Discolored Tissue and Bleaching
Similar conditions: Bleaching can be misidentified as:
- yellow band disease (YBD) lesions which are pale yellow bands blotches
surrounded by fully pigmented tissue. On a bleached coral, the YBD is usually darker
than surrounding tissue (E). YBD can also be similar in color to
bleached patches (A).
- Large white bands of recent tissue loss from WP appear bleached, but lack tissue
and have visible skeletal elements.
- dark spots disease (DSD) dark spots or bands at the margin or within
the tissue (G, J).
Bleaching affects the entire colony (B, C, H), upper surfaces
(F), the base, or focal to multifocal patches (I,P). Coloration
may vary from pale to white within individual species (L-N); white
irregular patches of tissue loss may occur near bleached areas (L).
Corals that bleach (C) may recover (D). A
scale of bleaching from 1-5 can be used: 1= white; 2= light yellow; 3=yellow; 4=
light brown; 5= normal.
Severity of bleaching can range from: pale: colonies that are lighter than normal;
partially bleached: the loss of some or all color in a random mosaic
pattern; mostly bleached: colonies that are uniformly pale yellow to off white;
and fully bleached: colonies that appear uniformly white and the
skeleton is seen through translucent coral tissue; Other patterns of bleaching also
occur including ring bleaching : rings of pale or white tissue
up to 4 cm in diameter and 2-5 mm in width, each with a center of unbleached tissue.
Bleached colonies may exhibit a distinct blue (K), yellow, green,
or reddish (N) fluorescence. Corals that bleach may be more susceptible
to other diseases such as BBD (O).
View other
Biotic Diseases, or
Non-Biotic Diseases of the Western Atlantic.