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. Aphyonous Basketwork eel Black dragonfish Blind lobster Blob fish Carrier shell Chimaera fish Chimaera pup Coffinfish Crab Fangtooth Firefly squid Gunard Hatchetfish Lizard fish Oreo dory Prickly shark Sea spider Shovel nosed lobster Stargazer Stone crab Swimmer crab Tongue sole Umbrella mouth gulper eel Viperfish