Coral Animals Pump Out Ocean Aroma
Oct. 23, 2012 --
For 37 years the Nikon Small World photography competition showcases the beauty and extreme details captured using light microscopes. Every year the world below the waves provides many interesting subjects for the Small World competition. Most examples of aquatic life are entered by professionals in, or students of marine biology, but many of these images were provided by entrants from other disciplines who simply find marine life fascinating. Here, photomicrographer Arlene Wechezak of Anacortes, Wash., and 10th place winner of the 2009 Small World Contest, magnified 10x an Obelia species of hydrozoa with extruded medusae as a fresh sea water mount using a darkfield.
Here we see the same species as before only this time magnified 40x its original size. The extruded medusae of the Obelia hydrozoa contain tentacles that sting and capture the animal's prey.
Bruno Pernet and Russell Zimmer, California S
In this image, biologists magnified 20x a species of bryozoan of the genus Membranipora found on seaweed and kelp using stereomicroscopy.
James H. Nicholson, Hanian Lang, and Sylvia G
Almost transparent tissue covers the hard skeleton "cups" of each polyp in this brightfield photo of brain coral in the genus Goniastrea magnified 25x.
Marine biologist Alvaro Migotto of the University of São Paulo in Brazil used stereomicroscopy and a darkfield to capture this photo of a brittle star magnified 8x.
Photographer David Maitland of Feltwell, UK, zoomed in with 100x magnification on coral sand over a brightfield.
Tomasz Kozielec, Nicolaus Copernicus Universi
Surface of shark skin tanned with a chromium compound magnified 40x with reflected light.
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John Dolan, CNRS/University of Paris Laborato
On its side this marine ciliate (Rhabdonella spiralis)looks like a trumpet; when the image is turned vertical it looks like a champagne flute - a fine photo from French oceanographer John Dolan, who used a differential interference contrast technique and 40x magnification.
Robert Brons Insula College Dordrecht in Spij
A freshwater Bryozoan, or moss animal, Cristatella mucedo in a darkfield magnified 6.5x.
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Biologist Diana Lipscomb of George Washington University in Washington, used Nomarski Interference Contrast and a magnification of 400x the original size to showcase a suctorian ciliate, Acineta tuberosa, in the phylum Ciliophora.
Using Nomarski Interference Contrast and a magnification of 400x the original size this photo shows a ciliate in the genus Sonderia that preys upon various algae, diatoms, and cyanobacteria.
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A sea breeze can carry the scent of the ocean inland for miles, and the source of that smell is a perfume made from living corals.
Biologists already knew that reef-building corals serve as the planet’s main producer of dimethylsulphoniopropionate (DMSP), a chemical that serves as a seed for clouds and gives the ocean its unique scent. However, they thought DMSP only came from the algae living with the coral animals.
Recently, marine scientists discovered that the tiny animals themselves also produce the chemical. Young coral animals, or polyps, caused DMSP levels to increase by 54 percent in an experiment documented in the journal Nature.
“The characteristic ‘smell of the ocean’ is actually derived from this compound, indicating how abundant the molecule is in the marine environment. In fact we could smell it in a single baby coral,” said study co-author Cherie Motti, an Australian Institute of Marine Science (AIMS) chemist, in a press release.
When the researchers turned up the heat, the polyps produced even more DMSP. Levels increased by 76 percent when the coral suffered in uncomfortably warm water.
Higher surface water temperatures threaten corals globally, along with declining water quality, ocean acidification, and other menaces. Coral die-offs could cause DMSP levels to spike at first and then crash.
DMSP can serve as the seed, or nucleus, for cloud formation. So alterations in levels of the chemical could influence cloud cover.
“Cloud production, especially in the tropics, is an important regulator of climate — because clouds shade the Earth and reflect much of the sun’s heat back into space,” said lead author Jean-Baptiste Raina, a marine scientist at AIMS, in a press release. “If fewer clouds are produced, less heat will be reflected — which ultimately will lead to warmer sea surface temperatures.”
With warmer surface waters heat-stressing and ultimately bleaching corals, this could create a negative feedback loop with the potential to deodorize the ocean.
IMAGE: A coral reef in shallow water (Jim Maragos, U.S. Fish and Wildlife Service, Wikimedia Commons)