IEEE Access Special Section Editorial: Emerging Trends, Issues, and Challenges in Underwater Acoustic Sensor Networks

Saline water covers approximately 360000000 km
²
, approximately 71% of Earth’s surface and 90% of Earth’s biosphere. The ocean contains 97% of Earth’s water, and oceanographers have stated that less than 5% of the World Ocean has been explored. The total volume is approximately 1.35 billion cubic kilometers with an average depth of nearly 3700 m. Our ocean and coasts provide jobs for millions of people in coastal communities across the world. Ocean industries such as commercial and recreational fisheries, tourism and recreation, and marine transportation generate thousands of billions of dollars every year. We must protect the ocean’s long-term health, not only for habitats and marine life that depend on it but also for the humans that have relied on its resources for generations. All of this requires maintaining a healthy ocean ecosystem, even as human demands and stresses to the ocean are increasing. It is more important than ever to understand how the ocean interacts with various offshore applications. To this end, underwater acoustic sensor networks (UASNs) play an important role in the ocean’s protection. However, ocean monitoring and research are not an easy task, since the ocean is big and most of the underwater environment is still unknown to us. In addition, due to the high pressures in deep water, it is not suitable for people to work a long time underwater.