The Development Strategy of China's Underwater Ocean Observation Network

2017-03-01

The ocean is a vital lifeline for the development of a coastal nation. Entering the new century, the ocean's role in China's socialist development has become increasingly prominent. The report of the 18th National Congress of the Communist Party of China clearly emphasized the need to "enhance the capability to develop marine resources, develop the marine economy, protect the marine ecological environment, resolutely safeguard national maritime rights and interests, and build a maritime power."

Ocean observation is a fundamental discipline for understanding the ocean and a foundational support for building a maritime power. The marine economy has become a new growth driver for China's economic development. The State Council has successively approved the establishment of multiple coastal economic development zones. Under the new normal of economic development, the evolving marine economy poses new demands on observing the fundamental marine environment and providing product and service capabilities. The increase in new forms of production, such as marine resource development, maritime transportation, marine fisheries, island tourism, and marine engineering, has also led to a rise in maritime emergencies. Climate change has exacerbated disasters such as sea level rise and extreme weather events. Coastal areas face intensified coastal disasters, including flooding, storm surges, coastal erosion, and saltwater intrusion. The intensity and destructiveness of landfalling typhoons have also increased. These factors urgently call for enhanced ocean observation capabilities. Furthermore, the strategic deployment of the 21st Century Maritime Silk Road places new requirements on China's marine environmental security capabilities and the construction of an ocean observation system.

1 Analysis of the Strategic Role of China's Underwater Ocean Observation Network

1.1 Enhancing Underwater Defense Capabilities to Safeguard National Security

Currently and in the foreseeable future, maritime threats pose the primary strategic challenge to China's security. The United States has implemented its "Pivot to Asia" strategy, continuously strengthening military deployments in Japan, South Korea, the Philippines, and even the central Indian Ocean, as well as deploying underwater acoustic surveillance systems in straits. Since 2012, Chinese fishermen have salvaged underwater unmanned vehicles in nearshore waters off Sanya, underscoring significant challenges to China's underwater defense capabilities due to such activities.

1.2 Safeguarding Maritime Rights and Strengthening Comprehensive Marine Governance

In recent years, disputes and conflicts over maritime rights, including island sovereignty, maritime boundary delimitation, and marine resources, have become increasingly prominent and intensified between China and neighboring countries. In the East China Sea, strategic disputes surrounding the Diaoyu Islands' sovereignty, continental shelf delimitation, exclusive economic zones, and resource exploitation have persisted between China and Japan. In the South China Sea, countries like Vietnam and the Philippines have not only sought political and legal grounds but also strengthened their maritime military forces, actively constructing and developing tourism on illegally occupied islands and reefs. This complicates dispute resolution and creates de facto non-military utilization.

1.3 Protecting the Marine Ecological Environment and Building a Harmonious Marine Civilization

As the marine economy develops, China's nearshore waters are under increasing environmental pressure. Influenced by global climate change and human activities, critical marine functional zones face severe degradation, marine biodiversity is at risk, fisheries resources are depleting, red tides occur frequently, and oil pollution incidents are increasing. These challenges pose significant obstacles to safeguarding the nearshore marine ecological environment. While China's marine authorities have continually improved marine environmental regulations and intensified ecological protection efforts, the deteriorating trend of nearshore environments remains uncurbed.

1.4 Supporting Marine Economic Development and Marine Disaster Early Warning

China's coastal areas account for over 60% of the national economic output and house more than 40% of the population. The marine economy, contributing nearly 10% to the national economy, has become a new economic growth driver. Growing activities in fisheries, petroleum, renewable marine energy, and maritime transportation demand higher standards for marine environmental security. Meanwhile, China is prone to frequent marine disasters, such as storm surges, red tides, waves, tsunamis, and sea ice, which are highly destructive and pose significant threats to the economic development and safety of coastal regions. Furthermore, located between the Pacific Ring of Fire and the Mediterranean-Himalayan seismic zones, China experiences frequent earthquakes, with Taiwan and southeastern coastal areas being major seismic regions.

1.5 Promoting Marine Scientific Research and Advancing Marine Technology

Marine science, a strategic discipline based on observation, is a vital indicator of a nation's scientific and technological strength. As marine science has progressed, the necessity of long-term, continuous marine environmental observation has become increasingly evident since the global change research initiated in the late 1980s. Marine powers such as the United States, Europe, Canada, and Japan have developed long-term underwater observation networks to provide extensive datasets for studying the ocean's role in global climate, deep-sea ecosystems, marine processes, and nearshore oceanography. These networks also support real-time monitoring of seabed gas hydrates and seismic activity. In comparison, China is in the early stages of developing such infrastructure and lags at least a decade behind leading international levels. It is imperative for China to accelerate the construction of a seabed observation network to close this gap.

2 The Development Status of Underwater Ocean Observation Networks Abroad

2.1 Relevant Policies of Developed Maritime Nations

During the 12th Five-Year Plan period, the United States released three critical policies:

(1) In 2010, President Obama signed an executive order approving the "National Policy for the Stewardship of the Ocean, Our Coasts, and the Great Lakes" submitted by the White House Council on Environmental Quality's Interagency Ocean Policy Task Force. This established the National Ocean Council at the federal level to coordinate major issues such as national security, energy and climate change, and economic policy.

(2) In 2011, the U.S. National Research Council's Ocean Infrastructure Strategy Group published the report "Critical Infrastructure for Ocean Research and Societal Needs in 2030", analyzing the capacity of national infrastructure to meet the demands of ocean science over the next 20 years. The report identified vessels, satellite remote sensing, in-situ observation arrays, and coastal experimental bases as central to ocean research infrastructure.

(3) In 2013, the U.S. National Science and Technology Council released "Science for an Ocean Nation: Update of the Ocean Research Priorities Plan", which outlined the nation's priority ocean research fields in alignment with policy needs. These priorities included natural science topics like ocean acidification and Arctic change, as well as societal challenges such as the impacts of marine ecosystems on climate change.

In Japan, the "Basic Act on Ocean Policy" came into effect in 2007. Under this act, the government formulated the "Basic Plan on Ocean Policy", revised every five years. In April 2013, Japan's Cabinet approved the revised Basic Plan (2013-2017), outlining initiatives for the next five years, such as:

• Commercializing methane hydrate extraction technologies by 2018.

• Gradually supporting private enterprises in commercializing seafloor hydrothermal deposits between 2023 and 2028.

• Conducting research on the resource volumes and production technologies for manganese nodules and cobalt-rich crusts.

Rare earth elements are one of Japan's focal points in marine mineral development. In January 2013, a joint research team from the Japan Agency for Marine-Earth Science and Technology and the University of Tokyo used the deep-sea research vessel Shinkai to discover high-concentration rare earth elements in seabed mud near Minamitorishima, Japan's easternmost point. Analysis revealed rare earth concentrations of up to 0.66% in shallow sediments about 3 meters below the seabed, marking the world's highest industrially viable concentration.

In 2009, Australia's Marine Policy Science Advisory Group released a strategic framework titled "A Marine Nation", detailing the needs of the nation, industry, and public for marine research, development, and innovation. The report recommended coordinating marine scientific research at the national level, focusing on issues such as exploration, discovery, sustainability, observation, understanding, prediction, marine industry development, public engagement, and knowledge transfer. In March 2013, the group released "Marine Nation 2025: Marine Science to Support Australia's Blue Economy", listing six global challenges closely related to Australia from a strategic perspective: marine sovereignty and security, energy security, food security, biodiversity and ecological conservation, climate change, and resource allocation.

2.2 Key Research Projects in Developed Maritime Nations

2.2.1 U.S. Ocean Surveillance Information System (OSIS)

The 1970s marked the transition of the U.S. Navy intelligence system from strategic purposes to tactical applications. OSIS was established in the early 1970s to process various intelligence data and produce maritime target imagery. The fixed undersea acoustic surveillance system, SOSUS, served as OSIS's underwater information source.

In the 1960s, the U.S. installed SOSUS acoustic surveillance systems comprising deep-sea hydrophone arrays on the east and west coasts of the Atlantic and Pacific, with total cable lengths of 30,000 miles. Three surveillance lines were established in the Atlantic and Pacific, one of which extended from Russia's Kamchatka Peninsula through the Japanese Archipelago to the Philippines and the Strait of Malacca. This system played a significant role in monitoring submarine activities. By the late 1980s, the U.S. Navy had deployed 36 hydrophone arrays across the three oceans and key maritime chokepoints, covering three-quarters of the Northern Hemisphere's waters. At the end of the 20th century, the U.S. upgraded SOSUS into the Integrated Undersea Surveillance System (IUSS), comprising the Fixed Distributed System (FDS), Surveillance Directional System (SDS), Deployable System (ADS), and Surface Towed Array Sensor System (SURTASS), designed to detect quiet conventional and nuclear submarines operating in deep and shallow waters.

2.2.2 U.S. Persistent Littoral Undersea Surveillance Network (PLUSNet)

In the 21st century, the U.S. Office of Naval Research launched the PLUSNet project, consisting of sensitive seabed hydrophones, electromagnetic sensors, and mobile sensor platforms such as underwater gliders and autonomous underwater vehicles (AUVs). Fixed observation devices and mobile platforms could communicate bidirectionally, forming a semi-autonomous seabed observation system. The system aims to adaptively detect, classify, locate, and track low-noise diesel-electric submarines, especially in shallow waters like the Western Pacific. In 2006, PLUSNet conducted large-scale trials in Monterey Bay, using sensor-equipped submersibles to monitor ocean parameters such as temperature, salinity, currents, and chemical elements, achieving underwater target detection, tracking, classification, and localization. The network was planned to reach operational capability by 2015.

2.2.3 Northeast Pacific Time-Series Underwater Network Experiment (NEPTUNE)

NEPTUNE was proposed by the U.S. in 1999 as part of its National Ocean Observatory Initiative to study Earth's ocean dynamics. Its goal was to establish an underwater network platform covering 200,000 square kilometers of the Juan de Fuca Plate to research five frontier scientific topics: tectonic and seismic dynamics, subseafloor fluid flux and gas hydrate dynamics, regional ocean/climate dynamics and biological impacts, deep-sea ecosystem dynamics, and marine engineering technologies. NEPTUNE is a typical dual-use civilian and military infrastructure. The U.S. implemented the project under the Ocean Observatories Initiative (OOI), while Canada implemented it as NEPTUNE Canada.

OOI's seabed network platform includes 900 km of backbone fiber-optic cables and seven main nodes, with all seabed observation arrays completed and data available via the Internet by October 2015. The NEPTUNE Canada seafloor network platform has laid a backbone cable spanning 800 kilometers and deployed five main nodes. It has been in operational use for nearly six years. Together with other systems, it conducts observations across the Juan de Fuca Plate, from nearshore areas to the deep ocean at depths of up to 3,000 meters. This network has played a significant role in the real-time detection of seafloor events and the discovery of new phenomena.

2.2.4 European Multidisciplinary Seafloor Observatory (EMSO)

In 2008, the EMSO program, jointly implemented by 12 European countries, was launched. EMSO incorporated the planning elements of the previous European Seafloor Observatory Network (ESONET). It aims to establish 12 deep-sea observatories spanning regions from the Arctic, Sub-Arctic, and North Atlantic to the subtropical Atlantic, the Mediterranean, and the Black Sea. These observatories form a comprehensive European seafloor observation network, focusing on ocean environment change processes. The system employs two main approaches: independent acoustic seafloor observatories and cabled observatories.

2.2.5 Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET)

As an earthquake-prone country, Japan established cabled long-term seafloor observation stations near its coast and in the Pacific Ocean's far reaches as early as the late 20th century, operating at depths of up to 3,000 meters and primarily used for seismic science observation. In 2006, Japan initiated the construction of DONET in the Nankai Trough region, featuring 750 km of seafloor backbone optical cables and 49 observation stations. The system can accurately detect seismic and tsunami activities and is divided into three reliability levels: high-reliability cabled backbone networks, replaceable scientific nodes, and expandable measurement instruments.

2.3 New Technological Equipment in Developed Maritime Nations

Seafloor Network Equipment

Constant-voltage and constant-current underwater power supply connection devices are currently the mainstream products in international seafloor network equipment. Both technologies enable subsea connections at depths of 3,000 meters and power supplies of up to 10 kW, mastered by the United States, Japan, and Canada. Constant-voltage power connection devices are more mature and widely used in projects like the U.S. OOI seafloor observation arrays, Canada's NEPTUNE and VENUS networks, among others. Constant-current power connection devices are primarily applied to repurposed undersea communication cables, such as Japan's DONET and the U.S.’ s ALOHA seafloor observatories.

Mobile Underwater Observation Platforms

Autonomous profiling floats (Argo), underwater gliders, and Autonomous Underwater Vehicles (AUVs) represent the most mature technologies for mobile underwater observation networks. AUVs have been developed into a series of products ranging from micro to large sizes. Leading models include the U.S. Bluefin and REMUS series, Norway’s Hugin series, the UK’s AutoSub series, and Iceland's Gavia series, which dominate the AUV market. These AUVs are equipped with specialized deployment and recovery systems, significantly reducing turnaround time between missions.

The U.S. leads in underwater glider technology, employing multiple gliders for rapid and extensive observation in applications like tracking oil spills and observing ocean movements caused by hurricanes. Notably, the Scripps Institution of Oceanography has developed the next-generation “ZRay,” with a lift-to-drag ratio of 30:1 and a 29-channel hydrophone array.

3 Analysis of Challenges Facing China's Underwater Ocean Observation

Globally, integrated observation networks combining marine, land, and aerial systems have become an effective means of three-dimensional ocean observation and are expected to continue developing steadily. Underwater observation is diverging into two paths: long-term continuous monitoring and mobile, flexible systems. Seafloor networks, as the third major ocean observation platform after research vessels and satellites, are expected to form a global system within the next 20 years.

In recent years, China has achieved some progress in underwater observation technology and equipment through various scientific programs. However, compared to developed maritime nations, significant gaps remain, presenting challenges to achieving its maritime power goals:

(1) Weak Foundation in Basic Research and Lagging Key Engineering Technologies

China's underwater observation network construction is still in its infancy. Basic research on technologies like underwater sensors, platforms, long-term high-pressure power supply, wet-mate connectors, and underwater mobile communication networks has not achieved substantive breakthroughs. Research on long-term observation equipment and big data processing technologies is also lagging, leaving China's engineering technologies for seafloor scientific observation networks significantly behind.

(2) Lack of Standards in the Pilot Phase and Slow Industrialization

China's relatively mature marine observation technologies lack a well-established pilot phase before entering scientific or operational applications. The absence of public marine platforms for testing and verifying observation equipment has resulted in low stability and reliability, hindering the industrialization of observation technologies.

(3) Fragmented Marine Science and Technology Efforts and Insufficient High-Level Research Teams

Although more than two years have passed since the launch of the maritime power strategy, no comprehensive strategic framework document has been formulated for its implementation. Investments in marine science and technology across various systems have increased annually but remain fragmented. Different institutions have formed under the banner of maritime power to access diverse funding sources. However, no strong, integrated research force has emerged, nor has a research team effectively combining science and technology been established.

4. Recommendations for the Development of China's Underwater Ocean Observation Network

Under the new circumstances, the development of China’s underwater ocean observation capabilities should focus on the construction of a maritime power. The aim is to establish a comprehensive underwater observation system and, through approximately 20 years of development, bring the overall level to international standards. The following key areas of work are recommended:

(1) Conduct Top-Level Design for China's Underwater Ocean Observation Network

Develop an observation network centered on seafloor networks and extended by mobile networks. Integrate these with remote sensing platforms and survey vessels to form a comprehensive, multi-dimensional observation system.

(2) Undertake Strategic Research for Comprehensive Deployment

Develop a phased expansion strategy: from coastal areas to the open ocean, from nearshore regions to polar zones, and from shallow to deep waters. Build a uniquely Chinese underwater observation network composed of experimental and operational systems.

(3) Focus on Key Engineering Projects

Launch a dedicated program for China's seafloor observation network to support the development of dual-use (military and civilian) technologies. Deploy underwater observation systems in China's managed and sensitive maritime areas.

(4) Establish Industry Alliances

Accelerate the research and development of key technologies, promote the establishment of standardized systems, and enhance the localization of observation equipment.

(5) Promote International Technical Exchanges and Collaboration

Engage in global cooperation to cultivate high-level talent and teams with international influence.