1. US EPA National Health and Environmental Effects Research Laboratory, Atlantic Ecology Division, Narragansett, Rhode Island 02882, USA
2. US EPA National Health and Environmental Effects Research Laboratory, Gulf Ecology Division, Gulf Breeze, Florida 32561, USA
3. US EPA National Exposure Research Laboratory, Research Triangle Park, North Carolina 27709, USA
4. Bio-Optical Physical Processes and Remote Sensing Section, Naval Research Laboratory, Stennis Space Center, Mississippi 39529, USA