Alaska Fisheries Science Center National Marine Fisheries Service U.S DEPARTMENT OF COMMERCE AFSC PROCESSED REPORT 2006-12 Eulachon: A Review of Biology and an Annotated Bibliography August 2006 This report does not constitute a publication and is for information only. All data herein are to be considered provisional. Notice to Users of this Document This document is being made available in .PDF format for the convenience of users; however, the accuracy and correctness of the document can only be certified as was presented in the original hard copy format. EULACHON: A REVIEW OF BIOLOGY AND AN ANNOTATED BIBLIOGRAPHY by 1 2 3 4 M. F. Willson , R. H. Armstrong , M. C. Hermans , and K Koski 1 University of Alaska Southeast School of Fisheries and Ocean Sciences Juneau, AK 99801 2 5870 Thane Road, Juneau, AK 99801 3 9630 Moraine Way, Juneau, AK 99801 4 Auke Bay Laboratory Alaska Fisheries Science Center National Marine Fisheries Service 11305 Glacier Hwy. Juneau, AK 99801-8626 Auke Bay Laboratory Alaska Fisheries Science Center National Marine Fisheries Service National Oceanic and Atmospheric Administration 11305 Glacier Hwy. Juneau, AK 99801-8626 August 2006 iii PREFACE This review and annotated bibliography was stimulated by the realization that while eulachon are an important forage fish, they are also under-studied. Historically, eulachon have had relatively little commercial value, compared to more widely known species such as herring. However, this oil-rich little fish has had an important role in the culture of Natives on the coast of southeast and south-central Alaska, and First Nations on the cost of British Columbia. Eulachon ‘grease’ was a major item of trade with Natives of Interior Alaska, as well as an important food source for coastal peoples. Subsistence use of eulachon continues, at least in some areas. By the 1990s, the value of eulachon spawning runs to many wildlife species began to draw increased scientific attention, including several new studies of eulachon biology per se. Nevertheless, much remains to learn, not only about eulachon biology, but also about the ecological patterns and consequences for the predators of eulachon. The authors of this review hope that it will help stimulate research on the ecology and evolution of eulachon and their predators. This review was completed in the fall of 2003. References from fall 2003 to date are listed in an addendum at the end of this manuscript. Mary F. Willson 31 May 2006 v CONTENTS Preface……………………………………………………………………………………iii Contents…………………………………………………………………………………...v List of Tables…………………………………………………………………………….vii List of Figures…………………………………………………………………………….ix Review of Biology Introduction………………………………………………………………………………..1 Taxonomy…………………………………………………………………………………2 Scientific Nomenclature…………………………………………………………...2 Common Names…………………………………………………………………...3 English…………………………………………………………………….3 Native Languages………………………………………………………….3 Distribution………………………………………………………………………………..3 Freshwater Distribution………………………………...…………………………3 Oceanic Distribution………………………………………………………………4 Morphology……………………………………………………………………………….6 Sexual Dimorphism……………………………………………………………….7 Annual and Population Differences……………………………………………….7 Prey………………………………………………………………………………………..8 Body Composition………………………………………………………………………...8 Age, Growth, Maturation………………………………………………………………...11 vi Age at Spawning…………………………………………………………………11 Age and Length…………………………………………………………………..12 Fecundity versus Age and Body Size……………………………………..……..14 Sex Ratio…………………………………………………………………………………14 Spawning…………………………………………………………………………………16 Run Timing………………………………………………………………………18 Eggs and Larvae………………………………………………………………….23 Predators…………………………………………………………………………………25 Parasites………………………………………………………………………………….29 Eulachon Fisheries……………………………………………………………………….29 Acknowledgments……………………………………………………………………….32 Annotated Bibliography Introduction………………………………………………………………………………50 Bibliography……………………………………………………………………………..52 Web Sites……………..………………………………………………………………...215 Keyword Index……………………………………………………………………….…217 Addendum to Bibliography (2003-2006 Publications)…………………………………228 vii LIST OF TABLES 1. Eulachon spawning rivers……………………………………………………………..33 2a. Summary of eulachon body-size data for different river systems …………………...38 2b. Body size of male eulachon from the Stikine River…………………………………40 2c. Eulachon body size data……………………………………………………………...41 2d. Fork lengths and body masses for eulachon in the Twentymile River ……………...42 2e. Standard lengths and weights of eulachon from the Copper River, for four years..…43 3. Fecundity of eulachon from different river systems…………………………….…….44 4. Water temperature and incubation times of eulachon eggs in different river systems..45 ix LIST OF FIGURES 1. Eulachon spawning sites west of Cape Suckling in Alaska..……………………….…46 2. Eulachon spawning sites in Southeast Alaska………………………………………...47 3. Eulachon spawning sites in British Columbia…………………………………….…..48 4. Eulachon spawning sites in Washington, Oregon, and California.…………………...49 Review of Biology INTRODUCTION The first known reference to eulachon in English is probably that of the Lewis and Clark expedition, overwintering near the mouth of the Columbia River in 1806. The eulachon began to run in late February, and the expedition traded for them from the Clatsop Tribe for a rich and welcome change in diet. Lewis found that the fish were so oily that no additional seasoning was needed and, indeed, they were the best fish he recalled ever eating (Ambrose 1996, p. 329, Ref. 16). Eulachon have been of relatively little commercial importance and therefore less is known about them than more commercially important fishes, such as salmon. Their role in Native culture has been studied more than their basic biology and ecology. With increasing interest in the role of eulachon as important prey for many predators, including species such as Steller sea lions (Eumetopius jubatus) that are the focus of current conservation efforts, there is growing interest in knowing more about the biology and ecology of this small fish. This review is intended to bring together the available literature on eulachon and synthesize the information to provide a platform for the research that is needed to fill in the many gaps in our understanding of this species. This annotated bibliography compiles the references we have found. The vast majority of the papers are in the “gray literature”, not in refereed professional journals, which renders them less accessible to most investigators (including us); this also often makes them unacceptable, or only reluctantly acceptable, as citations for papers published in refereed professional journals. The information these “gray” papers contain 2 can be useful to researchers, however, particularly because these papers frequently represent the only written records about the species of interest. One problem with many of these gray papers is that they sometimes recycle lore or statements without attribution; it then can be hard to discern whether the information is original to that report or merely recycled from some other source. In other cases, such as web sites, the material is commonly recycled from other sources. There are a number of references for which we provide bibliographic information and keywords, but which we were unable to obtain through local library services or the Internet. The websites cited are those present when the review was published, but all websites are likely to be transient. TAXONOMY Scientific Nomenclature Eulachon have been classified previously in various other ways and placed in different genera (e.g., Scott and Crossman 1973, Ref. 390), but the present systematic classification follows Mecklenburg et al. (2002, Ref. 306): Phylum: Chordata Subphylum: Vertebrata Superclass: Gnathostomata Grade: Teleostomi Class: Actinopterygii Subclass: Neopterygii Division: Teleostei Subdivision: Euteleostei 3 Superorder: Protacanthopterygii Order: Osmeriformes Suborder: Osmeroidei Superfamily: Osmeroidea Family: Osmeridae (smelts) Genus and species: Thaleichthys pacificus (Richardson, 1836) Common Names (Hart and McHugh 1944, Ref. 192) English Eulachon: derived from the Chinook language, a synthetic trading language derived from French, English, and various First Nations languages (Hay and McCarter 2000, Ref. 210); candlefish; less commonly salvation fish, saviour fish, fathom fish. Native languages Many variants of eulachon, including hoolakan, hooligan, hoolikan, olachan, ollachan, oolachan, oolichan, oulachan, oulachon, ulchen, ulichan, uthlecan; also yshuch, swavie, chucka, juk’wan or za’xwen meaning ‘jittery fish’ in Haisla language, saak in Tlingit. DISTRIBUTION Freshwater Distribution Eulachon occur only on the coast of northwestern North America, from northern California to southwestern Alaska. They are anadromous fish, spawning in the lower reaches of mainland rivers in early spring; only a few island runs have been reported (Blackburn et al. 1981, Ref. 71). Spawning runs have been reported to occur in as few as 4 30 rivers (Hay et al. 1997, Ref. 202; Department of Fisheries and Oceans-Canada 1999, Ref. 122) or 50-60 rivers (Hay in Eulachon Research Council 2000, Ref. 145). Clearly, the number of runs depends, in part, on how they are counted: if every stream known to have a run is counted, the number is considerably larger than 60; but if one counts only the inlets, bays, and major rivers where the fish enter from the open sea, thence dispersing to the spawning sites, the number is much smaller. We have tabulated