Reference Work Entry

Encyclopedia of Modern Coral Reefs

Part of the series Encyclopedia of Earth Sciences Series pp 1032-1034

Spurs and Grooves

  • Eugene A. ShinnAffiliated withCollege of Marine Science, University of South Florida


Spurs and grooves form a comb-tooth structure common to many coral reef fronts. Best developed on the windward side of reefs, the structure consists of elongate channels or grooves, a few meters wide and deep, separated by seaward-extending coral ridges or spurs (Figure 1) (Maxwell, 1968, p. 110). Grooves are commonly floored with coral rubble or carbonate sand. Where actively accreting, spurs are covered with living corals. Where accretion has ceased, spurs harbor associated benthic organisms (Shinn, 1963).
Spurs and Grooves. Figure 1

Spurs and grooves at Sombrero Key Reef in the middle Florida Keys offer a popular dive site. The spurs are no longer growing but nonetheless consist of colorful hardbottom communities. (Reprinted from Lidz et al., 2007, with permission.)


One of the most obvious of reef features that is found worldwide is the spur-and-groove system, finger-like coral projections located on the seaward side of coral reefs. Early authors ...

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