More fish in the gloom of the ocean - País.com (Spain)

small fish that live in the ocean average depth between 200 and a thousand feet below the water surface, and are the most numerous vertebrate biosphere. But little is yet known of its biology and even their abundance, the researchers write in the Spanish Malaspina expedition that have been now released a new estimate of their biomass. The data collected during the expedition’s circumnavigation on board research vessels Hesperides and Sarmiento de Gamboa (between December 2010 and July 2011), scientists have come concluded that previous estimates (based mainly on catches of trawling) biomass of these fish, about one billion tons, fall far short of reality, since it could be around 10,000 million.

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Irigoien, a researcher at King Abdullah University of Saudi arabia, and colleagues, presented today in the journal Nature Communications their work and results obtained by analysis of data obtained during the echo sounder issue with computational models and show “that the biomass of mesopelagic fish in the open ocean is about one order of magnitude higher than previously estimated.” The records were taken between 40 degrees North and 40 degrees South latitude, from 200 to one thousand meters deep and day. These fish come out at night to the upper layers of the ocean to feed and return to the depths day to avoid predators.

“Malaspina has offered us a unique opportunity to assess the stock of mesopelagic fish in the ocean,” says Carlos Duarte, leader of the expedition. “So far our disposal only the data provided by trawling. Recently it has been discovered that these fish are able to detect network and run, which makes trawling in a biased tool when accounting for biomass, “the researcher said in a statement the Higher Council for Scientific Research ( CSIC).

These results, the researchers say in their paper, should be reviewed indicate that the geochemical cycles and ocean ecosystems. “That the biomass of mesopelagic and therefore also the fish biomass, is at least 10 times higher than previously thought has important implications in the understanding of carbon fluxes in the ocean and operation than to now we considered ocean deserts “says Irigoien. Displacement day / night these fish at different depths “accelerate the transport of organic matter into the ocean, the engine of the biological pump that removes carbon dioxide from the atmosphere, because instead of sinking slowly from the surface, transported rapidly to the 500 and 700 meters deep and is released as feces, “the CSIC.