Coral reef a protective area, or it may lie between the reef and the shore, and in this case is a flat, rocky area. Fish tend to prefer it when it is present. The reef lagoon is an entirely enclosed region, which creates an area less affected by wave action and often contains small reef patches. However, the "topography of coral reefs is constantly changing. Each reef is made up of irregular patches of algae, sessile invertebrates, and bare rock and sand. The size, shape and relative abundance of these patches changes from year to year in response to the various factors
Open Polar Sea project that by the end of the 21st century, the annual summer withdrawal of the polar ice cap could expose large areas of the Arctic Ocean as open water, and an ice-free Arctic is possible in the future due to Arctic shrinkage. Although the North Pole itself could potentially remain ice-covered in winter, a navigable seasonal sea passage from Europe to the Pacific could develop along the north coast of Asia. Russell Potter, "The Open Polar Sea," "Encyclopedia of the Arctic" (Routledge, 2004) Michael Robinson, "The Coldest Crucible: Arctic Exploration and American Culture" (Chicago, 2006). Michael Robinson, "Reconsidering the Theory