FISH SPECIES OF SPECIAL CONCERN IN CALIFORNIA Second Edition by PETER B. MOYLE, RONALD M. YOSHIYAMA, JACK E. WILLIAMS, AND ERIC D. WIKRAMANAYAKE Department of Wildlife & Fisheries Biology University of California, Davis Davis, California 95616 The California Department of Fish and Game commissioned this study as part of the Inland Fisheries Division Endangered Species Project. Specific recommendations from this study and in this report are made as options by the authors for the Department to consider. These recommendations do not necessarily represent the findings, opinions or policies of the Department. Prepared for the State of California The Resources Agency, Department of Fish and Game, Inland Fisheries Division Rancho Cordova Final Report for Contract No. 2128IF June 1995 TABLE OF CONTENTS PREFACE................................................................................................................... v INTRODUCTION..................................................................................................... 1 ACKNOWLEDGMENTS ....................................................................................... 4 KERN BROOK LAMPREY ................................................................................... 13 GOOSE LAKE LAMPREY. ................................................................................... 17 KLAMATH RIVER LAMPREY............................................................................ 20 RIVER LAMPREY ................................................................................................... 23 GREEN STURGEON .............................................................................................. 26 SPRING-RUN CHINOOK SALMON .............................................................. 36 SACRAMENTO RIVER LATE-FALL CHINOOK SALMON .................... 48 COHO SALMON........................................................................................................ 53 PINK SALMON ..................................................................................................... 60 CHUM SALMON.............................................................................................. 64 SUMMER STEELHEAD ....................................................................................... 95 SOUTHERN STEELHEAD .................................................................................. 79 EAGLE LAKE RAINBOW TROUT .................................................................... 85 KERN RIVER RAINBOW TROUT ................................................................... 91 VOLCANO CREEK GOLDEN TROUT .......................................................... 94 GOOSE LAKE REDBAND TROUT.. .................................................................. 98 MCCLOUD RIVER REDBAND TROUT .......................................................... 105 COASTAL CUTTHROAT TROUT. ..................................................................... 109 LONGFIN SMELT ................................................................................................ 114 EULACHON ............................................................................................................... 123 ii LAHONTAN LAKE TUI CHUB ..................................................................... 128 COWHEAD LAKE TUI CHUB ............................................................................. 132 EAGLE LAKE TUI CHUB .............................................................................. 136 GOOSE LAKE TUI CHUB ................................................................................. 139 HIGH ROCK SPRING TUI CHUB ................................................................. 143 BLUE CHUB ..................................................................................................... 147 ARROYO CHUB ................................................................................................... 150 CLEAR LAKE HITCH . .............................................................................................. 153 CALIFORNIA ROACH ............................................................................................ 158 SACRAMENTO SPLITTAIL ................................................................................. 164 HARDHEAD................................................................................................................. 171 AMARGOSA CANYON SPECKLED DACE ................................................... 175 SANTA ANA SPECKLED DACE ....................................................................... 179 OWENS SPECKLED DACE ................................................................................ 184 GOOSE LAKE SUCKER ............................................................................... 188 OWENS SUCKER ............................................................................................... 191 KLAMATH LARGESCALE SUCKER ............................................................... 194 MOUNTAIN SUCKER ............................................................................................. 197 SANTA ANA SUCKER ........................................................................................... 201 SARATOGA SPRINGS PUPFISH. ........................................................................ 206 AMARGOSA PUPFISH ............................................................................................... 211 SHOSHONE PUPFISH.................................................................................... 215 SALT CREEK PUPFISH. .................................................................................... 219 SHAY CREEK THREESPINE STICKLEBACK ............................................ 222 SACRAMENTO PERCH ..................................................................................... 227 iii RUSSIAN RIVER TULE PERCH......................................................................... 232 TIDEWATER GOBY............................................................................................... 235 BIGEYE MARBLED SCULPIN....................................................................... 240 RETICULATE SCULPIN.................................................................................... 243 LITERATURE CITED.............................................................................................. 246 iv INTRODUCTION The freshwater fish fauna of California is in serious trouble. Species, subspecies, salmon runs, and unique populations are on a fast track to extinction (Moyle and Williams 1989). The rapid rate of loss is of more than just local interest: 66 of the 116 native fish taxa are found only in California, and many of the remainder are shared with only a few other western states. In the event these fishes are lost from California, they will be globally extinct; there are no populations in some distant or remote location that can be used to resurrect the local populations. These fishes represent millions of years of evolutionary response to the fluctuating and often harsh aquatic environments of the state. As a result, there is extraordinary diversity of form and function among the native fishes. They are found in habitats ranging from tiny desert springs, to rivers that have huge fluctuations in flow, to high mountain streams, to shallow alkaline lakes, to salty estuaries. Although the native fishes are admirably suited for surviving the vagaries of nature, they have done poorly when forced to compete with humans for the waters that are their homes. Most streams have been dammed, diverted, turned inside out by mining, or altered by poor watershed management. Many lakes and marshes have been drained or filled in. Waters of all types have been polluted to one degree or another. Furthermore, numerous non-native fishes have been introduced that compete with or prey on the natives. In the first edition of this report (Moyle et al. 1989) we delineated the severity of the problem by documenting 52 species, subspecies, or salmon runs that required special protection or management to prevent their ultimate extinction. In addition to these 52 taxa, six forms already were extinct and 15 others had been formally listed as threatened or endangered by the state. In total, these 73 taxa represented 64 percent of the freshwater fish fauna of California. Unfortunately, in the short period since the first report, the situation has become substantially worse, in large part because prolonged drought accelerated the declines of many species. In the present report, we have added seven species accounts (green sturgeon1, longfin smelt, eulachon, chum salmon, Sacramento late-fall run chinook salmon, southern steelhead, and blue chub) and have removed three (Modoc brook lamprey, delta smelt, and winter-run chinook salmon). The lamprey was removed because we no longer regard it as a valid species, and the delta smelt and winter-run chinook were removed because they have been formally listed by the state as threatened or endangered species. Among the forms included in both editions, 19 have been downgraded to a worse category (e.g., from special concern to threatened or endangered) and only two (Gualala roach and Lahontan lake tui chub) have been upgraded. In this report, we treat 54 taxa (Table 1), of which 25 are recommended for threatened or endangered status in California and 27 others are regarded as needing special attention to prevent further declines. Two of the species are probably extinct in the state (pink salmon, High Rock Spring