Assessing the Impacts of Clam Gardens on Invertebrate Species Diversity in the Salish Sea

The world’s oceans are impacted by human interactions that create largely negative consequences, however Indigenous societies have developed technologies and management practices that have been shown to have positive benefits on ecosystems and have sustained resources for millennia. One such technology is clam gardens; clam gardens are rock wall structures constructed by First Nations people within the intertidal area that trap sediment and extend the area for productive clam growth. Clam gardens have been shown to increase the abundance and growth rate of clams when compared to non-walled beaches. While researchers have primarily focused on how clam gardens have increased the productivity of clams, the rock wall structure may also alter conditions for other invertebrate species. In fact, ethnographic studies have shown that clam gardens had multiple purposes besides being productive bivalve habitats. To better understand the ecological role of clam gardens, this study quantified invertebrate community structure on a clam garden rock wall and compared it to a control non-walled beach with similar tidal height and wave energy. This research shows that the clam garden rock wall has greater invertebrate diversity and a different ecological community structure than similar non-walled beaches. This study acts as an example of how traditional technologies can aid in maintaining complex marine invertebrate communities. In this way, we can look to First Nations technologies that have worked for millennia and see how they may be implemented in modern applications to create sustainable solutions that can positively impact resilient ecosystems