We study variation in the structure and function of aquatic ecosystems and its consequences for people. We are particularly interested in the interactive roles of climate, predators and resources, and the importance of evolutionary change for ecological processes. Variability is everywhere you look in the natural world; some places are green and lush, others barren; some have more species than you could ever count, others just a few; some are dominated by plants, others by animals. These contrasts matter tremendously for human welfare, and ecosystems can become degraded to the point where our health and well-being are impaired. Ultimately, questions of how ecological and evolutionary changes affect human well-being, and how best to maintain the value of ecosystem services, motivate our research.