Download Unit 11 Notes- The Marine Environment

Unit 11 Notes- The Marine Environment
The diversity of marine life

The ocean is home to a wide variety of organisms

Marine organisms range from microscopic bacteria and algae to the largest animal in the world (blue whale)

Number of known marine species: _______________
Classification of living things



Organisms can be classified into one of three domains of life:
o
_____________
o
_____________
o
_____________
Organisms can also be classified into one of five kingdoms:
o
Monera
o
Protoctista
o
Fungi
o
Plantae
o
Animalia
Taxonomic classification includes the following increasingly specific groupings:
o
Kingdom
o
Phylum (Division for plants)
o
Class
o
Order
o
Family
o
Genus
o
Species
Classification of marine organisms

Marine organisms can be classified into one of three groups based on ____________ and ____________:

____________ (floaters)
o
Phytoplankton (drifting plants and algae)
o
Zooplankton (drifting animals)

____________ (swimmers)

____________ (bottom dwellers)
Life cycle of a squid

Squid experience benthic, planktonic, and nektonic stages

Squid are considered meroplankton (opposite = holoplankton)
Distribution of species on Earth

The land has more species because it has greater ____________ ____________than the ocean

Most ocean species are ____________because of greater environmental variability compared to pelagic
environments
Adaptations of organisms to the marine environment


The marine environment presents many challenges to organisms because seawater:
o
Is dense enough to support organisms
o
Has high viscosity
o
Experiences variations in temperature and salinity
o
Contains variable amounts of dissolved gases
o
Has high transparency
o
Has a dramatic change of pressure with depth
Marine organisms have various adaptations for the conditions of the marine environment
Need for physical support

Condition:
o
Seawater is ____________enough to support marine organisms
o
Adaptations:
o
Many marine organisms lack rigid skeletons, appendages, or vast root systems
o
Instead, they rely on ____________and friction to maintain their position within the water column
Seawater’s viscosity controlled by temperature


Condition:
o
Seawater’s ____________ (resistance to flow) is strongly affected by temperature
o
Cold water has higher viscosity than warm water, so is more difficult to swim through
o
Warm water has lower viscosity, so organisms tend to ____________within the water column
Adaptations:
o
Many warm-water organisms have ornate appendages to say ____________
o
Many cold-water organisms are streamlined to ____________more easily
Seawater’s viscosity and adaptations of phytoplankton

Condition:
o

Phytoplankton must remain in ____________surface waters
Adaptations:
o
Small size increases surface area to volume ratio
o
Appendages increase ____________resistance
o
Tiny droplet of low density oil increases buoyancy
Variations in temperature

Condition:
o

Coastal water temperatures vary more than the open ocean or at depth
Adaptations:
o
Many coastal organisms can withstand a wide temperature range (are ____________)
o
Most open ocean and deep-water organisms can withstand only a small temperature range (are
_________________)
Variations in salinity

Condition:
o

Coastal environments experience greater salinity variation than the open ocean or at depth
Adaptations:
o
Many shallow-water coastal organisms can withstand a wide salinity range (are ____________)
o
Most open ocean and deep-water organisms can withstand only a small change in salinity (are
_________________)
Osmosis



Condition:
o
Osmosis is the movement of water molecules through a semipermeable membrane from
____________to ____________concentrations
o
Osmosis removes water from hypotonic organisms
o
Osmosis adds water to hypertonic organisms
Adaptations – Marine Fish (Hypotonic)
o
Drink large quantities of water
o
Secrete salt through special cells
o
Small volume of highly concentrated urine
Adaptations – Freshwater fish (Hypertonic)
o
Do not drink
o
Cells absorb salt
o
Large volume of dilute urine
Dissolved gases: Oxygen

Condition:
o

Marine animals need ____________to survive
Adaptations:
o
Many marine animals use gills to extract dissolved oxygen from seawater
o
Marine mammals must breathe air
Abundance of dissolved oxygen and nutrients with depth (study and understand curve on powerpoint)
Seawater’s high transparency

Condition:
o

Seawater has high transparency
Adaptations:
o
Transparency
o
Camouflage
o
Countershading
o
Migration (DSL)
The deep scattering layer (DSL)

Organisms within the deep scattering layer undertake a daily ____________to hide in deep, darker waters
during daytime
Increase of pressure with depth

Condition:
o

Pressure increases rapidly with depth
Adaptations:
o
Most marine organisms lack large compressible air pockets inside their bodies
o
Water-filled bodies exert the same amount of pressure as is pushing inward, so marine organisms do
not feel the high pressure at depth
Divisions of the marine environment

Main divisions:
o
Pelagic (open sea)
o
Benthic (sea bottom)