Loving a River
to Death

Habitat Changes on the
Kenai River

by Terry Bendock and Jon Lyman

 Fishing on Kenai
The survival of the Kenai River's world famous king salmon depends upon water flows of less than one foot per second. Although the adult fish have little trouble swimming against swift flows, the young require the reduced velocity and cover provided by naturally vegetated banks to survive. Each spring, young chinook and coho salmon migrate from the upriver areas where they were hatched to the rich feeding grounds along the mainstem. Each fall they return to overwinter in Skilak, Kenai, and other lakes. The role of the streambank vegetation in modulating flow speed and providing cover is essential to the successful upriver journey of the young fish.
Flooding on Kenai

The Alaska Department of Fish and Game has long focused on managing the Kenai River's returning populations of adult salmon to ensure adequate numbers of spawners to reproduce the runs. Given good returns from the Pacific Ocean, management plans and modern technology assure us that sufficient salmon will survive to spawn. This, however, is only part of the picture. We must also be concerned with the young fish rearing in the river and the continuing degradation of their habitat.

Anglers cannot influence most of the forces that affect the return of salmon to the Kenai River. High seas interception, harvest in mixed stock commercial fisheries, the use or misuse of private and public property along the river, natural mortality due to forces we do not understand - all have a great impact on the number of returning salmon. The one place where anglers can have the greatest long term impact on these fish is on the bank of the river.
Anglers and landowners need to participate in local land use planning efforts to develop public solutions to the continued degradation of river habitat. The key to maintaining the long term health of the Kenai River is the development of land use regulations to control incompatible uses along the river. While the Division of Parks and the City of Soldotna are attempting to regulate bank use on their lands, other landowners, public and private, have yet to take action to protect the habitat necessary for fish. By working with the following organizations, individuals can begin to shape the future of the river and its salmon resources.
Riverbank erosion
Salmon fry

Natural vegetation that overhangs the banks or trails in the water provides food for aquatic organisms which juvenile salmon eat. natural vegetation also stabilizes banks and helps prevent erosion.

Cover is the woody vegetation along the shoreline, irregular and undercut banks, aquatic vegetation, log jams, large woody debris, rootwads, sweepers, large rocks or boulders, and the turbidity of the glacier water itself. Cover slows the speed of the river along the streambanks, creating ideal flows for young fish. Over 80 percent of the young salmon in the Kenai River can be found within 6 feet of the bank.

 

User Impact on Fish Habitat   Anglers Can Reduce Impacts
Private and commercial developments eliminate riparian vegetation. This weakens the streambank and reduces cover and food for juvenile salmon.   Use developed trails, ladders, and boardwalks, when available, to access the river
Land clearing increases subsurface drainage rates streambank erosion.   Always launch and retrieve boats at a developed launch site.
Structures along the shoreline alter water velocity and decrease useable habitat from juvenile salmon.   Select either an exposed or protected site when beaching you boat to avoid crushing bank vegetation.
Draining wetlands reduces subsurface flow and nutrients for juvenile salmon.   Minimize damage from boat wakes whenever possible by lowering speed and traveling in mid-channel.
Boat wakes increase erosion along banks where the vegetation has been damaged.   Fuel your boat at a site that does not discharge into the river should an accident occur.
Foot trails damage vegetation and root systems increasing the risk of erosion.   Avoid trampling and damaging vegetation along the waters edge.
Removing log jams and woody debris eliminates important rearing habitat for young salmon.   Move away from the waters edge when walking up and downstream.
Parking riverboats along the shoreline often results in damaged vegetation and increased erosion.   Use hip boots or chest waders to avoid standing on the bank while fishing.
Steep banks and water-saturated soils are subject to erosion and are easily damaged by foot traffic.   Avoid steep banks and water-saturated soils when bank fishing.

Unfiltered runoff from city and state highways and parking lots is discharged directly into the Kenai River--lowering water quality.

  Remember that fish habitat and bank stability are often determined by the amount and quality of streamside vegetation.
  Ocean king salmon Participate in local discussions on land use regulations and the need to protect fish habitat.
Tell friends and visitors of the importance of maintaining riverbanks.

Be a role model!

Alaska's Wildlife * Supplement May/June 1993