Icebergs: Icy Hotspots of Life
Icebergs—how they are formed and their contribution to aquatic life
The massive floating islands that are made of freshwater ice floating around the north and south poles are called icebergs. These blue icy giants are one of the iconic symbols of the polar region together with penguins and polar bears. How are they formed and what are they exactly?
Found in the seas of the Arctic, the Southern Oceans, and the North Atlantic, icebergs are the parts that split or are calved from a glacier. These huge body of ice are made of freshwater that is why they float in the salty waters of the oceans. The floating ice islands come in different sizes from growlers (smaller than cars) to bergy bits (as big as houses) to the giant bergs. Two of the largest icebergs floating in the ocean today are the B-15, larger than the whole island nation of Jamaica, and the C-19, which has a surface area larger than 5,500 square km.
A Life of a Berg
Bergs are not living creatures. However, they undergo a life cycle. Life for bergs starts from being a part of a glacier. After thousands of years, a part of the glacier calves in and starts to float away from the said glacier. Once separated from the glacier, icebergs typically last for about three to six years or shorter if they happen to float toward warmer waters. Although, some icebergs just melt away, others collapse into smaller bergs due to crashing waves and warmer weather.
Life in an Icy Island
So what do icebergs contribute aside from famously sinking the Titanic? From afar, an iceberg might look like a lifeless giant block of ice floating in the sea aimlessly. However, scientists have discovered that icebergs are teeming with life.
The underside of an iceberg is where ice algae grow. These types of algae are main players in primary production that occur through photosynthesis or through chemosynthesis. The marine ecosystem depends on the ice algae too. Due to the presence of the algae, swarms of krill that feed on phytoplankton swim near iceberg. This, in turn, attracts other animals that feed on krill to stay on the iceberg.
Some small fishes also swim under the bergs to protect themselves from larger ones. Penguins ride on icebergs to rest and find food. Some birds even make their nest on the iceberg crevices. Sometimes, polar bears also seek refuge in larger icebergs.
Icebergs—growlers or the larger ones—are full of both plant and animal life. They may not last forever, but for time, animals make them as their floating icy homes.
Feel free to express your thoughts by leaving a comment below. You may also share your insights with me through Facebook, Twitter, and Goodreads. To know more about Icy’s adventure, please check out my book, Icy the Iceberg.
Fries-Gaither, Jessica and Lockman, Alison Schirmer. 2009. “All About Icebergs.” Beyond Penguins and Polar Bears. Accessed on June 4, 2018. http://beyondpenguins.ehe.osu.edu/issue/icebergs-and-glaciers/all-about-icebergs.
Smith, Brett. 2017. “Animals that Live on Glaciers and Icebergs.” Last modified April 25. Accessed on June 4, 2018. http://sciencing.com/animals-live-glaciers-icebergs-8265816.html.
University of California–San Diego. 2007. “Antarctic Icebergs: Hotspots of Ocean Life.” ScienceDaily, June 22. Accessed on June 4, 2018. https://www.sciencedaily.com/releases/2007/06/070621140754.htm.