Annual Survey Question

Cliff

Well-Known Member
#1
In your annual survey report you mentioned that the gizzard shad spawn in the spring. Do the stripers and other fish feed upon the gizzard shad fry in addition to the threadfin shad? Are they another source of protein for bass and stripers? Obviously when they are as big as some of the ones we caught in the net survey, they are pretty safe from predation.
 

wayne gustaveson

Moderator
Staff member
#2
Yes the very best thing about gizzard shad is that they are huge fish with lots of eggs and they spawn every spring. That provides food for all the game fish in spring when food is scarce. Gizzard shad are critically important in the food web of Lake Powell predators
 
#3
Yes the very best thing about gizzard shad is that they are huge fish with lots of eggs and they spawn every spring. That provides food for all the game fish in spring when food is scarce. Gizzard shad are critically important in the food web of Lake Powell predators
Wayne, do you think the food they supply as fry outweighs what the larger gizzard fry consume of other game fish? Considering that they don't seem to be consistently caught on a rod and reel I have to wonder if they are a plus or a minus in the longer run.
 

Cliff

Well-Known Member
#4
Are gizzard shad a predator of other fish? That is the question I have.
I have no idea what they eat but it seems their mouth is pretty small in comparison.
 

Dorado

Well-Known Member
#5
Gizzard shad are planktivores, that is why they are so infrequently caught by anglers. So no, they do not eat game fish. In some lakes they are such efficient planktivores that they outcompete juvenile game fish and take over. But in lake Powell, plankton is not the limiting factor for game fish. But the quaggas might change this, hopefully not....
 

wayne gustaveson

Moderator
Staff member
#6
Yes I think the small gizzard shad produced each spring keep our striped bass population going along with small bass, and crappie. To have a banner year we need threadfin to have successful reproduction in addition to gizzard shad. Without threadfin the open water food source is just enough for survival and not enough for abundance or a super productive year.

Gizzards start out as planktivores but as they transition to adult size their mouth migrates to the under side of the jaw and become bottom feeders just like carp. I hope as adults they can eat some quaggas but so far we do not have verification of that hope.