Marine monitoring can be improved by Internet of Things (IoT) technology, helping to preserve ocean health and biodiversity. It describes IoT applications in maritime monitoring to protect marine ecosystems. Real-time data collected from IoT devices and sensor networks allow accurate monitoring of marine factors such as water quality, salinity, temperature, dissolved oxygen levels, and fertilizer concentrations. These sensors provide data to centralized platforms for quick analysis and informed marine conservation decisions. IoT is used in maritime monitoring for species tracking. IoT-enabled tags and satellite systems help detect marine animals' moving routes, breeding sites, and places sensitive to human disruptions. This data supports conservation planning. IoT also detects and mitigates marine ecological hazards. IoT-enabled smart boats and underwater drones monitor pollution, oil spills, and invasive plants and animals. Anomalies may prompt alerts and automatic solutions, solving environmental issues quickly. These technologies enable enhanced data analysis, predictive modeling, and ecological disturbance early-warning systems. Decision-makers may prevent permanent damage by predicting dangerous algal blooms, coral bleaching, and other ecological disturbances. IoT applications provide real-time data collecting, species monitoring, and environmental hazard identification, supporting sustainable practices and protecting the planet's most vital ecosystems.