Which species of marine mammals are utilized for mine detection and marking?

The correct answer is that dolphins and sea lions are utilized for mine detection and marking due to their advanced cognitive abilities and agility in water. Dolphins, in particular, are known for their echolocation skills, which allow them to detect underwater objects, including mines, by emitting sound waves and interpreting the returning echoes. Sea lions also possess a strong sense of smell and are trainable, making them effective in identifying and marking the locations of underwater hazards. Their training and capabilities enable them to work in challenging marine environments, assisting military and research operations in mine warfare.

In contrast, seals and whales, while they are also marine mammals, are typically not trained specifically for mine detection. Sharks and rays are important in their ecological roles, but they lack the trainable behavioral aspects that make dolphins and sea lions suitable for such tasks. Likewise, octopuses and squids are cephalopods and do not typically engage in tasks like mine detection; their skills and intelligence are oriented towards different survival strategies in their marine environments. This makes dolphins and sea lions the primary choice for mine detection and marking based on their unique abilities and training potential.