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The Navy has an extensive undersea acoustic surveillance 

 system known as lUSS (Integrated Undersea Surveillance System), 

 lUSS includes the existing SOSUS (SOund Surveillance System) and 

 SURTASS (Surveillance Towed Arrat Sonar System) systems, and future 

 systems. Historically the Navy has found these systems to offer an 

 important and unique window into long term monitoring of the oceans 

 (submarine activities) which is complementary to other remote 

 sensing systems. 



Many of the applications of these acoustic systems to 

 important scientific problems and public policy issues fall within 

 the ocean monitoring responsibilities of NOAA. These include the 

 difficult biodiversity and conservation problems associated with 

 marine mammals, particularly the great whales. The lUSS systems 

 offer the unique potential for ocean basin wide long-term 

 monitoring of the activities of these mammals, and for obtaining 

 credible estimates of changes in species populations. 



In November of 1992, the Navy initiated a test of the Sound 

 Surveillance System — called SOSUS — to track whales. SOSUS is 

 a subsystem of lUSS which enables researchers to listen to the 

 sounds made by undersea mammals. The results of the six month test 

 were remarkable. At one site, the SOSUS made more detections of 

 blue, finback and minke whales than were contained in existing data 

 bases for all previous coastal whale studies. 



The growing number of fixes on finbacks and humpbacks 

 contradict much of the former scientific knowledge for the seasonal 

 distribution of these animals. In the case of the humpbacks, it 

 was believed that they were found in less than 100 meters of water. 

 But the Navy documented humpbacks singing in deep water off the 

 West Indies. lUSS enables researchers to do what they weren't 

 available to do before — to go offshore into deep water and listen 

 for these undersea mammals. 



The lUSS can also be used to monitor activities of fishing 

 vessels possibly involved in illegal drift net fishing or in 

 whaling banned by international agreement. Undersea acoustic 

 systems can also provide the means for monitoring seismic activity 

 levels along the mid-ocean ridges at detection sensitivities 

 significantly better than the Global Seismic Network. These 

 systems may also be useful or precisely geolocating sea floor 

 phenomena such as hydrothermal vents and turbidity flows in 

 preparation for in situ exploration with submersibles . These 

 important applications are currently being explored by NOAA and by 

 other scientists. 



Through storage of heat and greenhouse gasses (e.g., CO^), the 

 worlds oceans play a major role in climate change. The transport 

 of heat and gases between the oceans and the atmosphere are among 

 the most critical dynamical processes at work in determining the 

 resultant rate of global warming. At present, our understanding of 

 the ocean storage and air-sea exchange of heat and gasses, and 

 their global transport through ocean circulation is primitive, 

 based primarily on current inference from theoretical models. The 

 most critical need is for direct measurements of ocean temperatures 

 over broad areas and long time periods. A project has begun to 



