The effectiveness of baitfish as a means to catch fish cannot be argued, but careless use of baitfish can also cause irreparable harm to a fishery. One only has to look to the Adirondacks where our state fish, the brook trout, has been pushed out of much of its original range due to the introduction of competitive fish species, most likely via a bait bucket. Sometimes this is simply a result of an angler discarding unused bait at the end of the day. In other cases the introduction may be purposely done by an angler who feels that a bait species may provide beneficial forage for a particular species that he or she desires to fish for.
What is not understood is that a fish population in a pond, lake or stream is part of a stable community that has evolved over many years. Add a foreign fish to this community and the entire system can be thrown out of balance. Species such as brook trout that have evolved with few, if any, competitive fish species and rarely feed on fish, can be eliminated from a pond if baitfish or other non-native species are introduced. Baitfish such as alewife can also directly impact a fishery by feeding on the young of desirable fish species such as walleye. Black crappie and other notorious larval fish predators can also be mixed in with bait, particularly if it was harvested in the wild. This is why DEC prohibits the stocking of fish, including the simple act of dumping a bait bucket, without a stocking permit.
Baitfish can also harm native fish communities by spreading disease. Just like a human with a cold can spread his or her illness to other humans, so too can diseased fish. In fact, movement of baitfish from water to water by unknowing anglers is thought to be the primary mechanism by which viral hemorrhagic septicemia (VHS), a serious fish disease recently identified in New York, has spread from the Great Lakes to inland waters. Diseases may also be introduced by bait wholesalers who do not test their fish before they are sold to bait dealers.
To address this problem, DEC has established regulations to control the use of baitfish. Among other things, these regulations restrict the use of personally collected baitfish to the water they were collected from and prohibit their transport from these waters. Only 21 species of fish may now be sold for bait in New York. Except for baitfish sold for use on the same water they were collected from, all baitfish must also be certified to be disease free. Certified disease-free baitfish are the only form of live baitfish that may be transported overland outside of the three designated travel corridors without a DEC permit, and these fish must be used within 10 days of purchase. See a complete discussion in Baitfish Regulations.