New Angle On Northwest Coast Fish Trap Technologies:
Gis Total Station Mapping Of Intertidal Wood-Stake Features At Comox Harbour, B.C.
by Nancy A. Greene
(website (c) 2005 Nancy A. Greene)
(a brief overview of a paper presented at the CAA 2005
Conference in Nanaimo;
a manuscript is being prepared for submission to the Canadian Journal of Archaeology)
GIS total station
mapping of exceptionally well-preserved intertidal wood-stake fish trap
features at Comox Harbour, along the east coast of Vancouver Island,
Columbia, suggests an intensive fishery (1230-120 BP) using mass
harvesting technologies. The large sizes, shapes and numbers of these
archaeological features appear to be unique for the Northwest Coast,
and they hold potential for an expanded interpretation and
understanding of fishing technology in the region.
The features can been seen in concentrations of complex, overlapping alignments of wood-stake remains on the surface of the tidal flats, as clearly seen in the photograph to the right. More than 200 locations of these concentrations have been GPS mapped in two previously unrecorded archaeological sites (DkSf-43 and DkSf-44) in the harbour. Eleven of these concentrations of wood stake remains were selected from a range of tidal elevations for further mapping. To date, over 11,000 individual wood stakes have been mapped with a total station, a small percentage of the well-preserved wood-stake remains that are extensively distributed on the mudflats.
Current total station mapping and radiometric dating of wood stake remains suggest two temporally distinct feature types, or structural designs, of tidal fish trap technology, as shown in the illustration to the left.
The older technology appears to be represented by large heart-shaped enclosures with a flattened, or truncated, rear wall, with an opening toward the shoreline, and aligned with the outgoing tide. The younger technology is represented by numerous, large chevron-winged enclosures, likewise with openings toward the shoreline. Both technologies appear to have functioned using leads.
Complex 009 is an example of the total station-mapping of individual wood stakes within one of the GPS-mapped concentrations on the tidal flats. The single heart-shaped feature, with a diameter of about 42 meters, was 14C dated at 1,070 yr BP. The chevron-winged technology is represented by at least four temporally distinct overlapping trap structures. The two separate enclosures of one of the chevron-winged structures have been dated at 220 yr BP and 230 yr BP, respectively, confirming that the elements are temporally associated and likely functioned in combination to catch fish.
Mapping, radiometric dating, analysis of features, and analysis of fish species potentially harvested in these large traps are ongoing.