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Deep Sea Habitats. Marine Biology Dr. Ouida Meier. Factors Driving Deep Sea Systems. High pressure (1 atm/33 ft) Low temperature (4 ◦ C) Depth Lack of sunlight Lack of photosynthesis Scarcity of food resources Enormous volume of water further reduces encounter probability (mates, prey).
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Deep Sea Habitats Marine Biology Dr. Ouida Meier
Factors Driving Deep Sea Systems • High pressure (1 atm/33 ft) • Low temperature (4◦C) • Depth • Lack of sunlight • Lack of photosynthesis • Scarcity of food resources • Enormous volume of water further reduces encounter probability (mates, prey)
Deep Sea biota • 75% of sea floor is below 3000 m depth • Imported nutrients from photic zone • Seasonal pulses of organic matter • Seafloor communities low biomass but surprisingly high biodiversity • Most benthic organisms in the deep sea (polychaetes, arthropods, molluscs, echinoderms) survive on detritus in sediment • Low biomass but high diversity of fish species (why?): scavengers and predators
Factors Driving Hydrothermal Vent Systems • High pressure • Low temperature • Depth • Lack of sunlight • Lack of photosynthesis • Scarcity of food resources • Enormous volume of water further reduces encounter probability Counteracted by: • Chemosynthetic bacteria (primary producers) • Hot, mineral-rich water • Location – advantages and disadvantages
Succession in Hydrothermal Vents • New vent forms at diverging plates • Chemosynthetic bacteria • Amphipods, copepods • Grazers/filter feeders: limpets, clams, mussels • Scavengers: vent crabs, worms, fish • Predators: vent crabs, octopi • Symbiotic with primary producers (bacteria): vestimentiferan worms, giant clams • 1. Tevnia jerichonana • 2. Riftia pachyptilia Longevity of vent itself estimated at years to decades
Factors Driving Methane Vent (Cold Seep) Systems • High pressure • Low temperature • Depth • Lack of sunlight • Lack of photosynthesis • Scarcity of food resources • Enormous volume of water further reduces encounter probability Counteracted by: • Chemosynthetic bacteria (primary producers) • Cold, mineral-rich water • Location – advantages and disadvantages
Bioluminescence • http://www.lifesci.ucsb.edu/~biolum/chem/ Luciferin + Luciferase + O2 -> Oxyluciferin + light or Photoprotein + Ca2+ -> light
Deep Sea and Midwater Creatures Reportedly brought to surface or washed ashore in Phuket following the earthquake and tsunami of 26 Dec. 2004. Origin and authorship of photos unknown: these were circulated via email with no references given. Captions are taken from titles of images.
