The 2nd international workshop on the ICED Southern Ocean Sentinel was held at CCAMLR Headquarters on 7-11 May 2012 in Hobart, Australia, hosted by the Australian Antarctic Division and the Antarctic Climate and Ecosystems Cooperative Research Centre. This paper provides a preliminary report on the discussion on strategies for measuring change in Southern Ocean marine ecosystems, including ship-based and land-based monitoring and integrated studies. The workshop agreed a work plan for benchmarking Southern Ocean ecosystems in 2020 and for establishing routine activities for estimating change in those ecosystems. As part of ICED and contributing to Theme 6 Biology of the Southern Ocean Observing System, this program of work will build on the work of the CCAMLR Ecosystem Monitoring Program, GLOBEC and other international programs. It is recommended that the Scientific Committee of CCAMLR become involved in this work, particularly through the Working Group on Ecosystem Monitoring and Management and the experts involved in the CCAMLR Ecosystem Monitoring Program. The outcomes of this work will be important for CCAMLR in measuring the status and trends of Southern Ocean ecosystems, particularly in support of developing management procedures for fisheries and in conserving marine biodiversity.