Found this on another forum. While maybe not ruined, it may be to great of a risk to consume what you have already pickled.
Caution: The Broad Fish Tapeworm
The broad fish tapeworm infection can be contracted by humans from eating raw or under-cooked species of fish found in the Great Lakes area.
The larvae of the broad fish tapeworm pass through smaller fish until they lodge as hatched small worms in the flesh of large carnivorous species of fish, like northern pike, walleye pike, sand pike, burbot, and yellow perch. This worm, if eaten by humans in its infective stage, can attach to the small intestine and grow to lengths of 10 to 30 feet.
The infective worms are destroyed readily either by cooking or freezing. Two recent (my edit: this was posted in 1990) outbreaks of this tapeworm in Minnesota were related to eating uncooked pickled pike. Those who wish to prepare raw pickled fish should first freeze the fish at 0° F for 48 hours.