Fish Disection- Solider fish

Deep-sea life

Threatened by global warming

A new study of deep-sea life across the globe aims to understand how natural gradients in food and temperature in the dark, frigid waters of the deep sea affect the snails, clams, and other creatures that live there. Similar studies have been conducted for animals in the shallow oceans, but our understanding of the impact of food and temperature on life in the deep sea the Earth's largest and most remote ecosystem has been more limited.The results will help scientists understand what to expect in the deep sea under future climate change, the researchers say. "Our findings indicate that the deep sea, once thought remote and buffered against climatic change, may function quite differently in the future," they write.

  All living things need energy in the form of food, heat and light to survive, grow, and reproduce. But for life in the deep sea — defined as anything beyond 600 feet (200 m) — energy of any kind is in short supply. Descend more than a few hundred feet beneath the ocean surface, and you'll find a blue-black world of near-freezing temperatures, and little or no light. Because so little of the sun's light penetrates the surface waters, there are no plants for animals to eat. Most deep-sea animals feed on tiny particles of dead and decaying organic matter drifting down from the sunlit waters above. It is estimated that less than 1% of the food at the surface reaches the ocean's watery depths.The researchers wanted to know what this energy deprivation means for deep sea habitats across the globe, and for the animals that live there. "How much of the differences that we see across different groups of deep-sea animals in terms of growth, or lifespan, or the number of species, are related to differences in the temperature or amount of food where they occur?" said co-author Craig McClain of the National Evolutionary Synthesis Center in Durham, North Carolina.To find out, the researchers compiled previously published data for hundreds of different deep-sea organisms across the globe, ranging from crabs and snails, to fish and tube worms. The data included parameters like metabolic rate, lifespan, growth, biomass, abundance, size and diversity.

Assorted invertebrates on deep seafloor off the California coast (depth 1950 m).