Why Not Hybrids?

[Wayne SW/MO]

I would be curious to know why the MDC isn't considering Wipers for Bull Shoals? They have a lot of experience and success in the fish . I realize that Bull Shoals has some native Strippers, but it appears very few, certainly not enough to worry about false spawns.

Any thoughts?

[Outside Bend]

I'm not entirely sure, but my guess would be it's because wipers are infertile, and MDC doesn't have enough hatchery capacity to produce them for Bull Shoals.

[Evolution]

Why not just trade with other states for hybrids instead of raising them? I'm pretty sure we have more than enough stocker trouts to make a arrangement to trade for hybrids. Being infertile it may be easier to maintain their numbers but their aggressiveness may be a problem but that's were fisherman come in and take them out. lol. I can imagine it now, chucking trout swimbait for hybrids.

[Wayne SW/MO]

I'm not entirely sure, but my guess would be it's because wipers are infertile, and MDC doesn't have enough hatchery capacity to produce them for Bull Shoals.

I would think the infertility would be a plus for control. The hatchery capacity is a good argument up to a point, they are already obligated to several other wiper programs. On the other side however would it make a difference if they were producing stripers instead of wipers?

[Tim Smith]

I would think the infertility would be a plus for control. The hatchery capacity is a good argument up to a point, they are already obligated to several other wiper programs. On the other side however would it make a difference if they were producing stripers instead of wipers?

Slightly.

There is an outside chance stripers could manage to reproduce (as they do in Texhoma). Stripers also live longer and grow bigger and more slowly. That puts more large predator biomass in the pelagic zone for a longer period of time (assuming they're not fished out).

That's important because...

....a secondary (or sometimes primary) reason for stocking temperate bass is to get a predator into the open water habitat that gizzard shad use. Gizzard shad compete heavily with the larvae of sport fish for zooplankton, and quickly grow to sizes that even the largest Centrarchids simply can't consume. That means there's a lot of unusable forage fish biomass competing with and repressing the sportfishery during juvenile stages unless you have a dense population of extra large predators capable of reducing their numbers.

If Bull Shoals is like most other Middle American reservoirs, this may be part of the rationale. Stocking stripers doesn't always work to regulate gizzard shad, but it usually doesn't hurt either.

[Stoneroller]

as tim said sometimes it has a lot to do with forage base. Stripers are typically the best option for lakes overrun with adult gizzard shad. Not sure if this is an issue at Bull Shoals, but that's typically one of the major reasons that stripers will be picked over whipers for a given body of water.

[Wayne SW/MO]

Given the fact that wipers are as capable of taking large gizzard shad, admittedly not the largest, wouldn't they eventually consume more do to increased numbers?

It would be interesting to know what the biomass's of the two fish are in LOZ and Truman.

[Tim Smith]

Given the fact that wipers are as capable of taking large gizzard shad, admittedly not the largest, wouldn't they eventually consume more do to increased numbers?

It would be interesting to know what the biomass's of the two fish are in LOZ and Truman.

There's probably not a huge advantage of stripers over wipers to control shad, but the wipers have known limitations.

Wipers don't live very long and they can't take adult fish. They even pass up larger juvenile shad and it's not clear they're up to the job in most places (although striped bass might not be adequate either since they don't grow rapidly). If you can stock either of them at higher densities, they'll make a bigger dent.

If you want the science here's an evaluation of wipers from Ohio.

Potential regulation of age-0 gizzard shad by hybrid striped bass in Ohio reservoirs

Author(s): Dettmers JM, Stein RA, Lewis EM

Source: TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY Volume: 127 Issue: 1 Pages: 84-94 Published: JAN 1998

Times Cited: 10 References: 53 Citation Map

Abstract: Piscivores can control prey populations in north temperate lakes, leading to increased zooplankton and reduced phytoplankton. In reservoirs with gizzard shad Dorosoma cepedianum, an omnivorous planktivore, this cascade occurs with lower probability because while this fish is shorter than 60 mm in total length (TL) it readily consumes zooplankton but also switches to phytoplankton and detritus. Prospects for gizzard shad control probably hinge on piscivore consumption of age-0 individuals. Hence, we quantified capture efficiency of hybrids of striped bass Morone saxatilis X white bass M. chrysops (small: 190-250 mm, TL; large: 310-360 mm, TL) 500-L aquarium. Small hybrid striped bass selected 40-mm gizzard shad but preferred neither 60-mm nor 80-mm prey. Large hybrid striped bass demonstrated no selection for 40-120-mm gizzard shad. We incorporated these data into a bioenergetics model to evaluate whether hybrid striped bass could sufficiently reduce abundance of age-0 gizzard shad in Ohio reservoirs to permit increased zooplankton, thereby improving the potential for resident sport fish recruitment in reservoirs. Hybrid striped bass potentially increased larval sport fish occurrence only when they were stocked at high densities (greater than or equal to 350 fish/ha or greater than or equal to 22 kg/ha) coupled with age-0 gizzard shad suffering low natural mortality and occurring at an intermediate peak density of 25 fish/m(3) or less. We believe gizzard shad are largely immune to control by hybrid striped bass in Ohio reservoirs. Hence, managers must consider combining watershed management with predator stocking to regulate gizzard shad.

[drew03cmc]

I would be curious to know why the MDC isn't considering Wipers for Bull Shoals? They have a lot of experience and success in the fish . I realize that Bull Shoals has some native Strippers, but it appears very few, certainly not enough to worry about false spawns.

Any thoughts?

Wayne, not to nitpick, but stripers are not native to anywhere west of the Atlantic Coast. Strippers, however, are native to every city in America and I thank them for that.

Stripers are a relatively slow growing species whereas the wiper is a fast growing eating machine that thrives in moving and still waters. I say stock the wipers and if they make the fishery better, keep stocking them. Kansas has PLENTY of wiper and would probably trade some for some silver bullets...

[Wayne SW/MO]

Wayne, not to nitpick, but stripers are not native to anywhere west of the Atlantic Coast. Strippers, however, are native to every city in America and I thank them for that.

Stripers are a relatively slow growing species whereas the wiper is a fast growing eating machine that thrives in moving and still waters. I say stock the wipers and if they make the fishery better, keep stocking them. Kansas has PLENTY of wiper and would probably trade some for some silver bullets...

I'm aware that they are a saltwater fish that was landlocked in NC. Bad use of words on my part, I should have said "resident" probably. I simply meant there was a population all ready there.

Wipers don't live very long and they can't take adult fish.

That's interesting and would relegate the wiper to little more than a sport fish, as opposed to accomplishing an adjustment in the environment.

Over the decades in watching huge masses of gizzard shad one has to wonder what it does to the environment. They were common in the rivers around my home when growing up, but never in large numbers. I assumed that was because of physical constraints in the environment where they remained vulnerable. In the huge, unnatural, reservoirs they seemed to find safety in numbers and area.

I hope they are stocked, stripers, but I was curious as to why wipers weren't given the fact they have a termination built in. If they don't work out, they die out.