Sediment runoff is a primary driver of coral reef degradation globally. Herbivorous fish (i.e., those that eat algae) are seen as a critical defense by managers worldwide to control the overgrowth of algae on corals. Yet, populations of these herbivores are rapidly declining on nearshore reefs impacted by sedimentation. Current evidence firmly establishes that fish gills undergo structural changes in response to increased levels of suspended sediment (SuS), suggesting a link between morphological alterations and potential respiratory impairment. Direct measurements of oxygen uptake in fish during SuS exposure would provide valuable insight into the physiological mechanism underpinning fish abundance. For this study, we 3D-printed novel respirometry chambers, explicitly designed with a cone-bottom shape, to allow sedimented water to enter underneath test fish and keep sediment suspended throughout respirometry experiments. Here, we present preliminary results on the oxygen uptake rate in the bioculturally important Pacific bullethead parrotfish, Chlorurus spilurus, measured not only post-exposure but also concurrently during exposure to SuS. We hypothesized that fish exposed to SuS would have a reduced metabolic scope and an extended recovery time to return to their standard metabolic rate—resulting in higher excess post-exercise oxygen consumption and signifying substantially reduced gill function.