<p>With the increase in marine spatial planning efforts the need for robust environmental assessments that account for multiple pressures of human activities on marine ecosystems is more critical than ever. However, Cumulative Effects Assessment (CEA) practice, a requirement of Strategic Environmental Assessment (SEA) of marine spatial plans, remains insufficient. This paper explores the integration of ecosystem-based approaches into SEA stages for holistic environmental assessments of marine spatial plans that prioritize ecological integrity. It also reviews advancements in marine CEA research, focusing on risk-based approaches for assessing cumulative effects, and addresses the existing disconnection between CEA science and environmental assessment practice. Emphasis is placed on improving key SEA stages that are critical to CEA by identifying principles and approaches that systematically and spatially address the interactions of various pressures and ecosystem receptors across the four dimensions (4D) of marine environments to assess cumulative effects risks. This novel approach, presents a holistic framework aimed at enhancing CEA practice within SEA of marine spatial plans, for more sustainable and ecosystem-focused planning outcomes in marine environments.</p>