Coastal landscapes & indigenous histories of shellfish harvesting in Atlantic Canada: Mya arenaria as a new proxy for shellfish harvesting pressure in Port Joli, Nova Scotia.

Predham, Ian Thomas Gordon (2023) Coastal landscapes & indigenous histories of shellfish harvesting in Atlantic Canada: Mya arenaria as a new proxy for shellfish harvesting pressure in Port Joli, Nova Scotia. Masters thesis, Memorial University of Newfoundland.

[English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (5MB)

Abstract

Marine bivalves from archaeological shell middens sites reveal critical information about past environments, harvesting strategies, and human impacts on shellfish populations. However, robust sample sizes are required to develop meaningful interpretations over time and space. Port Joli, Nova Scotia (NS), has the densest concentration of shell midden deposits in Atlantic Canada, dating to ~1600 cal BP. A protocol for rapid-age at-death assessments of Mya arenaria, was developed by analysing live-collected M. arenaria to establish a baseline for interpreting archaeological shell growth patterns. Rapid-age-at-death assessments of M. arenaria reveal insights for both sclerochronological methods and archaeological interpretation. One-hundred archaeological shells were selected from six shell middens to interpret regional trends in shellfish harvesting. Chondrophores were sectioned to 3mm, mounted on slides, polished, and imaged using reflected light at 20x. Each image was analysed by four independent observers to assess: 1) quality of growth lines; 2) shell portion with the clearest lines; 3) relative age; 4) ontogenetic age; 5) season of death. Variation in growth patterns was observed between modern and archaeological specimens, with modern shells having better clarity. Further variation was observed with readability between archaeological sites and variation in the average age between sites, suggesting that some clam beds were harvested more than others. The results also demonstrate the level of experience in sclerochronology will produce more conservative age and seasonality estimates, and that novice readers are more likely to miss-characterize growth patterns.

Actions (login required)

View Item