Climate change is affecting fundamental aspects of our oceans and increasing the impact of other pressures The pressures with the highest impact on the Australian marine environment remain climate change (affecting water temperature, salinity, acidification, circulation and ocean nutrients), fishing, pollution (especially plastics; debris; and land-based inputs of sediments, excess nutrients and chemicals), oil and gas industries, and marine noise. In many areas, the combination of pressures is having a cumulative negative effect. Substantial and widespread degradation of Australia’s marine environmental values is expected if these pressures are not addressed. Pressures arising from climate change and pollution are not adequately managed; nor are cumulative effects. Water temperature, salinity, acidification, circulation and nutrients are all changing, and heatwaves are becoming more frequent and severe, with flow-on impacts on habitats and species. Plastics and other land-based pollution, in particular, are affecting marine food webs and many species. There are some success stories and improvements where human uses are the main pressures (e.g. commercial and recreational fisheries, mineral oil and gas industries). However, policy guidance for management of specific pressures is largely ad hoc and by sector, or absent. Many Australian marine habitats are healthy, but our reefs are declining Australian marine habitats, communities, taxa groups, species and ecosystem processes are predominantly in good, stable condition overall. However, reefs (both coral reefs and temperate rocky reefs) and reef-associated species (including fishes and sea snakes) are in poor condition and deteriorating as a result of the effects of climate change and cumulative pressures. Also, many habitats and communities that are in good condition overall nationally are highly impacted in some locations. Similarly, many species groups that are in good condition overall nationally include species that have undergone substantial declines. Continued improvement in scientific knowledge and investment in ocean observing have improved understanding, with assessments of state and trend now possible for several taxa groups and ecosystem processes that could not be assessed in 2016 because of inadequate information (e.g. sharks and rays, sea snakes, microbial processes). However, assessing pressures individually does not account for the interactions and feedbacks among them. Australia’s deep-sea habitats, communities and species remain poorly observed and understood. Better monitoring and marine management are needed A carefully co-designed, integrated, adaptive, long-term monitoring strategy for Australia’s marine environment is needed. This would enable future system-level assessments to help us manage cumulative effects. The requirements for such a monitoring and assessment system are known (see case study: Baselines, monitoring and integrated ecosystem assessments). What is now needed is the will and resources to achieve aspirations. Our Prime Minister is a member of the High Level Panel for a Sustainable Ocean Economy, which entails a commitment to sustainably manage our marine estate. This commitment recognises the ocean as crucial to our nation’s economy, which is also reflected in the 2021 Federal Budget, with the inclusion of a $100 million Ocean Leadership Package. The Budget announcement also recognises that the oceans and our climate are inextricably linked. First Nations’ valuing of Country (in which there is no separation of land and ocean, and no jurisdictions) is an example of the holistic approach required for future sustainability. Investing in the growth of Indigenous and organisational capabilities will strengthen our readiness for collaboration by increasing confidence and capability for cross-cultural relationship building. Fragmentation in management will persist in Australia if there is no investment in giving our communities decision-making agency, and allowing them to participate in the management, adaptation and restoration of our marine environment. Even the best management will not stop environmental decline if we do not address climate change and cumulative effects Since 2016, we have seen a dramatic increase in awareness – both nationally and internationally – of the importance of the oceans and the need for transformational change to achieve the oceans we need. Focus has been placed on the need for integrated stewardship of our oceans. This includes reconciling with Indigenous stewardship, leadership and decision-making, and sea Country management that embraces Traditional Owners as rights holders. In 2020–21, in particular, important national commitments have been made to sustainable and inclusive management to strengthen momentum and partnerships across various sectors. There is a need to reconcile tensions to meet a variety of human needs, traditional rights and agendas concerning the oceans. This will require addressing imbalances and hierarchies that policy-makers and ocean managers often know exist but may find difficult to correct. Achieving equitable, sustainable development for the oceans is a continuing challenge that will require ongoing work, restructuring for co-designed decision-making, development of models that include deeper immersion in traditional knowledge and participation, and accountable actions so that issues do not slip between the cracks.