CHAPTER 12 Marine Life and the Marine Environment

1. CHAPTER 12 Marine Life and the Marine Environment Fig. 12.5

2. http://marinebio.org/i/IMG_0022.jpg Overview • More than 250,000 identified marine species • Most live in sunlit surface seawater • Species success depends on ability to • Find food • Avoid predation • Reproduce • Cope with physical barriers to movement http://www.soest.hawaii.edu/oceanography/faculty/drazen/images/deep-sea%20diagram.jpg

3. Classification of living organisms • Physical characteristics • Three domains • Archaea • Bacteria • Eukarya Fig. 12.1

4. Classification of living organisms • Based on physical characteristics • Five kingdoms • Monera • Protoctista • Fungi • Plantae • Animalia Fig. 12.1

5. http://www.blog.thesietch.org/wp-content/uploads/2007/03/bacteria.jpghttp://www.blog.thesietch.org/wp-content/uploads/2007/03/bacteria.jpg Five kingdoms • Monera simplest organisms, single-celled • Cyanobacteria, heterotrophic bacteria, archaea • Protoctista (Protista) single and multicelled with nucleus • Algae, protozoa • Fungi • Mold, lichen http://www.chelonia.demon.co.uk/assets/images/autogen/a_LR_aug_17_05_011.jpg http://www.carleton.ca/toxin/Front_page.jpg

6. http://www.starfish.ch/photos/plants-Pflanzen/Seagrass.jpg Five kingdoms • Plantae • multicelled photosynthetic plants • Surf grass, eelgrass, mangrove, marsh grasses • Animalia • multicelled animals • Simple sponges to complex vertebrates http://www.ryanphotographic.com/images/JPEGS/Sponges%20vertical.jpg

7. Taxonomic classification • Systemized classification of organisms • Kingdom • Phylum • Class • Order • Family • Genus • Species • Fundamental unit • Population of genetically similar, interbreeding individuals

8. Classification by habitat and mobility • Plankton (floaters) • Nekton (swimmers) • Benthos (bottom dwellers) Fig. 12.6

9. http://i.ehow.com/images/GlobalPhoto/Articles/2110315/icephytoplankton-main_Full.jpghttp://i.ehow.com/images/GlobalPhoto/Articles/2110315/icephytoplankton-main_Full.jpg Plankton • Most biomass on Earth consists of plankton • Phytoplankton • Autotrophic • Zooplankton • Heterotrophic • Bacterioplankton • Virioplankton http://www.dkimages.com/discover/previews/880/90003448.JPG

10. Plankton • Holoplankton • Entire lives as plankton • Meroplankton • Part of lives as plankton • Juvenile or larval stages • Macroplankton • Large floaters such as jellyfish or Sargassum • Picoplankton • Very small floaters such as bacterioplankton http://www.geocities.com/capecanaveral/lab/4171/net.jpg

11. Nekton • Independent swimmers • Most adult fish and squid • Marine reptiles • Marine mammals Fig. 12.3

12. Figure 12.4

13. Benthos • Epifauna live on surface of sea floor • Infauna live buried in sediments • Nektobenthos swim or crawl through water above seafloor • Most abundant in shallower water http://www.senckenberg.de/images/content/forschung/projekte/nordsee/wattschnittkorrig.jpg

14. Figure 12.5

15. Hydrothermal vent biocommunities • Abundant and large deep-ocean benthos • Discovered in 1977 • Associated with hot vents • Bacteria-like archaeon produce food using heat and chemicals http://bioinfo.bact.wisc.edu/themicrobialworld/Hydrothermal_vent.jpg

16. Number of marine species • More land species than marine species • Ocean relatively uniform conditions • Less adaptation required, less speciation • Marine species overwhelmingly benthic rather than pelagic

17. Adaptations of marine organisms • Physical support • Buoyancy • How to resist sinking • Different support structures in cold (fewer) rather than warm (more appendages) seawater • Smaller size Ciliate Chaining tunicate http://www.solaster-mb.org/mb/images http://science.discovery.com/convergence/scienceofdeep/photos/gallery

18. Adaptations to marine life • Appendages to increase surface area • Oil in micro-organisms to increase buoyancy Fig. 12.9 Fish egg with oil droplet http://www.rpgroup.caltech.edu/~natsirt/aph162/webpages/dylanandco/lab1/image

19. Adaptations to marine life • Streamlining important for larger organisms • Less resistance to fluid flow • Flattened body • Tapering back end – fusiform Fig. 12.10 http://www.wissenschaft-online.de/sixcms/media.php/591

20. Adaptations to marine life • Narrow range temperature in oceans • Smaller variations (daily, seasonally, annually) • Deep ocean nearly isothermal Fig. 12.11

21. Adaptations to marine life • Cold- versus warm-water species • Smaller in cooler seawater • More appendages in warmer seawater • Tropical organisms grow faster, live shorter, reproduce more often • More species in warmer seawater • More biomass in cooler seawater (upwelling)

22. Adaptations to marine life • Stenothermal • Organisms withstand small variation in temperature • Typically live in open ocean • Eurythermal • Organisms withstand large variation in temperature • Typically live in coastal waters

23. Adaptations to marine life • Stenohaline • Organisms withstand only small variation in salinity • Typically live in open ocean • Euryhaline • Organisms withstand large variation in salinity • Typically live in coastal waters, e.g., estuaries

24. Adaptations to marine life • Extracting minerals from seawater • High concentration to low concentration • Diffusion • Cell membrane permeable to nutrients, for example • Waste passes from cell to ocean Fig. 12.12

25. Adaptations to marine life • Osmotic pressure • Less concentrated to more concentrated solutions • Isotonic • Hypertonic • Hypotonic Fig. 12.13

26. Marine versus freshwater fish Fig. 12.14

27. Adaptations to marine life • Dissolved gases • Animals extract dissolved oxygen (O2) from seawater through gills Fig. 12.15

28. Adaptations to marine life • Water’s transparency • Many marine organisms see well • Some marine organisms are nearly transparent to avoid predation

29. Adaptations to marine life • Camouflage through color patterns • Countershading • Disruptive coloring Fig. 12.17a Fig. 12.17b

30. Adaptations to marine life • Water pressure • Increases about 1 atmosphere (1 kg/cm2) with every 10 m (33 ft) deeper • Many marine organisms do not have inner air pockets • Collapsible rib cage (e.g., sperm whale)

31. Main divisions of the marine environment • Pelagic (open sea) • Neritic (< 200 m) and oceanic • Benthic (sea floor) • Subneritic and suboceanic • Another classification scheme: • Euphotic • Disphotic • Aphotic

32. Pelagic environments • Epipelagic • Mesopelagic • Bathypelagic • Abyssopelagic Fig. 12.19

33. Daily Movement of the Deep Scattering Layer

34. Pelagic environments • Dissolved O2 minimum layer about 700-1000 m • Nutrient maximum at about same depths • O2 content increases with depth below Fig. 12.20

35. Benthic environments • Supralittoral • Subneritic • Littoral • Sublittoral • Inner • Outer • Suboceanic • Bathyal • Abyssal • Hadal Fig. 12.19

36. End of CHAPTER 12Marine Life and the Marine Environment