Richard P. Stumpf (no longer with USGS) Megan L. Frayer 2005 project http://sofia.usgs.gov/projects/index.php?project_url=sed_turbidity A decline in water clarity in Florida Bay has been observed following the seagrass dieoffs starting in the late 1980's. Algal blooms and discolored water have been reported in Florida Bay over the last several years and factors such as resuspension of material and nutrients from the bottom have been suggested as a cause. Monthly monitoring programs by Florida International University (FIU) and Florida Department of Environmental Protection (FDEP) have provided documentation of blooms through chlorophyll measurements. This study used remote sensing to examine resuspension events, the distribution of turbid water and changes in the patterns of water clarity in the Bay. This project used data collected by the Advanced Very High Resolution Radiometer (AVHRR) on water reflectance for the Florida Bay region over the 12-year period from July 1985 to September 1997, and field data on light attenuation and changes in bottom cover. The project is conducting comparisons between chlorophyll values collected from the shipboard monitoring programs and pre-cruise reflectances to assess whether there is a link between resuspension events and algal blooms. The next stage in the project is to expand the AVHRR data set backward to before the seagrass dieoffs and to incorporate Landsat data for limited high resolution analysis. As of March 15, 2005, USGS is no longer processing AVHRR images. For recent imagery, please visit the Institute for Marine Remote Sensing (IMaRS) website at http://imars.usf.edu/cgi-bin/db?site=gulf&index=1&type=st&mode=daily. 198507 199709 Publication date Complete None planned -81.25 -80.3 25.8 24.75 none biology hydrogeology mapping algal blooms chlorophyll reflectance remote sensing seagrass secchi depths turbidity ISO 19115 Topic Category biota environment imageryBaseMapsEarthCover 002 007 010 014 geoscientificInformation 008 oceans Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions, Federal Information Processing Standard (FIPS) 10-4, Washington, D.C., National Institute of Standards and Technology United States US U.S. Department of Commerce, 1987, Codes for the identification of the States, the District of Columbia and the outlying areas of the United States, and associated areas (Federal Information Processing Standard 5-2): Washington, D. C., NIST Florida FL Department of Commerce, 1990, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas, FIPS 6-3, Washington, DC, National Institute of Standards and Technology Monroe County Miami-Dade County USGS Geographic Names Information System Johnson Key Sprigger Bank Twin Key Florida Bay Biscayne Bay none Central Everglades South East Coast Rankin Lake none none Rob Wertz U.S. Geological Survey Mailing address

600 Fourth Street South

St. Petersburg FL 33701 USA 727 803-8747 ext. 3045 727 803-2030 rwertz@usgs.gov Ransibrahmanakul, Varis Stumpf, Richard P. 2002 publication Journal of Coastal Research v. 18, no. 2, p. 267-273 Royal Palm Beach, FL Coastal Education and Research Foundation (CERF) accessed as of 5/10/2011 The full article is available via journal subscription or single article purchase. The first page of the article may be viewed on the website below. http://www.jstor.org/pss/4299073 Stumpf, R. P. Frayer, M. L.; Durako, M. J.; Brock, J. C. 1999 publication Estuaries v.22, n. 2B, p. 431-444 New York, New York Springer New York accessed as of 5/10/2011 http://www.springerlink.com/content/108013678486nk25/fulltext.pdf Mueller-Dombois, D. Ellerberg, H. 1974 publication New York, NY John Wiley and Sons Stumpf, R. P. Pennock, J. R. 1989 publication Journal of Geophysical Research - Oceans v. 94, n. C10, p. 14363-14371 Washington, DC American Geophysical Union accessed as of 5/10/2011 The full article is available via journal subscription or single article purchase. The abstract may be viewed on the website below. http://www.agu.org/pubs/crossref/1989/JC094iC10p14363.shtml Stumpf, R. P. Pennock, J. R. 1991 publication Remote Sensing of Environment v. 38, n. 3, p.183-191 Amsterdam, The Netherlands Elsevier Science B. V. accessed as of 5/10/2011 The full article is available via journal subscription or single article purchase. The abstract may be viewed on the website below by selecting the volume and issue number. http://www.sciencedirect.com/science/journal/00344257 Iverson. R. L. Bittaker, H. F. 1986 publication Estuarine, Coastal and Shelf Science v. 22, n. 5, p. 577-602 Amsterdam, The Netherlands Elsevier B. V. accessed as of 5/16/2011 The full article is available via journal subscription or single article purchase. The abstract may be viewed on the website by selecting the volume and issue number. http://www.sciencedirect.com/science?_ob=PublicationURL&_cdi=6776&_pubType=J&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=91c7416b7963284487cc2de903417873&jchunk=22#22 Rao, C. R. N. Chen, J. 1995 publication International Journal of Remote Sensing v. 16, n. 11, p. 1931-1942 online Taylor & Francis Gourp accessed as of 5/16/2011 The full article is available via journal subscription or single article purchase. The abstract may be viewed on the website below. http://www.informaworld.com/smpp/content~db=all~content=a777880524~frm=titlelink Rao, C. R. N. Chen, J. 1996 publication International Journal of Remote Sensing v. 17, n. 14, p. 2743-2747 online Taylor & Francis Group accessed as of 5/16/2011 The full article is available via journal subscription or single article purchase. The abstract may be viewed on the website below. http://www.informaworld.com/smpp/content~db=all~content=a777974124~frm=titlelink Stumpf, R. P. 1992 publication Ann arbor, MI Environmental Research Institute of Michigan in Proceedings of Remote Sensing of Marine and Coastal Environments, Society of Photo-Instrumentation Engineers 1930; N. Wallman, ed. The AVHRR on the National Oceanic and Atmospheric Administration’s polar-orbiting meteorological satellite provides almost daily imagery at 1-km pixel resolution. Monthly average image values were corrected month-by-month for a systematic bias for greater offsets with earlier scenes at the Gulf Stream site (Stumpf et al. 1997). In addition to reflectance calculations, cloud-contaminated pixels were flagged using a combination of techniques: thresholds on sea-surface temperature and channel 2, and spatial variations on channel 2 and a thermal band. While each AVHRR sensor is calibrated prior to launch, the lack of onboard calibration raised concerns for post-launch calibration and sensor deterioration. The problem was resolved when a relative calibration of the sensors on the afternoon satellites was developed (Rao and Chen, 1995 & 1996) Nearly 1700 scenes were used from over 2000 scenes processed with about 1000 nominally cloud-free scenes. The analysis used the afternoon satellites, NOAA-9, NOAA-11, and NOAA-14, as these have the best relative calibration and provided more robust datasets in the winter when the sun is lowest. The failure of NOAA-13 on launch in 1993 left NOAA-11 as the primary satellite in 1994. The orbit of NOAA-11 had precessed to late afternoon precluding quality imagery in winter 1994 due to low sun angles. NOAA-11 failed in September 1994 and an afternoon satellite was not available till the launch of NOAA-14 in late December. The datasets were mapped to a Mercator projection with a pixel size of 1.13 km at latitude 25 deg North and residual navigational errors were removed by registering the image within a pixel of the NOAA digital shoreline. The datasets were mapped to a Mercator projection with a pixel size of 1.13 km at latitude 25 deg North and residual navigation errors were removed by registering the image within a pixel of the NOAA digital shoreline. The Gulf Stream site showed a slight trend of decreasing reflectance over the 12 years, suggesting a systematic bias to greater offsets with earlier scenes, Monthly average image values were corrected for this bias. In addition cloud-contaminated pixels were flagged using a combination of techniques: thresholds on sea-surface temperatures and channel 2, and spatial variations on channel 2 and a thermal band. In the dataset the typical month has 3-9 nominally cloud-free scenes prior to a1994 and 8-16 scenes starting in 1995. Winter 1994 had only four acceptable scenes owing to the extremely late overpass time of NOAA-11 (1600 local standard time). Scenes with solar angles >70 degrees were discarded. Gaps occur in late summer months for 1988-1989. From the available images, monthly average images were determined using the cloud-free pixels. Then the mean winter reflectance from December to March and the mean summer reflectance June to September were determined. Field ecologists in the project area document light attenuation using scalar radiometers that measure photo-synthetically-active radiation (PAR, 400-700nm). We used a Licor 4pi PAR sensor for profiles of scalar irradiance at 0.25-m increments from 0.25 m (or 0.5m) depth to the bottom. SEAGRASSES Bottom coverage of Thalassia testudium in Rankin Lake, Johnson Key Basin, and Rabbit Key Basin was determined using a modified Braun-Blanquet cover-abundance method (Mueller-Dombois and Ellerberg, 1974). Coverage for 1991 was obtained by randomly sampling 10 locations per basin from a 0.5-nautical (nmi) grid. Coverage for 1994-1996 was obtained by systematic random sampling within 30-35 tessellated hexagons per basin. All data were obtained by sampling four 0.25 meter square quadrats per station (north, east, south and west of the vessel). The density values correspond to the following modified Braun-Blanquet cover-abundance scale: 5=cover of more than 75% of the quadrat; 4=50-75% cover; 3=25-50% cover; 2=5-25% cover, 1=numerous stems with less than 5% cover or scattered with up to 5% cover; 0.5=few stems with small cover; 0.1=solitary, with small cover, and 0=not present. Frequency of occurrence and density information for each species within a particular basin was calculated using the formulas: Frequency = no. of occupied quad/total no. of quads and Density = sum of B-B scale values/total no. of quads. The areal extent of each cover was estimated by kriging the mean station data for each basin using Surfer software package Golden Software. With the nominal 1-km spacing of the samples, each 1-m sq sample site fell in a different pixel. Reflectances for all pixels with sites in a basin were averaged; the combination of kriging and averaging dampens out the scaling problems between the 1-m sq samples with the individual 1.2 km sq pixels. Any use of trade, product, or firm names is for descriptive purposes only and does not constitute endorsement by the U.S. Government 2000 Rob Wertz U.S. Geological Survey Mailing address

600 Fourth Street South

St. Petersburg FL 33701 USA 727 803-8747 ext. 3045 727 803-2030 rwertz@usgs.gov Florida Bay, Biscayne Bay Rob Wertz U.S. Geological Survey Mailing address

600 Fourth Street South

St. Petersburg FL 33701 USA 727 803-8747 ext. 3045 727 803-2030 rwertz@usgs.gov Florida Bay satellite images The data have no implied or explicit guarantees. GIF http://coastal.er.usgs.gov/flbay/ Images may be downloaded through SOFIA from the USGS Coastal & Marine Geology Program website none 20110516 Heather Henkel U.S. Geological Survey mailing and physical address

600 Fourth Street South

St. Petersburg FL 33701 USA 727 803-8747 ext 3028 727 803-2030 sofia-metadata@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 none This metadata record may have been copied from the SOFIA website and may not be the most recent version. Please check http://sofia.usgs.gov/metadata to be sure you have the most recent version.