Variability and change in the west Antarctic Peninsula marine system: research priorities and opportunities

•The WAP shelf ecosystem is regionally important for krill and higher trophic levels.•Long-term climate change and short-term natural variability control sea ice dynamics.•Physical changes regulate ecosystem functioning, biogeochemistry and air-sea exchange.•The WAP is a model system for how sea ice changes can restructure polar ecosystems.•Future research requires international cooperation and interdisciplinary integration.