The marine systems surrounding the Galapagos are unique and fragile. It is imperative then that an encompassing monitoring system be implemented not only to establish a necessary baseline for comparison, but also to provide direct relationships between various external proxies and the health of the aquatic environment. The suggested plan implements multiple devices ranging in use from standard equipment readily available for purchase to fast approaching new technologies. Each sensor identifies the vital role of a specific factor that affects the Galapagos and incorporates it into the overall system.
In order to monitor the marine environment, a system of buoys will be deployed with sensors attached in the ocean areas around the coasts of the islands. These sensor buoys already exist, and are called RUSS (Remote Underwater Sampling Station). They were used for lake monitoring, so several modifications to the original design (Host, George E., Will, Norman R., et. al. - http://wow.nrri.umn.edu/urisa/#_ftn1) will be used. There will be a ring of these buoys placed at a distance of 1 kilometer off the shore and a second ring 5 kilometers beyond the first ring (6 kilometers from shore). Each of the buoys will be 5 kilometers from its nearest neighbor. The buoys will be cylindrical and approximately 2 meters in diameter. The sensors will be attached to the underside and submerged to an appropriate level dependent upon the depth in which the buoy is located . The top surface of the buoy will have a solar panel to generate power in an eco-friendly manner and an RF transmitter to communicate with other buoys and to send its information to the main data collector.
In order to prevent drift, the buoys will be tethered to the ocean floor. However, a second, submerged buoy will be needed. If one of these second buoys is not in place, the tether will be under a large tension and the buoy will drift in a circle with a large radius, which is not optimal. With the submerged buoy attached to the tether, a ten percent slack ratio will be in the tether and the buoy, though still moving in a circle, will not drift too far from the location in which it was set. The surface, or "master" buoy, will carry a separate tether that will hold the sensors, such that they will not be effected by the tensions involved in anchorage.
There will be three different varieties of buoys based upon the locale of the the sensor systems. Those in reef systems will be equipped with the extra equipment necessary to establish the unique health issues that effect this more fragile ecosystem. Also, buoys within reef systems with be on a winch system capable changing the altitude of the sensors for varying levels of measurement. Another non-standard device for monitoring sea level will be employed in areas closer to shore.
The reef system buoys will primarily employ the YSI 6600 sonde, available for purchase from YSI Environmental, capable of measuring temperature, conductivity/salinity, dissolved oxygen, pH and turbidity. YSI systems have been employed in many water quality systems, provide accurate measurements, use low levels of power, have easily replaceable individual sensors, and are easily programmed to communicate within conventional options. The YSI 6600 sonde is not employed in deeper waters as it is functional only to a maximum depth of 200 meters. In addition to the sondes, the buoys will be equipped with sensors for measuring concentrations of dissolved nitrate and iron ions. Current technology does not provide the necessary precision for these measurements; an improved technology would therefore be necessary to conduct these vital marine tests.
Standard/deep water buoys will be less equipped than the reef system; certain measurements will not require the same level of precision as coral reefs and will be taken via other methods. Each buoy will be equipped with the same dissolved ion sensors for iron and nitrate, and the same winch system to adjust the sensor depth. Salinity and Temperature are of importance and will be measured with an electrical conductivity sensor, model EC 250, provided by "Advanced Measurements and Controls, Inc". This sensor monitors conductivity coupled with temperature to provide more accurate data regarding concentration of dissolved salts. Turbidity in deep water systems will be measured via spectroscopic methods from satellite. Chlorophyll-a concentrations in the Galapagos region is already being measured from satellite imaging and should be continued.
Another sensor will be employed on buoys at specific locations. Buoys situated near travel shipping routes or near ports will be equipped with a "Spill Sentry" sensor provided by Applied Microsystems. The spill sentry monitors hydrocarbon levels, taking regular measurements, and would provide an early warning system for even low level petroleum leaks (five microns of sheen) or the gradual pollution of heavily influenced areas. The device could be easily incorporated into the system and is designed to calibrate itself to natural or normal levels at specific locales.
On near-shore stations, a device for measuring sea level will also be employed. The Aquatrak system, provided by the Aquatrak Corporation, is an available and attractive option for this data and monitors levels via a non-contact acoustic ratiometric technique, sending acoustic waves from the surface to the ocean level. It is capable of self calibration and is not affected by wave action. It has a successful history and is a standard tool used by both the Australian National Tidal Facility and the NOAA. In the Galapagos, it will be employed near mangrove regions, which are particularly susceptible to changes in sea level.
Each data element collected is of specific value towards the healthy sustainment of the marine ecosystem surrounding the Galapagos. Temperature and salinity within the region fluctuate seasonally due to the deep sea currents abutting the Galapagos Islands. The Humboldt current, which brings cold water from the antarctic region, keeps the marine temperature much colder than expected (sometimes less than 20 degrees centigrade). During the warmer seasons, changes in currents bathe the region in warmer equatorial cross currents that drastically alter the environment and bring with them massive die offs in populations. The deeper cold water currents are also responsible for the inflow of micronutrients that from the base of the marine food chain. It is therefore critical to monitor the position of these currents which is done most efficiently through temperature and salinity monitoring. The primary nutrients resulting from upwelling in which the galapagos are reliant are nitrates (which are fixed by phytoplankton to form proteins) and dissolved Iron (which facilitates nitrogen fixation). They should subsequently be monitored. In reef systems, the clarity of water is of extreme importance to algal components and turbidity is the most effective method of measurement. Chlorophyll-a concentrations recognize the presence and populations of phytoplankton, which primarily congregate on the ocean surface and are the very foundation of the food chain. Sea level directly affects the health of mangrove ecosystems, which are both fragile and continuously threatened by human interference. Also, sea level directly implicates the interaction between the islands fresh water supply and undrinkable sea water, which is a constant concern. Hydrocarbon concentration directly monitors the drastic human interference to the ecosystem caused by fossil fuels.
In addition to these techniques, the use of spectroscopy could eventually be of value towards evaluating the health of coral reefs. Recent studies using radiometers have been used to establish the light spectra emitted by specific species of coral. When corals are in poor health, they begin to bleach and their subsequent colors change. It is believed that there are direct correlations between these changes in emitted spectra and ecosystem health which could be used to quantify the overall health of the system. Currently, only tethered underwater devices are used to take measurements and baselines on species surrounding the galapagos have not been undertaken. However, with the implementation of spectroscopic devices within the eco-sensor system, the eventual inclusion of this technique is feasible and recommended.
Works Cited:
Palacios, D. M. (2003) Seasonal Patterns of Sea-Surface Temperature and Ocean Color Around the Galapagos: Regional and Local Influences. College of Oceanic and Atmospheric Sciences, Oregon State University.
Galapagos Climate and Oceanography (n.d). Retrieved September 17, 2004 from: http://www.geo.cornel.edu/geology/GalapagosWWW/GalapagosClimate.html.
Scandol, J. (2003/2004). Monitoring for Fishery Management Strategies in 2003/2004. Retrieved October 14, 2004 from NSW Department of Primary Industries Web site: http://www.fisheries.nsw.gov.au/sci/projects/fs/scandol-fms.htm.
Olsen, L. D. (2003). Selected Applications of Hydrologic Science and Research in Maryland, Delaware and Washington D.C. 2001-2003. Retrieved October 17, 2004 from USGS web site: http://md.water.usgs.gov/publications/fs-126-03/html/.
PRR Radiometers (n.d). Retrieved November 15, 2004 from http://www.biospherical.com/BSI%20WWW/Products/Aquatic/prr2800.htm.
Aquatrak Products (n.d). Retrieved November 15 2004 from Aquatrak Inc Web site: http://www.aquatrak.com/Products.htm.
The Seaframe Monitoring Sensor (n.d). Retrieved November 15, 2004 from the National Tidal Facility-Australia Web site: http://www.ntf.flinders.edu.au/TEXT/PRJS/PACIFIC/seaframe.html.
Mississippi Headwaters Board. "Water Quality Monitoring Plan: Summary of Water Indicators." http://www.mhbriverwatch.dst.mn.us/river_watch/plan.html.
Host, George E., Will, Norman R., Axler, Richard P., Owen, Christopher J., Munson, Bruce H. Interactive Technologies for Collecting and Visulizing Water Data.
Found Online at: http://wow.nrri.umn.edu/urisa/#_ftn1.
YSI 6600 Sonde. Retrieved November 15, 2004 from YSI Environmental Web site: http://www.ysi.com/extranet/EPGKL.nsf/447554deba0f52f2852569f500696b21/8d9c4f232154feb2852569e7005bf75b!OpenDocument.
Spill Sentry Systems (n.d.). Retrieved November 15, 2004 from Applied Microsystems Web site: http://www.appliedmicrosystems.com/systems/spill-sentry.html.
Electrical Conductivity Sensors (n.d.). Retrieved November 15, 2004 from Advanced Measurements and Controls, Inc Web site: http://www.advmnc.com/greenspan/ec.htm.
Guild, Liane., Ganapol, Barry., Kramer, Philip., Armstrong, Roy., Gleason, Art., Torres, Juan., Johnson, Lee., Garfield, Toby., So, Brian. Clues to Coral Reef Health: Spectral Analysis and Radiative Transfer Modeling of Coral Reef Ecosystem Health. Retrieved November 15, 2004 from NASA Web site: http://geo.arc.nasa.gov/sge/coral-health/.
