1. Marine Biology and Ecology

2. Marine biology is the study of organisms in the ocean, or other marine bodies of water Marine biology differs from marine ecology, which focuses on how marine organisms interact with one another and their environment

3. Characteristics of Life All living organisms (marine or otherwise) share the following characteristics in common – Organization – Metabolism (the ability to transfer energy from their environment) – Reproduction – Interaction/response to their environment – Evolutionary adaptation – DNA

4. The First Law of Thermodynamics Life cannot exist without energy Energy cannot be created or destroyed (but it can be transferred or transformed) A plant can transform light energy into chemical energy An animal can transform chemical energy into energy of movement, heat, etc.

5. Primary Productivity is the synthesis of organic materials Light energy from the sun is absorbed by primary producers (plants, algae, and certain bacteria) and converted into chemical energy through a process known as photosynthesis This energy is stored as organic material (carbohydrates, fats, proteins) and later released as it is used for growth, movement, reproduction, repair and other functions

6. Photosynthesis www.bio.miami.edu/dana226/226F08_10.html

7. What kind of ‘troph’ are you? Primary producers are known as autotrophs; organisms that use sources of energy (sun) to produce their own organic matter (food) All other organisms are heterotrophs, which must obtain nourishment by consuming food from other organisms (autotrophs or other heterotrophs) – Heterotrophs are consumers

9. Marine Food Webs A food web describes ‘who eats who’ and illustrates the transfer of energy through the marine ecosystem Very complex! Changes with life history (age), food availability, location, and our knowledge!

10. Marine Food Webs Consumers can make up many levels of the food web, or trophic levels Primary consumers eat producers Secondary consumers eat primary consumers Tertiary consumers eat secondary consumers, and so on….

11. c c Arrows always point to the consumer (to whom the energy is being transferred)

12. The Second Law of Thermodynamics The transfer of energy is never 100% efficient; some of this energy is lost as heat – Why you sweat while you run – Why your car generates heat while it runs! Only 10% of the energy stored in “food” is transferred to the next trophic level Lost as heat, movement, metabolism

13. Marine Food Webs

16. The marine environment is classified into distinct zones Scientists divide the marine environment into zones Primarily, these zones include pelagic (open water) and benthic (bottom) regions, but are further broken down by light, by depth, or by distance from shore

18. The Pelagic Zone The pelagic zone describes the open water region of the oceans – Subdivided into the neritic zone (nearshore over the continental shelf) and the deep water oceanic zone The pelagic community consists of organisms that live suspended in the water column – They either drift (plankton) or swim (nekton)

19. The Pelagic Zone Nekton are pelagic organisms that swim Plankton drift or swim very weakly, unable to move against a current

20. Into the Deep The oceanic zone is further subdivided by depth: – Epipelagic zone - upper 200 meters of ocean; includes photic zone – Mesopelagic zone – 200-1000m “middle” zone; some light penetrates but insufficient for photosynthesis – Bathypelagic zone – 1000-4000m; aphotic, cold (4°C) – Abyssopelagic zone – 4000-6000m; very deep, at or near the bottom

21. Deep Sea Communities 75% of the ocean does not receive sunlight; yet the twilight mesopelagic zone and the perpetually dark bathy- and abysso-pelagic zones are not devoid of life Organisms here have evolved special adaptations for surviving darkness, sparse food, sparse mates, cold temperatures, and immense pressures

22. Deep Sea Communities Food is extremely limited in the deep ocean (no photosynthesis!) Animals here depend on food supplied from the photic zone via fall-out (“marine snow”) or the settling of large carcasses (fish, whales, etc) from above

23. Deep Sea Biology Adaptations for deep sea organisms include: – Small body size (~ <10 inches) – Slow metabolism; “sit and wait” – Watery bodies – Extendable, hinged jaws – Hermaphroditism – Upward-looking eyes (or no eyes) – Bioluminescence

24. Deep Sea Organisms: Dragonfish Small body size Extendable, hinged jaw Bioluminescent barb Photophores on underside of body Dark body coloration

25. Deep Sea Organisms: Hatchetfish Small body size Large, upward-facing eyes Photophores on underside Large, extendable mouth Silver body coloration

26. Deep Sea Organisms: Fangtooth Small body size Black Large, extendable jaw Sensory systems along body

27. Deep Sea Organisms: Anglerfish Bioluminescent angler (lure) Small body size Black body Extendable jaw Watery composition Parasitic sexual reproduction!

28. And you thought your boyfriend was clingy Because mates are few and far between, the male anglerfish is equipped with specialized olfactory organs to detect and find a female When he does, he bites into her skin, fusing with the female and atrophies; loses digestive system, brain, heart and eyes, but not gonads! http://rmbr.nus.edu.sg/news/images/20050129-photocorynus_spiniceps-male_female.jpg Parasitic male!

29. Deep Sea Organisms: Ctenophores 96% water Sticky (not stinging) cells for capturing food Bioluminescent Capable of capturing small prey

30. The Benthic Zone The benthic zone includes all bottom terrain of the oceans Subdivided into – Littoral (intertidal zone) – Sublittoral (subtidal) – Bathyl (includes continental slope) – Abyssal (deep ocean floor) – Hadal (deepest of all; associated with trench walls and floors)

31. Hydrothermal Vent Communities Bottom water surrounding hydrothermal vents is loaded with oxygen, carbon dioxide, and poisonous hydrogen sulfide No sunlight reaches this area, yet astounding life forms exist on and around the vent systems Chemosynthetic bacteria use the energy contained in the hydrogen sulfide to convert carbon dioxide into organic matter (just as solar energy is used in photosynthesis!)

32. Hydrothermal Vent Communities The bacteria form the base of the food web Large, mouthless (and gutless!) tube worms house the bacteria and in return for shelter, obtain nourishment from the bacteria Large abundances of shrimp feed on the bacteria (primary consumers), while fish feed on the shrimp (secondary consumers) and so on supporting a rich food web www.flickr.com/photos/aakova/6493192/

33. Hydrothermal Vent Communities Origin of life on Earth? Are dead whales stepping stones for transitional vent communities? Each vent community hosts a unique assemblage of species! http://www.whoi.edu/page.do?pid=12458&tid=441&cid=5709&ct=61&article=2505