Whales: the death that leads to life!

Usually when a whale dies it sinks into the ocean – an event called whale-fall. When it reaches the deep ocean – a very unproductive area – it provides an ephemeral habitat [1] by providing shelter, a hard substrate and, more importantly, plenty of food, something scarce at depth. This habitat can last up to one hundred years (depending on the whale size) being colonized by very specific animals, some endemic [2] of these “organic islands” and others (rarer), that also exist in hydrothermal vents or cold seeps, both extreme habitats.

The discovery of the first and only whale-fall in the “Southern Ocean” dates back to 2010 and was accidental, as most of the discoveries of this nature. The animal’s carcass was located east of Scottia Sea between 1444-1447 m deep, and was in an advanced decomposition state. A DNA analysis allow the identification of the carcass to belong to an Antarctic minke whale (Baleonoptera bonaerensis), whose bones had been colonized by gastropods, crustaceans, polychaetes (marine worms), among others, and new species were identified.

Examples of species found in bones

The discovery of this whale-fall off the coast of Antarctica was an important step in the study of these habitats because, although this part of the world has enough whales, no carcass had been found in the deep ocean. The study of their colonizing communities helped the knowledge development of these ‘organic islands’, on which there has been a global effort to better understand their ecological influence on the world fauna.

Whale skeleton

[1] Temporary

[2] Only exist in this type of habitat

Source:

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Amon DJ, Glover AG, Wiklund H, Marsh L, Linse K, Rogers AD, et al. The discovery of a natural whale fall in the Antarctic deep sea. Deep Res Part II Top Stud Oceanogr [Internet]. Elsevier; 2013;92:87–96. doi: 10.1016/j.dsr2.2013.01.028

Author: José Queirós

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