Sea Lions Are Nothing Compared To Smallmouth Bass

Ray

Active Member
A buddy of mine is doing research on fall chinook in the Snake River basin. During the out migration, they estimate that the predation on smolts is in the neighborhood of 10,000 smolts per mile due to smallmouth bass. And that's just in the free flowing section above Asotin. And then they have to negotiate the bass and walleye filled reservoir pools in the Snake and Columbia.

This may be one of the best arguments for keeping hatchery production. With the large population of predator fish in the system, the hatchery smolts are the "cannon fodder" that allow their more crafty wild cousins a better chance to outmigrate unscathed. Suddenly cutting hatchery production would expose all of the wild smolts to an onslaught of predators, potentially collapsing the wild fishery before the predator population dropped.

Anyway, food for thought.

https://pubs.er.usgs.gov/publication/70148107

Abstract
The portion of the Snake River fall Chinook Salmon Oncorhynchus tshawytscha ESU that spawns upstream of Lower Granite Dam transitioned from low to high abundance during 1992–2014 in association with U.S. Endangered Species Act recovery efforts and other Federally mandated actions. This annual report focuses on (1) numeric and habitat use responses by natural- and hatchery-origin spawners, (2) phenotypic and numeric responses by natural-origin juveniles, and (3) predator responses in the Snake River upper and lower reaches as abundance of adult and juvenile fall Chinook Salmon increased. Spawners have located and used most of the available spawning habitat and that habitat is gradually approaching redd capacity. Timing of spawning and fry emergence has been relatively stable; whereas the timing of parr dispersal from riverine rearing habitat into Lower Granite Reservoir has become earlier as apparent abundance of juveniles has increased. Growth rate (g/d) and dispersal size of parr also declined as apparent abundance of juveniles increased. Passage timing of smolts from the two Snake River reaches has become earlier and downstream movement rate faster as estimated abundance of fall Chinook Salmon smolts in Lower Granite Reservoir has increased. In 2014, consumption of subyearlings by Smallmouth Bass was highest in the upper reach which had the highest abundance of Bass. With a few exceptions, predation tended to decrease seasonally from April through early July. A release of hatchery fish in mid-May significantly increased subyearling consumption by the following day. We estimated that over 600,000 subyearling fall Chinook Salmon were lost to Smallmouth Bass predation along the free-flowing Snake River in 2014. More information on predation is presented in Appendix A.3 (page 51). These findings coupled with stock-recruitment analyses presented in this report provide evidence for density-dependence in the Snake River reaches and in Lower Granite Reservoir that was influenced by the expansion of the recovery program. The long-term goal is to use the information covered here in a comprehensive modeling effort to conduct action effectiveness and uncertainty research and to inform fish population, hydrosystem, harvest, hatchery, and predation and invasive species management RM&E.
 

Alosa

Active Member
Releasing more Hatchery smolt would only serve to increase the smallmouth bass population by providing food. I think a better approach would be to promote the recreational fishery and remove any bag limits and size limitations that could be in place. I'm not all that familiar with the sport regulations for smallmouth bass in the Columbia, so maybe this is already been done...
 

cabezon

Sculpin Enterprises
WFF Premium
Yeah, the worst thing in the world is to be an endangered species whose predators have an abundant alternative food source. The predator biomass builds up and, even if you are less at risk because of the alternate food source, the increased number of encounters because of the higher predator numbers just murders your population.

A case study similar to this occurred in the Channel Islands off Santa Barbara (see https://www.nps.gov/chis/learn/nature/island-fox.htm). The islands are known for an endemic species of red fox - the Channel Island Fox. Private land owners introduced sheep to the islands as open-range ranches. The sheep attracted golden eagles (= small mouth bass) and the golden eagles took the niche of the resident bald eagles whose populations had been devastated by DDT. While the golden eagles primarily fed on lambs and sheep carcasses, they picked off lots of young foxes and the fox numbers plummeted. The situation got even worse when the feds, as part of the development of Channel Islands National Park, removed the sheep (and feral pigs) by sectioning the islands and hiring commercial marksmen to clean the sheep out of each section (carcasses fed lots of eagles). Not only did the number of goldens increase, but in areas where the sheep had been cleaned out, the eagles really hammered the foxes (though less so as the vegetation recovered from massive overgrazing). To prevent extinction of the foxes, the feds had to authorize removal of the golden eagles to the mainland, reintroduction of bald eagles to keep the goldens out, and instituted a captive breeding program ("hatcheries") for foxes. Fortunately, the fox populations appear to be on the mend.

Yes, the logical process is to reduce the abundance of predators (northern pikeminnow bounty applied to smallmouth???) and foster the reproductive potential of the remaining wild fish. Will sports anglers cooperate?

Steve
 
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The T.O. Show

Buenos Hatches Ese
Yes, the logical process is to reduce the abundance of predators (northern pikeminnow bounty applied to smallmout???) and foster the reproductive potential of the remaining wild fish. Will sports anglers cooperate?

I've always wondered why there is a bounty on pikeminnow but not bass? Particularly in the lower Yak. Is this just because they are such a popular sport fish?
 

Bruce Baker

Active Member
Releasing more Hatchery smolt would only serve to increase the smallmouth bass population by providing food. I think a better approach would be to promote the recreational fishery and remove any bag limits and size limitations that could be in place. I'm not all that familiar with the sport regulations for smallmouth bass in the Columbia, so maybe this is already been done...

There is no minimum size or daily limit on bass, walleye and channel catfish in the Columbia River up to Chief Joseph Dam. There is no minimum size or daily limit on bass, walleye and channel catfish in the Columbia River.
 

Yard Sale

Huge Member
Since I live along the Columbia now, I'm going to get dialed on smallmouth this summer and fill some coolers.

@Yard Sale you down?

In! Although I'm not sure you want to eat anything that lives in the Big C...

Can we at least wait for the ice to break up? I just took a 4 day skunking up north and my ego needs some rest.
 

Yard Sale

Huge Member
On the smallie vs Steelie thing: They do seem to get along OK in some rivers like the John Day and the Umpqua. I recall reading something about smolt out-migration timing and enough water to flush them out(snow pack or dam spill) but the details escape me now...
 

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