Blue Shepherd addresses the growing issue of whale and dolphin strandings through a speculative design approach focused on prevention rather than rescue. The system consists of autonomous drones that monitor coastal areas and deploy underwater acoustic devices when risk is detected. Each device emits species- and context-specific signals—such as orca deterrents or fish swarm sounds—to gently guide cetaceans away from danger. The intervention is autonomous but allows for real-time observation and adjustments by marine scientists through a digital interface. By combining future technologies, sustainable practices, and ethical considerations for animal welfare, Blue Shepherd proposes a shift from reactive conservation efforts to proactive ecological care, envisioning a future where marine life is protected before harm occurs.