Benthic Zones Flashcards
What are benthic zones?
Ecological regions at the lowest level of a body of water, including the sediment surface and sub-surface layers
What is the intertidal zone?
The area between high and low tide, exposed to air at low tide and submerged at high tide
Also called Littoral zone
What are environmental conditions in the intertidal zone?
Fluctuating temperature, salinity, wave action, and exposure to air
What kind of life is found in the intertidal zone?
Barnacles, mussels, crabs, sea anemones, snails, algae, and shorebirds
What is the subtidal zone?
The region always submerged, just beyond the low tide line, often extending to the edge of the continental shelf
Also called Sublittoral zone
What are conditions like in the subtidal zone?
More stable than the intertidal zone, with moderate light and rich nutrient availability
What kind of life is found in the subtidal zone?
Kelp, corals, seagrasses, reef fish, sea urchins, lobsters, and a wide variety of benthic invertebrates
What is the bathyal zone?
The benthic region on the continental slope, from 200 to 2,000 meters deep
What are environmental conditions in the bathyal zone?
Cold temperatures, high pressure, and no sunlight
What kind of life is found in the bathyal zone?
Deep-sea fish, crinoids, brittle stars, and sessile filter-feeders like sponges and corals
What is the abyssal zone?
The flat, deep-sea floor found between 2,000 and 6,000 meters, covering much of the ocean basin
What are conditions in the abyssal zone?
Near-freezing temperatures, extreme pressure, total darkness, and low nutrient availability
What kind of life is found in the abyssal zone?
Sea cucumbers, tube worms, amphipods, echinoderms, and bacteria feeding on marine snow
What is the hadal zone?
The deepest benthic zone found in ocean trenches, 6,000 –11,000 meters deep
What kind of conditions exist in the hadal zone?
Extreme pressure, near-zero temperatures, total darkness, and minimal food input
What kind of life is found in the hadal zone?
Microbial extremophiles, hadal amphipods, snailfish, and species near hydrothermal vents
What is the neritic zone?
The shallow marine zone extending from the low tide mark to the edge of the continental shelf, typically down to about 200 meters
How do benthic organisms differ from pelagic ones?
Benthic organisms live on or in the seafloor; pelagic organisms live in the water column
What is marine snow, and why is it important in deep benthic zones?
Marine snow is a continuous shower of organic material (dead plankton, fecal matter) that sinks and provides food to deep-sea benthic communities
