Palaeontologia Electronica http://palaeo-electronica.org ATLAS OF COMMON SQUAMATOLOGICAL (FISH SCALE) MATERIAL IN COASTAL BRITISH COLUMBIA AND AN ASSESSMENT OF THE UTILITY OF VARIOUS SCALE TYPES IN PALEOFISHERIES RECONSTRUCTION R. Timothy Patterson, Cynthia Wright, Alice S. Chang, Leslie A. Taylor, Patrick D. Lyons, Audrey Dallimore, and Arun Kumar R. Timothy Patterson. Ottawa-Carleton Geoscience Center and Department of Earth Sciences, Carleton University, Ottawa, Ontario, K1S 5B6 CANADA. Cynthia Wright. Institute of Ocean Sciences, Fisheries and Oceans Canada, 9860 West Saanich Rd., Sid- ney, BC, V8L 4B2, CANADA Alice S. Chang. Ottawa-Carleton Geoscience Center and Department of Earth Sciences, Carleton Univer- sity, Ottawa, Ontario, K1S 5B6 CANADA. Leslie A. Taylor. Department of Earth Sciences, Carleton University, Ottawa, Ontario, K1S 5B6, CANADA. Patrick D. Lyons. Department of Earth Sciences, Carleton University, Ottawa, Ontario, K1S 5B6, CAN- ADA. Audrey Dallimore. Ottawa-Carleton Geoscience Center and Department of Earth Sciences, Carleton Uni- versity, Ottawa, Ontario, K1S 5B6 CANADA. Arun Kumar. Department of Earth Sciences, Carleton University, Ottawa, Ontario, K1S 5B6, CANADA. ABSTRACT Squamatological (fish scale) material from 48 common species found in coastal waters of British Columbia is presented. Fish-scale remains of extant species are well- preserved in Holocene core sediments in various anoxic basins along the coast of Brit- ish Columbia. These remains are of considerable value in assessing natural variation in fish populations over time. Comparative micrographs of modern fish scales as well as an assessment of their preservation potential is provided. Photographs of various scales preserved in the sedimentary record (e.g., herring, rockfish, sardines, surfperch) are provided and discussed in the context of the taphonomic alteration that typically occurs after burial. This monograph—the first atlas of fish-scale material available for the northeast Pacific—will help resolve identification problems for future fish taxono- mists, paleoceanographers, and fisheries-oriented researchers. Key words: fish scales, squamatology, paleoceanography, Holocene, British Columbia, NE Pacific Ocean. Patterson, R. Timothy, Cynthia Wright, Alice S. Chang, Leslie A. Taylor, Patrick D. Lyons, Audrey Dallimore, and Arun Kumar. 2002. Brit. Columbia Fish-Scale Atlas. Palaeontologia Electronica 4(1):88pp, 12MB; http://palaeo-electronica.org/paleo/2001_2/fish/issue2_01.htm R. TIMOTHY PATTERSON, CYNTHIA WRIGHT, ALICE S. CHANG, LESLIE A. TAYLOR, PATRICK D. LYONS, AUDREY DALLIMORE, AND ARUN KUMAR: BRIT. COLUMBIA FISH-SCALE ATLAS Copyright: Palaeontological Association, 25 January 2002 Submission: 6 March 2001. Accepted: 19 November 2001 INTRODUCTION encompass the entire North American Upwelling Zone (Baumgartner et al., 1992). There has been a resurgence of interest in the We now know that many of the oceanic driv- relationship between fish population dynamics and ers that affect fish population dynamics in the NE oceanographic processes since the highly publi- Pacific (Ware and Thomson, 1991) have greater cized Pacific salmon crisis off the west coast of than decadal scale return times, and since the set- British Columbia and the collapse of the Atlantic tlement history of the region, particularly British cod fishery. A relationship between ”ocean climate” Columbia, is relatively short, available anecdotal changes and fish populations can be inferred, but and commercial fishing records are of limited use in the Canadian context, real data are meager. in assessing long-term variation in fish populations. Shifts in the position and intensity of the Aleutian Therefore, other methodologies are required for Low-Pressure System, (over the northern North this research (Leaman, 1993). The use of osteo- Pacific) exert a major control on fisheries recruit- logical and squamatological (scale) fish remains as ment off British Columbia by influencing stratifica- proxies to estimate paleofish populations was pio- tion and coastal upwelling that can alter plankton neered in the 1960s to better understand clupeid abundance (Brodeur and Ware, 1992). Unfortu- (sardine, herring, anchovy) population dynamics nately, the nature of long-term oscillations in this off the coast of southern California (Soutar, 1966; system and the accompanying effect on fish stocks Soutar and Isaacs, 1969; Soutar and Isaacs, are not known. Thus, the analysis of a long record 1974). Subsequently research has been expanded of fish abundance data and accompanying ocean- all along the coast of the Americas (O’Connell and climate ”regime shifts” in coastal British Columbia Tunnicliffe, 2001), most recently in Effingham Inlet is of strategic value to the Canadian west coast on Vancouver Island (Dallimore, 2001). Effingham fishing industry. For example, the collapse of the Inlet has proven to be an ideal area for this Atlantic cod fishery has been partially linked to research because varved sediments deposited in North Atlantic temperature/climate variation (Smith the quiet and anoxic bottom waters of the con- and Page, 1996). tained basins archive a very well-preserved record Fishery collapses (in addition to the recent of osteological (bone) and squamatological (scale) problems experienced by the salmon fishery) have fish remains and other biologic proxies, such as occurred before on the west coast of North Amer- diatoms, dinoflagellates, and foraminifera (Patter- ica. For example, the northern Pacific sardine fish- son et al., 2000). ery, initiated in the 1920s, began to collapse in the Despite the existing body of research on fish early to mid-1940s. By the early 1950s the central remains available, it has proven surprisingly diffi- Californian fishery had also collapsed, followed by cult to identify fish remains, not because of poor the southern Californian fishery in the 1960s. This preservation, but due to a lack of accessible progressive collapse from north to south was resource material. Most of the few research groups apparently aided by a significant change in the involved in this line of research have collections pelagic habitat in the California Current system and available on hand but there have been relatively no was associated with large-scale climate change in attempts at publishing definitive comparative refer- the Pacific during the 1940s (Francis and Hare, ences, with the exception of a few non illustrated 1994). The gradual return of sardines to waters off keys (see Casteel, 1976, for summary). In this Vancouver Island since 1990 is associated with the paper we aim to rectify this deficiency by present- gradual recuperation of the populations off south- ing a detailed atlas of squamatological material col- ern California (Baumgartner et al., 1992). A grad- lected from living representatives of common ual expansion of the population probably began pelagic fish species found in southern British soon after a large-scale climate shift of the Pacific Columbia coastal waters. In addition, as some in 1977 (Robinson, 1994). Thus, although the his- important types of scales (e.g., sardines, herrings, torical fisheries record is limited for the Pacific and anchovies) become altered and fragmented in coast of North America, sardine populations are the sedimentary record, making identification diffi- known to expand and contract over time-scales of cult, we provide comparative examples of selected several decades or more and over distances that fossilized material obtained from Effingham Inlet (Figure 1). 2 R. TIMOTHY PATTERSON, CYNTHIA WRIGHT, ALICE S. CHANG, LESLIE A. TAYLOR, PATRICK D. LYONS, AUDREY DALLIMORE, AND ARUN KUMAR: BRIT. COLUMBIA FISH-SCALE ATLAS Figure 1. A. Location map of southern British Columbia showing geographic features discussed in this paper. B. Details of Effing- ham Inlet showing location of core where scales were recovered. SCALE CHARACTERISTICS scale characteristics include (1) overall scale shape; (2) position and shape of focus; (3) circuli Most fish have a covering of scales, which can appearance; (4)the appearance of the lateral, ante- be divided into a variety of types, over the outer rior, and posterior fields; and (5) to some extent, surface of their bodies. These types include the thickness/robustness of the scale. plate-like placoid scales of sharks; the diamond- As there is considerable variation in scale shaped ganoid scales of the gars; the thin, smooth, shape even between different areas of the same disk-like cycloid scales of most freshwater fish and individual fish, scale outline is not always the best many marine species; and the ctenoid scales (with indicator for identification (Figure 2; Casteel, 1972; ctenii—small projections along the posterior mar- Chikuni, 1968). Size is also generally not a desir- gins) of perches and sunfish (Casteel, 1976). All able characteristic, as scale size varies and over- the species presented in this atlas are referable to lap occurs not only between species and the cycloid and ctenoid types. Distinguishable individuals, but also within a single specimen. Cyc- 3 R. TIMOTHY PATTERSON, CYNTHIA WRIGHT, ALICE S. CHANG, LESLIE A. TAYLOR, PATRICK D. LYONS, AUDREY DALLIMORE, AND ARUN KUMAR: BRIT. COLUMBIA FISH-SCALE ATLAS due to the lack of distinguishing characteristics, species-level assignments for many groups are not possible. The terminology used to describe scales usu- ally refers to topographical features such as sur- face sculpturing or internal variations (Figures 3, 4). Lagler (1947)