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10 Cards in this Set
- Front
- Back
Types of bottom samplers
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Dredges
Sleds Grabs Corers -lecture 30, slide 2 |
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Seabed Landscape
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-mainly sand and mud
-patchy larval settlement, patchy distribution of organic material -Population densities are patchy |
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Input of Organic Matter in Water Column
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-declines with depth and distance from shore
==>Continental shelf sediment organic matter = 2 - 5% ==>Open ocean sediment organic matter = 0.5 - 1.5% ==>Open ocean abyssal bottoms beneath gyre centers < 0.25% |
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Hot vents
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-oceanic ridges where hot water emerges from vents associated with volcanic activity
-sulfide emerges which supports sulfide-oxidizing bacteria ==>Sulfide bacteria can be free living or symbionts within vent organisms -Animals near hot vents are uncharacteristically large and fast growing for deep sea -Bivalves and members of tube-worm group Vestimentifera have symbiotic sulfide bacteria, which are used as a food source |
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Vestimentifera
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-hot vent worm
-Has red plume, which takes up water and sulfide, and trophosome, which contains symbiotic bacteria -Symbiotic bacteria take up sulfide, derive energy from it - |
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Cold Seeps - Other Deep Sea Trophic Islands
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-maybe sites leaking high concentrations of hydrocarbons or sulfides
-Temp of hydrocarbons and sulfides are similar to that of ambient seawater -release of methane -same type of organisms as hot vet but food supply lower than hot vents and organism growth also lower |
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Whale carcass falls --> Islands (localized source of decaying organic matter) Stages
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1. Mobile scavenger stage
2. Enriched sediment stage 3. Sulfide stage 4. Reef stage -slide 20, lecture 30 |
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Deep-sea Biodiversity Changes
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-Number of species in deep sea soft bottoms increases to maximum at 1500 - 2000 m depth
-then decreases with increasing depth to 4000m on abyssal bottoms -Environmental stability hypothesis -Population size effect ==>Explains decline in abyss carnivores |
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Environmental Stability in the Deep Sea
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-Shelf waters more physically constant than deep waters
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Diversity Gradients
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-Latitudinal Diversity Gradient: Number of species increases towards the equator
-Inshore-estuarine habitats tend to be lower in diversity than open marine habitats -Deep-sea diversity increases, relative to comparable shelf habitats, then decreases to abyssal depths |