Which factors influence Manila clam survival on Lummi Nation tidal flats?

Over recent decades, Manila clam populations have steadily declined on the tidal flats of the Lummi Reservation just outside of Bellingham, Washington. The loss of this important food source directly impacts tribal food security and sovereignty of the Lummi people. The Northwest Indian College (NWIC) Salish Sea Research Center has teamed up with Oregon State University to study what is causing the decline. With two NIFA grants, we are looking at two possible causes: altered sulfur cycling and changes in food supply. Hydrogen sulfide is a compound that is toxic to most animals. On tide flats, sulfide can become more prevalent if the abundance of organic carbon increases, which leads to bacterial growth that exhausts the oxygen supply and generates hydrogen sulfide. Our goal is to understand the role of sulfide in limiting the clam populations to devise effective management schemes. Manila clams are suspension feeders, meaning they filter the water and surface sediments for food items such as plankton, detritus, and bacteria. Many factors influence the abundance of these various food sources seasonally, which can be a limiting feature to the success of a population. Through quantifying what the clams are eating and how this changes seasonally, we hope to better understand the link between food supply and clam survival. By the end of this project we will better understand what is impacting the Manila clam and will have provided hands on experiences for many Native Scholars