Special Publication No. 02-02 Biological Issues of the Kenai River and Kasilof River Early-run King Salmon Fisheries By Timothy R. McKinley, Bruce E. King, James J. Hasbrouck, and Robert A. Clark October 2002 Alaska Department of Fish and Game Division of Sport Fish Symbols and Abbreviations The following symbols and abbreviations, and others approved for the Système International d'Unités (SI), are used in Division of Sport Fish Fishery Manuscripts, Fishery Data Series Reports, Fishery Management Reports, and Special Publications without definition. All others must be defined in the text at first mention, as well as in the titles or footnotes of tables and in figures or figure captions. Weights and measures (metric) General Mathematics, statistics, fisheries centimeter cm All commonly accepted e.g., Mr., Mrs., alternate hypothesis HA deciliter dL abbreviations. a.m., p.m., etc. base of natural e gram g All commonly accepted e.g., Dr., Ph.D., logarithm hectare ha professional titles. R.N., etc. catch per unit effort CPUE kilogram kg And & coefficient of variation CV 2 kilometer km at @ common test statistics F, t, , etc. Compass directions: liter L confidence interval C.I. meter m east E correlation coefficient R (multiple) metric ton mt north N correlation coefficient r (simple) south S milliliter ml covariance cov millimeter mm west W degree (angular or ° Copyright temperature) Weights and measures (English) Corporate suffixes: degrees of freedom df cubic feet per second ft3/s Company Co. divided by ÷ or / (in foot ft Corporation Corp. equations) gallon gal Incorporated Inc. equals = inch in Limited Ltd. expected value E mile mi et alii (and other et al. fork length FL ounce oz people) greater than > O pound lb et cetera (and so forth) etc. greater than or equal to quart qt exempli gratia (for e.g., harvest per unit effort HPUE example) yard yd less than < id est (that is) i.e., ? Spell out acre and ton. less than or equal to latitude or longitude lat. or long. logarithm (natural) ln Time and temperature monetary symbols $, ¢ logarithm (base 10) log (U.S.) day d logarithm (specify base) log2, etc. months (tables and Jan,...,Dec mideye-to-fork MEF degrees Celsius °C figures): first three degrees Fahrenheit °F letters minute (angular) ' hour (spell out for 24-hour clock) h number (before a # (e.g., #10) multiplied by x minute min number) not significant NS second s pounds (after a number) # (e.g., 10#) null hypothesis HO Spell out year, month, and week. registered trademark percent % trademark probability P Physics and chemistry United States U.S. probability of a type I all atomic symbols (adjective) error (rejection of the null hypothesis when alternating current AC United States of USA America (noun) true) ampere A U.S. state and District use two-letter probability of a type II calorie cal of Columbia abbreviations error (acceptance of direct current DC abbreviations (e.g., AK, DC) the null hypothesis when false) hertz Hz horsepower hp second (angular) " hydrogen ion activity pH standard deviation SD parts per million ppm standard error SE parts per thousand ppt, ‰ standard length SL volts V total length TL watts W variance Var SPECIAL PUBLICATION NO. 02-02 BIOLOGICAL ISSUES OF THE KENAI RIVER AND KASILOF RIVER EARLY-RUN KING SALMON FISHERIES by Timothy R. McKinley, Bruce E. King, Division of Sport Fish, Soldotna James J. Hasbrouck, and Robert A. Clark Division of Sport Fish, Soldotna Alaska Department of Fish and Game Division of Sport Fish, Research and Technical Services 333 Raspberry Road, Anchorage, Alaska, 99518-1599 October 2002 The Special Publications series was established in 1991 for the publication of techniques and procedures manuals, informational pamphlets, special subject reports to decision-making bodies, symposia and workshop proceedings, application software documentation, in-house lectures, and other documents that do not fit in another publication series of the Division of Sport Fish. Special Publications are intended for fishery and other technical professionals. Special Publications are available through the Alaska State Library and on the Internet: http://www.sf.adfg.state.ak.us/statewide/divreports/html/intersearch.cfm This publication has undergone editorial and peer review. Timothy R. McKinley and Bruce E. King Alaska Department of Fish and Game, Division of Sport Fish 43961 Kalifornsky Beach Road, Suite B, Soldotna, Alaska, 99669-8367, USA and James J. Hasbrouck and Robert A. Clark 333 Raspberry Road, Anchorage, Alaska 99518-1599, USA This document should be cited as: McKinley, T. R., B. E. King, J. J. Hasbrouck, and R. A. Clark. 2002. Biological issues of the Kenai River and Kasilof River early-run king salmon fisheries. Alaska Department of Fish and Game, Special Publication No. 02-02, Anchorage. The Alaska Department of Fish and Game administers all programs and activities free from discrimination based on race, color, national origin, age, sex, religion, marital status, pregnancy, parenthood, or disability. The department administers all programs and activities in compliance with Title VI of the Civil Rights Act of 1964, Section 504 of the Rehabilitation Act of 1973, Title II of the Americans with Disabilities Act of 1990, the Age Discrimination Act of 1975, and Title IX of the Education Amendments of 1972. If you believe you have been discriminated against in any program, activity, or facility, or if you desire further information please write to ADF&G, P.O. Box 25526, Juneau, AK 99802-5526; U.S. Fish and Wildlife Service, 4040 N. Fairfax Drive, Suite 300 Webb, Arlington, VA 22203 or O.E.O., U.S. Department of the Interior, Washington DC 20240. For information on alternative formats for this and other department publications, please contact the department ADA Coordinator at (voice) 907-465-4120, (TDD) 907-465-3646, or (FAX) 907-465-2440. TABLE OF CONTENTS Page LIST OF TABLES .................................................................................................................................................iii LIST OF FIGURES................................................................................................................................................iii EXECUTIVE SUMMARY ..................................................................................................................................1 HISTORY AND CURRENT REGULATIONS.............................................................................................1 BIOLOGICAL ISSUES.........................................................................................................................................2 At current levels of effort and harvest potential, we are unable to meet minimum escapement objectives for early-run Kenai River king salmon without further inseason restrictions to the fishery..........................................................................................................................................................................2 What is the escapement objective for early-run Kenai River king salmon? .............................................................2 Prior to 2002 we had been meeting the early-run BEG, so what is the problem?.....................................................3 In what fisheries are early-run Kenai River king salmon harvested?........................................................................3 The long-term genetic effects of targeting large king salmon are unknown ..........................................6 Is there a problem with the numbers of large early-run king salmon in the Kenai River?........................................6 What is causing the problem with large early-run king salmon? ..............................................................................6 What is the rationale for the current slot limit at 40 inches and 55 inches?..............................................................7 There are potential long-term effects of disproportionately targeting early arriving or late arriving king salmon for harvest..........................................................................................................................................7 Why is it a problem to harvest early-run king salmon only early or late in the season?...........................................7 Have we been having a problem with early or late harvests of early-run king salmon?...........................................7 Has the disproportionate harvest in restricted years caused any changes in run timing?..........................................8 Savings made to early-run king salmon escapements in May and June can be lost to harvest during July. ................................................................................................................................................................8 Where do early-run Kenai River king salmon spawn? .............................................................................................8 Do we need to protect early-run king salmon in July?..............................................................................................8 The effects of catch-and-release mortality need to be considered in regulatory options that promote the release of king salmon....................................................................................................................8 What is the catch-and-release mortality of early-run king salmon?..........................................................................8 What about fish that are hooked multiple