Excess nutrients can be problematic in many ecosystems, and the application of biological response indicators can help provide a more holistic understanding of impairments. Nutrient concentrations alone, particularly in a nutrient-rich estuary, are not sufficient to evaluate potential impacts. High temporal and spatial variability is the back-drop for assessing change over time, and different processes can dominate in different areas of the estuary over varying time scales. When available, multiple response indicators can inform assessments. In this example, potential eutrophication water column processes in Central Puget Sound, WA are assessed. Specifically, nutrient and chlorophyll levels, phytoplankton abundance and species composition, physical characteristics, and dissolved oxygen levels are reported.  In Central Puget Sound, while macronutrient concentrations have increased over the last two decades, chlorophyll and dissolved oxygen observations do not show clear trends or changes over time. Together, these data suggest that other drivers such as the hydrological cycle, estuarine circulation, and climate play important roles in modulating these indicators. These processes and interactions are complicated, and indicators of ecosystem health and sensitivity can be difficult to communicate to policy makers and the general public.