Most islands have very limited resources that consequentially also restrict their capacity to deal with longterm development and environmental goals. The major disadvantage of small islands is not only their geographic remoteness but also the fact that they are more susceptible to climate change and sea-level increase. By nature, small islands also have extensive coastal zones requiring sound sustainable development that in many islands is beyond their financial means. The more recent political development in the South and East China Seas demonstrates additional constraints many island governments have in executing the rights of their Exclusive Economic Zones. The environmental and global changes that are predicted span over a timeframe of years, even decades, and action to mitigate the anthropogenic impact on climate change faces hindrances mainly on the political level. Not many alternatives are left for the small islands for mitigation. Movement towards limiting coastal development as well as a retreat from the coast may probably be the only considerations left for governments in reducing future disasters.

In the Philippines about 37% of the total water pollution originates from agricultural practices, which include use of animal waste, fertilizer and pesticide runoff. As a consequence, eutrophication is observed in the Manila coastal region in connection with the major drainage region around Manila. The PasigMarikina-Laguna de Bay Basin as a water drain to Manila Bay is unique because it represents an interconnection between several water bodies and is partly controlled by the Manggahan Floodway and the Napindan Hydraulic Control Structure. The high nutrient emission from Manila and the catchment area around the Manila Bay results in eutrophication of the bay and its adjacent coastal waters. Chlorophyll estimates with satellite measurements show elevated levels and it seems that eutrophication of Manila Bay is present throughout the year but is decoupled from the monsoon seasons.

Fraunhofer lines and atmospheric absorption bands interfere with the spectral location of absorption bands of photosynthetic pigments in plankton. Hyperspectral data were used to address this interference on identifying absorption bands by applying derivative analysis of radiance spectra. Algal blooms show elevated radiance data even at longer wavelengths compared to oligotrophic water and may reach radiance values of around 800 W/m2/micrometer/sr at a wavelength of about 0.8 μm. Therefore, the use of a spectral range beyond 0.55 μm is useful to describe bloom characteristics. In particular, the slope between 0.55 μm to 0.80 μm shows an advantage to depict gradients in plankton blooms. Radiance spectra in the region from 0.4 to 0.8 μm for oligotrophic water and near coastal water show similar location of absorption bands when analyzed with derivative analysis but with different amplitudes. For this reason, radiance spectra were also analyzed without atmospheric correction, and various approaches to interpret radiance data over plankton blooms were investigated. Cluster analysis and ratio techniques at longer wavelengths were found to assist in the separation of ocean color gradients and distinguish bio-geochemical provinces in near-coastal waters. Furthermore, using the slope of spectra from plankton blooms, in connection with scatter diagrams at various wavelengths, shows that details can be revealed that would not be recognized in single channels at lower wavelength.

Data with 0.4-m spatial resolution acquired ~2 km off the southeast Florida coast using the airborne Portable Hyperspectral Imager for Low-Light Spectroscopy (PHILLS) have been analyzed with the objective of identifying drifting surface macroalgae (Sargassum) through its spectral signature in at-sensor radiance. The observed spectral features of Sargassum include a peak at a wavelength of ~0.570 μm and a photosynthetic 'red edge' between 0.673 and 0.699 μm. Sargassum also exhibits high radiance in the reflected near-infrared but is impacted by the atmospheric absorption bands of water vapor at 0.720 μm and oxygen at 0.756 μm. The spectral signature is clearest and largest in amplitude where the Sargassum occurs as small surface aggregations, or rafts, which tend to lie at the downwind ends of narrow Sargassum windrows. The quantity of floating Sargassum was estimated within a single pixel by linearly mixing a spectrum of Sargassum-free water with varying percentages of a spectrum from a pixel assumed completely filled with floating plants. For our study site about 2.3% of the ocean area is classified as having some Sargassum coverage, with pixels completely filled with Sargassum being rare (only 0.2% of the classified Sargassum pixels) and pixels with the least-resolvable amount of Sargassum (~10% filled) being the most common.

It is demonstrated that hyperspectral imagery can be used, without atmospheric correction, to determine the presence of accessory phytoplankton pigments in coastal waters using derivative techniques. However, care must be taken not to confuse other absorptions for those caused by the presence of pigments. Atmospheric correction, usually the first step to making products from hyperspectral data, may not completely remove Fraunhofer lines and atmospheric absorption bands and these absorptions may interfere with identification of phytoplankton accessory pigments. Furthermore, the ability to resolve absorption bands depends on the spectral resolution of the spectrometer, which for a fixed spectral range also determines the number of observed bands. Based on this information, a study was undertaken to determine under what circumstances a hyperspectral sensor may determine the presence of pigments. As part of the study a hyperspectral imager was used to take high spectral resolution data over two different water masses. In order to avoid the problems associated with atmospheric correction this data was analyzed as radiance data without atmospheric correction. Here, the purpose was to identify spectral regions that might be diagnostic for photosynthetic pigments. Two well proven techniques were used to aid in absorption band recognition, the continuum removal of the spectra and the fourth derivative. The findings in this study suggest that interpretation of absorption bands in remote sensing data, whether atmospherically corrected or not, have to be carefully reviewed when they are interpreted in terms of photosynthetic pigments.

High-resolution spectroscopy using the Portable Hyperspectral Imager for LowLight Spectroscopy (PHILLS) was applied to the problem of detecting potentially harmful algae blooms in the coastal environment. Data were collected on two aircraft passes, 30-min apart, over the tidally influenced part of the Potomac River. Use of two wavelengths, 0.676 and 0.700 mu m, permitted the detection of surface algae accumulations while avoiding the need for atmospheric corrections, which are problematic in Case-2 water. The analysis identified algal accumulations derived from frontal processes, and narrow, linearly coherent streaks, derived from Langmuir circulation. The streaks increased markedly in number between the two passes and formed a two-dimensional pattern across the river, consistent with the advection time of surface material into windrows. The effect of wind on the patches is primarily a local reorganization of the algal material into new streaks. Spectra from within the streaks compared to those from ambient water showed absorption characteristics consistent with the presence of cyanobacteria. This interpretation is reinforced by available in-situ data. This study illustrates the value of high spectral and temporal resolutions in observing the spatial distribution of the algae, in identifying dominant functional groups, and in understanding the response of the algae to physical forcing.

Water-leaving spectral signatures were used in the spectral regions where chlorophyll has its first and second absorption bands in order to recognize biogeochemical provinces in the pelagic and coastal ocean. The global data set for MODIS used in this study data has a 4.89-km pixel resolution that is mapped on a cylindrical equidistant map projection. The data presented are based on an interpretation of the ratios R443/R551 and R678/R667 that use the spectral region of the two absorption bands of chlorophyll, the fluorescence of chlorophyll at 678 nm und the hinge point at 551 nm. Examples have been presented for eutrophic and oligotrophic oceanic regions.

The objective of this Letter is to introduce a concept for identifying marine provinces by applying two band ratios that are indicative of chlorophyll distribution patterns. The ratios of water-leaving radiances 443 nm/551nm and 678 nm/ 667 nm are close to the two absorption bands of chlorophyll; however, as photon penetration depth at the applied wavelengths varies, each ratio responds to different depths. This allows a qualitative interpretation of separated clusters in scatter diagrams. Pattern classification separates the major biogeochemical provinces as documented with the Peruvian upwelling system and the convergence zone in the Brazil-Falkland/Malvinas current system.

Water-leaving spectral signatures were used in the spectral regions where chlorophyll has its first and second absorption bands in order to recognize biogeochemical provinces in the pelagic and coastal ocean. The analysis of spectra collected in eutrophic coastal waters identified a very narrow spectral bandwidth in which the highest correlation between chlorophyll and the first derivative is apparent. A ratio technique using the defined envelope showed that a good relationship exists between the ratio of the reflectance R667/R678 and surface chlorophyll concentrations. The global data set for MODIS 3 used in this study data has a 4.89-km pixel resolution that is mapped on a cylindrical equidistant map projection. The data presented are based on an interpretation of the ratios R443/R551 and R678/R667 that use the spectral region of the two absorption bands of chlorophyll, the fluorescence of chlorophyll at 678 nm und the hinge point at 551 nm. The two selected ratios indicate the response of provinces according to the depth location of absorbing pigments as well as the overall response to integrated concentrations of pigments in the euphotic zone. The results show that biogeochemical provinces can be identified by the ratio technique and upwelling regions, current systems and river discharge can be spectrally separated.

Biogeochemical provinces vary due to physical and chemical changes in the marine environment. Water-leaving radiance has been used to investigate naturally occurring pigments in phytoplankton communities. Whereas in the open, ocean colour can easily be converted to total pigment concen- trations, there are shortcomings in determining photosynthetic pigments in eutrophied coastal re- gimes. This is based on the fact that water-leaving radiance in coastal regions varies in relation to the changing composition of the main contributor to the water-leaving radiance. In order to observe the spectral response of water over a wide range of chlorophyll and accessory pigments, a test site was selected that supports high plankton blooming through nutrient transport from a waste water treatment facility to the marine ecosystem. Several carotenoids were found to correlate with the spectral region where chlorophyll is shown in the second absorption band. As the same pigments are also correlated with each other, this correlation can be regarded as an artifact The first derivative of reflectance in the near 690 nm region was investigated in this study. The re- sults showed that measurements of spectral reflectance ratios for water-leaving radiance in the spectral region of the second absorption band of chlorophyll could be effective for empirically de- rived semi-quantitative relationships for concentrations of chlorophyll and related pigments. Meas- urements with MODIS demonstrate that the ratio 667/678 may be useful as an indicator for high chlorophyll concentrations close to the surface and can be used to describe the upper layer of the euphotic zone. The ratio technique was applied for separating bio-geochemical provinces when compared with chlorophyll measurements based on the first absorption band of chlorophyll. Pre- liminary results are presented for several oceanic regions using a clustering approach to relate chlorophyll data and the ratio technique.

Shapes and variations of reflectance spectra in estuarine water were investigated for the purpose of monitoring chlorophyll in situ by optical means. A survey undertaken in an estuarine environment, using reflectance measurements between 400 and 850 nm with a full-width half maximum (FWHM) of about 2 nm, revealed that the first derivative in the neighbourhood of the chlorophyll absorption band shows a defined spectral region which can be used to estimate chlorophyll concentrations. Correlation between chlorophyll and the first derivative was found to be low, but a good relationship exists between the ratio of the reflectance R680/R670 and chlorophyll concentrations. Based on dissolved organic carbon measurements, it is assumed that chromophoric dissolved organic compounds mask the absorption band of chlorophyll in the blue part of the spectrum, resulting in a low correlation coefficient in that spectral range. Therefore, the use of the red bands is an alternative for measuring photosynthetic pigments in coastal water at longer wavelengths. Results presented here demonstrate that the spectral locations of bands in the visible are not adequate and that hyperspectral data are required for positioning the very narrow bands for measuring chlorophyll at longer wavelengths.

Patchiness, indicated by ship measurements from the International Indian Ocean Expedition, was checked against the most advanced sea surface temperature program based on satellite observations. The statistical analysis of structures observed with sea surface temperature measurements showed that they are highly correlated with the time span of observations; i. e., structures or patches in the temperature field can be artificially created by the “age” of temperature observations. Simulated multi-ship observations, based on satellite temperature measurements over a time frame of several weeks, show patches that were created by the time span during which the measurements were taken.

In a study on eutrophication of estuaries, NOAA/AVHRR satellite data have been analyzed for the Changjiang River plume and the adjacent coastal areas. The different regimes identified in the satellite thermal image include river discharge, upwelling water, the Huanghai Sea Longshore Current, and warm water from the Taiwan Current. A feature in the offshore region is patches generated by the river discharge and upwelling process. By using different spectral channels, patterns created by bottom topography, sediment discharge from rivers and possible plankton blooms can be differentiated. These images indicate that the observed turbidity patterns are not necessarily caused by the outflow from the Changjiang River.

1. General Aspects of the Use of Satellite Remote Sensing for Resources Exploration in Developing Countries.- 2. Present Status of Microwave Remote Sensing from Space with Respect to Natural Resources Monitoring.- 3. SPOT: The First Operational Remote Sensing Satellite.- 4. Spacelab Metric Camera Experiments.- 5. Coastal Zone Color Scanner (CZCS) and Related Technologies.- 6. Selected Features of the SEASAT Satellite.- 7. First Results of the European Spacelab Photogrammetric Camera Mission.- 8. Thematic Mapping of Natural Resources with the Modular Optoelectronic Multispectral Scanner (MOMS).- 9. Availability of Remotely Sensed Data and Information from the U.S. National Oceanic and Atmospheric Administration's Satellite Data Services Division.- 10. A Future Outlook.- 11. Interpretation and Application of Spaceborne Imaging Radar Data to Geologic Problems.- List of Participants.