Hypoxia and cumulative impacts on seafloor ecosystem function

Although previous research has documented changes associated with reduced oxygen and bottom trawling, we know little about how these human perturbations act in concert. The continental margin off Vancouver Island offers a unique opportunity to examine the cumulative effects of these drivers of change because oxygen concentrations and trawling activities have both been mapped in detail and indicate locations where these activities overlap and locations with either one of the activities or neither occurs. These maps provide an opportunity to examine separate and combined effects of these activities on seabed organisms spanning from microbes to small invertebrates to fish adaptation. This work will include experimental manipulations of oxygen to determine how changes alter function in short-term incubations. We will also examine how these activities influence flatfish, an “ecosystem engineer” that plays a major role in role in recycling silica and other nutrients.