed 80g per fish (similar to large market size perch at 3/lb). Growth rates at the end of the study averaged 1g/day with some fish in the cohort growing faster than 2g/day, so one could have 250g hybrids by February. The fillets from those fish would be 125g the same as filleting a 265g perch! Keep in mind that that these fish are less than 1 year old!!!
Several commercial producers here in Wisconsin have expressed considerable interest in the walleye project. They thought the "baby walleye fillets" were very tasty and were able to market the fish we produced. Of course this was only a pilot study and there are still questions to be answered concerning broodstock, culture density and economics among others. The bottom line is these walleye and hybrid techniques can benefit both public and private sector producers in the North Central region and provide a new direction for RAS operators.
I think that it would be great if this idea got some serious discussion and consideration prior to and at the upcoming NCRAC meeting. I hope that you pass this message on to any producers in your state that may be interested.
Regards.
Jim Held Aquaculture Outreach Specialist UW-Extension jaheld@wisc.edu =
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by Snipe |
Snipe |
If in large grow outs, no sorting is done. The states theory is natural course of action to get the best growth from the best fish. The first 48 hr of hatch last year was stocked in a 7ac pond at 14,350 per acre (about 100,000 fry) we collected 62,000 and still had fish left. We were able to pull a late seine and collected another 13,000 from that pond, so 75,000 with no sorting isn't bad.. in fact it's probably really good, all things considered but we also stocked at a much lower rate than was recommended because I wasn't sure we could keep up with fertilizer program. Personally, I think it best if those slower than average growers disappear.. I've tried to separate fish of other species this way and it always ends up that you have a small number of fish that are less than stelar performers and wasted space trying to save them, but I'm mostly a one man, sometimes 2 man operation trying to do 3 men's jobs. Honestly, I think SMB are harder to manage than WAE..wicked little monsters.
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Nutria
by J. E. Craig - 12/03/24 04:10 PM
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Koi
by PAfarmPondPGH69, October 22
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