Recovery of Fish Populations in Lakes Affected by the May 18, 1980 Eruption of Mount St. Helens by Bob Lucas and John Weinheimer Washington Department of Fish and Wildlife Report Number: FPT 03-07 Recovery of Fish Populations in Lakes Affected by the May 18, 1980 Eruption of Mount St. Helens by Bob Lucas and John Weinheimer Washington Department of Fish and Wildlife 600 Capitol Way North Olympia, Washington 98501-1091 ACKNOWLEDGMENTS We owe thanks to a number of people who helped with fish surveys of lakes in the vicinity of Mount St. Helens and shared in our continued amazement at the pace of natural recovery. Although there were many individuals involved with field work immediately after the 1980 eruption, this list is confined to those who helped after 1986. We are grateful to Charlie Crisafulli, Bruce Crawford, and Cameron Sharpe for reviewing this manuscript. Volunteers Aaron Kilgore Hal Manke Tom Paulu Roger Werth Don and Alice Hack Washington Department of Fish and Wildlife Bob Bicknell Craig Burley Jim Byrd Bruce Crawford Paul Dunlap Steve Gray Stacey Kelsey John Loch Dan Niemi John Pahutski Larry Peterson Chris Wagemann Weyerhaeuser Ray Pleasant United States Forest Service Amy Bryant Charlie Crisafulli: tremendous support throughout this project Debbie Haapala Malia Hee Kenneth Oh Betsy Scott Brian Spitek: created the outstanding vicinity map for this report We owe special thanks to John Loch. His commitment to recovery of wild fish in the Mount St. Helens area was an inspiration to us all. TABLE OF CONTENTS List of Figures ................................................ iii List of Tables.................................................. v Executive Summary............................................. 1 Introduction ................................................... 2 Methods ...................................................... 5 Individual Lake Summaries....................................... 7 Boot.................................................... 8 Castle.................................................. 11 Coldwater .............................................. 17 Elk.................................................... 23 Fawn .................................................. 28 Forest.................................................. 33 Ghost.................................................. 36 Grizzly................................................. 40 Hanaford ............................................... 43 Holmstedt .............................................. 48 Island.................................................. 50 Little Venus ............................................. 53 Meta................................................... 57 Obscurity............................................... 61 O’Conner ............................................... 65 Panhandle .............................................. 68 Ryan................................................... 72 St. Helens............................................... 76 Shovel ................................................. 81 Snow .................................................. 85 Spirit .................................................. 88 Strawberry.............................................. 95 Tradedollar ............................................. 98 Venus................................................. 102 Discussion .................................................. 107 Literature Cited .............................................. 114 ii List of Figures Figure 1. Lakes affected by the May 18, 1980 eruption ........................... 4 Figure 2. Boot Lake-1980 .................................................. 9 Figure 3. Boot Lake-2001 .................................................. 9 Figure 4. Castle Lake-1981 ................................................ 12 Figure 5. Castle Lake-2002 ................................................ 12 Figure 6. Castle Lake rainbow trout-1999 ..................................... 14 Figure 7. Coldwater Lake-1980 ............................................. 18 Figure 8. Coldwater Lake-2002 ............................................. 18 Figure 9. Coldwater Lake rainbow trout-7/9/98 ................................ 20 Figure 10. Elk Lake-1981 ................................................. 24 Figure 11. Elk Lake-2001 ................................................. 24 Figure 12. Elk Lake brook and rainbow trout-7/12/00 ........................... 25 Figure 13. Fawn Lake-7/1/80 ............................................... 28 Figure 14. Fawn Lake-7/11/00 .............................................. 28 Figure 15. Processing brook trout from Fawn Lake-7/11/00 ....................... 30 Figure 16. Forest Lake-1981 ............................................... 33 Figure 17. Forest Lake-2001 ............................................... 33 Figure 18. Brook trout collected at Forest Lake-7/12/00 ......................... 35 Figure 19. Ghost Lake-2002 ............................................... 37 Figure 20. Grizzly Lake-1980 .............................................. 40 Figure 21. Grizzly Lake-7/25/01 ............................................ 40 Figure 22. Hanaford Lake-7/01 ............................................. 43 Figure 23. Hanaford Lake brook trout-7/12/00 ................................. 45 Figure 24. Hanaford Lake Twin Lakes cutthroat trout-7/12/00 ..................... 45 Figure 25. Holmstedt Lake-7/26/00 .......................................... 48 Figure 26. Island Lake-1980 ............................................... 50 Figure 27. Island Lake-7/25/01 ............................................. 50 Figure 28. Island Lake Twin Lakes cutthroat trout-7/25/01 ....................... 52 Figure 29. Little Venus Lake-7/29/01 ........................................ 53 Figure 30. Little Venus Lake rainbow trout-7/31/01 ............................. 56 Figure 31. Meta Lake-7/80 ................................................ 57 Figure 32. Meta Lake-8/23/02 .............................................. 57 Figure 33. Meta Lake brook trout-6/16/83 .................................... 59 Figure 34. Obscurity Lake-7/80 ............................................. 61 Figure 35. Obscurity Lake-7/25/01 .......................................... 61 Figure 36. Obscurity Lake brook trout-8/24/02 ................................. 63 Figure 37. O’Conner Lake-7/80 ............................................. 65 Figure 38. O’Conner Lake-7/26/01 .......................................... 65 Figure 39. Panhandle Lake-7/26/01 .......................................... 68 Figure 40. Panhandle Lake brook trout-7/26/01 ................................ 71 Figure 41. Ryan Lake-7/80 ................................................ 72 Figure 42. Ryan Lake-8/22/01 .............................................. 72 Figure 43. Ryan Lake brook trout-8/22/01 .................................... 74 Figure 44. St. Helens Lake-6/81 ............................................ 76 iii List of Figures (cont.) Figure 45. St. Helens Lake-9/11/00 .......................................... 76 Figure 46. Lake trout from St. Helens Lake-9/11/00 ............................. 78 Figure 47. Shovel Lake-7/80 ............................................... 82 Figure 48. Shovel Lake-8/24/02 ............................................ 82 Figure 49. Snow Lake- 1984 ............................................... 85 Figure 50. Snow Lake-8/24/02 ............................................. 85 Figure 51. Spirit Lake-1977 ................................................ 89 Figure 52. Spirit Lake-7/80 ................................................ 89 Figure 53. Spirit Lake-8/23/02 .............................................. 89 Figure 54. Spirit Lake rainbow trout-7/26/00 .................................. 92 Figure 55. Spirit Lake rainbow trout-7/26/00 .................................. 92 Figure 56. Strawberry Lake-8/23/02 ......................................... 95 Figure 57. Strawberry Lake brook trout-6/3/81 ................................. 97 Figure 58. Strawberry Lake brook trout-8/24/02 ................................ 97 Figure 59. Tradedollar Lake-7/80 ........................................... 98 Figure 60. Tradedollar Lake-7/11/00 ......................................... 98 Figure 61. Venus Lake-7/80 .............................................. 102 Figure 62. Venus Lake-7/29/01 ............................................ 102 Figure 63. Venus Lake rainbow trout-7/31/01 ................................. 105 iv List of Tables Table 1. Boot Lake water quality data ......................................... 9 Table 2. Boot Lake fish plants.............................................. 10 Table 3. Castle Lake water quality data ....................................... 12 Table 4. Castle Lake rainbow trout fishery surveys ............................. 14 Table 5. Castle Lake rainbow trout growth rates ................................ 15 Table 6. Coldwater Lake water quality data ................................... 18 Table 7. Coldwater Lake fish plants ......................................... 19 Table 8. Coldwater Lake rainbow trout fishery surveys .......................... 21 Table 9. Coldwater Lake rainbow trout growth rates ............................ 22 Table 10. Elk Lake water quality data-8/12/00 ................................. 24 Table 11. Elk Lake fish plants .............................................. 24 Table 12. Elk Lake brook trout fishery surveys