What are reefs?

Some articles on reefs, reef:

Saumarez Reefs - History
... Zenobia, saw Sir JAMES SAUMAREZ' SHOAL (now Saumarez Reefs) and named the reef system after Saumarez ... There is reason to suppose that many other reefs exist to the North-West of this position.” Lihou had just previously discovered Lihou Reef and Cays on 23 February 1823 ... After a hazardous passage through the reef the ship departed the Great Barrier Reef via an opening near Murray Islands ...
Destruction of Sponge Reefs
... The reefs are susceptible to damage by fishing, especially bottom trawling and dredging ... The impacts of bottom trawling have been observed in three of the reefs in the QCB ... as crustacean trapping may also damage the reefs ...
Sponge Reef - Protection
... It was requested in 1999 that groundfish trawlers voluntarily avoid sponge reefs ... were initiated in areas where sponge reefs were known ... effective method, and new damage to the reefs was reported between 1999 and 2002, indicating that the reefs were not entirely missed ...
Liquid Jungle Lab (LJL) Panama - Coral Reefs of The Eastern Tropical Pacific (ETP)
... Coral reefs usually exist in the euphotic zone (shallow areas of the sea where light can penetrate) along coastal or island areas, and require clear, oligotrophic (low nutrient) water in a narrow temperature ... Republic of Panamá, there is estimated 290 km2 of reefs along both Caribbean and Pacific coasts, however much higher diversity (about 68 hard coral species) occurs in the Caribbean, compared to 33 known ... enhances the potential threats to these coral reef systems ...
Saumarez Reefs
... Saumarez Reef is one of the southernmost reefs to be located in the Coral Sea Islands and part of the Coral Sea Shelf it contains three main reefs and numerous smaller reefs ... The reefs were first seen on 27 of February 1823 by Lieutenant John Lihou aboard the vessel HMS Zenobia and named after Vice-Admiral of the United Kingdom James Saumarez ...