slide1 l.
Skip this Video
Loading SlideShow in 5 Seconds..
Plankton PowerPoint Presentation
Download Presentation

Loading in 2 Seconds...

play fullscreen
1 / 33

Plankton - PowerPoint PPT Presentation

  • Uploaded on

Plankton. Marine life 3 categories: Benthos : bottom dwellers; sponges, crabs Nekton : strong swimmers- whales, fish, squid Plankton : animal/plants that drift in water. The have little control over their movement. Includes: diatoms, dinoflagellates, larvae, jellyfish, bacteria.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Plankton' - libitha

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

Marine life 3 categories:

  • Benthos: bottom dwellers; sponges, crabs
  • Nekton: strong swimmers- whales, fish, squid
  • Plankton: animal/plants that drift in water. The have little control over their movement.
  • Includes: diatoms, dinoflagellates, larvae, jellyfish, bacteria.

Plankton classified by:

    • Size
    • Habitat
    • Taxonomy


  • Picoplankton (.2-2 µm) bacterioplankton
  • Nanoplankton (2 - 20 µm) protozoans
  • Microplankton (20-200 µm) diatoms, eggs, larvae
  • Macroplankton (200-2,000 µm) some eggs, juvenile fish
  • Megaplankton (> 2,000 µm) includes jellyfish, ctenophores, Mola mola


  • Holoplankton-spends entire lifecycle as plankton
  • Ex. Jellyfish, diatoms, copepods
  • Meroplankton- spend part of lifecycle as plankton
  • Ex. fish and crab larvae, eggs






  • Pleuston- organisms that float passively at the seas surface
  • Ex. Physalia, Velella
  • Neuston – organisms that inhabit the uppermost few mm of the surface water
  • Ex. bacteria, protozoa, larvae; light intensity too high for phytoplankton

Phytoplankton- restricted to the euphotic zone where light is available for photosynthesis.

  • Blooms:
  • High nutrients
  • Upwelling
  • Seasonal conditions

Some important types of phytoplankton

  • Diatoms: temperate and polar waters, silica case or shell
  • Dinoflagellates: tropical and subtropical waters.... also summer in temperate
  • Coccolithophores: tropical, calcium carbonate shells or "tests"
  • Silicoflagellates: silica internal skeleton... found world wide, particularly in Antarctic
  • Cyanobacteria (blue-green algae): not true algae, often in brackish nearshore waters and warm water gyres
  • Green Algae: not common except in lagoons and estuaries

Some important types of zooplankton

  • Crustaceans: Copepods
    • Krill
    • Cladocera
    • Mysids
    • Ostracods
  • Jellies
  • Coelenterates (True jellies, Man-of-wars, By-the-wind-sailors)
  • Ctenophores (comb jellies)
  • Urochordates (salps and larvacea)
  • Worms (Arrow worms, polychaetes)
  • Pteropods (planktonic snails)

Jelly-like house


Marine snow


Zooplankton:larvae, copepods. Some produce oil to help them float. Smaller population size than the phytoplanktoton. Zooplankton population size increases after phytoplankton size increases.



Winter Spring Summer Fall


Nutritional modes of zooplankton:

  • Herbivores: feed primarily on phytoplankton
  • Carnivores: feed primarily on other zooplankton (animals)
  • Detrivores: feed primarily on dead organic matter (detritus) 
  • Omnivores: feed on mixed diet of plants and animals and detritus

Diel vertical Migration

Each species has its own preferred day and night depth range, which may vary with lifecycle.

  • Nocturnal Migration
    • single daily ascent near sunset
  • Twilight migration (crepuscular period)
    • two ascents and two descents
  • Reverse migration
    • rise during day and descend at night

Advantages for Diurnal vertical migration

  • An antipredator strategy; less visual to predators
  • Zooplankton migrate to the surface at night and below during the day to the mesopelagic zone. Copepods avoid euphasiids which avoid chaetognaths.

Advantages for DVM

  • 1. Energy conservation
  • Encounter new feeding areas
  • Get genetic mixing of populations
  • Hastens transfer of organic material produced in the euphotic zone to the deep sea

Plankton Patchiness

  • Zooplankton not distributed uniformly or randomly
  • Aggregated into patches of variable size
  • Difficult to detect with plankton nets
  • - Nets “average” the catch over the length of the tow
  • May explain enormous variability in catches from net tows at close distances apart

Causes of Patchiness

  • Aggregations around phytoplankton
  • - If phytoplankton occurs in patches, grazers will be drawn to food
  • - Similar process that led to phytoplankton patches will form zooplankton patches
  • Grazing “holes”
  • Physical process
  • - Langmuir Cells
  • - Internal waves

Accumulation of Plankton in Langmuir Cells

  • Buoyant particles and upward-swimming zooplankton will accumulate over downwelling zones

Deep sea scattering layer:

Composite echogram of hydroacoustic data showing a distinct krill scattering layer.

Black line represents surface tracking of a blue whale feeding