ASSESSING THE IMPACTS OF CLAM GARDENS ON INVERTEBRATE SPECIES DIVERSITY IN THE SALISH SEA
Amy Irons1, Skye Augustine2, Marco Hatch1.
1Salish Sea Research Center, Northwest Indian College, Bellingham, WA, 2Gulf Islands National Park Reserve and Northwest Indian College, Bellingham, WA.
The world’s oceans are impacted by human interactions that create largely negative consequences. However, Indigenous societies developed technologies and management practices that positively benefit ecosystems and have sustained resources for millennia. One such technology is clam gardens. Clam gardens are intertidal rock-wall structures constructed by First Nations people that trap sediment and extend the area for productive clam growth. Clam gardens have been shown to increase abundance and growth rate of clams when compared to non-walled beaches. In fact, ethnographic studies have shown that clam gardens had multiple purposes besides being productive clam habitats. To better understand the ecological role of clam gardens, the purpose of this study was to quantify increased biodiversity associated with clam garden rock walls. Specifically, the following hypothesis would be tested: a clam garden rock wall will have greater species diversity when compared to a non-walled beach. Invertebrate species diversity was determined by using randomly placed 50 x 50 cm quadrats and identifying all species to the lowest taxonomic level. Preliminary results show that invertebrate biodiversity is higher on a clam garden wall when compared to a non-walled beach. This research shows the ecological impact of clam gardens on intertidal invertebrate species’ richness and 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 these technologies may be implemented in modern applications to create sustainable solutions that can positively impact resilient ecosystems.