The LEO-15 Coastal Cabled Observatory – Phase II For the Next Evolutionary Decade of Oceanography

The Long term cabled Ecosystem Observatory at 15 meters (LEO-15) deployed in 1996 has served the scientific community well for over a decade. Simultaneously, methods to acquire spatial datasets that were difficult to sustain in the 1990s have evolved to the point where sustained operation over ecologically relevant regional scales is a reality. Rutgers University, with four industry partners, has developed a sustained regional coastal observatory for the Mid-Atlantic continental shelf. The observation network includes remote sensing systems (satellite imagery and HF radar) providing spatial data for the surface ocean and two long-duration subsurface sampling systems (autonomous gliders and cabled observatories). The network is controlled in an operations center located on Rutgers main campus so that it is both sustainable and readily accessible for research and teaching. The cabled network has been undergoing extensive upgrades after decade at sea, and those upgrades improving the integration the LEO-15 Coastal Cabled Observatory into the broader ocean observing network are described. The world’s continental shelves cover only 10% of the surface of the globe but account for most of the world’s primary productivity and are home to most of the world’s fish species. The coastal oceans throughout the world are undergoing profound transformations due to a massive increase in the flux of nutrients, fishing pressures, and introduction of exotic species that result directly from the inevitable population growth of humans. For example. coastal eutrophication alters microbial community diversity and metabolism, leading to a long-term change in the chemistry of continental shelves. The change in chemistry is often catastrophic to humans, leading to massive losses of fisheries, the production of extremely potent green house gases, altered food webs, and potentially permanent loss of marine biodiversity (extinction). These changes are driven by human-induced at both local pressures and global changes to the oceanclimate system. Therefore it is not surprising that the U.S. Commission on Ocean Policy, stated the need for “sound science for wise decisions” to ensure the sustainable use of our coastal oceans for this and future generations. The Commission also highlighted the need for, “a robust infrastructure of cutting edge technology forms the backbone of modern ocean and coastal science and effective resource management and enforcement”. It was against this backdrop, the Rutgers Coastal Ocean Observing Laboratory (COOL) evolved. Here we describe Rutgers history and present status in its long term effort to bring new observational technologies to the field of coastal oceanography. We will also highlight how it fulfills many of the needs highlighted by the U.S. Commission on Ocean Policy. LEO-15 Coastal Cabled Observatory In the early 1990’s Fred Grassle (Rutgers University, RU) and Chris von Alt (Woods Hole Oceanographic Institution, WHOI) designed a visionary cabled observatory system for the sea floor [1]. Their 1993 proposal to NSF (Figure 1) was funded before the World Wide Web was even considered useful by the scientific community. The Long-term Ecosystem Observatory (LEO-15) was constructed at WHOI, a 10 km long electro-fiber optic cable connected to the Rutgers Marine Field Station (RUMFS) near Tuckerton, New Jersey was buried in the seabed, and, in 1996, science Nodes A and B were deployed in 15 m of water, located 8.1 and 9.6 km, respectively, offshore [2]. Table 1. The Desired Goals for LEO-15 in the 1990’s. 1) Continuous observations at frequencies from seconds to decades, 2) Spatial scales of measurement from millimeters to kilometers, 3) Practically unlimited power and broad bandwidth, twoway transmission of data and commands, 4) An ability to operate during storms, 5) An ability to plug in any type of new sensor and to operate them over the Internet, 6) Bottom mounted winches cycling instruments up and down in the water, either automatically or on command, 7) Docking stations for a new generation of autonomous (robotic) underwater vehicles (AUVs), 8) An ability to assimilate node data into models and make three-dimensional forecasts for the oceanic environment, 9) Means for making the data available in real-time to schools and the public over the Internet, and 10) Low cost relative to the cost of building and maintaining manned aboveand below-water systems. Through NOAA support for research, operations and maintenance, the LEO-15 system has served the scientific community well for over a decade [3-6], with most of the initial goals achieved (Table 1). The general public, and pre-collegiate educational programs, have also utilized the data [7-8]. In the process, many lessons have been learned [9].