Hey Nessy,
We have a ton of stickleback here in Alaska, too. I've considered feeding them to my snakes but decided not to. They are almost always heavily parasitized. You can usually find a white, fluke-like parasite called
schistocephalus sp. in their abdomens simply by squeezing it out their cloaca. You'll notice many populations of stickleback with small, black spots on them. Those are another kind of parasite, but I don't remember it's name at the moment. Another common parasite forms pustules. Some inhabit the eye. The list is nearly endless. I spoke with parasitologists from England and Norway last fall (early August) who use the threespine stickleback as a model organism on which to study parasites, so the infestation of this species complex is extremely widespread.
Rick
Here's a link to a National Academy of Sciences report that says which fish contain or lack thiaminase. Unfortunately, stickleback were not analyzed. Notice that the table is two pages long. The top part lists fish with thiaminase, and the bottom part (and second page) lists those without.
Nutrient Requirements of Mink and Foxes,