Unit 11 the marine environment
Sponsored Links
This presentation is the property of its rightful owner.
1 / 27

Unit 11 The Marine Environment PowerPoint PPT Presentation


  • 162 Views
  • Uploaded on
  • Presentation posted in: General

Unit 11 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: 250,000 Video on Bioluminescence.

Download Presentation

Unit 11 The Marine Environment

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Unit 11The 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: 250,000

  • Video on Bioluminescence


Classification of living things

  • Organisms can be classified into one of three domains of life:

    • Archaea

    • Bacteria

    • Eukarya


Classification of living things

  • Organisms can also be classified into one of five kingdoms:

    • Monera

    • Protoctista

    • Fungi

    • Plantae

    • Animalia


Classification of living things

  • Taxonomic classification includes the following increasingly specific groupings:

    • Kingdom

    • Phylum (Division for plants)

    • Class

    • Order

    • Family

    • Genus

    • Species


Taxonomic classification of selected organisms


Classification of marine organisms

  • Marine organisms can be classified into one of three groups based on habitatand mobility:

    • Plankton(floaters)

      • Phytoplankton (drifting plants and algae)

      • Zooplankton (drifting animals)

    • Nekton (swimmers)

    • Benthos(bottom dwellers)


Plankton: Examples

Phytoplankton

Zooplankton


Nekton: Examples


Benthos: Examples


Life cycle of a squid

  • Squid experience benthic, planktonic, and nektonic stages

  • Squid are considered meroplankton (partially planktonic)

  • Organisms that spend their entire lives as plankton are holoplankton)


Distribution of species on Earth

  • The land has more species because it has greater environmental variability than the ocean

  • Most ocean species are benthic 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:

    • Is dense enough to support organisms

    • Has high viscosity

    • Experiences variations in temperature and salinity

    • Contains variable amounts of dissolved gases

    • Has high transparency

    • 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:

    • Seawater is denseenough to support marine organisms

  • Adaptations:

    • Many marine organisms lack rigid skeletons, appendages, or vast root systems

    • Instead, they rely on buoyancy and friction to maintain their position within the water column


Seawater’s viscosity controlled by temperature

  • Condition:

    • Seawater’s viscosity (resistance to flow) is strongly affected by temperature

    • Cold water has higher viscosity than warm water, so is more difficult to swim through

    • Warm water has lower viscosity, so organisms tend to sink within the water column


Seawater’s viscosity controlled by temperature

  • Adaptations:

    • Many warm-water organisms have ornate appendages to stay afloat

    • Many cold-water organisms are streamlined to swim more easily

Warm-water copepod

Cold-water copepod


Seawater’s viscosity and adaptations of phytoplankton

  • Condition:

    • Phytoplankton must remain in sunlit surface waters

  • Adaptations:

    • Small size increases surface area to volume ratio

    • Appendages increase frictional resistance

    • Tiny droplet of low density oil increases buoyancy


Variations in temperature

  • Condition:

    • Coastal water temperatures vary more than the open ocean or at depth

  • Adaptations:

    • Many coastal organisms can withstand a wide temperature range (are eurythermal)

    • Most open ocean and deep-water organisms can withstand only a small temperature range (are stenothermal)


Variations in salinity

  • Condition:

    • Coastal environments experience greater salinity variation than the open ocean or at depth

  • Adaptations:

    • Many shallow-water coastal organisms can withstand a wide salinity range (are euryhaline)

    • Most open ocean and deep-water organisms can withstand only a small change in salinity (are stenohaline)


Osmosis

  • Condition:

    • Osmosis is the movement of water molecules through a semipermeable membrane from lowerto higherconcentrations

    • Osmosis removes water from hypotonic organisms

    • Osmosis adds water to hypertonic organisms


Osmosis

  • Adaptations:


Dissolved gases: Oxygen

  • Condition:

    • Marine animals need oxygen to survive

  • Adaptations:

    • Many marine animals use gills to extract dissolved oxygen from seawater

    • Marine mammals must breathe air


Abundance of dissolved oxygen and nutrients with depth


Seawater’s high transparency

  • Condition:

    • Seawater has high transparency

  • Adaptations:

    • Transparency

    • Camouflage

    • Countershading

    • Migration (DSL)

Camouflage

Countershading


The deep scattering layer (DSL)

  • Organisms within the deep scattering layer undertake a daily migration to hide in deep, darker waters during daytime


Increase of pressure with depth

  • Condition:

    • Pressure increases rapidly with depth

  • Adaptations:

    • Most marine organisms lack large compressible air pockets inside their bodies

    • 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:

    • Pelagic (open sea)

    • Benthic (sea bottom)


  • Login