Releasing bait fis h, or transferring fish or water to another water bod y, could ruin angling. Do n’tRelease That Fish

an exotic species is involved, could eventu - ally become a national disaster. Some people believe a fisheries biolo - gist can simply remove undesirable fish ic species or undesir - by electrofishing, or shocking. This is able native species. After impossible in even the smallest pond. Fry t might seem charitable. years of poor fishing, an expen - and small fish are not collected in signifi - Or Conservation minded. sive rehabilitation using a piscicide (fish cant numbers by electrofishing. The only Fishermen often believe that by poison) called rotenone is required, fol - way to effectively remove undesirable releasing bait minnows or game fish lowed by restocking. And then there is species of fish from a water body is to into local lakes and ponds they are the angling time lost while waiting for drain it completely or use rotenone, I helping to improve the resource. the quality to redevelop. which kills all the fish, most of the time. Their logic: Releases help feed the The damages don’t stop there. The Some anglers may believe that only gamefish and improve fishing. budgets of resource management exotic (not native) species of fish Unfortunately, most of the time, agencies, such as the Department of stocked into a water body would be the nothing could be further from the Natural Resources, are impacted, as likely culprits to blame for reduced fish - truth. Usually these activities are are revenues of local businesses sup - ing quality. This is true in many destructive to fishing quality and may plying fishermen with bait, drinks, instances, with common carp being a result in the potential spread of an exot - food, gas and lodging. On occasion, prime example. However, even native the results are irreversible and, when species can damage fishing quality 8 / Outdoor Illinois May 2011 In some situations, native species, Unfortunately, native fish, including around the Great Lakes. In the fall of such as golden shiners, can be crappie, stripers (yellow bass), drum 2008, an emergency administrative rule perch (freshwater drum), yellow bellies was adopted making it illegal in Illinois detrimental when introduced to an (bullhead catfish) and sunfish (various to move fish from one water body to aquatic system. species of the genus Lepomis )—and another without written permission non-native carp—are too often stocked from DNR, in an attempt to curtail the from one water body to another by spread of this disease. well-intentioned fishermen. These fish Even moving water, possibly with can reproduce well in most waters. minnows or gamefish, from one water Some believe these fish will grow big body to the next can be harmful. and improve fishing. Crappie may grow An exotic species of water flea, well for a short time, but all these Daphnia lumholtzi , originally found in , l e

species compete with bluegill and bass Africa, Australia k c e o t

in small lakes and ponds for the limited and southern S s e m

food resources. Eventually, good repro - Asia, is common a J y ) s . e n t

duction, and then competition for limit - in many of Illinois’ r r u u b o u c A o ed food resources, results in slow larger lakes. / t S Daphnia lumholtzi o H h P N ( growth rates for all species and poor Although they I fishing, unless poisoned and restocked. may be the right size for fish to eat, an Responsible fishermen release fish only elongated, sharp spine deters consump - back into the same water body from tion. Water fleas are easily transferred which they were caught. from one water body to the next, and Largemouth bass virus is an intro - are believed to reduce numbers of duced disease which can seriously native water fleas, a preferred food for odde.) Adele H o By (Phot affect bass numbers in a lake for years fish hatchlings. after causing a bass kill. Many species, Zebra ( Dreissena polymorpha ) and including bluegill, crappie and sunfish, quagga ( D. rostriformis ) mussels are Story By Mike Mounce carry the disease as well. Moving fish another major concern. The microscop - Photos By Eric Engbretson from one lake to another may have not ic young, called veligers, may live for ww w. underwaterfishphoto s. co m. have been a problem for spreading dis - days in a bait bucket or the water-pump eases in the past, but now it is. Large - when introduced into certain situa - mouth bass virus cannot be treated in a tions. At least 160 species of plants and hatchery or in the wild. Transporting water from one place animals have been identified that dam - Recently, the pathogen causing Viral to another has resulted in the age waterways in states around the Hemorragic Septicemia has been devas - spread of exotic water fleas (above) Great Lakes, including Illinois. Many tating fish populations in water bodies and zebra mussels (below). are not exotics, but are native species. For example, golden shiners are a Dreissena polymorpha native species and a common and pop - ular bait minnow available at most bait shops. Generally sold as 2-3 inch min - nows, these fish are capable of avoid - ing being eaten by bass and other fish predators when released in lakes or ponds. They can quickly grow to 8 inches and reproduce successfully in nearly all water bodies. In small lakes and ponds, they compete with bluegill for the same—usually limited—food resources, resulting in a slow-growing bluegill population and the eventual demise of the bass population as well. Poor fishing for all species then fol - lows. Responsible anglers never release their bait into the water but will dis - pose of unused bait in the trash. May 2011 Outdoor Illinois / 9 yellow bass

longear sunfish ) . s w e r Well-intentioned anglers stocking d Fish biologists spend a significant n A y

h amount of time and money eliminating t yellow bass, sunfish and black bull - a K

y undesirable native and exotic species of b

o heads all too often find these fish t o

h fish and plants from Illinois water bod - P ( out-compete bass and bluegill for ies, exotics that were released by fisher - housing of a boat motor until “released” limited food supplies. men and others. Only in small water into another water body, where they bodies are these attempts successful. compete with native organisms for food, reducing native fish survival rates. Some fish species are resistant to food resources. Bleach treatments can Fish, other animals and even aquaria rotenone, which results in additional kill these hitch-hikers. plants should never be turned loose expense and time. into the wild. Responsible pet owners Fishermen interested in helping to will find another home, return animals “make fishing better” can work with to the pet shop where the pet(s) were their local fisheries biologist to deter - purchased, or dispose of the pet mine the suitability of a particular humanely and properly. species instead of taking matters into Releasing pet fish into the wild may their own hands. eventually require that a biologist poi - Those not heeding this advice will sig - son the water body, killing the entire nificantly lower—perhaps even ruin—the fish population just to remove one fishing quality for themselves and other undesirable species. This situation anglers, possibly permanently. occurred recently in Maryland and Vir - ginia where, despite significant efforts by biologists to eradicate the northern Mike Mounce is a district fisheries biolo - gist and based in the Charleston DNR snakehead, it still persists. Hopefully, no office. He can be reached at (217) one would want to be responsible for 345-2420 or [email protected]. causing such an ecological nightmare.

black bullhead On occasion, misinformed people release aquatic pets after tiring of car - ing for them. Goldfish, for example, can grow to 10 to 12 inches and successfully repro - duce in most water bodies. Their young compete with native fish hatchlings for

Protecting Illinois’ waterways means not releasing bait, pet fish or aquaria plants into the wild.

10 / Outdoor Illinois May 2011