This resource explores the concept of symbiosis within marine ecosystems, particularly focusing on coral reefs. It describes the different types of symbiotic relationships: mutualism, commensalism, and parasitism. Each type is defined and illustrated with examples from the ocean environment, such as bees and flowers representing mutualism, barnacles and whales for commensalism, and ticks as parasites. The document encourages critical thinking by posing questions about real-life interactions and the potential changes in these relationships over time. It also includes activities for identifying local symbiotic relationships, enhancing engagement and understanding of biological interactions in nature.