The Arctic Ocean: Climate, Biodiversity, and Unique Ecosystem

Introduction. Compared to the other oceans presented in this volume, the Arctic is the Earth’s smallest ocean with about 14 million km² (or 5.4 million m²). It is located in the Northern Hemisphere and is almost entirely surrounded by the landmasses of Eurasia, Greenland (the Earth’s largest island), and North America. The cold temperatures emanating from these landmasses leave the Arctic covered with either seasonal or permanent sea ice, which in turn has influenced the maritime history of this ocean. The term “Arctic” originally is derived from the Greek arktikos, which refers to the most prominent northern constellation of the Great Bear (Ursa Major). Both land and ocean areas in the Arctic are contested. The most obvious definition holds all the area above the Arctic Circle (approximately 66°N) as part of the Arctic. An alternative definition is based on temperature and includes all those areas where the average temperature does not exceed 10°C (50°F) during the hottest month of July.

BOTANICAL AND ZOOLOGICAL OVERVIEW. The Arctic Ocean is home to many species of fauna and flora, most of which have adapted to the extreme conditions of the region. However, to understand the Arctic Ocean’s role in their survival, the region must first be defined. The University of Alaska has classified the Arctic Ocean based on the surrounding flora. Keeping an outlined area in mind, it must be noted that the species that survive deal with an average temperature below 10 to 12°C during the hottest month of the year. It is not the ocean size or landmass that matters here but rather the climate that has allowed diverse species to thrive.

There are three subsections of flora in the Arctic. They are classified into vascular plants, bryophytes, and algae. Vascular plants and bryophytes (nonvascular plants, including mosses, among others) are the fundamental components of terrestrial vegetation, whereas algae are limited to freshwater and marine ecosystems.

As far as vascular plants are concerned, there are only a limited number of species. Approximately 2,200 vascular plant species and subspecies exist in the Arctic that is, roughly 0.85 percent of the Earth’s total known vascular species. The majority of the species within the Arctic domain have a circumpolar distribution. According to modern scientists, no Arctic vascular plants have gone extinct in over 250 years that have had a direct relationship with human activities. For the bryophytes, the estimate is even lower, which sits around 900 species. Nearly 80 percent of the Arctic species are circumpolar as well. It should be noted that there are very few regions in the Arctic that do not contain bryophytes. It is currently estimated that there are 4,000 algae species in the Arctic. These species are crucial for the survival of the area as they make up the first layer of the food web in the freshwater and marine ecosystems. They occur in three different regions within the water. They can form an attachment to the sea ice, free-float throughout the upper layer of ocean water, or simply attach to the ocean floor. All of the reported species of algae are circumpolar.

Edward S. Curtis’s photograph of an Inuit family outside of their living quarters, c. 1899. Seals and furs are suspended from ropes and poles (Library of Congress)

The plant species in the Arctic Ocean region cover 5 million km² of the 7.1 million km² landmass sitting either on top of the Arctic Ocean itself or in the surrounding areas. Although sparsely populated, there has been an increasing threat from humans since the 1960s to these plant species. Eventhough the impact is minimal, it must be monitored to maintain a properly functioning ecosystem.

According to the most recent biodiversity assessment conducted by members of the Arctic Council and the scientific community, there are 102 different mammalian species that live in land/ice formations as well as in the ocean comprising the Arctic (the most famous being the polar bear). There are roughly 200 bird species that not only call the

Arctic home for part of the year but also use the Arctic as a breeding site. In terms of fish, the species found in the Arctic are composed of freshwater, diadromous (migrate to and from freshwater to the oceans), and marine. Currently, there are a total of 127 species of freshwater and diadromous fish in the Arctic biome as well as 633 known species of fish living in the Arctic Ocean and adjacent ocean areas connected to the Arctic Ocean. When it comes to describing the invertebrates of the Arctic Ocean region—as well as any other region of the world—the numbers are even more complicated. Scientists continue to find new species of invertebrates in all regions of the world, including the areas that are easier to analyze. In the Arctic, however, the current estimate is just over 1,300 species of invertebrates that live not only on land but also within the waterways of the region. Arctic animals are more regionally localized rather than circumpolar. The marine invertebrates are the last set of fauna to be covered. There are currently 337 species of marine invertebrates living in the Arctic Ocean, but this number is based solely on the data gained by monitoring trawling in the Barents Sea. It is extremely difficult to quantify the exact number of species in the Arctic Ocean because of the extreme climates and the number of waterways from the Pacific and Atlantic oceans that circulate in the Arctic Ocean system. Furthermore, the receding ice caps reveal multiple new animal and plant species yearly.

The “Doomsday” Vault. Spitsbergen, the largest island of the Arctic Svalbard Archipelago, houses the Global Seed Vault, which was opened in 2008 in a modified abandoned mine shaft. The ideal conditions of low tectonic activity (no earthquakes) and permafrost (the permanent frozen condition of the soil) help ensure seed preservation for a long time. The vault stores a total of 400,000 plant seed samples, roughly one-third of the Earth’s plant varieties. This “doomsday” storage is meant to preserve plant and seed loss that might occur during regional or global natural crises or warfare. Rainer F. Buschmann