Interpreting Early Species Range Descriptions for Pacific Salmon, Oncorhynchus Spp., in Coastal California Watersheds: the Historical Context
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Interpreting Early Species Range Descriptions for Pacific Salmon, Oncorhynchus spp., in Coastal California Watersheds: The Historical Context BRIAN C. SPENCE Introduction tablished viability criteria for each list- range of species should be done with Scientists and fish and wildlife man- ed DPS or ESU, and development of considerable care. agers are often asked to determine the recovery plans for these listed units. In seeking to define the natural fresh- historical ranges of species in areas Likewise, historical information on the water ranges of Pacific salmon, scien- where populations have been extirpat- freshwater distribution of Pacific salm- tists and managers have often turned ed as a result of anthropogenic actions. on influenced delineation of essential to writings and collection records of For Pacific salmonids,Oncorhynchus fish habitat under the Magnuson Act pioneering ichthyologists to substanti- spp., freshwater or spawning range de- (PFMC, 1999). ate the historical occurrence in partic- terminations have been critical in sev- Misidentification of historical sal- ular regions or watersheds. These ear- eral phases of Endangered Species Act monid habitats can have important ly descriptions and accounts are gen- (ESA) implementation. These include ramifications. On one hand, failure to erally assumed to provide evidence of the delineation of distinct popula- accurately identify a portion of a spe- occurrence during periods when the tion segments (DPS’s) or evolutionari- cies’ natural range could result in un- impacts of harvest and habitat degra- ly significant units (ESU’s) considered derestimation of habitat loss and lead dation were less pervasive. For salm- for ESA listing, designation of criti- to inadequate protection of habitats on in California, the writings of Da- cal habitats, development of technical that may be important to the long- vid Starr Jordan, Charles Henry Gil- guidance documents that both posited term recovery, persistence, evolution, bert, John Otterbein Snyder, and other historical population structure and es- or sustained production of an ESU or faculty and staff at Stanford University DPS. Conversely, incorrectly conclud- during the late 1800’s and early 1900’s ing that a species occupied a water- have been particularly influential (Fig. shed or region when it did not could 1). These scientists, as well as collab- Brian C. Spence is with the Fisheries Ecology Division, Southwest Fisheries Science Center, lead to costly recovery efforts and re- orators such as Barton Warren Ever- National Marine Fisheries Service, NOAA, 110 strictions on human activities in water- mann (a former student of Jordan’s Shaffer Road, Santa Cruz, CA 95060 (email: [email protected]). sheds where the likelihood of natural- at Indiana University), worked close- ly sustaining populations is negligible. ly with the United States Commission doi: https://doi.org/10.7755/MFR.81.1.1 Consequently, assessing the historical of Fish and Fisheries (U.S. Fish Com- ABSTRACT—Scientists and manag- scientists and others have often taken these es. Further confounding interpretation of ers implementing endangered species laws early range descriptions at face value, early reports is that the first systematic ex- often face the task of defining the histori- without critically examining the underlying plorations of coastal watersheds took place cal geographic ranges for threatened and historical context. When Jordan and his well after significant anthropogenic damage endangered species. To do so, they com- contemporaries first began writing about to salmon habitats had already occurred; monly turn to the writings of early biolo- the ranges of Pacific salmon, scientific ex- thus, failure to detect species on these sur- gists seeking accounts of species in regions ploration of coastal watersheds of Cali- veys does not necessarily indicate a species where they may have been extirpated as a fornia was in its infancy. Additionally, the was absent, either at the time of the survey result of anthropogenic activities over the taxonomy and nomenclature of Pacific sal- or in the years prior to significant human last 150–175 years. In the case of Pacific monids were in states of extreme disarray, disturbances. As a result, any single writ- salmon, Oncorhynchus spp., the writings with numerous putative species described ing of Jordan’s and his colleagues between of David Starr Jordan, Charles Henry Gil- based on variations due to age, sex, and the late 1870’s and the early 1900’s is like- bert, John Otterbein Snyder, and other fac- reproductive condition. ly to contain species range information that ulty and staff at Stanford University during Even after Jordan and Gilbert began is equivocal, if not demonstrably inaccu- the late 1800’s and early 1900’s have been to resolve Pacific salmon taxonomy in the rate. This is not to disparage Jordan and his particularly influential, as these scientists 1880’s, confusion in nomenclature, exacer- contemporaries in any way or to diminish were widely recognized as the leading au- bated by a primitive understanding of Pacif- their extraordinary scientific achievements. thorities on west coast fishes and salmo- ic salmon life histories, contributed to fre- However, scientists and managers need to nids in particular. quent misidentification of west coast salmo- be cognizant of these limitations when using Because of the tremendous achieve- nids and hence inaccurate descriptions of historical writings to guide management of ments of these pioneering ichthyologists, their historical freshwater spawning rang- endangered species. 81(1) 1 cal context within which these writ- ings and observations were embedded. This context has many dimensions, the understanding of which is critical to proper interpretation (Fig. 2). First, the earliest descriptions of the distributions of California fishes, in- cluding the Pacific salmonids, were based on a very limited number of scientific surveys or collections, with data from coastal watersheds of Cali- fornia being particularly sparse. Second, prior to the 1900’s, the tax- onomy and nomenclature of Pacific salmonids were in complete disarray; hence, not all reports of occurrence of a particular species in either the scien- tific or popular literature are necessar- ily reliable. Third, even after more systemat- ic surveys of California’s freshwater fish faunas were initiated and some of the taxonomic ambiguity had been re- solved, misidentification of collected specimens remained commonplace, in part because of the poor understanding of salmonid life histories that existed at the time. Fourth, significant artificial culture and transplanting of certain Pacific salmonids in California began in the 1870’s; thus, the potential exists for some early records of salmonid occur- rence to be the product of hatchery re- leases. Finally, by the mid- to late-1800’s, significant alteration of freshwater habitats had already occurred as a re- sult of logging, mining, cattle graz- ing, dam building, agricultural land conversions, water diversions, release Figure 1.—Renowned ichthyologists of the late 1800s whose writings and explora- of pollutants, and other human activ- tions of California’s fish fauna contained or influenced early range descriptions for ities. Thus, in many areas local extir- Pacific salmon, including (clockwise from top left) David Starr Jordan (ca. 1879), Charles Henry Gilbert (ca. 1880), John Otterbein Snyder (ca. 1900), and Barton pations of salmon and steelhead, O. Warren Evermann (ca. 1899). (Photos: Jordan, Gilbert, and Snyder from Stanford mykiss, populations likely occurred Historical Photograph Collection (SC1071). Evermann from California Academy well before any formal scientific sur- of Sciences GSMAEL.) veys of native fish faunas had taken place. All of these issues potentially mission) and were widely recognized and Lindsey, 1970; Scott and Cross- confound the interpretation of histori- as the leading authorities on fishes man, 1973; Behnke, 2002; Wydoski cal evidence. of North America during this era. In- and Whitney, 2003; Quinn, 2005). In this paper, I endeavor to provide deed, the Pacific salmon range descrip- Owing to the lofty achievements and historical context for interpreting ear- tions of Jordan and his contemporaries status these ichthyological luminar- ly Pacific salmon1 species distribu- from the late 1800’s continue to be ref- ies attained, scientists have often tak- 1In this paper, I use the term “Pacific salmon” erenced, either directly or indirectly, in en these early accounts at face value when referring to the five semelparous species many books and reports (e.g., McPhail without fully considering the histori- of Pacific salmon O.( tshawytscha, O. kisutch, 2 Marine Fisheries Review tion information in the coastal regions of California, focusing on the writings and collection records of David Starr Jordan and his contemporaries during the late 1800’s and early 1900’s. Cal- ifornia marks the southernmost lim- its of the current distributions of both coho salmon, O. kisutch, and Chinook salmon, O. tshawytscha. Pink, O. gor- buscha, chum, O. keta, and sockeye salmon, O. nerka, have also been re- ported in the state, though it remains equivocal as to whether or not persis- tent populations of these latter three species have occurred in California under climatic conditions that have prevailed in the past 150–200 years. This paper does not seek to provide definitive answers regarding the histor- ical freshwater ranges of the different species