Marine Biology Exam Iii Ch 16

Front 1

Types of bottom samplers

Back 1

Dredges
Sleds
Grabs
Corers
-lecture 30, slide 2

Front 2

Seabed Landscape

Back 2

-mainly sand and mud
-patchy larval settlement, patchy distribution of organic material
-Population densities are patchy

Front 3

Input of Organic Matter in Water Column

Back 3

-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%

Front 4

Hot vents

Back 4

-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

Front 5

Vestimentifera

Back 5

-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
-

Front 6

Cold Seeps - Other Deep Sea Trophic Islands

Back 6

-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

Front 7

Whale carcass falls --> Islands (localized source of decaying organic matter) Stages

Back 7

1. Mobile scavenger stage
2. Enriched sediment stage
3. Sulfide stage
4. Reef stage
-slide 20, lecture 30

Front 8

Deep-sea Biodiversity Changes

Back 8

-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

Front 9

Environmental Stability in the Deep Sea

Back 9

-Shelf waters more physically constant than deep waters

Front 10

Diversity Gradients

Back 10

-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