Landsat Thematic Mapper: Detection of Shifts in Community Composition of Coral Reefs

We assembled a time series of 20 Landsat thematic mapper images from 1982 to 1996 for Key Largo, Florida, to ascertain whether satellite imagery can detect temporal changes in coral reef communities. Selected reef and control areas were examined for changes in brightness, spectral reflectance, band ratios, spatial texture, and temporal texture ( pixel-to-pixel change over time). We compared the data to known changes in the reef ecosystem of Carysfort Reef and terrestrial sample sites. Changes in image brightness and spectral-band ratios were suggestive of shifts from coral- to algal-dominated community structure, but the trends were not statistically significant. The spatial heterogeneity of the reef community decreased in the early 1980s at scales consistent with known ecological changes to the coral community on Carysfort Reef. An analysis of pixel-scale variation through time, termed temporal texture, revealed that the shallow reef areas are the most variable in regions of the reef that have experienced significant ecological decline. Thus, the pro- cess of reef degradation, which alters both the spatial patterning and variability of pixel brightness, can be identified in unclassified thematic mapper images.

[1]  Richard T. Barber,et al.  African dust and the demise of Caribbean Coral Reefs , 2000 .

[2]  Wei Li,et al.  Spectral Signatures of Coral Reefs: Features from Space , 2001 .

[3]  P. Mumby,et al.  Digital analysis of multispectral airborne imagery of coral reefs , 1998, Coral Reefs.

[4]  H. Baldwin.  Is There a Natural Crop Rotation in Forests , 1934 .

[5]  Chris D. Clark,et al.  Coral reef habitat mapping: how much detail can remote sensing provide? , 1997 .

[6]  K. Baker,et al.  The bio‐optical state of ocean waters and remote sensing 1 , 1978 .

[7]  P. Dustan.  Community Structure of Reef-Building Corals in the Florida Keys: Carysfort Reef, Key Largo and Long Key Reef, Dry Tortugas , 1985 .

[8]  H. Lessios.  Diadema antillarum 10 years after mass mortality: still rare, despite help from a competitor , 1995, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[9]  D. R. Robertson,et al.  Spread of Diadema Mass Mortality Through the Caribbean , 1984, Science.

[10]  C. Mazel,et al.  Optical spectra and pigmentation of Caribbean reef corals and macroalgae , 1999, Coral Reefs.

[11]  L. Eklundh,et al.  Fourier series for analysis of temporal sequences of satellite sensor imagery , 1994 .

[12]  P. Dustan,et al.  Mapping and monitoring the health and vitality of coral reefs from satellite: a biospheric approach. , 2000, Life support & biosphere science : international journal of earth space.

[13]  P. Dustan.  Coral reefs under stress : sources of mortality in the Florida Keys , 1999 .

[14]  John R. Jensen,et al.  Introductory Digital Image Processing: A Remote Sensing Perspective , 1986 .

[15]  Spectral characterization of the LANDSAT-D multispectral scanner subsystems , 1982 .

[16]  C. Mazel.  Spectral measurements of fluorescence emission in Caribbean cnidarians , 1995 .

[17]  Ouida W. Meier,et al.  Quantification of Loss and Change in Floridian Reef Coral Populations , 1992 .

[18]  Effects of eutrophication on reef-building corals , 1987 .

[19]  Karen S. Baker,et al.  Bio-optical classification and model of natural waters. 21 , 1982 .

[20]  Chris P. Tsokos,et al.  Detection of Coral Reef Change by the Florida Keys Coral Reef Monitoring Project , 2001 .

[21]  B. Markham,et al.  Spectral characterization of the LANDSAT Thematic Mapper sensors , 1985 .

[22]  Parc Valrose,et al.  et cartographie de récifs coralliens en Mer Rouge (Golfe d'Aqaba) , 1985 .

[23]  Robert M. Haralick,et al.  Textural Features for Image Classification , 1973, IEEE Trans. Syst. Man Cybern..

[24]  T. Goreau.  The Ecology of Jamaican Coral Reefs I. Species Composition and Zonation , 1959 .

[25]  T. Hughes.  Catastrophes, Phase Shifts, and Large-Scale Degradation of a Caribbean Coral Reef , 1994, Science.

[26]  Ellsworth F. LeDrew,et al.  Spectral Discrimination of Healthy and Non-Healthy Corals Based on Cluster Analysis, Principal Components Analysis, and Derivative Spectroscopy , 1998 .

[27]  M. Pichon,et al.  DISCRIMINATION OF SCLERACTINIAN-DOMINATED FROM OTHER REEF COMMUNITIES USING SPOT SATELLITE IMAGERY , 1997 .

[28]  G. Carter.  Ratios of leaf reflectances in narrow wavebands as indicators of plant stress , 1994 .

[29]  Ricardo T. Biña,et al.  Coral reef mapping using landsat data : follow-up studies , 1978 .