June 9, 2016. Water / Oceans
In practical terms the polar regions could be defined as those that regularly experience seasonal sea ice
Cristina G. Mittermeier, Gregory S. Stone, Russell A. Mittermeier, Octavio Aburto-Oropeza, Claudio Campagna, Kent E. Carpenter, Laurence P. Madin, David Obura, Enric Sala, Sebastian Troëng, Peter A. Seligman & Stefan Gutermuth
Covered during winter or year-round by sea ice and subject to dramatic cycles in air temperature and light, Arctic and Antarctic marine environments are the most extreme and variable on earth. Air temperatures can range from -40° to -50°C up to 60°C, while light cycles vary between total darkness during midwinter and 24 hours of daylight in midsummer. In practical terms the polar regions could be defined as those that regularly experience seasonal sea ice.
The known diversity of organisms in the polar regions is somewhat less than in temperate and tropical regions, yet there are still an impressive number of marine species found in each region. Each polar region is characterized by an iconic animal: the polar bear in the Arctic and the penguin in the Antarctic.
Polar ecosystems are particularly vulnerable to ongoing climate change and accompanying changes in the extent and timing of seasonal sea ice. Species respond to climate change by contracting or expanding their ranges or with changes in abundance, in the timing of their life histories, and in their behavior.
Polar regions have long captured the imagination and passion of scientists, adventurers, students, and the global human community. Protecting and conserving these unique and strangely fragile seas is a responsibility common to all citizens of this Earth.
This is an excerpt from the CEMEX Conservation Series Book Oceans: Heart of Our Blue Planet (2011)