Rocas Alijos


Rocas Alijos, or Escollos Alijos are a group of tiny, steep and barren volcanic islets or above-water rocks in the Pacific Ocean at. They are part of Comondú municipality of the Mexican state of Baja California Sur, and situated about 300 km west of the mainland. The total surface area is less than 1,000 square metres. The official area figure of.
The group consists of three principal rocks and numerous smaller ones. South Rock, the largest of the group, is 34 meters high, with a diameter of only 14 meters . Middle Rock is 18 meters high and about 10 meters in diameter. North Rock, 200 meters north of South Rock, is 22 meters high, with a diameter of 12 meters.
The rocks in between those are either submerged or so low that they are barely visible among the heavily breaking waves.
The rocks seem to be known since the early Spanish history of Mexico; they can be found on a map from 1598. The first description is from 1704, by pirate John Clipperton. But only in 1791 the first exact description was made by a Spanish sailor. South Rock was climbed for the first time in 1990 by an expedition under the leadership of Robert Schmieder, who edited a monograph about the rocks.
The group is located at the transition zone between two major biologic provinces, at a latitude where the Pacific Current turns westward to form the North Pacific trans-oceanic current. The rocks are nesting sites of many seabirds.
The two other Mexican island groups in the Pacific Ocean that are not on the continental shelf are Guadalupe Island and Revillagigedo Islands.

Fauna

The breeding marine avifauna of Alijos Rocks currently consists of Leach's storm-petrel, red-billed tropicbird, masked booby, and sooty tern. The magnificent frigatebird is a regular winter visitor but probably does not breed. The Laysan albatross is currently an annual visitor to Alijos Rocks during its winter breeding season, and may start to nest there in the near future.

Literature