Questions for DNR on its trout programSome frequently asked questions about rainbow trout management on Lake Superior
Some frequently asked questions about rainbow trout management on Lake Superior:
Q What was the goal of the 1992 Steelhead Plan and was it achieved?
A The goal was to “stop the decline of adult steelhead and gather the necessary information to rehabilitate wild steelhead stocks.” This goal has generally been accomplished. The decline in adult steelhead abundance has been largely reversed, and although there are still information needs regarding wild steelhead, the knowledge base on steelhead in Minnesota has grown significantly over the last ten years. Objectives and accomplishments from the 1992 steelhead plan are listed in Appendix 2 of the proposed plan.
Q What is the goal and purpose of the proposed Rainbow Trout Management Plan?
A The long-term goal of the proposed plan is to “rehabilitate steelhead stocks using Minnesota strain fish to achieve a level that will allow limited angler harvest largely supported by naturally reproducing populations.” The purpose of this revised rainbow trout plan is to utilize the information gained from the previous plan and work with interested citizens to continue restoration of wild steelhead stocks.
Q Why have steelhead populations declined since the 1970s?
A The restoration of lake trout and the naturalization of coho and chinook salmon, along with a major decline in smelt abundance have increased competition and have made steelhead more vulnerable to predation. Angling pressure for steelhead increased approximately 10-fold from the 1960s to the late 1980s and increased harvest significantly reduced the number of spawners. Land use changes have negatively impacted temperature regimes and stream hydrology degrading spawning and nursery habitats that are necessary for successful reproduction and juvenile steelhead survival.
Q Why doesn’t Lake Superior produce more and larger rainbow trout like those caught in Lake Michigan?
A The physical environment of Lake Michigan is better suited for rainbow trout production. Lake Michigan has more in-lake shallow water habitat. Average surface temperature can be 10-15 degrees warmer, and the optimal growing season can be one to three months longer in Lake Michigan. The biological productivity of Lake Michigan is about three times that of Superior, creating an environment better suited for trout growth and survival.
Q Why doesn’t the DNR expand the kamloops stocking program beyond its present range?
A Based on studies conducted by DNR research biologists and university scientists, hybridization between kamloops and wild steelhead is a risk and would likely be detrimental to wild steelhead rehabilitation efforts through dilution of steelhead gametes. Specific studies have shown that:
- When in close proximity, kamloops and steelhead will interbreed and create hybrid juveniles in the wild.
- Kamloops eggs have higher mortality than steelhead eggs under natural stream conditions.
- Steelhead fry are much more wary than kamloops when startled.
- Relative survival of stocked steelhead fry to age one in North Shore streams was five times greater than survival of kamloops fry to age one.
- In all studies, hybrids between steelhead and kamloops performed at an intermediate level, with the maternal steelhead cross having higher survival than the maternal Kamloops cross.
Q Given the potential negative genetic impacts of Kamloops on naturalized steelhead, why doesn’t the DNR discontinue the program?
A Over half of the angling pressure in the spring fishery is directed at kamloops and the catch rates of kamloops are generally double those of steelhead. In addition, winter creel surveys show that fishing pressure for kamloops surpasses spring fishing pressure for all rainbow trout strains. Kamloops are the only rainbow trout that can be harvested in Minnesota’s portion of Lake Superior. The kamloops fishery is a relatively low cost hatchery program that provides both a winter and early spring shore fishery for rainbow trout where it otherwise would not exist. An alternative to elimination of the program is to restrict kamloops stocking to a limited geographic area and attempt to reduce straying from that area so the hybridization risk is minimized.
Q Why does this plan put so much emphasis on the Knife River system?
A The Knife River system contains about half of all migratory fish habitat in Minnesota and in the past has had one of the largest steelhead runs. The draft plan proposes to stock yearling steelhead to bolster the Knife River run, as the numbers of adult fish have not increased significantly. Although survival of hatchery-reared yearlings has been disappointing, they can have a significant impact on the number of adults returning to a stream, if a large number of yearlings are stocked in that stream. Analysis of wild downstream migrants captured in the Knife River smolt trap suggests declining returns of adults in 2005 and 2006. The option of not stocking the stream and letting it recover without intervention is appealing, however, rehabilitation would probably take much longer.
Q Why doesn’t the DNR increase the number of steelhead smolts stocked?
A Raising steelhead smolts is expensive and production costs average between $2.50 and $3 per fish. The return rate of adults derived from stocked steelhead smolts has been disappointing, averaging about one percent since the program began. Much of the scientific literature suggests that significant genetic risks accompany hatchery intervention in the rehabilitation of wild steelhead populations. Many anglers feel this risk is worth taking, and that there may be an even greater risk in allowing the present population to decline further. Stocking high numbers of hatchery-reared smolts in the Knife River where the outcome can be evaluated will help determine the effectiveness of this strategy.
Q Why does the MNDNR continue to stock steelhead fry as part of the proposed management plan?
A Stocking steelhead fry above natural barriers to supplement natural reproduction of steelhead in short run streams has been a successful method to increase smolt production. Information gained from the French River smolt trap indicates that smolts produced from stocked fry are ten times more likely to return as adults than hatchery-reared yearlings. The creation of a “wild” steelhead brood stock should supply a stable source of gametes for fry production. This is an experimental program, and will require some modifications to optimize, but has potential to significantly increase smolt production in streams where fry are stocked.
Q Will there be any new regulation changes with the revised plan?
A No, the plan proposes to continue restrictive harvest regulations to protect wild steelhead while allowing harvest of hatchery-reared kamloops. The DNR will work with interested anglers to explore the need for additional spawning closures on specific streams.
Q Will the DNR ever allow harvest of wild steelhead?
A As the rehabilitation process proceeds and adult steelhead abundance increases, we will consider relaxing restrictive harvest regulations on a group of streams that would be monitored extensively to determine how angling pressure and the steelhead populations respond. Based on what is learned from this approach we would develop and discuss new, less restrictive regulations with interested anglers.
Q What does the DNR do to protect and restore stream habitats within the Lake Superior watershed?
A Identification and removal of beaver dams and other obstructions by the DNR increases the spawning and nursery habitat available to steelhead. Sediment control through the review of development permits, consultation on roadway construction and culvert sightings, bank stabilization, and cooperative rip-rap projects are methods used by the DNR to minimize the erosion of stream banks. Easement and land acquisition programs along stream corridors have increased, but are expensive. Cooperative in-stream habitat improvement projects have been conducted by local angling groups and the DNR with the goal of increasing smolt production. On a broader scale, the DNR works with other agencies and private landowners to implement and monitor the success of watershed scale projects such as those on the Knife, Nemadji and Flute-Reed rivers.
Lake Superior fish rules
• Two lines may be used on Lake Superior. Only one is allowed within 100 yards from where a tributary stream enters the lake. Only one line may be used in those streams.
• Anglers are restricted to a single hook only – no treble hooks – on tributary streams and rivers up to the posted boundaries. Exceptions are the St. Louis River and the Pigeon River (Cook County).
• Angling hours on Lake Superior tributaries below the posted boundaries are from one hour before sunrise to one hour after sunset. Exceptions are the St. Louis and Pigeon.
• Special regulations on North Shore streams include posted sanctuaries on the Knife, Little Knife, Devil Track, and Kadunce Rivers and on Gauthier
• Steelhead trout must be immediately released on
Lake Superior and its tributaries. A clipped adipose fin, used to identify stocked trout (kamloops), must show a healed scar. Marking, tagging, or fin-clipping fish and then releasing them without a DNR
permit is unlawful.
• While on the Minnesota waters of Lake Superior, persons may possess only one daily limit of fish.
• Anyone fishing on the Minnesota waters of Lake Superior must possess a Minnesota license and trout stamp validation.
• A person cannot fish on Wisconsin waters of Lake Superior with a Minnesota angling license.
• Smelt may be taken night or day. Artificial lights may not be used to lure or attract smelt. There is no limit on smelt, and smelt from Lake Superior may be bought or sold. Live smelt may not be
possessed or trans ported.
• On Lake Superior tributaries below the posted boundaries, a fish that is hooked in any part of the body, except the mouth, must be immediately
returned to the water.