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Appendix C: An Analysis of Three Shellfish Assemblages from Tsʼishaa, Site DfSi-16 (204T), Benson Island, Pacific Rim National Park Reserve of Canada by Ian D. Sumpter Cultural Resource Services, Western Canada Service Centre, Parks Canada Agency, Victoria, B.C. Introduction column sampling, plus a second shell data collecting method, hand-collection/screen sampling, were This report describes and analyzes marine shellfish used to recover seven shellfish data sets for investi- recovered from three archaeological excavation gating the siteʼs invertebrate materials. The analysis units at the Tseshaht village of Tsʼishaa (DfSi-16). reported here focuses on three column assemblages The mollusc materials were collected from two collected by the researcher during the 1999 (Unit different areas investigated in 1999 and 2001. The S14–16/W25–27) and 2001 (Units S56–57/W50– source areas are located within the village proper 52, S62–64/W62–64) excavations only. and on an elevated landform positioned behind the village. The two areas contain stratified cultural Procedures and Methods of Quantification and deposits dating to the late and middle Holocene Identification periods, respectively. With an emphasis on mollusc species identifica- The primary purpose of collecting and examining tion and quantification, this preliminary analysis the Tsʼishaa shellfish remains was to sample, iden- examines discarded shellfood remains that were tify, and quantify the marine invertebrate species collected and processed by the site occupants for each major stratigraphic layer. Sets of quantita- for approximately 5,000 years. The data, when tive information were compiled through out the reviewed together with the recovered vertebrate analysis in order to accomplish these objectives. In fauna materials, will contribute to our understand- addition, the data sets were used to explore other ing of past ecosystems and subsistence patterns in interpretative studies, such as: to examine patterns the Barkley Sound area. Furthermore, the analy- in intertidal shell gathering strategies and subsist- ses of both invertebrate and vertebrate remains ence through time and space; to identify particular will augment interpretations regarding local food habitats exploited for shellfish gathering; to make resource availability, habitat exploitation, food intra-site comparisons between the late and early procurement strategies, scheduling of human and temporal components; and to contribute information food resources, and pre-contact economics. on shell midden site formation processes by exam- This study comprises four sections. It com- ining the grain-size distributions of specific shell mences with a description of the field and post- species per stratigraphic layer and excavation area. field procedures used in the identification and This section describes the procedures used for quantification of the invertebrate samples. The processing the marine shell samples in the field and second section consists of descriptions and com- laboratory and the methods of species identifica- parisons of the assemblages, highlighting intra-site tion and quantification. While the discussion below and temporal patterns. Other quantitative and inter- focuses on the three 1999 and 2001 column assem- pretative studies are presented in the third section blages, information pertaining to all seven column with discussions exploring grain size distributions, and hand-collection/screen sample data sets are bivalve umbo counts, dietary contributions of presented for interest to other researchers. different shellfish species, intertidal habitats exploited, and species ubiquity. The fourth section Field and Laboratory Processing of Column and includes a conclusion. Hand-Collection/Screen Samples The marine mollusc assemblages discussed below were obtained using a vertical column sampling Four vertical column and three hand-collection/ strategy. During the 3-year archaeological project, screen sample assemblages of various sizes and 136 volumes were collected during the 3-year excava- The three column samples were placed so that tion project at Tsʼishaa for the purpose of analyz- they would intersect all shell-bearing stratigraphic ing shellfish and small vertebrate remains. All layers within their corresponding excavation units. column and hand-collection/screen samples were The two early component column samples from removed by trowel. units S62–64/W62–64 and S56–57/W50–52 in- Two of the four columns (1999 Unit S14–16/ tersected four (A–D) and two (B–C) stratigraphic W25–27, 2000 Unit N2–4/W102–104) were col- layers, respectively. Late component column lected at the same time that their respective units sample, S14–16/W25–27, intersected six of seven were being excavated; two (2001 units S62–64/ stratigraphic layers extending through its unit W62–64 and S56–57/W50–52) were removed af- (A–C, E–G). Stratigraphic layers in the midden ter excavations were completed. In most cases, the deposits were not continuous between excavation sediment samples were collected in 10 cm levels units, and as such stratigraphic Layer A located in (at maximum) to the base of each matrix layer, the main village midden does not correspond with thus eliminating concerns regarding stratigraphic an upper-lying Layer A on the elevated landform mixing and ensuring uncontaminated samples for deposit behind the village. later inter-layer comparisons. In the field the sam- Three hand-collection/screen grab sample data ples were stored in plastic zip-lock bags for later sets were also collected for marine mollusc species water screening through a series of nested hand identification and quantification. These assem- screens comprising four mesh sizes: 25 mm (1"), blages included: two recovered from the village 1 12.5 mm (½"), 6.3 mm (¼"), and 3 mm ( ⁄8"). The midden proper, 1999 Unit S14–16/W25–27 and objective of processing the shellfish assemblages 2000 Unit N2–4/W102–104; together with screen through the nested screens was to quantify rela- materials recovered from 2001 Unit S62–64/W62– tive abundance of shellfish taxa, to interpret grain 64, positioned on an elevated landform behind the size distributions of selected invertebrate species, village midden proper. All hand-collection/screen and to examine breakage patterns and taphonomic grab samples were collected from three excava- processes by level and stratigraphic layer. One col- tion units that measured 2 x 2 metres. Most levels umn, from 1999 Unit S14–16/W25–27, was water measured 10 cm thick, but in some cases they screened and sorted on site for public interpretation varied in volume according to the thickness and purposes. The two 2001 columns were washed and configuration of the matrix layer. processed in the Parks Canada archaeology lab, The hand-collection/screen sample shellfish Victoria. Unit N2–4/W102–104 column sample, assemblages comprised mostly whole shell speci- recovered from the west end of the village midden mens, valves with hinges and umbones, and sam- in 2000, was not examined. ples of gastrapods, univalves, and barnacles that Due to time constrains and the rich abundance were troweled or hand collected during excavation of shell material, not all level samples from the or grabbed from the ¼" sifting screen. Following 1999 and 2001 column assemblages were ex- collection, the hand collected/screen specimens amined (Table 1). Approximately 50% or more were placed into their respective marked proven- level samples (odd number only) in columns ience bags (paper) and stored for later identifica- S62–64/W62–64 and S56–57/W50–52 from the tion. In using this strategy, larger and whole shell elevated landform behind the village were studied. specimens are well represented, while smaller and In column S14–16/W25–27, located in the central more friable molluscs tend to be under represented. portion of the village midden proper, only 12 of 37 The potential biases and subsequent results and level samples were analyzed because of the depth misinterpretations from using this judgemental of cultural deposits (3.5 m dbs). Table 1 summa- sampling technique have been stressed elsewhere rises column sample and volumetric data for those by Northwest Coast archaeologists (Frederick assemblages discussed in this study. 2002, pers comm.; Hanson 1991; Muckle 1986). Table 1. Tsʼishaa shellfish column sample and volume data. # of Major Vertical Depth # of Levels Sample Volume Level Sample Stratigraphic of Column Analytical Column Sample Examined (x 1000 cm3) Sample Size Fraction by Vol Layers in Column (m dbs) Sample Wt (g) S14–16/W25–27 12 71.9 25 x 25 x 10 33% 6 3.50 m 32,964.8 S56–57/W50–52 13 12.9 10 x 10 x 10 52% 2 2.49 m 5,812.3 S62–64/W62–64 5 20 20 x 20 x 10 55% 4 0.88 m 4,885.2 137 1 In the laboratory, all selected column sediment uring less than ⁄8" and calcite/calcium carbonate samples were weighed prior to processing. The debris accumulated as a result of sample handling samples were then dumped into the top of four and processing were not examined, but were saved stacked 8-inch diameter sieves (25 mm, 12.5 mm, for later inspection. 6.3 mm, 3 mm), gently shaken, and washed. The Shellfish remains were quantified using shell- contents from each sieve was placed onto news- fish weights and relative frequency. Quantification paper and air-dried for later sorting and weighing. measures of bivalve species are also supported 1 Sieved materials measuring less than ⁄8" (3 mm) with umbo (or beak) counts. While some research- were not examined. All dried samples were then ers have identified problems with using shellfish hand sorted and the constituents separated into weight and umbo count as shellfish quantification three groups: shell, vertebrate fauna, and non-fau- variables (Calvert 1980; Classen 1998), the appli- na. Non-fauna material comprised rocks, rootlets, cation of these variables with column sample data and charcoal. Found artifacts were collected and is deemed a more reliable representative unit of submitted for cataloguing. The constituents from measurement than relying on 6.3 mm (¼") hand- each mesh size were then weighed and the infor- collection/screen shell data.

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