Name: ______Per:______
Benthic Animals of the Deep Ocean Basin.
Sediment Covered Shore WS
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How a Baloney Sandwich Changed the way we think About the Deep Ocean
1. What part of the deep ocean basin did Alvin most likely land on?
2. What are the 2 main methods of feeding in this aria?
3. Why would bacteria in this aria have evolved to have such slow metabolisms?
The Giant Tube Worm
The giant tube worm, also known as Riftia pachyptila, was totally unknown to science until researchers exploring the deep Pacific Ocean floor discovered strange, hydrothermal vents. Powered by volcanic heat, these vents recirculate water that seeps down through cracks or faults in the rock. When the water emerges from the vent, it is rich in chemicals and minerals. This toxic soup of chemicals would be lethal to most animals, so scientists were shocked to find entire ecosystems of animals living around these vents. In spite of the near boiling temperature of the water, these animals were thriving in the complete absence of light. The organisms that live near these vents are unique because, unlike all other living things on earth, they do not depend on sunlight for their source of energy. Instead, they feed on tiny bacteria that get their energy directly from the chemicals in the water through a process known as chemosynthesis. These hydrothermal vents are known as "black smokers" because of the dark color of the material they eject. The giant tube worms are closely related to the many smaller species of tube worms that inhabit shallower waters. These giant tube worms grow up to eight feet (over two meters) in length and have no mouth and no digestive tract. They depend on bacteria that live inside them for their food. This type of mutually beneficial relationship between two organisms is known as symbiosis. The bacteria actually convert the chemicals from the hydrothermal vents into organic molecules that provide food for the worm. Perhaps the most noticeable characteristic of these worms is their bright red plume. This is a specialized organ used for exchanging compounds such as oxygen, carbon dioxide, and hydrogen sulphide with the seawater. The bright red color comes from the presence of large amounts of hemoglobin (blood). It is this plume that provides nutrients to the bacteria that live inside the worm. As amazing as these vent ecosystems are, they are also extremely fragile. As the Earth's crust shifts due to geothermal activity, the supply of chemicals through the vents can be cut off. When this happens, all of the incredible creatures that depend on these chemicals will wither and die. Scientists have returned to once thriving vent sites only to find them completely cold and dead. But the cycle begins again when new hydrothermal cents begin to grow elsewhere on the deep sea floor.
Questions:
4. What part of the deep ocean basin does the Giant tube worm live in?
5. What is the primary source of energy in this region?
6. What organism is considered to be the primary producer?
7. What type of relationship does the Giant Tube worm have with the chemosynthetic bacteria that lives in its plume?
8. What trophic level would a crab that eats giant tube worm plumes be considered?
Questions:
9. What part of the deep ocean basin is pictured?
10. What is the primary sourse of energy in this reagion?
11. What organism is considered to be the primary producer?
Whale Fall Bacteria & Tide Cold Water
The falls of large whales yield massive pulses of labile organic matter to the deep-sea floor. While scientists have long speculated on the ecological roles of such concentrated food inputs, observations have accumulated since the 1850s to suggest that deep-sea whale falls support a large ecosystem. Interest in whale-fall ecology heightened with the discovery in 1989 of a particular form of chemotropic bacteria that has only been found on whale falls. Related communities of bacteria were soon reported from whale falls in other bathyal and abyssal Pacific and Atlantic sites, and from 30 million year old sights in the northeast Pacific fossil record. Recent time-series studies of whale falls off California indicate that the carcasses passed through at least three successive stages. It is during the third stage when a chemotropic bacteria inhabit the bones of the former whale. This final stage can last for decades, and is categorized by the new complex food web that lives on the skeleton as it emits sulphide gas from the anaerobic breakdown of bone lipids. Local species diversity on large whale skeletons during the third stage is higher than in any other deep-sea community like cold seeps and hydrothermal vents. Finally, whale-fall bacteria have proven to be a novel source of cold-adapted enzymes of potential utility in cold-water detergents. Without whale fall bacteria, you would never have to view those stupid Tide commercials that advertise how much money you save by washing your cloths in cold water with cold water tide.
Questions:
12. What part of the deep ocean basin is pictured above?
13. Can there be primary production in this area?
14. How does this area relate to hydrothermal vents?
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