Deep-sea life in the fiords: Part 2The perpetual gloom of the Fiordland marine environment - concent
Deep-sea life in the fiords: Part 2The perpetual gloom of the Fiordland marine environment - concentrated within a narrow band between 5 and 40 metres (more information here: http://bit.ly/1MTaywj) - allows many a strange deep-sea creature to exist at much shallower depths than normal.Fiordland supports the largest population of black coral in the world. Ancient trees up to 200 years old cover the reef like a ghostly forest, predominating the ecosystem alongside red corals, ancient lampshells, and various sponges. Butterfly perch and other fish flit between them - as birds through terrestrial forests - and delicate brittlestars lay entwined within their branches, their arms resembling tiny coiled snakes.Meandering through the forest are various nudibranchs (pronounced NEW-dih-bronk): shell-less sea slugs which strikingly exhibit nature’s boundless creativity. One common species, Jason’s nudibranch, is able to incorporate the stinging cells of its prey into long white growths on its back, which it then uses to defend itself against predators.On the sandy bottom, the quill-like and aptly named sea-pens abound. Colonial animals that are composed of polyp clusters (which look similar to miniature sea anemones), sea-pens live in areas of strong currents, where they ensnare passing zooplankton. When touched they employ bioluminescence as a defensive tactic: deterring predators by emitting a bright greenish light (bioluminescence will be covered in more detail in a future post).On the seafloor also lurks the fearsome eleven-armed sea star, the largest in the antipodean. Reaching up to 30 centimetres in diameter, the eleven-armed sea star can have anywhere between seven and fourteen arms (though eleven is the most common). It scours the sea-floor seeking benthic invertebrates like mussels and crabs, on which to feed.And below 40 metres…Biodiversity fades. But even though it’s unfathomably dark, there is life here. In fact, the creatures that live at 450 metres - or, at the very bottom of the fiord basins - resemble those that live at depths of 1000 metres in the open ocean. I will be exploring deep-sea creatures further, but the next post will be about a very unique population of dolphins living in the fiords. Stay tuned!VPReferences: http://bit.ly/1V4764J, http://bit.ly/1VpMendImage credit: Rob & Kiersten Swale from Fiordland Discovery (http://bit.ly/1RV3PBh, https://www.facebook.com/FiordlandDiscovery/) -- source link
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