<Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> A seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff - rock . Seamounts are typically formed from extinct volcanoes that rise abruptly and are usually found rising from the seafloor to 1,000--4,000 m (3,300--13,100 ft) in height . They are defined by oceanographers as independent features that rise to at least 1,000 m (3,281 ft) above the seafloor, characteristically of conical form . The peaks are often found hundreds to thousands of meters below the surface, and are therefore considered to be within the deep sea . During their evolution over geologic time, the largest seamounts may reach the sea surface where wave action erodes the summit to form a flat surface . After they have subsided and sunk below the sea surface such flat - top seamounts are called "guyots" or "tablemounts" </P> <P> A total of 9,951 seamounts and 283 guyots, covering a total of 8,796,150 km (3,396,210 sq mi) have been mapped but only a few have been studied in detail by scientists . Seamounts and guyots are most abundant in the North Pacific Ocean, and follow a distinctive evolutionary pattern of eruption, build - up, subsidence and erosion . In recent years, several active seamounts have been observed, for example Loihi in the Hawaiian Islands . </P> <P> Because of their abundance, seamounts are one of the most common marine ecosystems in the world . Interactions between seamounts and underwater currents, as well as their elevated position in the water, attract plankton, corals, fish, and marine mammals alike . Their aggregational effect has been noted by the commercial fishing industry, and many seamounts support extensive fisheries . There are ongoing concerns on the negative impact of fishing on seamount ecosystems, and well - documented cases of stock decline, for example with the orange roughy (Hoplostethus atlanticus). 95% of ecological damage is done by bottom trawling, which scrapes whole ecosystems off seamounts . </P>

Where is the world's largest concentration of sea mounts found