Fish-spawning activities and marine mammal social activities are often difficult if not impossible to study continuously without passive acoustic systems, at least for those species that are documented in producing sound during spawning events. Similarly, human activity in remote aquatic environments is best assayed using passive acoustic techniques. The development of cost-effective passive acoustic receiver and data transfer/analysis systems would greatly enhance both biological and human activity assessment in aquatic environments, which are basically opaque to light. Kennedy Space Center is currently developing a programmable portable computer-hydrophone system that stores large volumes of acoustic data across a wide frequency spectrum with source recognition and filtering capabilities and records ambient temperatures when deployed to depths of up to 1,000 meters. This system is sufficiently robust that a number of environmental sensor systems may be integrated into a single portable unit. Deployment duration is dependent on preprogrammed sensor and computer activity rates. The ultimate goal is to deploy an array of hydrophone units in the protected waters of Kennedy Space Center to better understand the spawning habits of soniferous fish and effects of NASA KSC launch activities on the local aquatic resources.

A key component of the Passive Acoustic Monitoring System (PAMS) is the hydrophone. The hydrophone frequency range must be broad enough (10 to 80,000 hertz) to detect most low-frequency fish sounds, marine mammal sounds, boat sounds, and high-frequency sonic tags used on marine mammals and fish for migratory studies. Experimental tests using a variety of hydrophones are currently underway to determine the hydrophone specifications for optimum operation. A prototype PAMS unit was completed in mid August 2001 and tested in the upper Banana River Lagoon. Initial sea trials were conducted during the National Oceanic and Atmospheric Administration (NOAA) Ocean Exploration-sponsored Islands in the Stream Program during August and September 2001. The PAMS was deployed at a grouper spawning site used for research over the past 25 years. Groupers are soniferous, particularly when conducting prenuptial displays associated with social interactions, sex reversal, and spawning. The PAMS was found to be rugged and watertight.

The future principal deployment site will be a spotted sea trout spawning site in the upper Banana River Lagoon adjacent to Launch Pad 39A. This is also the site at which the Jet Propulsion Laboratory (JPL) Sensor Webs, led by Dr. Kevin Delin, was deployed in mid 2002. The JPL Sensor Webs and the KSC PAMS array deployment complemented one another in providing a powerful continuous underwater monitoring system for both environmental and biological activity.

Key accomplishments:

• Designed and fabricated prototype portable hydrophone/computer system (PAMS) unit.
• Deployed PAMS unit during NOAA Ocean Exploration Program expedition to the continental shelf off Kennedy Space Center.

Key milestones:

• Perform aquatic tests using a sound generator capable of accurately reproducing target biological sounds and evaluate operation of submerged PAMS unit.
• Develop additional programmable portable computer-hydrophone units.
• Investigate possible array configurations (depth, spacing between units, etc.).
• Develop laboratory protocols and software for data processing, management, and analyses.
• NOAA Ocean Exploration Program in the spring of 2003 will deploy the NASA PAMS unit again with manned submarines on the continental shelf adjacent to KSC in the Oculina Habitat, a Southeast Fisheries Council fishing reserve.
• For a full description of JPL’s Sensor Webs, see http://sensorwebs.jpl.nasa.gov/

Contact: C. Guidi (Cristina.Guidi-1@ksc.nasa.gov), XA-C, (321) 867-7864
Participating Organizations: YA-F2 (M.A. Lane and S.D. VanMeter) and Dynamac Corporation (Dr. R.G. Gilmore)