New technology for Ecosystem-Based Management: Marine monitoring with the ORCA Kilroy Network

Ecosystem-Based Management (EBM) requires marine monitoring in real time with high temporal frequency and high spatial density. It also requires sensors that can provide direct measurements of biological processes and the means to track water movement and evaluate water quality. These requirements can not realistically be met using huge amalgamations of the independent instruments traditionally used for marine monitoring. To do so would result in marine observatories that are prohibitively expensive, unnecessarily obtrusive, inefficient in power use, difficult to deploy and maintain, with sensors inappropriate for extended deployment and with an excessive level of redundant components. The Ocean Research & Conservation Association (ORCA), in an effort to better meet the need for marine monitoring, has designed and is testing the ORCA Kilroy Network, an observatory designed as a whole system down to the sensors at the component level. The ORCA Network consists of a wireless network of remote semi-autonomous marine sensor systems created by ORCA, and a central supervisory system that directs operations of the remote systems, collects data, and relays that via the Internet through a standard SOAP web service interface to a geospatial database. The network design is based on that of industrial control systems, where a central computer coordinates remote and mostly autonomous systems using Modbus, a mature, open-standard, fieldbus protocol. In this case, the coordination and data transfer are over GSM cellular Internet connections on a wide scale and cabled RS-485 connections at the station scale. To date, four remote subsystems of the ORCA Kilroy network are in use. Each is designed to take advantage of a shared power and communications infrastructure, and is integrated at the component level to lower cost, reduce size, and improve efficiency. Mass produced off-the-shelf parts have been selected over custom machined parts where possible. Power for an entire sensor station is shared, and to date, has been provided by a solar charged battery. First, the wireless and cabled communications are bridged by a device dubbed the ORCA Kilroy Voice (KV), which includes a GPS for position and UTC synchronization and acts as a GPRS Internet gateway to a sensor string - a shared serial communications and power line on which smart sensor systems can be daisy chained. Second, ORCA developed for use on that string a battery-operated sensor suite called ORCA Kilroy that from basic measurements, determines flow speed, flow direction, speed of sound, package orientation, turbidity, conductivity, temperature, water level, wave height, and wave period. Measurements are sent out upon request from the central supervisor through Modbus and are logged locally to nonvolatile memory to ensure no data is lost in the event of a power or communication outage. Third is the ORCA Kilroy I/O (KIO) - an adaptor providing serial access to the ORCA Network for instruments from other manufacturers. A forth system, also designed for sensor string operation, is the ORCA Bathyphotometer (BP). This is a flow-through bathyphotometer that provides measurements of bioluminescence intensity, which is a direct biological measurement. It uses bioluminescent flash dynamics to classify and estimate the abundance of bioluminescent organisms. The latest measurements are made available through a web page, with clickable color-coded icons positioned on a Google Map based upon the most recent GPS readings, making the presentation layer suitable for moving sensor platforms. Semi-transparent images of equivalent resolution as the Google Map are generated from National Centers for Environmental Prediction's (NCEP) early precipitation analysis and can be laid over the map. Our intent is to create equivalently intuitive image overlays of the other sensor measurements and to make the site publicly available. Correlating water flow, water quality, biological indicators (through bioluminescence) and local weather conditions (particularly storm water events) promises to provide resource managers critically needed data for effective Ecosystem Based Management.