Share the knowledge on the ocean

The ocean is the foundation of life on Earth. But its health is at grave risk as ecosystems and habitats approach or surpass critical tipping points. In the search for solutions, ocean science is indispensable. The third World Ocean Assessment offers the most comprehensive evaluation to date, providing Governments, institutions and the public with the evidence needed to shape coordinated, effective action.

Read the full summary

Sections and chapters

Section 1: Overall summary

The ocean covers more than 70% of the planet and is the largest and most interconnected ecosystem. It serves as the planet's primary life-support system and contains the majority of Earth's biodiversity. The ocean plays a crucial role in global nutrient cycles, particularly the carbon and nitrogen cycles, and is a major producer of oxygen.

Section 2: Approach to the assessment

The development of the third World Ocean Assessment was organized around three major steps: (a) scoping; (b) development of the outline; and (c) drafting and reviewing. Each of the steps is described in the present section. Interwoven within these steps were discussions on the frameworks and methodologies to be adopted, the strategies to be used to update the second Assessment, the expertise needed to produce the present Assessment, and the delivery methods to be employed.

Section 3: Global overview of ocean governance

Ocean governance is shaped by a complex and dynamic interplay of multilevel intergovernmental institutions, instruments and regimes in which concepts, principles and means of implementation are developed and adopted. The application of ocean governance concepts across global and regional institutions strengthens legal connectivity, enhancing coherence and synergies in governance. The present section is the first dedicated section on ocean governance in a World Ocean Assessment, as in previous Assessments it was addressed it within specific chapters, such as on fisheries.

Section 4: Changes since the second World Ocean Assessment

Section 4 of the third World Ocean Assessment is focused on providing details of the changes that have occurred in the ocean since the period covered by the second Assessment, i.e. between 2018 and 2023, relating directly to the corresponding chapters in the second Assessment. All relevant information is described with respect to various geographical ocean regions.

Section 5: Socioecological systems

The ocean is more than just a vast body of water-it is a dynamic, interconnected system where human societies and natural ecosystems are deeply intertwined. Human activities, from fishing and shipping to tourism and energy production, have a profound impact on marine ecosystems. At the same time, the ocean's health determines the well-being of communities worldwide, influencing food security, livelihoods and even public health. The present section contains an exploration of the complex socioecological systems of the ocean, emphasizing that sustainable management involves both conserving nature and ensuring the well-being of communities that rely on the ocean for their livelihoods.