1. GEOL 2503 Introduction to Oceanography
Topic 22 Plankton
GEOL 2503
Introduction to Oceanography

2. Characteristics
Floating organisms that drift with currents (although some forms are weak swimmers)
Generally microscopic although some forms larger
Largest biomass on the planet

3. A micrometer (m) is one millionth of a meter,
one thousandth of a millimeter

5. Reason for small size
Related to buoyancy. The smaller an organism the greater the surface area relative to weight
Surface area often increased by development of pores or spines
Flotation sometimes improved by secretion of low density oil
Rely on turbulence to stay afloat

6. Bacterioplankton
Kingdom Monera, smallest living organisms. Difficult to capture even with finest net
Most abundant organisms (planet & ocean)
Live at all ocean depths as free-living decomposers

7. Phytoplankton Floating plants 99.9% of the food source in the oceans
Mainly protista living in epipelagic zone
Diatoms—siliceous plants
Dinoflagellates—microscopic with flagella for minor locomotion
Cocolithophores—calcareous plants

8. Plankton are an energy source for marine ecosystems
Many plankton are primary producers. Over 90% of marine primary production (energy produced) is from phytoplankton! The rest is from marine plants and other sources.
Photo:
Accessed: November 2010
Photo: NOAA
This map shows productivity in the Oceans. Red and yellow are most productive, followed by green and blue. Black is least productive.

10. Coccolithophore:
calcareous phytoplankton

11. Diatoms
Single celled photosynthetic Protista which secrete small shell of SiO2
Reproduce by cell division until organism becomes too small; then develop auxospore
May discolor water during large blooms

12. Marine diatoms as seen through a microscope.
Image ID: corp2365, NOAA At The Ends of the Earth Collection Photographer: Dr. Neil Sullivan, University of Southern Calif.

13. Centric diatoms
Chain diatoms

14. Blooms
Diatoms and other phytoplankton can divide many times per day producing large blooms that are sometimes visible from space.

15. Dinoflagellates
Single celled Protista (most but not all photosynthetic)
Naked cell or covering of cellulose
Two whip-like flagella allow motility
Some forms bioluminescent
Blooms responsible for toxic red tides

19. Sargassum--brown algae

20. Zooplankton Floating animals (consumers)
Most abundant in epipelagic zone but also occur in mesopelagic zone
Foraminifera—single celled, calcareous
Radiolaria—single celled, siliceous
Krill—shrimp-like, food for baleen whales
Jellyfish—multicellular, colonial

21. Foraminifera & Radiolaria
Microscopic Protista which feed on phytoplankton
Foraminifera secrete shell of CaCO3
Radiolaria secrete shell of SiO2

22. Foraminifera—calcareous zooplankton

23. Foraminifer

25. Radiolaria—siliceous zooplankton

26. A living radiolaria

27. Medusa jellyfish

28. Moon Jelly
Gelatinous zooplankton common in temperate and tropical waters, stinging cells are not toxic and don’t sting like other jellyfish, 95% water but serve as food for many animals including turtles , feed by producing a sticky mucus that traps other plankton
Image ID: reef2547, NOAA's Coral Kingdom Collection Photographer: Florida Keys National Marine Sanctuary Staff Credit: Florida Keys National Marine Sanctuary (moon jelly)

29. Siphonophore

30. Comb jelly

31. Simple crustacean with jointed exoskeleton
Copepod
Image ID: fish3229, NOAA's Fisheries Collection Photographer: Matt Wilson/Jay Clark, NOAA NMFS AFSC
Simple crustacean with jointed exoskeleton
Use enlarged first antenna to swim
Among the most common animals on Earth (most abundant of the net zooplankton)

32. Krill
Not as abundant as copepods they aggregate into huge, dense schools, prefer colder polar waters, feed on diatoms and solid wastes of other zooplankton, important food for whales, tread water to stay afloat.
Image ID: sanc0126, NOAA's Sanctuaries Collection Location: Gulf of the Farallones National Marine Sanctuary Photographer: Jamie Hall

33. Pteropods (mollusks)

34. Holoplankton Regular old plankton
Spend their entire life cycle as plankton
Examples include: dinoflagellates, diatoms, foraminifera, krill

35. Meroplankton
Planktonic larval stages of animals which are not planktonic as adults
Larvae of snails, fish, barnacles, coral, etc.
Egg cases

36. Crab Larva
Some invertebrates have a whole series of different larval stages
Charleston Bump Expedition. Zooplankton. Crab larva. Image ID: expl0215, Voyage To Inner Space - Exploring the Seas With NOAA Collect Location: Southeast of Charleston, South Carolina Photo Date: 2003 August 10 Photographer: Jerry Mclelland Credit: Charleston Bump Expedition NOAA Office of Ocean Exploration; Dr. George Sedberry, South Carolina DNR, Principal Investigator

37. Brittle star larva
Skate egg case

38. Octopus Larva
Temporary members of the plankton, octopus and squid become nektonic (free swimming) and benthic (crawling).
Giant squid are the largest invertebrates in the ocean
Zooplankton. Octopus larva. Image ID: fish3612, NOAA's Fisheries Collection Photographer: Matt Wilson/Jay Clark, NOAA NMFS AFSC

39. Barnacle Larva

40. Fish Larvae
Image ID: fish3363, NOAA's Fisheries Collection Photographer: Matt Wilson/Jay Clark, NOAA NMFS AFSC
Coastal waters are rich in meroplankton (temporary members of the plankton)
Nearly all marine fish have planktonic larvae
Fish larvae may change from herbivores to carnivores as they grow